From f02cbbe657939489347cbda598401a56913ffcbd Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Tue, 2 Nov 2010 12:05:10 -0400 Subject: pci root complex: support for tile architecture This change enables PCI root complex support for TILEPro. Unlike TILE-Gx, TILEPro has no support for memory-mapped I/O, so the PCI support consists of hypervisor upcalls for PIO, DMA, etc. However, the performance is fine for the devices we have tested with so far (1Gb Ethernet, SATA, etc.). The header was tweaked to be a little bit more aggressive about disabling attempts to map/unmap IO port space. The hacky header was rolled into the header and the result was simplified. Both of the latter two headers were preliminary versions not meant for release before now - oh well. There is one quirk for our TILEmpower platform, which accidentally negotiates up to 5GT and needs to be kicked down to 2.5GT. Signed-off-by: Chris Metcalf --- arch/tile/kernel/pci.c | 621 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 621 insertions(+) create mode 100644 arch/tile/kernel/pci.c (limited to 'arch/tile/kernel/pci.c') diff --git a/arch/tile/kernel/pci.c b/arch/tile/kernel/pci.c new file mode 100644 index 0000000..a1ee25b --- /dev/null +++ b/arch/tile/kernel/pci.c @@ -0,0 +1,621 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + + +/* + * Initialization flow and process + * ------------------------------- + * + * This files containes the routines to search for PCI buses, + * enumerate the buses, and configure any attached devices. + * + * There are two entry points here: + * 1) tile_pci_init + * This sets up the pci_controller structs, and opens the + * FDs to the hypervisor. This is called from setup_arch() early + * in the boot process. + * 2) pcibios_init + * This probes the PCI bus(es) for any attached hardware. It's + * called by subsys_initcall. All of the real work is done by the + * generic Linux PCI layer. + * + */ + +/* + * This flag tells if the platform is TILEmpower that needs + * special configuration for the PLX switch chip. + */ +int __write_once tile_plx_gen1; + +static struct pci_controller controllers[TILE_NUM_PCIE]; +static int num_controllers; + +static struct pci_ops tile_cfg_ops; + + +/* + * We don't need to worry about the alignment of resources. + */ +resource_size_t pcibios_align_resource(void *data, const struct resource *res, + resource_size_t size, resource_size_t align) +{ + return res->start; +} +EXPORT_SYMBOL(pcibios_align_resource); + +/* + * Open a FD to the hypervisor PCI device. + * + * controller_id is the controller number, config type is 0 or 1 for + * config0 or config1 operations. + */ +static int __init tile_pcie_open(int controller_id, int config_type) +{ + char filename[32]; + int fd; + + sprintf(filename, "pcie/%d/config%d", controller_id, config_type); + + fd = hv_dev_open((HV_VirtAddr)filename, 0); + + return fd; +} + + +/* + * Get the IRQ numbers from the HV and set up the handlers for them. + */ +static int __init tile_init_irqs(int controller_id, + struct pci_controller *controller) +{ + char filename[32]; + int fd; + int ret; + int x; + struct pcie_rc_config rc_config; + + sprintf(filename, "pcie/%d/ctl", controller_id); + fd = hv_dev_open((HV_VirtAddr)filename, 0); + if (fd < 0) { + pr_err("PCI: hv_dev_open(%s) failed\n", filename); + return -1; + } + ret = hv_dev_pread(fd, 0, (HV_VirtAddr)(&rc_config), + sizeof(rc_config), PCIE_RC_CONFIG_MASK_OFF); + hv_dev_close(fd); + if (ret != sizeof(rc_config)) { + pr_err("PCI: wanted %zd bytes, got %d\n", + sizeof(rc_config), ret); + return -1; + } + /* Record irq_base so that we can map INTx to IRQ # later. */ + controller->irq_base = rc_config.intr; + + for (x = 0; x < 4; x++) + tile_irq_activate(rc_config.intr + x, + TILE_IRQ_HW_CLEAR); + + if (rc_config.plx_gen1) + controller->plx_gen1 = 1; + + return 0; +} + +/* + * First initialization entry point, called from setup_arch(). + * + * Find valid controllers and fill in pci_controller structs for each + * of them. + * + * Returns the number of controllers discovered. + */ +int __init tile_pci_init(void) +{ + int i; + + pr_info("PCI: Searching for controllers...\n"); + + /* Do any configuration we need before using the PCIe */ + + for (i = 0; i < TILE_NUM_PCIE; i++) { + int hv_cfg_fd0 = -1; + int hv_cfg_fd1 = -1; + int hv_mem_fd = -1; + char name[32]; + struct pci_controller *controller; + + /* + * Open the fd to the HV. If it fails then this + * device doesn't exist. + */ + hv_cfg_fd0 = tile_pcie_open(i, 0); + if (hv_cfg_fd0 < 0) + continue; + hv_cfg_fd1 = tile_pcie_open(i, 1); + if (hv_cfg_fd1 < 0) { + pr_err("PCI: Couldn't open config fd to HV " + "for controller %d\n", i); + goto err_cont; + } + + sprintf(name, "pcie/%d/mem", i); + hv_mem_fd = hv_dev_open((HV_VirtAddr)name, 0); + if (hv_mem_fd < 0) { + pr_err("PCI: Could not open mem fd to HV!\n"); + goto err_cont; + } + + pr_info("PCI: Found PCI controller #%d\n", i); + + controller = &controllers[num_controllers]; + + if (tile_init_irqs(i, controller)) { + pr_err("PCI: Could not initialize " + "IRQs, aborting.\n"); + goto err_cont; + } + + controller->index = num_controllers; + controller->hv_cfg_fd[0] = hv_cfg_fd0; + controller->hv_cfg_fd[1] = hv_cfg_fd1; + controller->hv_mem_fd = hv_mem_fd; + controller->first_busno = 0; + controller->last_busno = 0xff; + controller->ops = &tile_cfg_ops; + + num_controllers++; + continue; + +err_cont: + if (hv_cfg_fd0 >= 0) + hv_dev_close(hv_cfg_fd0); + if (hv_cfg_fd1 >= 0) + hv_dev_close(hv_cfg_fd1); + if (hv_mem_fd >= 0) + hv_dev_close(hv_mem_fd); + continue; + } + + /* + * Before using the PCIe, see if we need to do any platform-specific + * configuration, such as the PLX switch Gen 1 issue on TILEmpower. + */ + for (i = 0; i < num_controllers; i++) { + struct pci_controller *controller = &controllers[i]; + + if (controller->plx_gen1) + tile_plx_gen1 = 1; + } + + return num_controllers; +} + +/* + * (pin - 1) converts from the PCI standard's [1:4] convention to + * a normal [0:3] range. + */ +static int tile_map_irq(struct pci_dev *dev, u8 slot, u8 pin) +{ + struct pci_controller *controller = + (struct pci_controller *)dev->sysdata; + return (pin - 1) + controller->irq_base; +} + + +static void __init fixup_read_and_payload_sizes(void) +{ + struct pci_dev *dev = NULL; + int smallest_max_payload = 0x1; /* Tile maxes out at 256 bytes. */ + int max_read_size = 0x2; /* Limit to 512 byte reads. */ + u16 new_values; + + /* Scan for the smallest maximum payload size. */ + while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) { + int pcie_caps_offset; + u32 devcap; + int max_payload; + + pcie_caps_offset = pci_find_capability(dev, PCI_CAP_ID_EXP); + if (pcie_caps_offset == 0) + continue; + + pci_read_config_dword(dev, pcie_caps_offset + PCI_EXP_DEVCAP, + &devcap); + max_payload = devcap & PCI_EXP_DEVCAP_PAYLOAD; + if (max_payload < smallest_max_payload) + smallest_max_payload = max_payload; + } + + /* Now, set the max_payload_size for all devices to that value. */ + new_values = (max_read_size << 12) | (smallest_max_payload << 5); + while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) { + int pcie_caps_offset; + u16 devctl; + + pcie_caps_offset = pci_find_capability(dev, PCI_CAP_ID_EXP); + if (pcie_caps_offset == 0) + continue; + + pci_read_config_word(dev, pcie_caps_offset + PCI_EXP_DEVCTL, + &devctl); + devctl &= ~(PCI_EXP_DEVCTL_PAYLOAD | PCI_EXP_DEVCTL_READRQ); + devctl |= new_values; + pci_write_config_word(dev, pcie_caps_offset + PCI_EXP_DEVCTL, + devctl); + } +} + + +/* + * Second PCI initialization entry point, called by subsys_initcall. + * + * The controllers have been set up by the time we get here, by a call to + * tile_pci_init. + */ +static int __init pcibios_init(void) +{ + int i; + + pr_info("PCI: Probing PCI hardware\n"); + + /* + * Delay a bit in case devices aren't ready. Some devices are + * known to require at least 20ms here, but we use a more + * conservative value. + */ + mdelay(250); + + /* Scan all of the recorded PCI controllers. */ + for (i = 0; i < num_controllers; i++) { + struct pci_controller *controller = &controllers[i]; + struct pci_bus *bus; + + pr_info("PCI: initializing controller #%d\n", i); + + /* + * This comes from the generic Linux PCI driver. + * + * It reads the PCI tree for this bus into the Linux + * data structures. + * + * This is inlined in linux/pci.h and calls into + * pci_scan_bus_parented() in probe.c. + */ + bus = pci_scan_bus(0, controller->ops, controller); + controller->root_bus = bus; + controller->last_busno = bus->subordinate; + + } + + /* Do machine dependent PCI interrupt routing */ + pci_fixup_irqs(pci_common_swizzle, tile_map_irq); + + /* + * This comes from the generic Linux PCI driver. + * + * It allocates all of the resources (I/O memory, etc) + * associated with the devices read in above. + */ + + pci_assign_unassigned_resources(); + + /* Configure the max_read_size and max_payload_size values. */ + fixup_read_and_payload_sizes(); + + /* Record the I/O resources in the PCI controller structure. */ + for (i = 0; i < num_controllers; i++) { + struct pci_bus *root_bus = controllers[i].root_bus; + struct pci_bus *next_bus; + struct pci_dev *dev; + + list_for_each_entry(dev, &root_bus->devices, bus_list) { + /* Find the PCI host controller, ie. the 1st bridge. */ + if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI && + (PCI_SLOT(dev->devfn) == 0)) { + next_bus = dev->subordinate; + controllers[i].mem_resources[0] = + *next_bus->resource[0]; + controllers[i].mem_resources[1] = + *next_bus->resource[1]; + controllers[i].mem_resources[2] = + *next_bus->resource[2]; + + break; + } + } + + } + + return 0; +} +subsys_initcall(pcibios_init); + +/* + * No bus fixups needed. + */ +void __devinit pcibios_fixup_bus(struct pci_bus *bus) +{ + /* Nothing needs to be done. */ +} + +/* + * This can be called from the generic PCI layer, but doesn't need to + * do anything. + */ +char __devinit *pcibios_setup(char *str) +{ + /* Nothing needs to be done. */ + return str; +} + +/* + * This is called from the generic Linux layer. + */ +void __init pcibios_update_irq(struct pci_dev *dev, int irq) +{ + pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq); +} + +/* + * Enable memory and/or address decoding, as appropriate, for the + * device described by the 'dev' struct. + * + * This is called from the generic PCI layer, and can be called + * for bridges or endpoints. + */ +int pcibios_enable_device(struct pci_dev *dev, int mask) +{ + u16 cmd, old_cmd; + u8 header_type; + int i; + struct resource *r; + + pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type); + + pci_read_config_word(dev, PCI_COMMAND, &cmd); + old_cmd = cmd; + if ((header_type & 0x7F) == PCI_HEADER_TYPE_BRIDGE) { + /* + * For bridges, we enable both memory and I/O decoding + * in call cases. + */ + cmd |= PCI_COMMAND_IO; + cmd |= PCI_COMMAND_MEMORY; + } else { + /* + * For endpoints, we enable memory and/or I/O decoding + * only if they have a memory resource of that type. + */ + for (i = 0; i < 6; i++) { + r = &dev->resource[i]; + if (r->flags & IORESOURCE_UNSET) { + pr_err("PCI: Device %s not available " + "because of resource collisions\n", + pci_name(dev)); + return -EINVAL; + } + if (r->flags & IORESOURCE_IO) + cmd |= PCI_COMMAND_IO; + if (r->flags & IORESOURCE_MEM) + cmd |= PCI_COMMAND_MEMORY; + } + } + + /* + * We only write the command if it changed. + */ + if (cmd != old_cmd) + pci_write_config_word(dev, PCI_COMMAND, cmd); + return 0; +} + +void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max) +{ + unsigned long start = pci_resource_start(dev, bar); + unsigned long len = pci_resource_len(dev, bar); + unsigned long flags = pci_resource_flags(dev, bar); + + if (!len) + return NULL; + if (max && len > max) + len = max; + + if (!(flags & IORESOURCE_MEM)) { + pr_info("PCI: Trying to map invalid resource %#lx\n", flags); + start = 0; + } + + return (void __iomem *)start; +} +EXPORT_SYMBOL(pci_iomap); + + +/**************************************************************** + * + * Tile PCI config space read/write routines + * + ****************************************************************/ + +/* + * These are the normal read and write ops + * These are expanded with macros from pci_bus_read_config_byte() etc. + * + * devfn is the combined PCI slot & function. + * + * offset is in bytes, from the start of config space for the + * specified bus & slot. + */ + +static int __devinit tile_cfg_read(struct pci_bus *bus, + unsigned int devfn, + int offset, + int size, + u32 *val) +{ + struct pci_controller *controller = bus->sysdata; + int busnum = bus->number & 0xff; + int slot = (devfn >> 3) & 0x1f; + int function = devfn & 0x7; + u32 addr; + int config_mode = 1; + + /* + * There is no bridge between the Tile and bus 0, so we + * use config0 to talk to bus 0. + * + * If we're talking to a bus other than zero then we + * must have found a bridge. + */ + if (busnum == 0) { + /* + * We fake an empty slot for (busnum == 0) && (slot > 0), + * since there is only one slot on bus 0. + */ + if (slot) { + *val = 0xFFFFFFFF; + return 0; + } + config_mode = 0; + } + + addr = busnum << 20; /* Bus in 27:20 */ + addr |= slot << 15; /* Slot (device) in 19:15 */ + addr |= function << 12; /* Function is in 14:12 */ + addr |= (offset & 0xFFF); /* byte address in 0:11 */ + + return hv_dev_pread(controller->hv_cfg_fd[config_mode], 0, + (HV_VirtAddr)(val), size, addr); +} + + +/* + * See tile_cfg_read() for relevent comments. + * Note that "val" is the value to write, not a pointer to that value. + */ +static int __devinit tile_cfg_write(struct pci_bus *bus, + unsigned int devfn, + int offset, + int size, + u32 val) +{ + struct pci_controller *controller = bus->sysdata; + int busnum = bus->number & 0xff; + int slot = (devfn >> 3) & 0x1f; + int function = devfn & 0x7; + u32 addr; + int config_mode = 1; + HV_VirtAddr valp = (HV_VirtAddr)&val; + + /* + * For bus 0 slot 0 we use config 0 accesses. + */ + if (busnum == 0) { + /* + * We fake an empty slot for (busnum == 0) && (slot > 0), + * since there is only one slot on bus 0. + */ + if (slot) + return 0; + config_mode = 0; + } + + addr = busnum << 20; /* Bus in 27:20 */ + addr |= slot << 15; /* Slot (device) in 19:15 */ + addr |= function << 12; /* Function is in 14:12 */ + addr |= (offset & 0xFFF); /* byte address in 0:11 */ + +#ifdef __BIG_ENDIAN + /* Point to the correct part of the 32-bit "val". */ + valp += 4 - size; +#endif + + return hv_dev_pwrite(controller->hv_cfg_fd[config_mode], 0, + valp, size, addr); +} + + +static struct pci_ops tile_cfg_ops = { + .read = tile_cfg_read, + .write = tile_cfg_write, +}; + + +/* + * In the following, each PCI controller's mem_resources[1] + * represents its (non-prefetchable) PCI memory resource. + * mem_resources[0] and mem_resources[2] refer to its PCI I/O and + * prefetchable PCI memory resources, respectively. + * For more details, see pci_setup_bridge() in setup-bus.c. + * By comparing the target PCI memory address against the + * end address of controller 0, we can determine the controller + * that should accept the PCI memory access. + */ +#define TILE_READ(size, type) \ +type _tile_read##size(unsigned long addr) \ +{ \ + type val; \ + int idx = 0; \ + if (addr > controllers[0].mem_resources[1].end && \ + addr > controllers[0].mem_resources[2].end) \ + idx = 1; \ + if (hv_dev_pread(controllers[idx].hv_mem_fd, 0, \ + (HV_VirtAddr)(&val), sizeof(type), addr)) \ + pr_err("PCI: read %zd bytes at 0x%lX failed\n", \ + sizeof(type), addr); \ + return val; \ +} \ +EXPORT_SYMBOL(_tile_read##size) + +TILE_READ(b, u8); +TILE_READ(w, u16); +TILE_READ(l, u32); +TILE_READ(q, u64); + +#define TILE_WRITE(size, type) \ +void _tile_write##size(type val, unsigned long addr) \ +{ \ + int idx = 0; \ + if (addr > controllers[0].mem_resources[1].end && \ + addr > controllers[0].mem_resources[2].end) \ + idx = 1; \ + if (hv_dev_pwrite(controllers[idx].hv_mem_fd, 0, \ + (HV_VirtAddr)(&val), sizeof(type), addr)) \ + pr_err("PCI: write %zd bytes at 0x%lX failed\n", \ + sizeof(type), addr); \ +} \ +EXPORT_SYMBOL(_tile_write##size) + +TILE_WRITE(b, u8); +TILE_WRITE(w, u16); +TILE_WRITE(l, u32); +TILE_WRITE(q, u64); -- cgit v1.1