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authorLinus Torvalds <torvalds@linux-foundation.org>2014-12-10 13:59:34 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-10 13:59:34 -0800
commita023748d53c10850650fe86b1c4a7d421d576451 (patch)
tree761d3f6d2a402ec0835c0ede44b7d55c1b15ec98 /arch/x86/include
parent773fed910d41e443e495a6bfa9ab1c2b7b13e012 (diff)
parent0dbcae884779fdf7e2239a97ac7488877f0693d9 (diff)
Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm tree changes from Ingo Molnar: "The biggest change is full PAT support from Jürgen Gross: The x86 architecture offers via the PAT (Page Attribute Table) a way to specify different caching modes in page table entries. The PAT MSR contains 8 entries each specifying one of 6 possible cache modes. A pte references one of those entries via 3 bits: _PAGE_PAT, _PAGE_PWT and _PAGE_PCD. The Linux kernel currently supports only 4 different cache modes. The PAT MSR is set up in a way that the setting of _PAGE_PAT in a pte doesn't matter: the top 4 entries in the PAT MSR are the same as the 4 lower entries. This results in the kernel not supporting e.g. write-through mode. Especially this cache mode would speed up drivers of video cards which now have to use uncached accesses. OTOH some old processors (Pentium) don't support PAT correctly and the Xen hypervisor has been using a different PAT MSR configuration for some time now and can't change that as this setting is part of the ABI. This patch set abstracts the cache mode from the pte and introduces tables to translate between cache mode and pte bits (the default cache mode "write back" is hard-wired to PAT entry 0). The tables are statically initialized with values being compatible to old processors and current usage. As soon as the PAT MSR is changed (or - in case of Xen - is read at boot time) the tables are changed accordingly. Requests of mappings with special cache modes are always possible now, in case they are not supported there will be a fallback to a compatible but slower mode. Summing it up, this patch set adds the following features: - capability to support WT and WP cache modes on processors with full PAT support - processors with no or uncorrect PAT support are still working as today, even if WT or WP cache mode are selected by drivers for some pages - reduction of Xen special handling regarding cache mode Another change is a boot speedup on ridiculously large RAM systems, plus other smaller fixes" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) x86: mm: Move PAT only functions to mm/pat.c xen: Support Xen pv-domains using PAT x86: Enable PAT to use cache mode translation tables x86: Respect PAT bit when copying pte values between large and normal pages x86: Support PAT bit in pagetable dump for lower levels x86: Clean up pgtable_types.h x86: Use new cache mode type in memtype related functions x86: Use new cache mode type in mm/ioremap.c x86: Use new cache mode type in setting page attributes x86: Remove looking for setting of _PAGE_PAT_LARGE in pageattr.c x86: Use new cache mode type in track_pfn_remap() and track_pfn_insert() x86: Use new cache mode type in mm/iomap_32.c x86: Use new cache mode type in asm/pgtable.h x86: Use new cache mode type in arch/x86/mm/init_64.c x86: Use new cache mode type in arch/x86/pci x86: Use new cache mode type in drivers/video/fbdev/vermilion x86: Use new cache mode type in drivers/video/fbdev/gbefb.c x86: Use new cache mode type in include/asm/fb.h x86: Make page cache mode a real type x86: mm: Use 2GB memory block size on large-memory x86-64 systems ...
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/cacheflush.h59
-rw-r--r--arch/x86/include/asm/fb.h6
-rw-r--r--arch/x86/include/asm/fixmap.h2
-rw-r--r--arch/x86/include/asm/highmem.h25
-rw-r--r--arch/x86/include/asm/io.h2
-rw-r--r--arch/x86/include/asm/pat.h7
-rw-r--r--arch/x86/include/asm/pgtable.h19
-rw-r--r--arch/x86/include/asm/pgtable_32_types.h2
-rw-r--r--arch/x86/include/asm/pgtable_types.h96
9 files changed, 111 insertions, 107 deletions
diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h
index 9863ee3747da..47c8e32f621a 100644
--- a/arch/x86/include/asm/cacheflush.h
+++ b/arch/x86/include/asm/cacheflush.h
@@ -5,65 +5,6 @@
#include <asm-generic/cacheflush.h>
#include <asm/special_insns.h>
-#ifdef CONFIG_X86_PAT
-/*
- * X86 PAT uses page flags WC and Uncached together to keep track of
- * memory type of pages that have backing page struct. X86 PAT supports 3
- * different memory types, _PAGE_CACHE_WB, _PAGE_CACHE_WC and
- * _PAGE_CACHE_UC_MINUS and fourth state where page's memory type has not
- * been changed from its default (value of -1 used to denote this).
- * Note we do not support _PAGE_CACHE_UC here.
- */
-
-#define _PGMT_DEFAULT 0
-#define _PGMT_WC (1UL << PG_arch_1)
-#define _PGMT_UC_MINUS (1UL << PG_uncached)
-#define _PGMT_WB (1UL << PG_uncached | 1UL << PG_arch_1)
-#define _PGMT_MASK (1UL << PG_uncached | 1UL << PG_arch_1)
-#define _PGMT_CLEAR_MASK (~_PGMT_MASK)
-
-static inline unsigned long get_page_memtype(struct page *pg)
-{
- unsigned long pg_flags = pg->flags & _PGMT_MASK;
-
- if (pg_flags == _PGMT_DEFAULT)
- return -1;
- else if (pg_flags == _PGMT_WC)
- return _PAGE_CACHE_WC;
- else if (pg_flags == _PGMT_UC_MINUS)
- return _PAGE_CACHE_UC_MINUS;
- else
- return _PAGE_CACHE_WB;
-}
-
-static inline void set_page_memtype(struct page *pg, unsigned long memtype)
-{
- unsigned long memtype_flags = _PGMT_DEFAULT;
- unsigned long old_flags;
- unsigned long new_flags;
-
- switch (memtype) {
- case _PAGE_CACHE_WC:
- memtype_flags = _PGMT_WC;
- break;
- case _PAGE_CACHE_UC_MINUS:
- memtype_flags = _PGMT_UC_MINUS;
- break;
- case _PAGE_CACHE_WB:
- memtype_flags = _PGMT_WB;
- break;
- }
-
- do {
- old_flags = pg->flags;
- new_flags = (old_flags & _PGMT_CLEAR_MASK) | memtype_flags;
- } while (cmpxchg(&pg->flags, old_flags, new_flags) != old_flags);
-}
-#else
-static inline unsigned long get_page_memtype(struct page *pg) { return -1; }
-static inline void set_page_memtype(struct page *pg, unsigned long memtype) { }
-#endif
-
/*
* The set_memory_* API can be used to change various attributes of a virtual
* address range. The attributes include:
diff --git a/arch/x86/include/asm/fb.h b/arch/x86/include/asm/fb.h
index 2519d0679d99..c3dd5e71f439 100644
--- a/arch/x86/include/asm/fb.h
+++ b/arch/x86/include/asm/fb.h
@@ -8,8 +8,12 @@
static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma,
unsigned long off)
{
+ unsigned long prot;
+
+ prot = pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK;
if (boot_cpu_data.x86 > 3)
- pgprot_val(vma->vm_page_prot) |= _PAGE_PCD;
+ pgprot_val(vma->vm_page_prot) =
+ prot | cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS);
}
extern int fb_is_primary_device(struct fb_info *info);
diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
index ffb1733ac91f..bf728e49c53c 100644
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -136,9 +136,7 @@ enum fixed_addresses {
extern void reserve_top_address(unsigned long reserve);
#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
-#define FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
-#define FIXADDR_BOOT_START (FIXADDR_TOP - FIXADDR_BOOT_SIZE)
extern int fixmaps_set;
diff --git a/arch/x86/include/asm/highmem.h b/arch/x86/include/asm/highmem.h
index 302a323b3f67..04e9d023168f 100644
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -38,17 +38,20 @@ extern unsigned long highstart_pfn, highend_pfn;
/*
* Ordering is:
*
- * FIXADDR_TOP
- * fixed_addresses
- * FIXADDR_START
- * temp fixed addresses
- * FIXADDR_BOOT_START
- * Persistent kmap area
- * PKMAP_BASE
- * VMALLOC_END
- * Vmalloc area
- * VMALLOC_START
- * high_memory
+ * high memory on: high_memory off:
+ * FIXADDR_TOP FIXADDR_TOP
+ * fixed addresses fixed addresses
+ * FIXADDR_START FIXADDR_START
+ * temp fixed addresses/persistent kmap area VMALLOC_END
+ * PKMAP_BASE temp fixed addresses/vmalloc area
+ * VMALLOC_END VMALLOC_START
+ * vmalloc area high_memory
+ * VMALLOC_START
+ * high_memory
+ *
+ * The temp fixed area is only used during boot for early_ioremap(), and
+ * it is unused when the ioremap() is functional. vmalloc/pkmap area become
+ * available after early boot so the temp fixed area is available for re-use.
*/
#define LAST_PKMAP_MASK (LAST_PKMAP-1)
#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)
diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index 0cdbe6e81b45..34a5b93704d3 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -318,7 +318,7 @@ extern void *xlate_dev_mem_ptr(phys_addr_t phys);
extern void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr);
extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
- unsigned long prot_val);
+ enum page_cache_mode pcm);
extern void __iomem *ioremap_wc(resource_size_t offset, unsigned long size);
extern bool is_early_ioremap_ptep(pte_t *ptep);
diff --git a/arch/x86/include/asm/pat.h b/arch/x86/include/asm/pat.h
index e2c1668dde7a..91bc4ba95f91 100644
--- a/arch/x86/include/asm/pat.h
+++ b/arch/x86/include/asm/pat.h
@@ -11,16 +11,17 @@ static const int pat_enabled;
#endif
extern void pat_init(void);
+void pat_init_cache_modes(void);
extern int reserve_memtype(u64 start, u64 end,
- unsigned long req_type, unsigned long *ret_type);
+ enum page_cache_mode req_pcm, enum page_cache_mode *ret_pcm);
extern int free_memtype(u64 start, u64 end);
extern int kernel_map_sync_memtype(u64 base, unsigned long size,
- unsigned long flag);
+ enum page_cache_mode pcm);
int io_reserve_memtype(resource_size_t start, resource_size_t end,
- unsigned long *type);
+ enum page_cache_mode *pcm);
void io_free_memtype(resource_size_t start, resource_size_t end);
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index aa97a070f09f..c112ea63f40d 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -9,9 +9,10 @@
/*
* Macro to mark a page protection value as UC-
*/
-#define pgprot_noncached(prot) \
- ((boot_cpu_data.x86 > 3) \
- ? (__pgprot(pgprot_val(prot) | _PAGE_CACHE_UC_MINUS)) \
+#define pgprot_noncached(prot) \
+ ((boot_cpu_data.x86 > 3) \
+ ? (__pgprot(pgprot_val(prot) | \
+ cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS))) \
: (prot))
#ifndef __ASSEMBLY__
@@ -404,8 +405,8 @@ static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
#define canon_pgprot(p) __pgprot(massage_pgprot(p))
static inline int is_new_memtype_allowed(u64 paddr, unsigned long size,
- unsigned long flags,
- unsigned long new_flags)
+ enum page_cache_mode pcm,
+ enum page_cache_mode new_pcm)
{
/*
* PAT type is always WB for untracked ranges, so no need to check.
@@ -419,10 +420,10 @@ static inline int is_new_memtype_allowed(u64 paddr, unsigned long size,
* - request is uncached, return cannot be write-back
* - request is write-combine, return cannot be write-back
*/
- if ((flags == _PAGE_CACHE_UC_MINUS &&
- new_flags == _PAGE_CACHE_WB) ||
- (flags == _PAGE_CACHE_WC &&
- new_flags == _PAGE_CACHE_WB)) {
+ if ((pcm == _PAGE_CACHE_MODE_UC_MINUS &&
+ new_pcm == _PAGE_CACHE_MODE_WB) ||
+ (pcm == _PAGE_CACHE_MODE_WC &&
+ new_pcm == _PAGE_CACHE_MODE_WB)) {
return 0;
}
diff --git a/arch/x86/include/asm/pgtable_32_types.h b/arch/x86/include/asm/pgtable_32_types.h
index ed5903be26fe..9fb2f2bc8245 100644
--- a/arch/x86/include/asm/pgtable_32_types.h
+++ b/arch/x86/include/asm/pgtable_32_types.h
@@ -37,7 +37,7 @@ extern bool __vmalloc_start_set; /* set once high_memory is set */
#define LAST_PKMAP 1024
#endif
-#define PKMAP_BASE ((FIXADDR_BOOT_START - PAGE_SIZE * (LAST_PKMAP + 1)) \
+#define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE * (LAST_PKMAP + 1)) \
& PMD_MASK)
#ifdef CONFIG_HIGHMEM
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index 07789647bf33..af447f95e3be 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -128,11 +128,28 @@
_PAGE_SOFT_DIRTY | _PAGE_NUMA)
#define _HPAGE_CHG_MASK (_PAGE_CHG_MASK | _PAGE_PSE | _PAGE_NUMA)
-#define _PAGE_CACHE_MASK (_PAGE_PCD | _PAGE_PWT)
-#define _PAGE_CACHE_WB (0)
-#define _PAGE_CACHE_WC (_PAGE_PWT)
-#define _PAGE_CACHE_UC_MINUS (_PAGE_PCD)
-#define _PAGE_CACHE_UC (_PAGE_PCD | _PAGE_PWT)
+/*
+ * The cache modes defined here are used to translate between pure SW usage
+ * and the HW defined cache mode bits and/or PAT entries.
+ *
+ * The resulting bits for PWT, PCD and PAT should be chosen in a way
+ * to have the WB mode at index 0 (all bits clear). This is the default
+ * right now and likely would break too much if changed.
+ */
+#ifndef __ASSEMBLY__
+enum page_cache_mode {
+ _PAGE_CACHE_MODE_WB = 0,
+ _PAGE_CACHE_MODE_WC = 1,
+ _PAGE_CACHE_MODE_UC_MINUS = 2,
+ _PAGE_CACHE_MODE_UC = 3,
+ _PAGE_CACHE_MODE_WT = 4,
+ _PAGE_CACHE_MODE_WP = 5,
+ _PAGE_CACHE_MODE_NUM = 8
+};
+#endif
+
+#define _PAGE_CACHE_MASK (_PAGE_PAT | _PAGE_PCD | _PAGE_PWT)
+#define _PAGE_NOCACHE (cachemode2protval(_PAGE_CACHE_MODE_UC))
#define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | \
@@ -156,41 +173,27 @@
#define __PAGE_KERNEL_RO (__PAGE_KERNEL & ~_PAGE_RW)
#define __PAGE_KERNEL_RX (__PAGE_KERNEL_EXEC & ~_PAGE_RW)
-#define __PAGE_KERNEL_EXEC_NOCACHE (__PAGE_KERNEL_EXEC | _PAGE_PCD | _PAGE_PWT)
-#define __PAGE_KERNEL_WC (__PAGE_KERNEL | _PAGE_CACHE_WC)
-#define __PAGE_KERNEL_NOCACHE (__PAGE_KERNEL | _PAGE_PCD | _PAGE_PWT)
-#define __PAGE_KERNEL_UC_MINUS (__PAGE_KERNEL | _PAGE_PCD)
+#define __PAGE_KERNEL_NOCACHE (__PAGE_KERNEL | _PAGE_NOCACHE)
#define __PAGE_KERNEL_VSYSCALL (__PAGE_KERNEL_RX | _PAGE_USER)
#define __PAGE_KERNEL_VVAR (__PAGE_KERNEL_RO | _PAGE_USER)
-#define __PAGE_KERNEL_VVAR_NOCACHE (__PAGE_KERNEL_VVAR | _PAGE_PCD | _PAGE_PWT)
#define __PAGE_KERNEL_LARGE (__PAGE_KERNEL | _PAGE_PSE)
-#define __PAGE_KERNEL_LARGE_NOCACHE (__PAGE_KERNEL | _PAGE_CACHE_UC | _PAGE_PSE)
#define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE)
#define __PAGE_KERNEL_IO (__PAGE_KERNEL)
#define __PAGE_KERNEL_IO_NOCACHE (__PAGE_KERNEL_NOCACHE)
-#define __PAGE_KERNEL_IO_UC_MINUS (__PAGE_KERNEL_UC_MINUS)
-#define __PAGE_KERNEL_IO_WC (__PAGE_KERNEL_WC)
#define PAGE_KERNEL __pgprot(__PAGE_KERNEL)
#define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO)
#define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC)
#define PAGE_KERNEL_RX __pgprot(__PAGE_KERNEL_RX)
-#define PAGE_KERNEL_WC __pgprot(__PAGE_KERNEL_WC)
#define PAGE_KERNEL_NOCACHE __pgprot(__PAGE_KERNEL_NOCACHE)
-#define PAGE_KERNEL_UC_MINUS __pgprot(__PAGE_KERNEL_UC_MINUS)
-#define PAGE_KERNEL_EXEC_NOCACHE __pgprot(__PAGE_KERNEL_EXEC_NOCACHE)
#define PAGE_KERNEL_LARGE __pgprot(__PAGE_KERNEL_LARGE)
-#define PAGE_KERNEL_LARGE_NOCACHE __pgprot(__PAGE_KERNEL_LARGE_NOCACHE)
#define PAGE_KERNEL_LARGE_EXEC __pgprot(__PAGE_KERNEL_LARGE_EXEC)
#define PAGE_KERNEL_VSYSCALL __pgprot(__PAGE_KERNEL_VSYSCALL)
#define PAGE_KERNEL_VVAR __pgprot(__PAGE_KERNEL_VVAR)
-#define PAGE_KERNEL_VVAR_NOCACHE __pgprot(__PAGE_KERNEL_VVAR_NOCACHE)
#define PAGE_KERNEL_IO __pgprot(__PAGE_KERNEL_IO)
#define PAGE_KERNEL_IO_NOCACHE __pgprot(__PAGE_KERNEL_IO_NOCACHE)
-#define PAGE_KERNEL_IO_UC_MINUS __pgprot(__PAGE_KERNEL_IO_UC_MINUS)
-#define PAGE_KERNEL_IO_WC __pgprot(__PAGE_KERNEL_IO_WC)
/* xwr */
#define __P000 PAGE_NONE
@@ -341,6 +344,59 @@ static inline pmdval_t pmdnuma_flags(pmd_t pmd)
#define pgprot_val(x) ((x).pgprot)
#define __pgprot(x) ((pgprot_t) { (x) } )
+extern uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM];
+extern uint8_t __pte2cachemode_tbl[8];
+
+#define __pte2cm_idx(cb) \
+ ((((cb) >> (_PAGE_BIT_PAT - 2)) & 4) | \
+ (((cb) >> (_PAGE_BIT_PCD - 1)) & 2) | \
+ (((cb) >> _PAGE_BIT_PWT) & 1))
+#define __cm_idx2pte(i) \
+ ((((i) & 4) << (_PAGE_BIT_PAT - 2)) | \
+ (((i) & 2) << (_PAGE_BIT_PCD - 1)) | \
+ (((i) & 1) << _PAGE_BIT_PWT))
+
+static inline unsigned long cachemode2protval(enum page_cache_mode pcm)
+{
+ if (likely(pcm == 0))
+ return 0;
+ return __cachemode2pte_tbl[pcm];
+}
+static inline pgprot_t cachemode2pgprot(enum page_cache_mode pcm)
+{
+ return __pgprot(cachemode2protval(pcm));
+}
+static inline enum page_cache_mode pgprot2cachemode(pgprot_t pgprot)
+{
+ unsigned long masked;
+
+ masked = pgprot_val(pgprot) & _PAGE_CACHE_MASK;
+ if (likely(masked == 0))
+ return 0;
+ return __pte2cachemode_tbl[__pte2cm_idx(masked)];
+}
+static inline pgprot_t pgprot_4k_2_large(pgprot_t pgprot)
+{
+ pgprot_t new;
+ unsigned long val;
+
+ val = pgprot_val(pgprot);
+ pgprot_val(new) = (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |
+ ((val & _PAGE_PAT) << (_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT));
+ return new;
+}
+static inline pgprot_t pgprot_large_2_4k(pgprot_t pgprot)
+{
+ pgprot_t new;
+ unsigned long val;
+
+ val = pgprot_val(pgprot);
+ pgprot_val(new) = (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |
+ ((val & _PAGE_PAT_LARGE) >>
+ (_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT));
+ return new;
+}
+
typedef struct page *pgtable_t;