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* powerpc/mm: Fix stupid bug in subpge protection handlingDavid Gibson2009-12-181-2/+2
| | | | | | | | | | | | | | Commit d28513bc7f675d28b479db666d572e078ecf182d ("Fix bug in pagetable cache cleanup with CONFIG_PPC_SUBPAGE_PROT"), itself a fix for breakage caused by an earlier clean up patch of mine, contains a stupid bug. I changed the parameters of the subpage_protection() function, but failed to update one of the callers. This patch fixes it, and replaces a void * with a typed pointer so that the compiler will warn on such an error in future. Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/mm: Fix hash_utils_64.c compile errors with DEBUG enabled.Sachin P. Sant2009-12-181-4/+4
| | | | | | | | | | | | | | | | | This time without the funny characters. Fix following build errors generated with DEBUG=1 cc1: warnings being treated as errors arch/powerpc/mm/hash_utils_64.c: In function 'htab_dt_scan_page_sizes': arch/powerpc/mm/hash_utils_64.c:343: error: format '%04x' expects type 'unsigned int', but argument 4 has type 'long unsigned int' arch/powerpc/mm/hash_utils_64.c:343: error: format '%08x' expects type 'unsigned int', but argument 5 has type 'long unsigned int' arch/powerpc/mm/hash_utils_64.c: In function 'htab_initialize': arch/powerpc/mm/hash_utils_64.c:666: error: format '%x' expects type 'unsigned int', but argument 4 has type 'long unsigned int' ... SNIP ... Signed-off-by: Sachin Sant <sachinp@in.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/mm: Fix pgtable cache cleanup with CONFIG_PPC_SUBPAGE_PROTDavid Gibson2009-12-081-3/+3
| | | | | | | | | | | | | | | | | Commit a0668cdc154e54bf0c85182e0535eea237d53146 cleans up the handling of kmem_caches for allocating various levels of pagetables. Unfortunately, it conflicts badly with CONFIG_PPC_SUBPAGE_PROT, due to the latter's cleverly hidden technique of adding some extra allocation space to the top level page directory to store the extra information it needs. Since that extra allocation really doesn't fit into the cleaned up page directory allocating scheme, this patch alters CONFIG_PPC_SUBPAGE_PROT to instead allocate its struct subpage_prot_table as part of the mm_context_t. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* Revert "powerpc/mm: Fix bug in pagetable cache cleanup with ↵Benjamin Herrenschmidt2009-12-021-3/+3
| | | | | | | | | | | CONFIG_PPC_SUBPAGE_PROT" This reverts commit c045256d146800ea1d741a8e9e377dada6b7e195. It breaks build when CONFIG_PPC_SUBPAGE_PROT is not set. I will commit a fixed version separately Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/mm: Fix bug in pagetable cache cleanup with CONFIG_PPC_SUBPAGE_PROTDavid Gibson2009-11-271-3/+3
| | | | | | | | | | | | | | | | | Commit a0668cdc154e54bf0c85182e0535eea237d53146 cleans up the handling of kmem_caches for allocating various levels of pagetables. Unfortunately, it conflicts badly with CONFIG_PPC_SUBPAGE_PROT, due to the latter's cleverly hidden technique of adding some extra allocation space to the top level page directory to store the extra information it needs. Since that extra allocation really doesn't fit into the cleaned up page directory allocating scheme, this patch alters CONFIG_PPC_SUBPAGE_PROT to instead allocate its struct subpage_prot_table as part of the mm_context_t. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* Export symbols for KVM moduleAlexander Graf2009-11-051-0/+2
| | | | | | | | | | We want to be able to build KVM as a module. To enable us doing so, we need some more exports from core Linux parts. This patch exports all functions and variables that are required for KVM. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/mm: Bring hugepage PTE accessor functions back into sync with normal ↵David Gibson2009-10-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | accessors The hugepage arch code provides a number of hook functions/macros which mirror the functionality of various normal page pte access functions. Various changes in the normal page accessors (in particular BenH's recent changes to the handling of lazy icache flushing and PAGE_EXEC) have caused the hugepage versions to get out of sync with the originals. In some cases, this is a bug, at least on some MMU types. One of the reasons that some hooks were not identical to the normal page versions, is that the fact we're dealing with a hugepage needed to be passed down do use the correct dcache-icache flush function. This patch makes the main flush_dcache_icache_page() function hugepage aware (by checking for the PageCompound flag). That in turn means we can make set_huge_pte_at() just a call to set_pte_at() bringing it back into sync. As a bonus, this lets us remove the hash_huge_page_do_lazy_icache() function, replacing it with a call to the hash_page_do_lazy_icache() function it was based on. Some other hugepage pte access hooks - huge_ptep_get_and_clear() and huge_ptep_clear_flush() - are not so easily unified, but this patch at least brings them back into sync with the current versions of the corresponding normal page functions. Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/mm: Cleanup initialization of hugepages on powerpcDavid Gibson2009-10-301-10/+0
| | | | | | | | | | | | | | | | | | | | | This patch simplifies the logic used to initialize hugepages on powerpc. The somewhat oddly named set_huge_psize() is renamed to add_huge_page_size() and now does all necessary verification of whether it's given a valid hugepage sizes (instead of just some) and instantiates the generic hstate structure (but no more). hugetlbpage_init() now steps through the available pagesizes, checks if they're valid for hugepages by calling add_huge_page_size() and initializes the kmem_caches for the hugepage pagetables. This means we can now eliminate the mmu_huge_psizes array, since we no longer need to pass the sizing information for the pagetable caches from set_huge_psize() into hugetlbpage_init() Determination of the default huge page size is also moved from the hash code into the general hugepage code. Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/mm: Allow more flexible layouts for hugepage pagetablesDavid Gibson2009-10-301-12/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently each available hugepage size uses a slightly different pagetable layout: that is, the bottem level table of pointers to hugepages is a different size, and may branch off from the normal page tables at a different level. Every hugepage aware path that needs to walk the pagetables must therefore look up the hugepage size from the slice info first, and work out the correct way to walk the pagetables accordingly. Future hardware is likely to add more possible hugepage sizes, more layout options and more mess. This patch, therefore reworks the handling of hugepage pagetables to reduce this complexity. In the new scheme, instead of having to consult the slice mask, pagetable walking code can check a flag in the PGD/PUD/PMD entries to see where to branch off to hugepage pagetables, and the entry also contains the information (eseentially hugepage shift) necessary to then interpret that table without recourse to the slice mask. This scheme can be extended neatly to handle multiple levels of self-describing "special" hugepage pagetables, although for now we assume only one level exists. This approach means that only the pagetable allocation path needs to know how the pagetables should be set out. All other (hugepage) pagetable walking paths can just interpret the structure as they go. There already was a flag bit in PGD/PUD/PMD entries for hugepage directory pointers, but it was only used for debug. We alter that flag bit to instead be a 0 in the MSB to indicate a hugepage pagetable pointer (normally it would be 1 since the pointer lies in the linear mapping). This means that asm pagetable walking can test for (and punt on) hugepage pointers with the same test that checks for unpopulated page directory entries (beq becomes bge), since hugepage pointers will always be positive, and normal pointers always negative. While we're at it, we get rid of the confusing (and grep defeating) #defining of hugepte_shift to be the same thing as mmu_huge_psizes. Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix crash on CPU hotplugMichael Ellerman2009-04-221-1/+1
| | | | | | | | | | | early_init_mmu_secondary() is called at CPU hotplug time, so it must be marked as __cpuinit, not __init. Caused by 757c74d2 ("powerpc/mm: Introduce early_init_mmu() on 64-bit"). Tested-by: Sachin Sant <sachinp@in.ibm.com> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
* powerpc/mm: Introduce early_init_mmu() on 64-bitBenjamin Herrenschmidt2009-03-241-2/+34
| | | | | | | | This moves some MMU related init code out of setup_64.c into hash_utils_64.c and calls it early_init_mmu() and early_init_mmu_secondary(). This will make it easier to plug in a new MMU type. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* cpumask: Use mm_cpumask() wrapper instead of cpu_vm_maskRusty Russell2009-03-241-6/+4
| | | | | | | | | | Makes code futureproof against the impending change to mm->cpu_vm_mask. It's also a chance to use the new cpumask_ ops which take a pointer (the older ones are deprecated, but there's no hurry for arch code). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/mm: Reduce hashtable size when using 64kB pagesAnton Blanchard2009-02-231-2/+3
| | | | | | | | | | | | | At the moment we size the hashtable based on 4kB pages / 2, even on a 64kB kernel. This results in a hashtable that is much larger than it needs to be. Grab the real page size and size the hashtable based on that Note: This only has effect on non hypervisor machines. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Don't use a 16G page if beyond mem= limitsJon Tollefson2008-10-221-2/+4
| | | | | | | | | If mem= is used on the boot command line to limit memory then the memory block where a 16G page resides may not be available. Thanks to Michael Ellerman for finding the problem. Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Get USE_STRICT_MM_TYPECHECKS working againDavid Gibson2008-10-141-2/+2
| | | | | | | | | | | | The typesafe version of the powerpc pagetable handling (with USE_STRICT_MM_TYPECHECKS defined) has bitrotted again. This patch makes a bunch of small fixes to get it back to building status. It's still not enabled by default as gcc still generates worse code with it for some reason. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Make the 64-bit kernel as a position-independent executablePaul Mackerras2008-09-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This implements CONFIG_RELOCATABLE for 64-bit by making the kernel as a position-independent executable (PIE) when it is set. This involves processing the dynamic relocations in the image in the early stages of booting, even if the kernel is being run at the address it is linked at, since the linker does not necessarily fill in words in the image for which there are dynamic relocations. (In fact the linker does fill in such words for 64-bit executables, though not for 32-bit executables, so in principle we could avoid calling relocate() entirely when we're running a 64-bit kernel at the linked address.) The dynamic relocations are processed by a new function relocate(addr), where the addr parameter is the virtual address where the image will be run. In fact we call it twice; once before calling prom_init, and again when starting the main kernel. This means that reloc_offset() returns 0 in prom_init (since it has been relocated to the address it is running at), which necessitated a few adjustments. This also changes __va and __pa to use an equivalent definition that is simpler. With the relocatable kernel, PAGE_OFFSET and MEMORY_START are constants (for 64-bit) whereas PHYSICAL_START is a variable (and KERNELBASE ideally should be too, but isn't yet). With this, relocatable kernels still copy themselves down to physical address 0 and run there. Signed-off-by: Paul Mackerras <paulus@samba.org>
* Merge branch 'linux-2.6'Paul Mackerras2008-09-101-7/+11
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| * powerpc: Only make kernel text pages of linear mapping executablePaul Mackerras2008-09-031-7/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit bc033b63bbfeb6c4b4eb0a1d083c650e4a0d2af8 ("powerpc/mm: Fix attribute confusion with htab_bolt_mapping()") moved the check for whether we should make pages of the linear mapping executable from htab_bolt_mapping into its callers, including htab_initialize. A side-effect of this is that the decision is now made once for each contiguous section in the LMB array rather than for each page individually. This can often mean that the whole of the linear mapping ends up being executable. This reverts to the previous behaviour, where individual pages are checked for being part of the kernel text or not, by moving the check back down into htab_bolt_mapping. Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
* | powerpc: Guard htab_dt_scan_hugepage_blocks appropriatelyTony Breeds2008-08-201-0/+2
|/ | | | | | | | htab_dt_scan_hugepage_blocks is only used when CONFIG_HUGETLB_PAGE is defined, so guard the declaration likewise. Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
* powerpc/mm: Fix attribute confusion with htab_bolt_mapping()Benjamin Herrenschmidt2008-08-111-24/+39
| | | | | | | | | | | | | | | | | | | | | | | | | The function htab_bolt_mapping() is used to create permanent mappings in the MMU hash table, for example, in order to create the linear mapping of vmemmap. It's also used by early boot ioremap (before mem_init_done). However, the way ioremap uses it is incorrect as it passes it the protection flags in the "linux PTE" form while htab_bolt_mapping() expects them in the hash table format. This is made more confusing by the fact that some of those flags are actually in the same position in both cases. This fixes it all by making htab_bolt_mapping() take normal linux protection flags instead, and use a little helper to convert them to htab flags. Callers can now use the usual PAGE_* definitions safely. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> arch/powerpc/include/asm/mmu-hash64.h | 2 - arch/powerpc/mm/hash_utils_64.c | 65 ++++++++++++++++++++-------------- arch/powerpc/mm/init_64.c | 9 +--- 3 files changed, 44 insertions(+), 32 deletions(-) Signed-off-by: Paul Mackerras <paulus@samba.org>
* powerpc: support multiple hugepage sizesJon Tollefson2008-07-241-5/+4
| | | | | | | | | | | | | | | | | | Instead of using the variable mmu_huge_psize to keep track of the huge page size we use an array of MMU_PAGE_* values. For each supported huge page size we need to know the hugepte_shift value and have a pgtable_cache. The hstate or an mmu_huge_psizes index is passed to functions so that they know which huge page size they should use. The hugepage sizes 16M and 64K are setup(if available on the hardware) so that they don't have to be set on the boot cmd line in order to use them. The number of 16G pages have to be specified at boot-time though (e.g. hugepagesz=16G hugepages=5). Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc: scan device tree for gigantic pagesJon Tollefson2008-07-241-1/+43
| | | | | | | | | | | | | The 16G huge pages have to be reserved in the HMC prior to boot. The location of the pages are placed in the device tree. This patch adds code to scan the device tree during very early boot and save these page locations until hugetlbfs is ready for them. Acked-by: Adam Litke <agl@us.ibm.com> Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc: Only demote individual slices rather than whole processPaul Mackerras2008-07-011-9/+27
| | | | | | | | | | | | | | | | | | | | | At present, if we have a kernel with a 64kB page size, and some process maps something that has to be mapped with 4kB pages (such as a cache-inhibited mapping on POWER5+, or the eHCA infiniband queue-pair pages), we change the process to use 4kB pages everywhere. This hurts the performance of HPC programs that access eHCA from userspace. With this patch, the kernel will only demote the slice(s) containing the eHCA or cache-inhibited mappings, leaving the remaining slices able to use 64kB hardware pages. This also changes the slice_get_unmapped_area code so that it is willing to place a 64k-page mapping into (or across) a 4k-page slice if there is no better alternative, i.e. if the program specified MAP_FIXED or if there is not sufficient space available in slices that are either empty or already have 64k-page mappings in them. Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* Merge branch 'linux-2.6' into powerpc-nextPaul Mackerras2008-05-161-2/+26
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| * [POWERPC] vmemmap fixes to use smaller pagesBenjamin Herrenschmidt2008-05-151-2/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This changes vmemmap to use a different region (region 0xf) of the address space, and to configure the page size of that region dynamically at boot. The problem with the current approach of always using 16M pages is that it's not well suited to machines that have small amounts of memory such as small partitions on pseries, or PS3's. In fact, on the PS3, failure to allocate the 16M page backing vmmemmap tends to prevent hotplugging the HV's "additional" memory, thus limiting the available memory even more, from my experience down to something like 80M total, which makes it really not very useable. The logic used by my match to choose the vmemmap page size is: - If 16M pages are available and there's 1G or more RAM at boot, use that size. - Else if 64K pages are available, use that - Else use 4K pages I've tested on a POWER6 (16M pages) and on an iSeries POWER3 (4K pages) and it seems to work fine. Note that I intend to change the way we organize the kernel regions & SLBs so the actual region will change from 0xf back to something else at one point, as I simplify the SLB miss handler, but that will be for a later patch. Signed-off-by: Paul Mackerras <paulus@samba.org>
* | [POWERPC] Move declaration of tce variables into mmu-hash64.hMichael Ellerman2008-05-141-2/+0
| | | | | | | | | | | | | | ... instead of having extern declarations in a .c file. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
* | [POWERPC] Fix sparse warnings in arch/powerpc/mmMichael Ellerman2008-05-141-2/+2
|/ | | | | | | | | Make two vmemmap helpers static in init_64.c Make stab variables static in stab.c Make psize defs static in hash_utils_64.c Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] htab_remove_mapping is only used by MEMORY_HOTPLUGStephen Rothwell2008-04-071-0/+2
| | | | | | | | This eliminates a warning in builds that don't define CONFIG_MEMORY_HOTPLUG. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Add error return from htab_remove_mapping()Badari Pulavarty2008-04-011-5/+9
| | | | | | | | If the platform doesn't support hpte_removebolted(), gracefully return failure rather than success. Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
* Merge branch 'linux-2.6'Paul Mackerras2008-03-261-3/+8
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| * [POWERPC] Don't use 64k pages for ioremap on pSeriesPaul Mackerras2008-03-241-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | On pSeries, the hypervisor doesn't let us map in the eHEA ethernet adapter using 64k pages, and thus the ehea driver will fail if 64k pages are configured. This works around the problem by always using 4k pages for ioremap on pSeries (but not on other platforms). A better fix would be to check whether the partition could ever have an eHEA adapter, and only force 4k pages if it could, but this will do for 2.6.25. This is based on an earlier patch by Tony Breeds. Signed-off-by: Paul Mackerras <paulus@samba.org>
* | Merge branch 'linux-2.6'Paul Mackerras2008-03-131-2/+2
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| * [POWERPC] Fix large hash table allocation on Cell bladesMichael Ellerman2008-03-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | My recent hack to allocate the hash table under 1GB on cell was poorly tested, *cough*. It turns out on blades with large amounts of memory we fail to allocate the hash table at all. This is because RTAS has been instantiated just below 768MB, and 0-x MB are used by the kernel, leaving no areas that are both large enough and also naturally-aligned. For the cell IOMMU hack the page tables must be under 2GB, so use that as the limit instead. This has been tested on real hardware and boots happily. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
* | [POWERPC] Add code for removing HPTEs for parts of the linear mappingBadari Pulavarty2008-02-261-0/+23
| | | | | | | | | | | | | | | | | | | | | | | | For memory remove, we need to clean up htab mappings for the section of the memory we are removing. This implements support for removing htab bolted mappings for pSeries logical partitions. Other sub-archs may need to implement similar functionality for hotplug memory remove to work on them. Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
* | [LIB]: Make PowerPC LMB code generic so sparc64 can use it too.David S. Miller2008-02-131-1/+2
|/ | | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* [POWERPC] Allocate the hash table under 1G on cellMichael Ellerman2008-01-311-3/+9
| | | | | | | | | | | | In order to support the fixed IOMMU mapping (in a subsequent patch), we need the hash table to be inside the IOMMUs DMA window. This is usually 2G, but let's make sure the hash table is under 1G as that will satisfy the IOMMU requirements and also means the hash table will be on node 0. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Provide a way to protect 4k subpages when using 64k pagesPaul Mackerras2008-01-241-14/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using 64k pages on 64-bit PowerPC systems makes life difficult for emulators that are trying to emulate an ISA, such as x86, which use a smaller page size, since the emulator can no longer use the MMU and the normal system calls for controlling page protections. Of course, the emulator can emulate the MMU by checking and possibly remapping the address for each memory access in software, but that is pretty slow. This provides a facility for such programs to control the access permissions on individual 4k sub-pages of 64k pages. The idea is that the emulator supplies an array of protection masks to apply to a specified range of virtual addresses. These masks are applied at the level where hardware PTEs are inserted into the hardware page table based on the Linux PTEs, so the Linux PTEs are not affected. Note that this new mechanism does not allow any access that would otherwise be prohibited; it can only prohibit accesses that would otherwise be allowed. This new facility is only available on 64-bit PowerPC and only when the kernel is configured for 64k pages. The masks are supplied using a new subpage_prot system call, which takes a starting virtual address and length, and a pointer to an array of protection masks in memory. The array has a 32-bit word per 64k page to be protected; each 32-bit word consists of 16 2-bit fields, for which 0 allows any access (that is otherwise allowed), 1 prevents write accesses, and 2 or 3 prevent any access. Implicit in this is that the regions of the address space that are protected are switched to use 4k hardware pages rather than 64k hardware pages (on machines with hardware 64k page support). In fact the whole process is switched to use 4k hardware pages when the subpage_prot system call is used, but this could be improved in future to switch only the affected segments. The subpage protection bits are stored in a 3 level tree akin to the page table tree. The top level of this tree is stored in a structure that is appended to the top level of the page table tree, i.e., the pgd array. Since it will often only be 32-bit addresses (below 4GB) that are protected, the pointers to the first four bottom level pages are also stored in this structure (each bottom level page contains the protection bits for 1GB of address space), so the protection bits for addresses below 4GB can be accessed with one fewer loads than those for higher addresses. Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Add hugepagesz boot-time parameterJon Tollefson2008-01-171-9/+2
| | | | | | | | | | | | This adds the hugepagesz boot-time parameter for ppc64. It lets one pick the size for huge pages. The choices available are 64K and 16M when the base page size is 4k. It defaults to 16M (previously the only only choice) if nothing or an invalid choice is specified. Tested 64K huge pages successfully with the libhugetlbfs 1.2. Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Use SLB size from the device treeMichael Neuling2007-12-111-0/+1
| | | | | | | | | | | | | Currently we hardwire the number of SLBs to 64, but PAPR says we should use the ibm,slb-size property to obtain the number of SLB entries. This uses this property instead of assuming 64. If no property is found, we assume 64 entries as before. This soft patches the SLB handler, so it shouldn't change performance at all. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Include udbg.h when using udbg_printfwill schmidt2007-11-081-0/+1
| | | | | | | | | | | | This fixes the error error: implicit declaration of function "udbg_printf" We have a few spots where we reference udbg_printf() without #including udbg.h. These are within #ifdef DEBUG blocks, so unnoticed until we do a #define DEBUG or #define DEBUG_LOW nearby. Signed-off-by: Will Schmidt <will_schmidt@vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] powerpc: Fix demotion of segments to 4K pagesBenjamin Herrenschmidt2007-10-291-2/+4
| | | | | | | | | | | | | | | | | | When demoting a process to use 4K HW pages (instead of 64K), which happens under various circumstances such as doing cache inhibited mappings on machines that do not support 64K CI pages, the assembly hash code calls back into the C function flush_hash_page(). This function prototype was recently changed to accomodate for 1T segments but the assembly call site was not updated, causing applications that do demotion to hang. In addition, when updating the per-CPU PACA for the new sizes, we didn't properly update the slice "map", thus causing the SLB miss code to re-insert segments for the wrong size. This fixes both and adds a warning comment next to the C implementation to try to avoid problems next time someone changes it. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Add 1TB workaround for PA6TOlof Johansson2007-10-171-0/+1
| | | | | | | | | | | | | | | PA6T has a bug where the slbie instruction does not honor the large segment bit. As a result, we have to always use slbia when switching context. We don't have to worry about changing the slbie's during fault processing, since they should never be replacing one VSID with another using the same ESID. I.e. there's no risk for inserting duplicate entries due to a failed slbie of the old entry. So as long as we clear it out on context switch we should be fine. Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Fix 1TB segment detectionOlof Johansson2007-10-171-1/+1
| | | | | | | | Buglet in the 1TB detection makes it return after checking the first property word, even if it's not a match. Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Use 1TB segmentsPaul Mackerras2007-10-121-31/+83
| | | | | | | | | | | | | | | | | | | | This makes the kernel use 1TB segments for all kernel mappings and for user addresses of 1TB and above, on machines which support them (currently POWER5+, POWER6 and PA6T). We detect that the machine supports 1TB segments by looking at the ibm,processor-segment-sizes property in the device tree. We don't currently use 1TB segments for user addresses < 1T, since that would effectively prevent 32-bit processes from using huge pages unless we also had a way to revert to using 256MB segments. That would be possible but would involve extra complications (such as keeping track of which segment size was used when HPTEs were inserted) and is not addressed here. Parts of this patch were originally written by Ben Herrenschmidt. Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Tidy up CONFIG_PPC_MM_SLICES codeStephen Rothwell2007-08-171-6/+0
| | | | | | | This removes some of the #ifdefs from .c files. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Clean out a bunch of duplicate includesJesper Juhl2007-08-171-1/+0
| | | | | | | | This removes several duplicate includes from arch/powerpc/. Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Fix invalid semicolon after if statementIlpo Järvinen2007-08-171-1/+1
| | | | | | | | | | | A similar fix to netfilter from Eric Dumazet inspired me to look around a bit by using some grep/sed stuff as looking for this kind of bugs seemed easy to automate. This is one of them I found where it looks like this semicolon is not valid. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Fixes for the SLB shadow buffer codeMichael Neuling2007-08-031-1/+1
| | | | | | | | | | | | | | On a machine with hardware 64kB pages and a kernel configured for a 64kB base page size, we need to change the vmalloc segment from 64kB pages to 4kB pages if some driver creates a non-cacheable mapping in the vmalloc area. However, we never updated with SLB shadow buffer. This fixes it. Thanks to paulus for finding this. Also added some write barriers to ensure the shadow buffer contents are always consistent. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] cell: CONFIG_SPE_BASE is a typoGeert Uytterhoeven2007-07-221-2/+2
| | | | | | | | | The config symbol for SPE support is called CONFIG_SPU_BASE, not CONFIG_SPE_BASE. Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [POWERPC] Kill typedef-ed structs for hash PTEs and BATsDavid Gibson2007-06-141-1/+1
| | | | | | | | | | | | | | Using typedefs to rename structure types if frowned on by CodingStyle. However, we do so for the hash PTE structure on both ppc32 (where it's called "PTE") and ppc64 (where it's called "hpte_t"). On ppc32 we also have such a typedef for the BATs ("BAT"). This removes this unhelpful use of typedefs, in the process bringing ppc32 and ppc64 closer together, by using the name "struct hash_pte" in both cases. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
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