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path: root/arch/x86/mm/pageattr.c
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2008-02-18x86: CPA, fix alias checksThomas Gleixner
c_p_a() did not discover all aliases correctly. (such as when called on vmalloc()-ed areas or ioremap()-ed areas) Push the alias checks to the lower, physical level and consistently discover all aliases that might exist: the low direct mappings and the high linear kernel-text mappings (on 64-bit). Thanks to Andi Kleen for pointing out that this was buggy. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-14x86: cpa, fix out of date commentIngo Molnar
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-14x86: cpa: ensure page alignmentThomas Gleixner
the cpa API is page aligned - warn about any weird alignments. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13x86: CPA: fix gbpages support in try_preserve_large_pageAndi Kleen
[ mingo@elte.hu: while gbpages cannot be enabled on mainline currently, keep the code uptodate and this fix is easy enough. ] Use correct page sizes and masks for GB pages in try_preserve_large_page() This prevents a boot hang on a GB capable system with CONFIG_DIRECT_GBPAGES enabled. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-09x86: cpa, strict range check in try_preserve_large_page()Thomas Gleixner
Right now, we check only the first 4k page for static required protections. This does not take overlapping regions into account. So we might end up setting the wrong permissions/protections for other parts of this large page. This can be optimized further, but correctness is the important part. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-09x86: cpa, use page poolThomas Gleixner
Switch the split page code to use the page pool. We do this unconditionally to avoid different behaviour with and without DEBUG_PAGEALLOC enabled. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-09x86: introduce page pool in cpaThomas Gleixner
DEBUG_PAGEALLOC was not possible on 64-bit due to its early-bootup hardcoded reliance on PSE pages, and the unrobustness of the runtime splitup of large pages. The splitup ended in recursive calls to alloc_pages() when a page for a pte split was requested. Avoid the recursion with a preallocated page pool, which is used to split up large mappings and gets refilled in the return path of kernel_map_pages after the split has been done. The size of the page pool is adjusted to the available memory. This part just implements the page pool and the initialization w/o using it yet. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-09x86: sparse warnings in pageattr.cHarvey Harrison
Adjust the definition of lookup_address to take an unsigned long level argument. Adjust callers in xen/mmu.c that pass in a dummy variable. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-06x86: remove suprious ifdefs from pageattr.cArjan van de Ven
The .rodata section really should just be read only; the config option is there to make breaking up the 2Mb page an option (so people whos machines give more performance for the 2Mb case can opt to do so). But when the page gets split anyway, this is no longer an issue, so clean up the code and remove the ifdefs Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-06x86: remove X2 workaroundIngo Molnar
With the spurious handler fix, the X2 does not lock up anymore. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-05stop c_p_a corrupting the pdsHugh Dickins
When change_page_attr splits a large page on x86_32 (without PAE), it is currently corrupting every process's page directory: fix that by removing the thinko which passes down a physical instead of a virtual address. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-04x86: cpa, micro-optimizationThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-04x86: cpa, clean up code flowIngo Molnar
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-04x86: cpa, eliminate CPA_ enumIngo Molnar
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-04x86: cpa, cleanupsIngo Molnar
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-04x86: implement gbpages support in change_page_attr()Andi Kleen
Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-04x86: add gbpages support to lookup_addressAndi Kleen
[ tglx@linutronix.de: fix bootup crash on sparse mappings. ] Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-04x86: fix page-present check in cpa_flush_rangeThomas Gleixner
pte_present() might return true for PROT_NONE mappings. Explicitely check the present bit. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-04x86: remove cpa warningIngo Molnar
this race is legit and can happen on SMP systems. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-04x86: CPA fix pagetable splitThomas Gleixner
Move the readout of the large entry into the spinlock section to prevent an unlikely but possible race. Mark the pmd/pud entry present after the split. We preserved the non present bit in the new split mapping. Remove the stale gfp_flags double initialization. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-04x86: rename LARGE_PAGE_SIZE to PMD_PAGE_SIZEAndi Kleen
Fix up all users. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-04x86: cpa, fix lookup_addressThomas Gleixner
lookup_address() returns a wrong level and a wrong pointer to a non existing pte, when pmd or pud entries are marked !present. This happens for example due to boot time mapping of GART into the low memory space. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-04x86: AMD Athlon X2 hard hang fixIngo Molnar
An Athlon 64 X2 test system showed hard hangs shortly after marking the kernel text read-only, if we tried to preserve largepages and changed the PSE entry from RW to RO. The pagetable code itself is correct, it's the CPU that locked up hard (and not even the NMI watchdog could punch through that hard hang). So be conservative and always do splitups - like we did in the past. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-04x86: cpa, preserve large pages if possibleThomas Gleixner
When CPA is called on a range which fits into a large page mapping, avoid to split the page when: 1) There is no change of attributes 2) The range to change is a complete large mapping Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-04x86: cpa, check if we changed anything and tlb flushing is necessaryThomas Gleixner
Flush tlbs only when there was a real change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-04x86: introduce struct cpa_dataThomas Gleixner
The number of arguments which need to be transported is increasing and we want to add flush optimizations and large page preserving. Create struct cpa data and pass a pointer instead of increasing the number of arguments further. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-04x86: cpa, only flush the cache if the caching attributes have changedAndi Kleen
We only need to flush the caches in cpa() if the the caching attributes have changed. Otherwise only flush the TLBs. This checks the PAT bits too although they are currently not used by the kernel. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-04x86: CPA return early when requested feature is not availableThomas Gleixner
Mask out the not supported bits (e.g. NX). If the clr/set masks are empty after the mask return without changing anything. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-04x86: CPA use the existing pfn in split as wellThomas Gleixner
When splitting large pages, we ge the pfn from the existing entry instead of calculating it ourself. This removes the last remaining range restriction of the cpa code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-04x86: use the pfn from the page when change its attributesArjan van de Ven
When changing the attributes of a pte, we should use the PFN from the existing PTE rather than going through hoops calculating what we think it might have been; this is both fragile and totally unneeded. It also makes it more hairy to call any of these functions on non-direct maps for no good reason whatsover. With this change, __change_page_attr() no longer takes a pfn as argument, which simplifies all the callers. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@tglx.de>
2008-02-04x86: teach the static_protection function about high mappingsArjan van de Ven
Right now, enforcing that the high mapping of the kernel text doesn't get the NX bit is done deep in the guts of CPA, rather than in the static_protection() function that enforces all other per-arch sanity checks. This patch moves this sanity check into the central static_protection() function instead, and makes it apply ONLY to the kernel text, not to all other areas in the high mapping. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-04x86: CPA remove bogus NX clearThomas Gleixner
In split_large_page we clear the NX bit for the new split ptes, but we need to preserve the original setting of it for the split ptes. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-31x86: change_page_attr_clear fixHuang, Ying
This patch replaces __change_page_attr_set_clr() with change_page_attr_set_clr() in change_page_attr_clear() to flush the TLB/cache properly. Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30x86: use the same pgd_list for PAE and 64-bitJeremy Fitzhardinge
Use a standard list threaded through page->lru for maintaining the pgd list on PAE. This is the same as 64-bit, and seems saner than using a non-standard list via page->index. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: cpa cleanup the 64-bit alias mathThomas Gleixner
Cleanup the address calculations, which are necessary to identify the high/low alias mappings of the kernel on 64 bit machines. Instead of calling __pa/__va back and forth, calculate the physical address once and base the other calculations on it. Add understandable constants so we can use the already available within() helper. Also add comments, which help mere mortals to understand what this code does. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30x86: cpa: fix the self-testIngo Molnar
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: fix clflush_page_range logicIngo Molnar
only present ptes must be flushed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30x86: optimize clflushThomas Gleixner
clflush is sufficient to be issued on one CPU. The invalidation is broadcast throughout the coherence domain. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30x86: clflush_page_range needs mfenceThomas Gleixner
clflush is an unordered operation with respect to other memory traffic, including other CLFLUSH instructions. This needs proper fencing with mfence. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30x86: cpa: rename global_flush_tlb() to cpa_flush_all()Thomas Gleixner
The function name global_flush_tlb() suggests something different from what the function really does. Rename it to cpa_flush_all(), which is an understandable counterpart to cpa_flush_range(). no global visibility of the old API anymore. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30x86: cpa: implement clflush optimizationThomas Gleixner
Use clflush on CPUs which support this. clflush is only used when the page attribute operation has been successful. On CPUs which do not support clflush and in the case of error the old fashioned global_flush_tlb() is called. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30x86: cpa use the new set_clr functionThomas Gleixner
Convert cpa_set and cpa_clear to call the new set_clr function. Seperate out the debug helpers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30x86: cpa create set_and_clr functionThomas Gleixner
Create a set_and_clr function to avoid the duplicate loops. Allows also to do combined operations for optimization. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30x86: cpa move the flush into set and clear functionsThomas Gleixner
To avoid the modification of the flush code for the clflush implementation, move the flush into the set and clear functions and provide helper functions for the debugging code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30x86: cpa: clean up change_page_attr_set/clear()Thomas Gleixner
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: cpa: fix loopIngo Molnar
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: cpa: fix split thinkoThomas Gleixner
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: fix pageattr-selftestArjan van de Ven
In Ingo's testing, he found a bug in the CPA selftest code. What would happen is that the test would call change_page_attr_addr on a range of memory, part of which was read only, part of which was writable. The only thing the test wanted to change was the global bit... What actually happened was that the selftest would take the permissions of the first page, and then the change_page_attr_addr call would then set the permissions of the entire range to this first page. In the rodata section case, this resulted in pages after the .rodata becoming read only... which made the kernel rather unhappy in many interesting ways. This is just another example of how dangerous the cpa API is (was); this patch changes the test to use the incremental clear/set APIs instead, and it changes the clear/set implementation to work on a 1 page at a time basis. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: cpa: move flush to cpaThomas Gleixner
The set_memory_* and set_pages_* family of API's currently requires the callers to do a global tlb flush after the function call; forgetting this is a very nasty deathtrap. This patch moves the global tlb flush into each of the callers Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: make various pageattr.c functions staticArjan van de Ven
change_page_attr_add is only used in pageattr.c now, so we can make this function static. change_page_attr() isn't used anywere at all anymore; this function is a really bad API anyway so just remove the bloat entirely. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>