![Dave Hansen](/assets/img/avatar_default.png)
kernel_map_sync_memtype() is called from a variety of contexts. The pat.c code that calls it seems to ensure that it is not called for non-ram areas by checking via pat_pagerange_is_ram(). It is important that it only be called on the actual identity map because there *IS* no map to sync for highmem pages, or for memory holes. The ioremap.c uses are not as careful as those from pat.c, and call kernel_map_sync_memtype() on PCI space which is in the middle of the kernel identity map _range_, but is not actually mapped. This patch adds a check to kernel_map_sync_memtype() which probably duplicates some of the checks already in pat.c. But, it is necessary for the ioremap.c uses and shouldn't hurt other callers. I have reproduced this bug and this patch fixes it for me and the original bug reporter: https://lkml.org/lkml/2013/2/5/396 Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20130307163151.D9B58C4E@kernel.stglabs.ibm.com Signed-off-by: Dave Hansen <dave@sr71.net> Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
885 lines
21 KiB
C
885 lines
21 KiB
C
/*
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* Handle caching attributes in page tables (PAT)
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*
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* Authors: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
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* Suresh B Siddha <suresh.b.siddha@intel.com>
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*
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* Loosely based on earlier PAT patchset from Eric Biederman and Andi Kleen.
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*/
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#include <linux/seq_file.h>
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#include <linux/bootmem.h>
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#include <linux/debugfs.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/rbtree.h>
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#include <asm/cacheflush.h>
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#include <asm/processor.h>
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#include <asm/tlbflush.h>
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#include <asm/x86_init.h>
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#include <asm/pgtable.h>
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#include <asm/fcntl.h>
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#include <asm/e820.h>
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#include <asm/mtrr.h>
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#include <asm/page.h>
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#include <asm/msr.h>
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#include <asm/pat.h>
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#include <asm/io.h>
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#include "pat_internal.h"
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#ifdef CONFIG_X86_PAT
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int __read_mostly pat_enabled = 1;
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static inline void pat_disable(const char *reason)
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{
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pat_enabled = 0;
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printk(KERN_INFO "%s\n", reason);
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}
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static int __init nopat(char *str)
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{
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pat_disable("PAT support disabled.");
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return 0;
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}
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early_param("nopat", nopat);
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#else
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static inline void pat_disable(const char *reason)
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{
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(void)reason;
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}
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#endif
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int pat_debug_enable;
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static int __init pat_debug_setup(char *str)
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{
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pat_debug_enable = 1;
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return 0;
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}
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__setup("debugpat", pat_debug_setup);
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static u64 __read_mostly boot_pat_state;
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enum {
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PAT_UC = 0, /* uncached */
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PAT_WC = 1, /* Write combining */
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PAT_WT = 4, /* Write Through */
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PAT_WP = 5, /* Write Protected */
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PAT_WB = 6, /* Write Back (default) */
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PAT_UC_MINUS = 7, /* UC, but can be overriden by MTRR */
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};
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#define PAT(x, y) ((u64)PAT_ ## y << ((x)*8))
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void pat_init(void)
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{
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u64 pat;
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bool boot_cpu = !boot_pat_state;
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if (!pat_enabled)
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return;
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if (!cpu_has_pat) {
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if (!boot_pat_state) {
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pat_disable("PAT not supported by CPU.");
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return;
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} else {
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/*
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* If this happens we are on a secondary CPU, but
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* switched to PAT on the boot CPU. We have no way to
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* undo PAT.
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*/
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printk(KERN_ERR "PAT enabled, "
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"but not supported by secondary CPU\n");
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BUG();
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}
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}
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/* Set PWT to Write-Combining. All other bits stay the same */
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/*
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* PTE encoding used in Linux:
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* PAT
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* |PCD
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* ||PWT
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* |||
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* 000 WB _PAGE_CACHE_WB
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* 001 WC _PAGE_CACHE_WC
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* 010 UC- _PAGE_CACHE_UC_MINUS
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* 011 UC _PAGE_CACHE_UC
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* PAT bit unused
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*/
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pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, UC) |
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PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC);
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/* Boot CPU check */
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if (!boot_pat_state)
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rdmsrl(MSR_IA32_CR_PAT, boot_pat_state);
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wrmsrl(MSR_IA32_CR_PAT, pat);
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if (boot_cpu)
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printk(KERN_INFO "x86 PAT enabled: cpu %d, old 0x%Lx, new 0x%Lx\n",
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smp_processor_id(), boot_pat_state, pat);
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}
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#undef PAT
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static DEFINE_SPINLOCK(memtype_lock); /* protects memtype accesses */
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/*
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* Does intersection of PAT memory type and MTRR memory type and returns
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* the resulting memory type as PAT understands it.
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* (Type in pat and mtrr will not have same value)
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* The intersection is based on "Effective Memory Type" tables in IA-32
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* SDM vol 3a
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*/
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static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type)
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{
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/*
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* Look for MTRR hint to get the effective type in case where PAT
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* request is for WB.
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*/
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if (req_type == _PAGE_CACHE_WB) {
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u8 mtrr_type;
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mtrr_type = mtrr_type_lookup(start, end);
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if (mtrr_type != MTRR_TYPE_WRBACK)
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return _PAGE_CACHE_UC_MINUS;
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return _PAGE_CACHE_WB;
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}
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return req_type;
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}
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struct pagerange_state {
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unsigned long cur_pfn;
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int ram;
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int not_ram;
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};
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static int
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pagerange_is_ram_callback(unsigned long initial_pfn, unsigned long total_nr_pages, void *arg)
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{
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struct pagerange_state *state = arg;
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state->not_ram |= initial_pfn > state->cur_pfn;
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state->ram |= total_nr_pages > 0;
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state->cur_pfn = initial_pfn + total_nr_pages;
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return state->ram && state->not_ram;
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}
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static int pat_pagerange_is_ram(resource_size_t start, resource_size_t end)
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{
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int ret = 0;
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unsigned long start_pfn = start >> PAGE_SHIFT;
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unsigned long end_pfn = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
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struct pagerange_state state = {start_pfn, 0, 0};
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/*
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* For legacy reasons, physical address range in the legacy ISA
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* region is tracked as non-RAM. This will allow users of
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* /dev/mem to map portions of legacy ISA region, even when
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* some of those portions are listed(or not even listed) with
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* different e820 types(RAM/reserved/..)
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*/
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if (start_pfn < ISA_END_ADDRESS >> PAGE_SHIFT)
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start_pfn = ISA_END_ADDRESS >> PAGE_SHIFT;
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if (start_pfn < end_pfn) {
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ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn,
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&state, pagerange_is_ram_callback);
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}
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return (ret > 0) ? -1 : (state.ram ? 1 : 0);
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}
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/*
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* For RAM pages, we use page flags to mark the pages with appropriate type.
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* Here we do two pass:
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* - Find the memtype of all the pages in the range, look for any conflicts
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* - In case of no conflicts, set the new memtype for pages in the range
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*/
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static int reserve_ram_pages_type(u64 start, u64 end, unsigned long req_type,
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unsigned long *new_type)
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{
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struct page *page;
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u64 pfn;
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if (req_type == _PAGE_CACHE_UC) {
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/* We do not support strong UC */
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WARN_ON_ONCE(1);
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req_type = _PAGE_CACHE_UC_MINUS;
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}
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for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) {
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unsigned long type;
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page = pfn_to_page(pfn);
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type = get_page_memtype(page);
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if (type != -1) {
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printk(KERN_INFO "reserve_ram_pages_type failed [mem %#010Lx-%#010Lx], track 0x%lx, req 0x%lx\n",
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start, end - 1, type, req_type);
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if (new_type)
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*new_type = type;
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return -EBUSY;
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}
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}
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if (new_type)
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*new_type = req_type;
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for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) {
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page = pfn_to_page(pfn);
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set_page_memtype(page, req_type);
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}
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return 0;
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}
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static int free_ram_pages_type(u64 start, u64 end)
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{
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struct page *page;
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u64 pfn;
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for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) {
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page = pfn_to_page(pfn);
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set_page_memtype(page, -1);
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}
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return 0;
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}
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/*
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* req_type typically has one of the:
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* - _PAGE_CACHE_WB
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* - _PAGE_CACHE_WC
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* - _PAGE_CACHE_UC_MINUS
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* - _PAGE_CACHE_UC
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*
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* If new_type is NULL, function will return an error if it cannot reserve the
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* region with req_type. If new_type is non-NULL, function will return
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* available type in new_type in case of no error. In case of any error
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* it will return a negative return value.
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*/
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int reserve_memtype(u64 start, u64 end, unsigned long req_type,
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unsigned long *new_type)
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{
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struct memtype *new;
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unsigned long actual_type;
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int is_range_ram;
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int err = 0;
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BUG_ON(start >= end); /* end is exclusive */
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if (!pat_enabled) {
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/* This is identical to page table setting without PAT */
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if (new_type) {
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if (req_type == _PAGE_CACHE_WC)
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*new_type = _PAGE_CACHE_UC_MINUS;
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else
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*new_type = req_type & _PAGE_CACHE_MASK;
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}
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return 0;
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}
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/* Low ISA region is always mapped WB in page table. No need to track */
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if (x86_platform.is_untracked_pat_range(start, end)) {
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if (new_type)
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*new_type = _PAGE_CACHE_WB;
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return 0;
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}
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/*
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* Call mtrr_lookup to get the type hint. This is an
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* optimization for /dev/mem mmap'ers into WB memory (BIOS
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* tools and ACPI tools). Use WB request for WB memory and use
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* UC_MINUS otherwise.
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*/
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actual_type = pat_x_mtrr_type(start, end, req_type & _PAGE_CACHE_MASK);
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if (new_type)
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*new_type = actual_type;
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is_range_ram = pat_pagerange_is_ram(start, end);
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if (is_range_ram == 1) {
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err = reserve_ram_pages_type(start, end, req_type, new_type);
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return err;
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} else if (is_range_ram < 0) {
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return -EINVAL;
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}
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new = kzalloc(sizeof(struct memtype), GFP_KERNEL);
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if (!new)
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return -ENOMEM;
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new->start = start;
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new->end = end;
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new->type = actual_type;
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spin_lock(&memtype_lock);
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err = rbt_memtype_check_insert(new, new_type);
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if (err) {
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printk(KERN_INFO "reserve_memtype failed [mem %#010Lx-%#010Lx], track %s, req %s\n",
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start, end - 1,
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cattr_name(new->type), cattr_name(req_type));
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kfree(new);
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spin_unlock(&memtype_lock);
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return err;
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}
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spin_unlock(&memtype_lock);
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dprintk("reserve_memtype added [mem %#010Lx-%#010Lx], track %s, req %s, ret %s\n",
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start, end - 1, cattr_name(new->type), cattr_name(req_type),
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new_type ? cattr_name(*new_type) : "-");
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return err;
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}
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int free_memtype(u64 start, u64 end)
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{
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int err = -EINVAL;
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int is_range_ram;
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struct memtype *entry;
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if (!pat_enabled)
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return 0;
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/* Low ISA region is always mapped WB. No need to track */
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if (x86_platform.is_untracked_pat_range(start, end))
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return 0;
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is_range_ram = pat_pagerange_is_ram(start, end);
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if (is_range_ram == 1) {
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err = free_ram_pages_type(start, end);
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return err;
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} else if (is_range_ram < 0) {
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return -EINVAL;
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}
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spin_lock(&memtype_lock);
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entry = rbt_memtype_erase(start, end);
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spin_unlock(&memtype_lock);
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if (!entry) {
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printk(KERN_INFO "%s:%d freeing invalid memtype [mem %#010Lx-%#010Lx]\n",
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current->comm, current->pid, start, end - 1);
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return -EINVAL;
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}
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kfree(entry);
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dprintk("free_memtype request [mem %#010Lx-%#010Lx]\n", start, end - 1);
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return 0;
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}
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/**
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* lookup_memtype - Looksup the memory type for a physical address
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* @paddr: physical address of which memory type needs to be looked up
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*
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* Only to be called when PAT is enabled
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*
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* Returns _PAGE_CACHE_WB, _PAGE_CACHE_WC, _PAGE_CACHE_UC_MINUS or
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* _PAGE_CACHE_UC
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*/
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static unsigned long lookup_memtype(u64 paddr)
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{
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int rettype = _PAGE_CACHE_WB;
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struct memtype *entry;
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if (x86_platform.is_untracked_pat_range(paddr, paddr + PAGE_SIZE))
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return rettype;
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if (pat_pagerange_is_ram(paddr, paddr + PAGE_SIZE)) {
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struct page *page;
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page = pfn_to_page(paddr >> PAGE_SHIFT);
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rettype = get_page_memtype(page);
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/*
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* -1 from get_page_memtype() implies RAM page is in its
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* default state and not reserved, and hence of type WB
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*/
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if (rettype == -1)
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rettype = _PAGE_CACHE_WB;
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return rettype;
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}
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spin_lock(&memtype_lock);
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entry = rbt_memtype_lookup(paddr);
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if (entry != NULL)
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rettype = entry->type;
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else
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rettype = _PAGE_CACHE_UC_MINUS;
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spin_unlock(&memtype_lock);
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return rettype;
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}
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/**
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* io_reserve_memtype - Request a memory type mapping for a region of memory
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* @start: start (physical address) of the region
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* @end: end (physical address) of the region
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* @type: A pointer to memtype, with requested type. On success, requested
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* or any other compatible type that was available for the region is returned
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*
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* On success, returns 0
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* On failure, returns non-zero
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*/
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int io_reserve_memtype(resource_size_t start, resource_size_t end,
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unsigned long *type)
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{
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resource_size_t size = end - start;
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unsigned long req_type = *type;
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unsigned long new_type;
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int ret;
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WARN_ON_ONCE(iomem_map_sanity_check(start, size));
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ret = reserve_memtype(start, end, req_type, &new_type);
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if (ret)
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goto out_err;
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if (!is_new_memtype_allowed(start, size, req_type, new_type))
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goto out_free;
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if (kernel_map_sync_memtype(start, size, new_type) < 0)
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goto out_free;
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*type = new_type;
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return 0;
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out_free:
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free_memtype(start, end);
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ret = -EBUSY;
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out_err:
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return ret;
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}
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/**
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* io_free_memtype - Release a memory type mapping for a region of memory
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* @start: start (physical address) of the region
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* @end: end (physical address) of the region
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*/
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void io_free_memtype(resource_size_t start, resource_size_t end)
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{
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free_memtype(start, end);
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}
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pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
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unsigned long size, pgprot_t vma_prot)
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{
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return vma_prot;
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}
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#ifdef CONFIG_STRICT_DEVMEM
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/* This check is done in drivers/char/mem.c in case of STRICT_DEVMEM*/
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static inline int range_is_allowed(unsigned long pfn, unsigned long size)
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{
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return 1;
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}
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#else
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/* This check is needed to avoid cache aliasing when PAT is enabled */
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static inline int range_is_allowed(unsigned long pfn, unsigned long size)
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{
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u64 from = ((u64)pfn) << PAGE_SHIFT;
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u64 to = from + size;
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u64 cursor = from;
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if (!pat_enabled)
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return 1;
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while (cursor < to) {
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if (!devmem_is_allowed(pfn)) {
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printk(KERN_INFO "Program %s tried to access /dev/mem between [mem %#010Lx-%#010Lx]\n",
|
|
current->comm, from, to - 1);
|
|
return 0;
|
|
}
|
|
cursor += PAGE_SIZE;
|
|
pfn++;
|
|
}
|
|
return 1;
|
|
}
|
|
#endif /* CONFIG_STRICT_DEVMEM */
|
|
|
|
int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
|
|
unsigned long size, pgprot_t *vma_prot)
|
|
{
|
|
unsigned long flags = _PAGE_CACHE_WB;
|
|
|
|
if (!range_is_allowed(pfn, size))
|
|
return 0;
|
|
|
|
if (file->f_flags & O_DSYNC)
|
|
flags = _PAGE_CACHE_UC_MINUS;
|
|
|
|
#ifdef CONFIG_X86_32
|
|
/*
|
|
* On the PPro and successors, the MTRRs are used to set
|
|
* memory types for physical addresses outside main memory,
|
|
* so blindly setting UC or PWT on those pages is wrong.
|
|
* For Pentiums and earlier, the surround logic should disable
|
|
* caching for the high addresses through the KEN pin, but
|
|
* we maintain the tradition of paranoia in this code.
|
|
*/
|
|
if (!pat_enabled &&
|
|
!(boot_cpu_has(X86_FEATURE_MTRR) ||
|
|
boot_cpu_has(X86_FEATURE_K6_MTRR) ||
|
|
boot_cpu_has(X86_FEATURE_CYRIX_ARR) ||
|
|
boot_cpu_has(X86_FEATURE_CENTAUR_MCR)) &&
|
|
(pfn << PAGE_SHIFT) >= __pa(high_memory)) {
|
|
flags = _PAGE_CACHE_UC;
|
|
}
|
|
#endif
|
|
|
|
*vma_prot = __pgprot((pgprot_val(*vma_prot) & ~_PAGE_CACHE_MASK) |
|
|
flags);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Change the memory type for the physial address range in kernel identity
|
|
* mapping space if that range is a part of identity map.
|
|
*/
|
|
int kernel_map_sync_memtype(u64 base, unsigned long size, unsigned long flags)
|
|
{
|
|
unsigned long id_sz;
|
|
|
|
if (base > __pa(high_memory-1))
|
|
return 0;
|
|
|
|
/*
|
|
* some areas in the middle of the kernel identity range
|
|
* are not mapped, like the PCI space.
|
|
*/
|
|
if (!page_is_ram(base >> PAGE_SHIFT))
|
|
return 0;
|
|
|
|
id_sz = (__pa(high_memory-1) <= base + size) ?
|
|
__pa(high_memory) - base :
|
|
size;
|
|
|
|
if (ioremap_change_attr((unsigned long)__va(base), id_sz, flags) < 0) {
|
|
printk(KERN_INFO "%s:%d ioremap_change_attr failed %s "
|
|
"for [mem %#010Lx-%#010Lx]\n",
|
|
current->comm, current->pid,
|
|
cattr_name(flags),
|
|
base, (unsigned long long)(base + size-1));
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Internal interface to reserve a range of physical memory with prot.
|
|
* Reserved non RAM regions only and after successful reserve_memtype,
|
|
* this func also keeps identity mapping (if any) in sync with this new prot.
|
|
*/
|
|
static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot,
|
|
int strict_prot)
|
|
{
|
|
int is_ram = 0;
|
|
int ret;
|
|
unsigned long want_flags = (pgprot_val(*vma_prot) & _PAGE_CACHE_MASK);
|
|
unsigned long flags = want_flags;
|
|
|
|
is_ram = pat_pagerange_is_ram(paddr, paddr + size);
|
|
|
|
/*
|
|
* reserve_pfn_range() for RAM pages. We do not refcount to keep
|
|
* track of number of mappings of RAM pages. We can assert that
|
|
* the type requested matches the type of first page in the range.
|
|
*/
|
|
if (is_ram) {
|
|
if (!pat_enabled)
|
|
return 0;
|
|
|
|
flags = lookup_memtype(paddr);
|
|
if (want_flags != flags) {
|
|
printk(KERN_WARNING "%s:%d map pfn RAM range req %s for [mem %#010Lx-%#010Lx], got %s\n",
|
|
current->comm, current->pid,
|
|
cattr_name(want_flags),
|
|
(unsigned long long)paddr,
|
|
(unsigned long long)(paddr + size - 1),
|
|
cattr_name(flags));
|
|
*vma_prot = __pgprot((pgprot_val(*vma_prot) &
|
|
(~_PAGE_CACHE_MASK)) |
|
|
flags);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
ret = reserve_memtype(paddr, paddr + size, want_flags, &flags);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (flags != want_flags) {
|
|
if (strict_prot ||
|
|
!is_new_memtype_allowed(paddr, size, want_flags, flags)) {
|
|
free_memtype(paddr, paddr + size);
|
|
printk(KERN_ERR "%s:%d map pfn expected mapping type %s"
|
|
" for [mem %#010Lx-%#010Lx], got %s\n",
|
|
current->comm, current->pid,
|
|
cattr_name(want_flags),
|
|
(unsigned long long)paddr,
|
|
(unsigned long long)(paddr + size - 1),
|
|
cattr_name(flags));
|
|
return -EINVAL;
|
|
}
|
|
/*
|
|
* We allow returning different type than the one requested in
|
|
* non strict case.
|
|
*/
|
|
*vma_prot = __pgprot((pgprot_val(*vma_prot) &
|
|
(~_PAGE_CACHE_MASK)) |
|
|
flags);
|
|
}
|
|
|
|
if (kernel_map_sync_memtype(paddr, size, flags) < 0) {
|
|
free_memtype(paddr, paddr + size);
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Internal interface to free a range of physical memory.
|
|
* Frees non RAM regions only.
|
|
*/
|
|
static void free_pfn_range(u64 paddr, unsigned long size)
|
|
{
|
|
int is_ram;
|
|
|
|
is_ram = pat_pagerange_is_ram(paddr, paddr + size);
|
|
if (is_ram == 0)
|
|
free_memtype(paddr, paddr + size);
|
|
}
|
|
|
|
/*
|
|
* track_pfn_copy is called when vma that is covering the pfnmap gets
|
|
* copied through copy_page_range().
|
|
*
|
|
* If the vma has a linear pfn mapping for the entire range, we get the prot
|
|
* from pte and reserve the entire vma range with single reserve_pfn_range call.
|
|
*/
|
|
int track_pfn_copy(struct vm_area_struct *vma)
|
|
{
|
|
resource_size_t paddr;
|
|
unsigned long prot;
|
|
unsigned long vma_size = vma->vm_end - vma->vm_start;
|
|
pgprot_t pgprot;
|
|
|
|
if (vma->vm_flags & VM_PAT) {
|
|
/*
|
|
* reserve the whole chunk covered by vma. We need the
|
|
* starting address and protection from pte.
|
|
*/
|
|
if (follow_phys(vma, vma->vm_start, 0, &prot, &paddr)) {
|
|
WARN_ON_ONCE(1);
|
|
return -EINVAL;
|
|
}
|
|
pgprot = __pgprot(prot);
|
|
return reserve_pfn_range(paddr, vma_size, &pgprot, 1);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* prot is passed in as a parameter for the new mapping. If the vma has a
|
|
* linear pfn mapping for the entire range reserve the entire vma range with
|
|
* single reserve_pfn_range call.
|
|
*/
|
|
int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
|
|
unsigned long pfn, unsigned long addr, unsigned long size)
|
|
{
|
|
resource_size_t paddr = (resource_size_t)pfn << PAGE_SHIFT;
|
|
unsigned long flags;
|
|
|
|
/* reserve the whole chunk starting from paddr */
|
|
if (addr == vma->vm_start && size == (vma->vm_end - vma->vm_start)) {
|
|
int ret;
|
|
|
|
ret = reserve_pfn_range(paddr, size, prot, 0);
|
|
if (!ret)
|
|
vma->vm_flags |= VM_PAT;
|
|
return ret;
|
|
}
|
|
|
|
if (!pat_enabled)
|
|
return 0;
|
|
|
|
/*
|
|
* For anything smaller than the vma size we set prot based on the
|
|
* lookup.
|
|
*/
|
|
flags = lookup_memtype(paddr);
|
|
|
|
/* Check memtype for the remaining pages */
|
|
while (size > PAGE_SIZE) {
|
|
size -= PAGE_SIZE;
|
|
paddr += PAGE_SIZE;
|
|
if (flags != lookup_memtype(paddr))
|
|
return -EINVAL;
|
|
}
|
|
|
|
*prot = __pgprot((pgprot_val(vma->vm_page_prot) & (~_PAGE_CACHE_MASK)) |
|
|
flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
|
|
unsigned long pfn)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (!pat_enabled)
|
|
return 0;
|
|
|
|
/* Set prot based on lookup */
|
|
flags = lookup_memtype((resource_size_t)pfn << PAGE_SHIFT);
|
|
*prot = __pgprot((pgprot_val(vma->vm_page_prot) & (~_PAGE_CACHE_MASK)) |
|
|
flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* untrack_pfn is called while unmapping a pfnmap for a region.
|
|
* untrack can be called for a specific region indicated by pfn and size or
|
|
* can be for the entire vma (in which case pfn, size are zero).
|
|
*/
|
|
void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
|
|
unsigned long size)
|
|
{
|
|
resource_size_t paddr;
|
|
unsigned long prot;
|
|
|
|
if (!(vma->vm_flags & VM_PAT))
|
|
return;
|
|
|
|
/* free the chunk starting from pfn or the whole chunk */
|
|
paddr = (resource_size_t)pfn << PAGE_SHIFT;
|
|
if (!paddr && !size) {
|
|
if (follow_phys(vma, vma->vm_start, 0, &prot, &paddr)) {
|
|
WARN_ON_ONCE(1);
|
|
return;
|
|
}
|
|
|
|
size = vma->vm_end - vma->vm_start;
|
|
}
|
|
free_pfn_range(paddr, size);
|
|
vma->vm_flags &= ~VM_PAT;
|
|
}
|
|
|
|
pgprot_t pgprot_writecombine(pgprot_t prot)
|
|
{
|
|
if (pat_enabled)
|
|
return __pgprot(pgprot_val(prot) | _PAGE_CACHE_WC);
|
|
else
|
|
return pgprot_noncached(prot);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pgprot_writecombine);
|
|
|
|
#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT)
|
|
|
|
static struct memtype *memtype_get_idx(loff_t pos)
|
|
{
|
|
struct memtype *print_entry;
|
|
int ret;
|
|
|
|
print_entry = kzalloc(sizeof(struct memtype), GFP_KERNEL);
|
|
if (!print_entry)
|
|
return NULL;
|
|
|
|
spin_lock(&memtype_lock);
|
|
ret = rbt_memtype_copy_nth_element(print_entry, pos);
|
|
spin_unlock(&memtype_lock);
|
|
|
|
if (!ret) {
|
|
return print_entry;
|
|
} else {
|
|
kfree(print_entry);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
static void *memtype_seq_start(struct seq_file *seq, loff_t *pos)
|
|
{
|
|
if (*pos == 0) {
|
|
++*pos;
|
|
seq_printf(seq, "PAT memtype list:\n");
|
|
}
|
|
|
|
return memtype_get_idx(*pos);
|
|
}
|
|
|
|
static void *memtype_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
|
{
|
|
++*pos;
|
|
return memtype_get_idx(*pos);
|
|
}
|
|
|
|
static void memtype_seq_stop(struct seq_file *seq, void *v)
|
|
{
|
|
}
|
|
|
|
static int memtype_seq_show(struct seq_file *seq, void *v)
|
|
{
|
|
struct memtype *print_entry = (struct memtype *)v;
|
|
|
|
seq_printf(seq, "%s @ 0x%Lx-0x%Lx\n", cattr_name(print_entry->type),
|
|
print_entry->start, print_entry->end);
|
|
kfree(print_entry);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations memtype_seq_ops = {
|
|
.start = memtype_seq_start,
|
|
.next = memtype_seq_next,
|
|
.stop = memtype_seq_stop,
|
|
.show = memtype_seq_show,
|
|
};
|
|
|
|
static int memtype_seq_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &memtype_seq_ops);
|
|
}
|
|
|
|
static const struct file_operations memtype_fops = {
|
|
.open = memtype_seq_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
|
|
static int __init pat_memtype_list_init(void)
|
|
{
|
|
if (pat_enabled) {
|
|
debugfs_create_file("pat_memtype_list", S_IRUSR,
|
|
arch_debugfs_dir, NULL, &memtype_fops);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
late_initcall(pat_memtype_list_init);
|
|
|
|
#endif /* CONFIG_DEBUG_FS && CONFIG_X86_PAT */
|