diff options
Diffstat (limited to 'Documentation/powerpc')
| -rw-r--r-- | Documentation/powerpc/00-INDEX | 20 | ||||
| -rw-r--r-- | Documentation/powerpc/SBC8260_memory_mapping.txt | 197 | ||||
| -rw-r--r-- | Documentation/powerpc/cpu_features.txt | 56 | ||||
| -rw-r--r-- | Documentation/powerpc/eeh-pci-error-recovery.txt | 332 | ||||
| -rw-r--r-- | Documentation/powerpc/hvcs.txt | 567 | ||||
| -rw-r--r-- | Documentation/powerpc/mpc52xx.txt | 39 | ||||
| -rw-r--r-- | Documentation/powerpc/ppc_htab.txt | 118 | ||||
| -rw-r--r-- | Documentation/powerpc/smp.txt | 34 | ||||
| -rw-r--r-- | Documentation/powerpc/sound.txt | 81 | ||||
| -rw-r--r-- | Documentation/powerpc/zImage_layout.txt | 47 |
10 files changed, 1491 insertions, 0 deletions
diff --git a/Documentation/powerpc/00-INDEX b/Documentation/powerpc/00-INDEX new file mode 100644 index 0000000..e7bea0a --- /dev/null +++ b/Documentation/powerpc/00-INDEX @@ -0,0 +1,20 @@ +Index of files in Documentation/powerpc. If you think something about +Linux/PPC needs an entry here, needs correction or you've written one +please mail me. + Cort Dougan (cort@fsmlabs.com) + +00-INDEX + - this file +cpu_features.txt + - info on how we support a variety of CPUs with minimal compile-time + options. +ppc_htab.txt + - info about the Linux/PPC /proc/ppc_htab entry +smp.txt + - use and state info about Linux/PPC on MP machines +SBC8260_memory_mapping.txt + - EST SBC8260 board info +sound.txt + - info on sound support under Linux/PPC +zImage_layout.txt + - info on the kernel images for Linux/PPC diff --git a/Documentation/powerpc/SBC8260_memory_mapping.txt b/Documentation/powerpc/SBC8260_memory_mapping.txt new file mode 100644 index 0000000..e6e9ee0 --- /dev/null +++ b/Documentation/powerpc/SBC8260_memory_mapping.txt @@ -0,0 +1,197 @@ +Please mail me (Jon Diekema, diekema_jon@si.com or diekema@cideas.com) +if you have questions, comments or corrections. + + * EST SBC8260 Linux memory mapping rules + + http://www.estc.com/ + http://www.estc.com/products/boards/SBC8260-8240_ds.html + + Initial conditions: + ------------------- + + Tasks that need to be perform by the boot ROM before control is + transferred to zImage (compressed Linux kernel): + + - Define the IMMR to 0xf0000000 + + - Initialize the memory controller so that RAM is available at + physical address 0x00000000. On the SBC8260 is this 16M (64M) + SDRAM. + + - The boot ROM should only clear the RAM that it is using. + + The reason for doing this is to enhances the chances of a + successful post mortem on a Linux panic. One of the first + items to examine is the 16k (LOG_BUF_LEN) circular console + buffer called log_buf which is defined in kernel/printk.c. + + - To enhance boot ROM performance, the I-cache can be enabled. + + Date: Mon, 22 May 2000 14:21:10 -0700 + From: Neil Russell <caret@c-side.com> + + LiMon (LInux MONitor) runs with and starts Linux with MMU + off, I-cache enabled, D-cache disabled. The I-cache doesn't + need hints from the MMU to work correctly as the D-cache + does. No D-cache means no special code to handle devices in + the presence of cache (no snooping, etc). The use of the + I-cache means that the monitor can run acceptably fast + directly from ROM, rather than having to copy it to RAM. + + - Build the board information structure (see + include/asm-ppc/est8260.h for its definition) + + - The compressed Linux kernel (zImage) contains a bootstrap loader + that is position independent; you can load it into any RAM, + ROM or FLASH memory address >= 0x00500000 (above 5 MB), or + at its link address of 0x00400000 (4 MB). + + Note: If zImage is loaded at its link address of 0x00400000 (4 MB), + then zImage will skip the step of moving itself to + its link address. + + - Load R3 with the address of the board information structure + + - Transfer control to zImage + + - The Linux console port is SMC1, and the baud rate is controlled + from the bi_baudrate field of the board information structure. + On thing to keep in mind when picking the baud rate, is that + there is no flow control on the SMC ports. I would stick + with something safe and standard like 19200. + + On the EST SBC8260, the SMC1 port is on the COM1 connector of + the board. + + + EST SBC8260 defaults: + --------------------- + + Chip + Memory Sel Bus Use + --------------------- --- --- ---------------------------------- + 0x00000000-0x03FFFFFF CS2 60x (16M or 64M)/64M SDRAM + 0x04000000-0x04FFFFFF CS4 local 4M/16M SDRAM (soldered to the board) + 0x21000000-0x21000000 CS7 60x 1B/64K Flash present detect (from the flash SIMM) + 0x21000001-0x21000001 CS7 60x 1B/64K Switches (read) and LEDs (write) + 0x22000000-0x2200FFFF CS5 60x 8K/64K EEPROM + 0xFC000000-0xFCFFFFFF CS6 60x 2M/16M flash (8 bits wide, soldered to the board) + 0xFE000000-0xFFFFFFFF CS0 60x 4M/16M flash (SIMM) + + Notes: + ------ + + - The chip selects can map 32K blocks and up (powers of 2) + + - The SDRAM machine can handled up to 128Mbytes per chip select + + - Linux uses the 60x bus memory (the SDRAM DIMM) for the + communications buffers. + + - BATs can map 128K-256Mbytes each. There are four data BATs and + four instruction BATs. Generally the data and instruction BATs + are mapped the same. + + - The IMMR must be set above the kernel virtual memory addresses, + which start at 0xC0000000. Otherwise, the kernel may crash as + soon as you start any threads or processes due to VM collisions + in the kernel or user process space. + + + Details from Dan Malek <dan_malek@mvista.com> on 10/29/1999: + + The user application virtual space consumes the first 2 Gbytes + (0x00000000 to 0x7FFFFFFF). The kernel virtual text starts at + 0xC0000000, with data following. There is a "protection hole" + between the end of kernel data and the start of the kernel + dynamically allocated space, but this space is still within + 0xCxxxxxxx. + + Obviously the kernel can't map any physical addresses 1:1 in + these ranges. + + + Details from Dan Malek <dan_malek@mvista.com> on 5/19/2000: + + During the early kernel initialization, the kernel virtual + memory allocator is not operational. Prior to this KVM + initialization, we choose to map virtual to physical addresses + 1:1. That is, the kernel virtual address exactly matches the + physical address on the bus. These mappings are typically done + in arch/ppc/kernel/head.S, or arch/ppc/mm/init.c. Only + absolutely necessary mappings should be done at this time, for + example board control registers or a serial uart. Normal device + driver initialization should map resources later when necessary. + + Although platform dependent, and certainly the case for embedded + 8xx, traditionally memory is mapped at physical address zero, + and I/O devices above physical address 0x80000000. The lowest + and highest (above 0xf0000000) I/O addresses are traditionally + used for devices or registers we need to map during kernel + initialization and prior to KVM operation. For this reason, + and since it followed prior PowerPC platform examples, I chose + to map the embedded 8xx kernel to the 0xc0000000 virtual address. + This way, we can enable the MMU to map the kernel for proper + operation, and still map a few windows before the KVM is operational. + + On some systems, you could possibly run the kernel at the + 0x80000000 or any other virtual address. It just depends upon + mapping that must be done prior to KVM operational. You can never + map devices or kernel spaces that overlap with the user virtual + space. This is why default IMMR mapping used by most BDM tools + won't work. They put the IMMR at something like 0x10000000 or + 0x02000000 for example. You simply can't map these addresses early + in the kernel, and continue proper system operation. + + The embedded 8xx/82xx kernel is mature enough that all you should + need to do is map the IMMR someplace at or above 0xf0000000 and it + should boot far enough to get serial console messages and KGDB + connected on any platform. There are lots of other subtle memory + management design features that you simply don't need to worry + about. If you are changing functions related to MMU initialization, + you are likely breaking things that are known to work and are + heading down a path of disaster and frustration. Your changes + should be to make the flexibility of the processor fit Linux, + not force arbitrary and non-workable memory mappings into Linux. + + - You don't want to change KERNELLOAD or KERNELBASE, otherwise the + virtual memory and MMU code will get confused. + + arch/ppc/Makefile:KERNELLOAD = 0xc0000000 + + include/asm-ppc/page.h:#define PAGE_OFFSET 0xc0000000 + include/asm-ppc/page.h:#define KERNELBASE PAGE_OFFSET + + - RAM is at physical address 0x00000000, and gets mapped to + virtual address 0xC0000000 for the kernel. + + + Physical addresses used by the Linux kernel: + -------------------------------------------- + + 0x00000000-0x3FFFFFFF 1GB reserved for RAM + 0xF0000000-0xF001FFFF 128K IMMR 64K used for dual port memory, + 64K for 8260 registers + + + Logical addresses used by the Linux kernel: + ------------------------------------------- + + 0xF0000000-0xFFFFFFFF 256M BAT0 (IMMR: dual port RAM, registers) + 0xE0000000-0xEFFFFFFF 256M BAT1 (I/O space for custom boards) + 0xC0000000-0xCFFFFFFF 256M BAT2 (RAM) + 0xD0000000-0xDFFFFFFF 256M BAT3 (if RAM > 256MByte) + + + EST SBC8260 Linux mapping: + -------------------------- + + DBAT0, IBAT0, cache inhibited: + + Chip + Memory Sel Use + --------------------- --- --------------------------------- + 0xF0000000-0xF001FFFF n/a IMMR: dual port RAM, registers + + DBAT1, IBAT1, cache inhibited: + diff --git a/Documentation/powerpc/cpu_features.txt b/Documentation/powerpc/cpu_features.txt new file mode 100644 index 0000000..4727398 --- /dev/null +++ b/Documentation/powerpc/cpu_features.txt @@ -0,0 +1,56 @@ +Hollis Blanchard <hollis@austin.ibm.com> +5 Jun 2002 + +This document describes the system (including self-modifying code) used in the +PPC Linux kernel to support a variety of PowerPC CPUs without requiring +compile-time selection. + +Early in the boot process the ppc32 kernel detects the current CPU type and +chooses a set of features accordingly. Some examples include Altivec support, +split instruction and data caches, and if the CPU supports the DOZE and NAP +sleep modes. + +Detection of the feature set is simple. A list of processors can be found in +arch/ppc/kernel/cputable.c. The PVR register is masked and compared with each +value in the list. If a match is found, the cpu_features of cur_cpu_spec is +assigned to the feature bitmask for this processor and a __setup_cpu function +is called. + +C code may test 'cur_cpu_spec[smp_processor_id()]->cpu_features' for a +particular feature bit. This is done in quite a few places, for example +in ppc_setup_l2cr(). + +Implementing cpufeatures in assembly is a little more involved. There are +several paths that are performance-critical and would suffer if an array +index, structure dereference, and conditional branch were added. To avoid the +performance penalty but still allow for runtime (rather than compile-time) CPU +selection, unused code is replaced by 'nop' instructions. This nop'ing is +based on CPU 0's capabilities, so a multi-processor system with non-identical +processors will not work (but such a system would likely have other problems +anyways). + +After detecting the processor type, the kernel patches out sections of code +that shouldn't be used by writing nop's over it. Using cpufeatures requires +just 2 macros (found in include/asm-ppc/cputable.h), as seen in head.S +transfer_to_handler: + + #ifdef CONFIG_ALTIVEC + BEGIN_FTR_SECTION + mfspr r22,SPRN_VRSAVE /* if G4, save vrsave register value */ + stw r22,THREAD_VRSAVE(r23) + END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) + #endif /* CONFIG_ALTIVEC */ + +If CPU 0 supports Altivec, the code is left untouched. If it doesn't, both +instructions are replaced with nop's. + +The END_FTR_SECTION macro has two simpler variations: END_FTR_SECTION_IFSET +and END_FTR_SECTION_IFCLR. These simply test if a flag is set (in +cur_cpu_spec[0]->cpu_features) or is cleared, respectively. These two macros +should be used in the majority of cases. + +The END_FTR_SECTION macros are implemented by storing information about this +code in the '__ftr_fixup' ELF section. When do_cpu_ftr_fixups +(arch/ppc/kernel/misc.S) is invoked, it will iterate over the records in +__ftr_fixup, and if the required feature is not present it will loop writing +nop's from each BEGIN_FTR_SECTION to END_FTR_SECTION. diff --git a/Documentation/powerpc/eeh-pci-error-recovery.txt b/Documentation/powerpc/eeh-pci-error-recovery.txt new file mode 100644 index 0000000..2bfe71b --- /dev/null +++ b/Documentation/powerpc/eeh-pci-error-recovery.txt @@ -0,0 +1,332 @@ + + + PCI Bus EEH Error Recovery + -------------------------- + Linas Vepstas + <linas@austin.ibm.com> + 12 January 2005 + + +Overview: +--------- +The IBM POWER-based pSeries and iSeries computers include PCI bus +controller chips that have extended capabilities for detecting and +reporting a large variety of PCI bus error conditions. These features +go under the name of "EEH", for "Extended Error Handling". The EEH +hardware features allow PCI bus errors to be cleared and a PCI +card to be "rebooted", without also having to reboot the operating +system. + +This is in contrast to traditional PCI error handling, where the +PCI chip is wired directly to the CPU, and an error would cause +a CPU machine-check/check-stop condition, halting the CPU entirely. +Another "traditional" technique is to ignore such errors, which +can lead to data corruption, both of user data or of kernel data, +hung/unresponsive adapters, or system crashes/lockups. Thus, +the idea behind EEH is that the operating system can become more +reliable and robust by protecting it from PCI errors, and giving +the OS the ability to "reboot"/recover individual PCI devices. + +Future systems from other vendors, based on the PCI-E specification, +may contain similar features. + + +Causes of EEH Errors +-------------------- +EEH was originally designed to guard against hardware failure, such +as PCI cards dying from heat, humidity, dust, vibration and bad +electrical connections. The vast majority of EEH errors seen in +"real life" are due to eithr poorly seated PCI cards, or, +unfortunately quite commonly, due device driver bugs, device firmware +bugs, and sometimes PCI card hardware bugs. + +The most common software bug, is one that causes the device to +attempt to DMA to a location in system memory that has not been +reserved for DMA access for that card. This is a powerful feature, +as it prevents what; otherwise, would have been silent memory +corruption caused by the bad DMA. A number of device driver +bugs have been found and fixed in this way over the past few +years. Other possible causes of EEH errors include data or +address line parity errors (for example, due to poor electrical +connectivity due to a poorly seated card), and PCI-X split-completion +errors (due to software, device firmware, or device PCI hardware bugs). +The vast majority of "true hardware failures" can be cured by +physically removing and re-seating the PCI card. + + +Detection and Recovery +---------------------- +In the following discussion, a generic overview of how to detect +and recover from EEH errors will be presented. This is followed +by an overview of how the current implementation in the Linux +kernel does it. The actual implementation is subject to change, +and some of the finer points are still being debated. These +may in turn be swayed if or when other architectures implement +similar functionality. + +When a PCI Host Bridge (PHB, the bus controller connecting the +PCI bus to the system CPU electronics complex) detects a PCI error +condition, it will "isolate" the affected PCI card. Isolation +will block all writes (either to the card from the system, or +from the card to the system), and it will cause all reads to +return all-ff's (0xff, 0xffff, 0xffffffff for 8/16/32-bit reads). +This value was chosen because it is the same value you would +get if the device was physically unplugged from the slot. +This includes access to PCI memory, I/O space, and PCI config +space. Interrupts; however, will continued to be delivered. + +Detection and recovery are performed with the aid of ppc64 +firmware. The programming interfaces in the Linux kernel +into the firmware are referred to as RTAS (Run-Time Abstraction +Services). The Linux kernel does not (should not) access +the EEH function in the PCI chipsets directly, primarily because +there are a number of different chipsets out there, each with +different interfaces and quirks. The firmware provides a +uniform abstraction layer that will work with all pSeries +and iSeries hardware (and be forwards-compatible). + +If the OS or device driver suspects that a PCI slot has been +EEH-isolated, there is a firmware call it can make to determine if +this is the case. If so, then the device driver should put itself +into a consistent state (given that it won't be able to complete any +pending work) and start recovery of the card. Recovery normally +would consist of reseting the PCI device (holding the PCI #RST +line high for two seconds), followed by setting up the device +config space (the base address registers (BAR's), latency timer, +cache line size, interrupt line, and so on). This is followed by a +reinitialization of the device driver. In a worst-case scenario, +the power to the card can be toggled, at least on hot-plug-capable +slots. In principle, layers far above the device driver probably +do not need to know that the PCI card has been "rebooted" in this +way; ideally, there should be at most a pause in Ethernet/disk/USB +I/O while the card is being reset. + +If the card cannot be recovered after three or four resets, the +kernel/device driver should assume the worst-case scenario, that the +card has died completely, and report this error to the sysadmin. +In addition, error messages are reported through RTAS and also through +syslogd (/var/log/messages) to alert the sysadmin of PCI resets. +The correct way to deal with failed adapters is to use the standard +PCI hotplug tools to remove and replace the dead card. + + +Current PPC64 Linux EEH Implementation +-------------------------------------- +At this time, a generic EEH recovery mechanism has been implemented, +so that individual device drivers do not need to be modified to support +EEH recovery. This generic mechanism piggy-backs on the PCI hotplug +infrastructure, and percolates events up through the hotplug/udev +infrastructure. Followiing is a detailed description of how this is +accomplished. + +EEH must be enabled in the PHB's very early during the boot process, +and if a PCI slot is hot-plugged. The former is performed by +eeh_init() in arch/ppc64/kernel/eeh.c, and the later by +drivers/pci/hotplug/pSeries_pci.c calling in to the eeh.c code. +EEH must be enabled before a PCI scan of the device can proceed. +Current Power5 hardware will not work unless EEH is enabled; +although older Power4 can run with it disabled. Effectively, +EEH can no longer be turned off. PCI devices *must* be +registered with the EEH code; the EEH code needs to know about +the I/O address ranges of the PCI device in order to detect an +error. Given an arbitrary address, the routine +pci_get_device_by_addr() will find the pci device associated +with that address (if any). + +The default include/asm-ppc64/io.h macros readb(), inb(), insb(), +etc. include a check to see if the the i/o read returned all-0xff's. +If so, these make a call to eeh_dn_check_failure(), which in turn +asks the firmware if the all-ff's value is the sign of a true EEH +error. If it is not, processing continues as normal. The grand +total number of these false alarms or "false positives" can be +seen in /proc/ppc64/eeh (subject to change). Normally, almost +all of these occur during boot, when the PCI bus is scanned, where +a large number of 0xff reads are part of the bus scan procedure. + +If a frozen slot is detected, code in arch/ppc64/kernel/eeh.c will +print a stack trace to syslog (/var/log/messages). This stack trace +has proven to be very useful to device-driver authors for finding +out at what point the EEH error was detected, as the error itself +usually occurs slightly beforehand. + +Next, it uses the Linux kernel notifier chain/work queue mechanism to +allow any interested parties to find out about the failure. Device +drivers, or other parts of the kernel, can use +eeh_register_notifier(struct notifier_block *) to find out about EEH +events. The event will include a pointer to the pci device, the +device node and some state info. Receivers of the event can "do as +they wish"; the default handler will be described further in this +section. + +To assist in the recovery of the device, eeh.c exports the +following functions: + +rtas_set_slot_reset() -- assert the PCI #RST line for 1/8th of a second +rtas_configure_bridge() -- ask firmware to configure any PCI bridges + located topologically under the pci slot. +eeh_save_bars() and eeh_restore_bars(): save and restore the PCI + config-space info for a device and any devices under it. + + +A handler for the EEH notifier_block events is implemented in +drivers/pci/hotplug/pSeries_pci.c, called handle_eeh_events(). +It saves the device BAR's and then calls rpaphp_unconfig_pci_adapter(). +This last call causes the device driver for the card to be stopped, +which causes hotplug events to go out to user space. This triggers +user-space scripts that might issue commands such as "ifdown eth0" +for ethernet cards, and so on. This handler then sleeps for 5 seconds, +hoping to give the user-space scripts enough time to complete. +It then resets the PCI card, reconfigures the device BAR's, and +any bridges underneath. It then calls rpaphp_enable_pci_slot(), +which restarts the device driver and triggers more user-space +events (for example, calling "ifup eth0" for ethernet cards). + + +Device Shutdown and User-Space Events +------------------------------------- +This section documents what happens when a pci slot is unconfigured, +focusing on how the device driver gets shut down, and on how the +events get delivered to user-space scripts. + +Following is an example sequence of events that cause a device driver +close function to be called during the first phase of an EEH reset. +The following sequence is an example of the pcnet32 device driver. + + rpa_php_unconfig_pci_adapter (struct slot *) // in rpaphp_pci.c + { + calls + pci_remove_bus_device (struct pci_dev *) // in /drivers/pci/remove.c + { + calls + pci_destroy_dev (struct pci_dev *) + { + calls + device_unregister (&dev->dev) // in /drivers/base/core.c + { + calls + device_del (struct device *) + { + calls + bus_remove_device() // in /drivers/base/bus.c + { + calls + device_release_driver() + { + calls + struct device_driver->remove() which is just + pci_device_remove() // in /drivers/pci/pci_driver.c + { + calls + struct pci_driver->remove() which is just + pcnet32_remove_one() // in /drivers/net/pcnet32.c + { + calls + unregister_netdev() // in /net/core/dev.c + { + calls + dev_close() // in /net/core/dev.c + { + calls dev->stop(); + which is just pcnet32_close() // in pcnet32.c + { + which does what you wanted + to stop the device + } + } + } + which + frees pcnet32 device driver memory + } + }}}}}} + + + in drivers/pci/pci_driver.c, + struct device_driver->remove() is just pci_device_remove() + which calls struct pci_driver->remove() which is pcnet32_remove_one() + which calls unregister_netdev() (in net/core/dev.c) + which calls dev_close() (in net/core/dev.c) + which calls dev->stop() which is pcnet32_close() + which then does the appropriate shutdown. + +--- +Following is the analogous stack trace for events sent to user-space +when the pci device is unconfigured. + +rpa_php_unconfig_pci_adapter() { // in rpaphp_pci.c + calls + pci_remove_bus_device (struct pci_dev *) { // in /drivers/pci/remove.c + calls + pci_destroy_dev (struct pci_dev *) { + calls + device_unregister (&dev->dev) { // in /drivers/base/core.c + calls + device_del(struct device * dev) { // in /drivers/base/core.c + calls + kobject_del() { //in /libs/kobject.c + calls + kobject_hotplug() { // in /libs/kobject.c + calls + kset_hotplug() { // in /lib/kobject.c + calls + kset->hotplug_ops->hotplug() which is really just + a call to + dev_hotplug() { // in /drivers/base/core.c + calls + dev->bus->hotplug() which is really just a call to + pci_hotplug () { // in drivers/pci/hotplug.c + which prints device name, etc.... + } + } + then kset_hotplug() calls + call_usermodehelper () with + argv[0]=hotplug_path[] which is "/sbin/hotplug" + --> event to userspace, + } + } + kobject_del() then calls sysfs_remove_dir(), which would + trigger any user-space daemon that was watching /sysfs, + and notice the delete event. + + +Pro's and Con's of the Current Design +------------------------------------- +There are several issues with the current EEH software recovery design, +which may be addressed in future revisions. But first, note that the +big plus of the current design is that no changes need to be made to +individual device drivers, so that the current design throws a wide net. +The biggest negative of the design is that it potentially disturbs +network daemons and file systems that didn't need to be disturbed. + +-- A minor complaint is that resetting the network card causes + user-space back-to-back ifdown/ifup burps that potentially disturb + network daemons, that didn't need to even know that the pci + card was being rebooted. + +-- A more serious concern is that the same reset, for SCSI devices, + causes havoc to mounted file systems. Scripts cannot post-facto + unmount a file system without flushing pending buffers, but this + is impossible, because I/O has already been stopped. Thus, + ideally, the reset should happen at or below the block layer, + so that the file systems are not disturbed. + + Reiserfs does not tolerate errors returned from the block device. + Ext3fs seems to be tolerant, retrying reads/writes until it does + succeed. Both have been only lightly tested in this scenario. + + The SCSI-generic subsystem already has built-in code for performing + SCSI device resets, SCSI bus resets, and SCSI host-bus-adapter + (HBA) resets. These are cascaded into a chain of attempted + resets if a SCSI command fails. These are completely hidden + from the block layer. It would be very natural to add an EEH + reset into this chain of events. + +-- If a SCSI error occurs for the root device, all is lost unless + the sysadmin had the foresight to run /bin, /sbin, /etc, /var + and so on, out of ramdisk/tmpfs. + + +Conclusions +----------- +There's forward progress ... + + diff --git a/Documentation/powerpc/hvcs.txt b/Documentation/powerpc/hvcs.txt new file mode 100644 index 0000000..c0a62e1 --- /dev/null +++ b/Documentation/powerpc/hvcs.txt @@ -0,0 +1,567 @@ +=========================================================================== + HVCS + IBM "Hypervisor Virtual Console Server" Installation Guide + for Linux Kernel 2.6.4+ + Copyright (C) 2004 IBM Corporation + +=========================================================================== +NOTE:Eight space tabs are the optimum editor setting for reading this file. +=========================================================================== + + Author(s) : Ryan S. Arnold <rsa@us.ibm.com> + Date Created: March, 02, 2004 + Last Changed: August, 24, 2004 + +--------------------------------------------------------------------------- +Table of contents: + + 1. Driver Introduction: + 2. System Requirements + 3. Build Options: + 3.1 Built-in: + 3.2 Module: + 4. Installation: + 5. Connection: + 6. Disconnection: + 7. Configuration: + 8. Questions & Answers: + 9. Reporting Bugs: + +--------------------------------------------------------------------------- +1. Driver Introduction: + +This is the device driver for the IBM Hypervisor Virtual Console Server, +"hvcs". The IBM hvcs provides a tty driver interface to allow Linux user +space applications access to the system consoles of logically partitioned +operating systems (Linux and AIX) running on the same partitioned Power5 +ppc64 system. Physical hardware consoles per partition are not practical +on this hardware so system consoles are accessed by this driver using +firmware interfaces to virtual terminal devices. + +--------------------------------------------------------------------------- +2. System Requirements: + +This device driver was written using 2.6.4 Linux kernel APIs and will only +build and run on kernels of this version or later. + +This driver was written to operate solely on IBM Power5 ppc64 hardware +though some care was taken to abstract the architecture dependent firmware +calls from the driver code. + +Sysfs must be mounted on the system so that the user can determine which +major and minor numbers are associated with each vty-server. Directions +for sysfs mounting are outside the scope of this document. + +--------------------------------------------------------------------------- +3. Build Options: + +The hvcs driver registers itself as a tty driver. The tty layer +dynamically allocates a block of major and minor numbers in a quantity +requested by the registering driver. The hvcs driver asks the tty layer +for 64 of these major/minor numbers by default to use for hvcs device node +entries. + +If the default number of device entries is adequate then this driver can be +built into the kernel. If not, the default can be over-ridden by inserting +the driver as a module with insmod parameters. + +--------------------------------------------------------------------------- +3.1 Built-in: + +The following menuconfig example demonstrates selecting to build this +driver into the kernel. + + Device Drivers ---> + Character devices ---> + <*> IBM Hypervisor Virtual Console Server Support + +Begin the kernel make process. + +--------------------------------------------------------------------------- +3.2 Module: + +The following menuconfig example demonstrates selecting to build this +driver as a kernel module. + + Device Drivers ---> + Character devices ---> + <M> IBM Hypervisor Virtual Console Server Support + +The make process will build the following kernel modules: + + hvcs.ko + hvcserver.ko + +To insert the module with the default allocation execute the following +commands in the order they appear: + + insmod hvcserver.ko + insmod hvcs.ko + +The hvcserver module contains architecture specific firmware calls and must +be inserted first, otherwise the hvcs module will not find some of the +symbols it expects. + +To override the default use an insmod parameter as follows (requesting 4 +tty devices as an example): + + insmod hvcs.ko hvcs_parm_num_devs=4 + +There is a maximum number of dev entries that can be specified on insmod. +We think that 1024 is currently a decent maximum number of server adapters +to allow. This can always be changed by modifying the constant in the +source file before building. + +NOTE: The length of time it takes to insmod the driver seems to be related +to the number of tty interfaces the registering driver requests. + +In order to remove the driver module execute the following command: + + rmmod hvcs.ko + +The recommended method for installing hvcs as a module is to use depmod to +build a current modules.dep file in /lib/modules/`uname -r` and then +execute: + +modprobe hvcs hvcs_parm_num_devs=4 + +The modules.dep file indicates that hvcserver.ko needs to be inserted +before hvcs.ko and modprobe uses this file to smartly insert the modules in +the proper order. + +The following modprobe command is used to remove hvcs and hvcserver in the +proper order: + +modprobe -r hvcs + +--------------------------------------------------------------------------- +4. Installation: + +The tty layer creates sysfs entries which contain the major and minor +numbers allocated for the hvcs driver. The following snippet of "tree" +output of the sysfs directory shows where these numbers are presented: + + sys/ + |-- *other sysfs base dirs* + | + |-- class + | |-- *other classes of devices* + | | + | `-- tty + | |-- *other tty devices* + | | + | |-- hvcs0 + | | `-- dev + | |-- hvcs1 + | | `-- dev + | |-- hvcs2 + | | `-- dev + | |-- hvcs3 + | | `-- dev + | | + | |-- *other tty devices* + | + |-- *other sysfs base dirs* + +For the above examples the following output is a result of cat'ing the +"dev" entry in the hvcs directory: + + Pow5:/sys/class/tty/hvcs0/ # cat dev + 254:0 + + Pow5:/sys/class/tty/hvcs1/ # cat dev + 254:1 + + Pow5:/sys/class/tty/hvcs2/ # cat dev + 254:2 + + Pow5:/sys/class/tty/hvcs3/ # cat dev + 254:3 + +The output from reading the "dev" attribute is the char device major and +minor numbers that the tty layer has allocated for this driver's use. Most +systems running hvcs will already have the device entries created or udev +will do it automatically. + +Given the example output above, to manually create a /dev/hvcs* node entry +mknod can be used as follows: + + mknod /dev/hvcs0 c 254 0 + mknod /dev/hvcs1 c 254 1 + mknod /dev/hvcs2 c 254 2 + mknod /dev/hvcs3 c 254 3 + +Using mknod to manually create the device entries makes these device nodes +persistent. Once created they will exist prior to the driver insmod. + +Attempting to connect an application to /dev/hvcs* prior to insertion of +the hvcs module will result in an error message similar to the following: + + "/dev/hvcs*: No such device". + +NOTE: Just because there is a device node present doesn't mean that there +is a vty-server device configured for that node. + +--------------------------------------------------------------------------- +5. Connection + +Since this driver controls devices that provide a tty interface a user can +interact with the device node entries using any standard tty-interactive +method (e.g. "cat", "dd", "echo"). The intent of this driver however, is +to provide real time console interaction with a Linux partition's console, +which requires the use of applications that provide bi-directional, +interactive I/O with a tty device. + +Applications (e.g. "minicom" and "screen") that act as terminal emulators +or perform terminal type control sequence conversion on the data being +passed through them are NOT acceptable for providing interactive console +I/O. These programs often emulate antiquated terminal types (vt100 and +ANSI) and expect inbound data to take the form of one of these supported +terminal types but they either do not convert, or do not _adequately_ +convert, outbound data into the terminal type of the terminal which invoked +them (though screen makes an attempt and can apparently be configured with +much termcap wrestling.) + +For this reason kermit and cu are two of the recommended applications for +interacting with a Linux console via an hvcs device. These programs simply +act as a conduit for data transfer to and from the tty device. They do not +require inbound data to take the form of a particular terminal type, nor do +they cook outbound data to a particular terminal type. + +In order to ensure proper functioning of console applications one must make +sure that once connected to a /dev/hvcs console that the console's $TERM +env variable is set to the exact terminal type of the terminal emulator +used to launch the interactive I/O application. If one is using xterm and +kermit to connect to /dev/hvcs0 when the console prompt becomes available +one should "export TERM=xterm" on the console. This tells ncurses +applications that are invoked from the console that they should output +control sequences that xterm can understand. + +As a precautionary measure an hvcs user should always "exit" from their +session before disconnecting an application such as kermit from the device +node. If this is not done, the next user to connect to the console will +continue using the previous user's logged in session which includes +using the $TERM variable that the previous user supplied. + +Hotplug add and remove of vty-server adapters affects which /dev/hvcs* node +is used to connect to each vty-server adapter. In order to determine which +vty-server adapter is associated with which /dev/hvcs* node a special sysfs +attribute has been added to each vty-server sysfs entry. This entry is +called "index" and showing it reveals an integer that refers to the +/dev/hvcs* entry to use to connect to that device. For instance cating the +index attribute of vty-server adapter 30000004 shows the following. + + Pow5:/sys/bus/vio/drivers/hvcs/30000004 # cat index + 2 + +This index of '2' means that in order to connect to vty-server adapter +30000004 the user should interact with /dev/hvcs2. + +It should be noted that due to the system hotplug I/O capabilities of a +system the /dev/hvcs* entry that interacts with a particular vty-server +adapter is not guarenteed to remain the same across system reboots. Look +in the Q & A section for more on this issue. + +--------------------------------------------------------------------------- +6. Disconnection + +As a security feature to prevent the delivery of stale data to an +unintended target the Power5 system firmware disables the fetching of data +and discards that data when a connection between a vty-server and a vty has +been severed. As an example, when a vty-server is immediately disconnected +from a vty following output of data to the vty the vty adapter may not have +enough time between when it received the data interrupt and when the +connection was severed to fetch the data from firmware before the fetch is +disabled by firmware. + +When hvcs is being used to serve consoles this behavior is not a huge issue +because the adapter stays connected for large amounts of time following +almost all data writes. When hvcs is being used as a tty conduit to tunnel +data between two partitions [see Q & A below] this is a huge problem +because the standard Linux behavior when cat'ing or dd'ing data to a device +is to open the tty, send the data, and then close the tty. If this driver +manually terminated vty-server connections on tty close this would close +the vty-server and vty connection before the target vty has had a chance to +fetch the data. + +Additionally, disconnecting a vty-server and vty only on module removal or +adapter removal is impractical because other vty-servers in other +partitions may require the usage of the target vty at any time. + +Due to this behavioral restriction disconnection of vty-servers from the +connected vty is a manual procedure using a write to a sysfs attribute +outlined below, on the other hand the initial vty-server connection to a +vty is established automatically by this driver. Manual vty-server +connection is never required. + +In order to terminate the connection between a vty-server and vty the +"vterm_state" sysfs attribute within each vty-server's sysfs entry is used. +Reading this attribute reveals the current connection state of the +vty-server adapter. A zero means that the vty-server is not connected to a +vty. A one indicates that a connection is active. + +Writing a '0' (zero) to the vterm_state attribute will disconnect the VTERM +connection between the vty-server and target vty ONLY if the vterm_state +previously read '1'. The write directive is ignored if the vterm_state +read '0' or if any value other than '0' was written to the vterm_state +attribute. The following example will show the method used for verifying +the vty-server connection status and disconnecting a vty-server connection. + + Pow5:/sys/bus/vio/drivers/hvcs/30000004 # cat vterm_state + 1 + + Pow5:/sys/bus/vio/drivers/hvcs/30000004 # echo 0 > vterm_state + + Pow5:/sys/bus/vio/drivers/hvcs/30000004 # cat vterm_state + 0 + +All vty-server connections are automatically terminated when the device is +hotplug removed and when the module is removed. + +--------------------------------------------------------------------------- +7. Configuration + +Each vty-server has a sysfs entry in the /sys/devices/vio directory, which +is symlinked in several other sysfs tree directories, notably under the +hvcs driver entry, which looks like the following example: + + Pow5:/sys/bus/vio/drivers/hvcs # ls + . .. 30000003 30000004 rescan + +By design, firmware notifies the hvcs driver of vty-server lifetimes and +partner vty removals but not the addition of partner vtys. Since an HMC +Super Admin can add partner info dynamically we have provided the hvcs +driver sysfs directory with the "rescan" update attribute which will query +firmware and update the partner info for all the vty-servers that this +driver manages. Writing a '1' to the attribute triggers the update. An +explicit example follows: + + Pow5:/sys/bus/vio/drivers/hvcs # echo 1 > rescan + +Reading the attribute will indicate a state of '1' or '0'. A one indicates +that an update is in process. A zero indicates that an update has +completed or was never executed. + +Vty-server entries in this directory are a 32 bit partition unique unit +address that is created by firmware. An example vty-server sysfs entry +looks like the following: + + Pow5:/sys/bus/vio/drivers/hvcs/30000004 # ls + . current_vty devspec name partner_vtys + .. detach_state index partner_clcs vterm_state + +Each entry is provided, by default with a "name" attribute. Reading the +"name" attribute will reveal the device type as shown in the following +example: + + Pow5:/sys/bus/vio/drivers/hvcs/30000003 # cat name + vty-server + +Each entry is also provided, by default, with a "devspec" attribute which +reveals the full device specification when read, as shown in the following +example: + + Pow5:/sys/bus/vio/drivers/hvcs/30000004 # cat devspec + /vdevice/vty-server@30000004 + +Each vty-server sysfs dir is provided with two read-only attributes that +provide lists of easily parsed partner vty data: "partner_vtys" and +"partner_clcs". + + Pow5:/sys/bus/vio/drivers/hvcs/30000004 # cat partner_vtys + 30000000 + 30000001 + 30000002 + 30000000 + 30000000 + + Pow5:/sys/bus/vio/drivers/hvcs/30000004 # cat partner_clcs + U5112.428.103048A-V3-C0 + U5112.428.103048A-V3-C2 + U5112.428.103048A-V3-C3 + U5112.428.103048A-V4-C0 + U5112.428.103048A-V5-C0 + +Reading partner_vtys returns a list of partner vtys. Vty unit address +numbering is only per-partition-unique so entries will frequently repeat. + +Reading partner_clcs returns a list of "converged location codes" which are +composed of a system serial number followed by "-V*", where the '*' is the +target partition number, and "-C*", where the '*' is the slot of the +adapter. The first vty partner corresponds to the first clc item, the +second vty partner to the second clc item, etc. + +A vty-server can only be connected to a single vty at a time. The entry, +"current_vty" prints the clc of the currently selected partner vty when +read. + +The current_vty can be changed by writing a valid partner clc to the entry +as in the following example: + + Pow5:/sys/bus/vio/drivers/hvcs/30000004 # echo U5112.428.10304 + 8A-V4-C0 > current_vty + +Changing the current_vty when a vty-server is already connected to a vty +does not affect the current connection. The change takes effect when the +currently open connection is freed. + +Information on the "vterm_state" attribute was covered earlier on the +chapter entitled "disconnection". + +--------------------------------------------------------------------------- +8. Questions & Answers: +=========================================================================== +Q: What are the security concerns involving hvcs? + +A: There are three main security concerns: + + 1. The creator of the /dev/hvcs* nodes has the ability to restrict + the access of the device entries to certain users or groups. It + may be best to create a special hvcs group privilege for providing + access to system consoles. + + 2. To provide network security when grabbing the console it is + suggested that the user connect to the console hosting partition + using a secure method, such as SSH or sit at a hardware console. + + 3. Make sure to exit the user session when done with a console or + the next vty-server connection (which may be from another + partition) will experience the previously logged in session. + +--------------------------------------------------------------------------- +Q: How do I multiplex a console that I grab through hvcs so that other +people can see it: + +A: You can use "screen" to directly connect to the /dev/hvcs* device and +setup a session on your machine with the console group privileges. As +pointed out earlier by default screen doesn't provide the termcap settings +for most terminal emulators to provide adequate character conversion from +term type "screen" to others. This means that curses based programs may +not display properly in screen sessions. + +--------------------------------------------------------------------------- +Q: Why are the colors all messed up? +Q: Why are the control characters acting strange or not working? +Q: Why is the console output all strange and unintelligible? + +A: Please see the preceding section on "Connection" for a discussion of how +applications can affect the display of character control sequences. +Additionally, just because you logged into the console using and xterm +doesn't mean someone else didn't log into the console with the HMC console +(vt320) before you and leave the session logged in. The best thing to do +is to export TERM to the terminal type of your terminal emulator when you +get the console. Additionally make sure to "exit" the console before you +disconnect from the console. This will ensure that the next user gets +their own TERM type set when they login. + +--------------------------------------------------------------------------- +Q: When I try to CONNECT kermit to an hvcs device I get: +"Sorry, can't open connection: /dev/hvcs*"What is happening? + +A: Some other Power5 console mechanism has a connection to the vty and +isn't giving it up. You can try to force disconnect the consoles from the +HMC by right clicking on the partition and then selecting "close terminal". +Otherwise you have to hunt down the people who have console authority. It +is possible that you already have the console open using another kermit +session and just forgot about it. Please review the console options for +Power5 systems to determine the many ways a system console can be held. + +OR + +A: Another user may not have a connectivity method currently attached to a +/dev/hvcs device but the vterm_state may reveal that they still have the +vty-server connection established. They need to free this using the method +outlined in the section on "Disconnection" in order for others to connect +to the target vty. + +OR + +A: The user profile you are using to execute kermit probably doesn't have +permissions to use the /dev/hvcs* device. + +OR + +A: You probably haven't inserted the hvcs.ko module yet but the /dev/hvcs* +entry still exists (on systems without udev). + +OR + +A: There is not a corresponding vty-server device that maps to an existing +/dev/hvcs* entry. + +--------------------------------------------------------------------------- +Q: When I try to CONNECT kermit to an hvcs device I get: +"Sorry, write access to UUCP lockfile directory denied." + +A: The /dev/hvcs* entry you have specified doesn't exist where you said it +does? Maybe you haven't inserted the module (on systems with udev). + +--------------------------------------------------------------------------- +Q: If I already have one Linux partition installed can I use hvcs on said +partition to provide the console for the install of a second Linux +partition? + +A: Yes granted that your are connected to the /dev/hvcs* device using +kermit or cu or some other program that doesn't provide terminal emulation. + +--------------------------------------------------------------------------- +Q: Can I connect to more than one partition's console at a time using this +driver? + +A: Yes. Of course this means that there must be more than one vty-server +configured for this partition and each must point to a disconnected vty. + +--------------------------------------------------------------------------- +Q: Does the hvcs driver support dynamic (hotplug) addition of devices? + +A: Yes, if you have dlpar and hotplug enabled for your system and it has +been built into the kernel the hvcs drivers is configured to dynamically +handle additions of new devices and removals of unused devices. + +--------------------------------------------------------------------------- +Q: For some reason /dev/hvcs* doesn't map to the same vty-server adapter +after a reboot. What happened? + +A: Assignment of vty-server adapters to /dev/hvcs* entries is always done +in the order that the adapters are exposed. Due to hotplug capabilities of +this driver assignment of hotplug added vty-servers may be in a different +order than how they would be exposed on module load. Rebooting or +reloading the module after dynamic addition may result in the /dev/hvcs* +and vty-server coupling changing if a vty-server adapter was added in a +slot inbetween two other vty-server adapters. Refer to the section above +on how to determine which vty-server goes with which /dev/hvcs* node. +Hint; look at the sysfs "index" attribute for the vty-server. + +--------------------------------------------------------------------------- +Q: Can I use /dev/hvcs* as a conduit to another partition and use a tty +device on that partition as the other end of the pipe? + +A: Yes, on Power5 platforms the hvc_console driver provides a tty interface +for extra /dev/hvc* devices (where /dev/hvc0 is most likely the console). +In order to get a tty conduit working between the two partitions the HMC +Super Admin must create an additional "serial server" for the target +partition with the HMC gui which will show up as /dev/hvc* when the target +partition is rebooted. + +The HMC Super Admin then creates an additional "serial client" for the +current partition and points this at the target partition's newly created +"serial server" adapter (remember the slot). This shows up as an +additional /dev/hvcs* device. + +Now a program on the target system can be configured to read or write to +/dev/hvc* and another program on the current partition can be configured to +read or write to /dev/hvcs*. Now you have a tty conduit between two +partitions. + +--------------------------------------------------------------------------- +9. Reporting Bugs: + +The proper channel for reporting bugs is either through the Linux OS +distribution company that provided your OS or by posting issues to the +ppc64 development mailing list at: + +linuxppc64-dev@lists.linuxppc.org + +This request is to provide a documented and searchable public exchange +of the problems and solutions surrounding this driver for the benefit of +all users. diff --git a/Documentation/powerpc/mpc52xx.txt b/Documentation/powerpc/mpc52xx.txt new file mode 100644 index 0000000..10dd4ab --- /dev/null +++ b/Documentation/powerpc/mpc52xx.txt @@ -0,0 +1,39 @@ +Linux 2.6.x on MPC52xx family +----------------------------- + +For the latest info, go to http://www.246tNt.com/mpc52xx/ + +To compile/use : + + - U-Boot: + # <edit Makefile to set ARCH=ppc & CROSS_COMPILE=... ( also EXTRAVERSION + if you wish to ). + # make lite5200_defconfig + # make uImage + + then, on U-boot: + => tftpboot 200000 uImage + => tftpboot 400000 pRamdisk + => bootm 200000 400000 + + - DBug: + # <edit Makefile to set ARCH=ppc & CROSS_COMPILE=... ( also EXTRAVERSION + if you wish to ). + # make lite5200_defconfig + # cp your_initrd.gz arch/ppc/boot/images/ramdisk.image.gz + # make zImage.initrd + # make + + then in DBug: + DBug> dn -i zImage.initrd.lite5200 + + +Some remarks : + - The port is named mpc52xxx, and config options are PPC_MPC52xx. The MGT5100 + is not supported, and I'm not sure anyone is interesting in working on it + so. I didn't took 5xxx because there's apparently a lot of 5xxx that have + nothing to do with the MPC5200. I also included the 'MPC' for the same + reason. + - Of course, I inspired myself from the 2.4 port. If you think I forgot to + mention you/your company in the copyright of some code, I'll correct it + ASAP. diff --git a/Documentation/powerpc/ppc_htab.txt b/Documentation/powerpc/ppc_htab.txt new file mode 100644 index 0000000..8b8c7df --- /dev/null +++ b/Documentation/powerpc/ppc_htab.txt @@ -0,0 +1,118 @@ + Information about /proc/ppc_htab +===================================================================== + +This document and the related code was written by me (Cort Dougan), please +email me (cort@fsmlabs.com) if you have questions, comments or corrections. + +Last Change: 2.16.98 + +This entry in the proc directory is readable by all users but only +writable by root. + +The ppc_htab interface is a user level way of accessing the +performance monitoring registers as well as providing information +about the PTE hash table. + +1. Reading + + Reading this file will give you information about the memory management + hash table that serves as an extended tlb for page translation on the + powerpc. It will also give you information about performance measurement + specific to the cpu that you are using. + + Explanation of the 604 Performance Monitoring Fields: + MMCR0 - the current value of the MMCR0 register + PMC1 + PMC2 - the value of the performance counters and a + description of what events they are counting + which are based on MMCR0 bit settings. + Explanation of the PTE Hash Table fields: + + Size - hash table size in Kb. + Buckets - number of buckets in the table. + Address - the virtual kernel address of the hash table base. + Entries - the number of ptes that can be stored in the hash table. + User/Kernel - how many pte's are in use by the kernel or user at that time. + Overflows - How many of the entries are in their secondary hash location. + Percent full - ratio of free pte entries to in use entries. + Reloads - Count of how many hash table misses have occurred + that were fixed with a reload from the linux tables. + Should always be 0 on 603 based machines. + Non-error Misses - Count of how many hash table misses have occurred + that were completed with the creation of a pte in the linux + tables with a call to do_page_fault(). + Error Misses - Number of misses due to errors such as bad address + and permission violations. This includes kernel access of + bad user addresses that are fixed up by the trap handler. + + Note that calculation of the data displayed from /proc/ppc_htab takes + a long time and spends a great deal of time in the kernel. It would + be quite hard on performance to read this file constantly. In time + there may be a counter in the kernel that allows successive reads from + this file only after a given amount of time has passed to reduce the + possibility of a user slowing the system by reading this file. + +2. Writing + + Writing to the ppc_htab allows you to change the characteristics of + the powerpc PTE hash table and setup performance monitoring. + + Resizing the PTE hash table is not enabled right now due to many + complications with moving the hash table, rehashing the entries + and many many SMP issues that would have to be dealt with. + + Write options to ppc_htab: + + - To set the size of the hash table to 64Kb: + + echo 'size 64' > /proc/ppc_htab + + The size must be a multiple of 64 and must be greater than or equal to + 64. + + - To turn off performance monitoring: + + echo 'off' > /proc/ppc_htab + + - To reset the counters without changing what they're counting: + + echo 'reset' > /proc/ppc_htab + + Note that counting will continue after the reset if it is enabled. + + - To count only events in user mode or only in kernel mode: + + echo 'user' > /proc/ppc_htab + ...or... + echo 'kernel' > /proc/ppc_htab + + Note that these two options are exclusive of one another and the + lack of either of these options counts user and kernel. + Using 'reset' and 'off' reset these flags. + + - The 604 has 2 performance counters which can each count events from + a specific set of events. These sets are disjoint so it is not + possible to count _any_ combination of 2 events. One event can + be counted by PMC1 and one by PMC2. + + To start counting a particular event use: + + echo 'event' > /proc/ppc_htab + + and choose from these events: + + PMC1 + ---- + 'ic miss' - instruction cache misses + 'dtlb' - data tlb misses (not hash table misses) + + PMC2 + ---- + 'dc miss' - data cache misses + 'itlb' - instruction tlb misses (not hash table misses) + 'load miss time' - cycles to complete a load miss + +3. Bugs + + The PMC1 and PMC2 counters can overflow and give no indication of that + in /proc/ppc_htab. diff --git a/Documentation/powerpc/smp.txt b/Documentation/powerpc/smp.txt new file mode 100644 index 0000000..5b581b8 --- /dev/null +++ b/Documentation/powerpc/smp.txt @@ -0,0 +1,34 @@ + Information about Linux/PPC SMP mode +===================================================================== + +This document and the related code was written by me +(Cort Dougan, cort@fsmlabs.com) please email me if you have questions, +comments or corrections. + +Last Change: 3.31.99 + +If you want to help by writing code or testing different hardware please +email me! + +1. State of Supported Hardware + + PowerSurge Architecture - tested on UMAX s900, Apple 9600 + The second processor on this machine boots up just fine and + enters its idle loop. Hopefully a completely working SMP kernel + on this machine will be done shortly. + + The code makes the assumption of only two processors. The changes + necessary to work with any number would not be overly difficult but + I don't have any machines with >2 processors so it's not high on my + list of priorities. If anyone else would like do to the work email + me and I can point out the places that need changed. If you have >2 + processors and don't want to add support yourself let me know and I + can take a look into it. + + BeBox + BeBox support hasn't been added to the 2.1.X kernels from 2.0.X + but work is being done and SMP support for BeBox is in the works. + + CHRP + CHRP SMP works and is fairly solid. It's been tested on the IBM F50 + with 4 processors for quite some time now. diff --git a/Documentation/powerpc/sound.txt b/Documentation/powerpc/sound.txt new file mode 100644 index 0000000..df23d95 --- /dev/null +++ b/Documentation/powerpc/sound.txt @@ -0,0 +1,81 @@ + Information about PowerPC Sound support +===================================================================== + +Please mail me (Cort Dougan, cort@fsmlabs.com) if you have questions, +comments or corrections. + +Last Change: 6.16.99 + +This just covers sound on the PReP and CHRP systems for now and later +will contain information on the PowerMac's. + +Sound on PReP has been tested and is working with the PowerStack and IBM +Power Series onboard sound systems which are based on the cs4231(2) chip. +The sound options when doing the make config are a bit different from +the default, though. + +The I/O base, irq and dma lines that you enter during the make config +are ignored and are set when booting according to the machine type. +This is so that one binary can be used for Motorola and IBM machines +which use different values and isn't allowed by the driver, so things +are hacked together in such a way as to allow this information to be +set automatically on boot. + +1. Motorola PowerStack PReP machines + + Enable support for "Crystal CS4232 based (PnP) cards" and for the + Microsoft Sound System. The MSS isn't used, but some of the routines + that the CS4232 driver uses are in it. + + Although the options you set are ignored and determined automatically + on boot these are included for information only: + + (830) CS4232 audio I/O base 530, 604, E80 or F40 + (10) CS4232 audio IRQ 5, 7, 9, 11, 12 or 15 + (6) CS4232 audio DMA 0, 1 or 3 + (7) CS4232 second (duplex) DMA 0, 1 or 3 + + This will allow simultaneous record and playback, as 2 different dma + channels are used. + + The sound will be all left channel and very low volume since the + auxiliary input isn't muted by default. I had the changes necessary + for this in the kernel but the sound driver maintainer didn't want + to include them since it wasn't common in other machines. To fix this + you need to mute it using a mixer utility of some sort (if you find one + please let me know) or by patching the driver yourself and recompiling. + + There is a problem on the PowerStack 2's (PowerStack Pro's) using a + different irq/drq than the kernel expects. Unfortunately, I don't know + which irq/drq it is so if anyone knows please email me. + + Midi is not supported since the cs4232 driver doesn't support midi yet. + +2. IBM PowerPersonal PReP machines + + I've only tested sound on the Power Personal Series of IBM workstations + so if you try it on others please let me know the result. I'm especially + interested in the 43p's sound system, which I know nothing about. + + Enable support for "Crystal CS4232 based (PnP) cards" and for the + Microsoft Sound System. The MSS isn't used, but some of the routines + that the CS4232 driver uses are in it. + + Although the options you set are ignored and determined automatically + on boot these are included for information only: + + (530) CS4232 audio I/O base 530, 604, E80 or F40 + (5) CS4232 audio IRQ 5, 7, 9, 11, 12 or 15 + (1) CS4232 audio DMA 0, 1 or 3 + (7) CS4232 second (duplex) DMA 0, 1 or 3 + (330) CS4232 MIDI I/O base 330, 370, 3B0 or 3F0 + (9) CS4232 MIDI IRQ 5, 7, 9, 11, 12 or 15 + + This setup does _NOT_ allow for recording yet. + + Midi is not supported since the cs4232 driver doesn't support midi yet. + +2. IBM CHRP + + I have only tested this on the 43P-150. Build the kernel with the cs4232 + set as a module and load the module with irq=9 dma=1 dma2=2 io=0x550 diff --git a/Documentation/powerpc/zImage_layout.txt b/Documentation/powerpc/zImage_layout.txt new file mode 100644 index 0000000..048e015 --- /dev/null +++ b/Documentation/powerpc/zImage_layout.txt @@ -0,0 +1,47 @@ + Information about the Linux/PPC kernel images +===================================================================== + +Please mail me (Cort Dougan, cort@fsmlabs.com) if you have questions, +comments or corrections. + +This document is meant to answer several questions I've had about how +the PReP system boots and how Linux/PPC interacts with that mechanism. +It would be nice if we could have information on how other architectures +boot here as well. If you have anything to contribute, please +let me know. + + +1. PReP boot file + + This is the file necessary to boot PReP systems from floppy or + hard drive. The firmware reads the PReP partition table entry + and will load the image accordingly. + + To boot the zImage, copy it onto a floppy with dd if=zImage of=/dev/fd0h1440 + or onto a PReP hard drive partition with dd if=zImage of=/dev/sda4 + assuming you've created a PReP partition (type 0x41) with fdisk on + /dev/sda4. + + The layout of the image format is: + + 0x0 +------------+ + | | PReP partition table entry + | | + 0x400 +------------+ + | | Bootstrap program code + data + | | + | | + +------------+ + | | compressed kernel, elf header removed + +------------+ + | | initrd (if loaded) + +------------+ + | | Elf section table for bootstrap program + +------------+ + + +2. MBX boot file + + The MBX boards can load an elf image, and relocate it to the + proper location in memory - it copies the image to the location it was + linked at. |
