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authorThomas Gleixner <tglx@linutronix.de>2014-11-16 18:59:19 +0100
committerThomas Gleixner <tglx@linutronix.de>2014-11-16 18:59:19 +0100
commit0dbcae884779fdf7e2239a97ac7488877f0693d9 (patch)
treec220ca7af9542397538dcd0f288794b258739f8f /arch/x86/mm/pat.c
parent47591df505129c9774af6cca2debf283a6e56ed7 (diff)
downloadop-kernel-dev-0dbcae884779fdf7e2239a97ac7488877f0693d9.zip
op-kernel-dev-0dbcae884779fdf7e2239a97ac7488877f0693d9.tar.gz
x86: mm: Move PAT only functions to mm/pat.c
Commit e00c8cc93c1a "x86: Use new cache mode type in memtype related functions" broke the ARCH=um build. arch/x86/include/asm/cacheflush.h:67:36: error: return type is an incomplete type static inline enum page_cache_mode get_page_memtype(struct page *pg) The reason is simple. get_page_memtype() and set_page_memtype() require enum page_cache_mode now, which is defined in asm/pgtable_types.h. UM does not include that file for obvious reasons. The simple solution is to move that functions to arch/x86/mm/pat.c where the only callsites of this are located. They should have been there in the first place. Fixes: e00c8cc93c1a "x86: Use new cache mode type in memtype related functions" Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Juergen Gross <jgross@suse.com> Cc: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/x86/mm/pat.c')
-rw-r--r--arch/x86/mm/pat.c69
1 files changed, 69 insertions, 0 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 4c60127..25d2c58 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -67,6 +67,75 @@ __setup("debugpat", pat_debug_setup);
static u64 __read_mostly boot_pat_state;
+#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_MODE_WB, _PAGE_CACHE_MODE_WC and
+ * _PAGE_CACHE_MODE_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_MODE_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 enum page_cache_mode 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_MODE_WC;
+ else if (pg_flags == _PGMT_UC_MINUS)
+ return _PAGE_CACHE_MODE_UC_MINUS;
+ else
+ return _PAGE_CACHE_MODE_WB;
+}
+
+static inline void set_page_memtype(struct page *pg,
+ enum page_cache_mode memtype)
+{
+ unsigned long memtype_flags;
+ unsigned long old_flags;
+ unsigned long new_flags;
+
+ switch (memtype) {
+ case _PAGE_CACHE_MODE_WC:
+ memtype_flags = _PGMT_WC;
+ break;
+ case _PAGE_CACHE_MODE_UC_MINUS:
+ memtype_flags = _PGMT_UC_MINUS;
+ break;
+ case _PAGE_CACHE_MODE_WB:
+ memtype_flags = _PGMT_WB;
+ break;
+ default:
+ memtype_flags = _PGMT_DEFAULT;
+ 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 enum page_cache_mode get_page_memtype(struct page *pg)
+{
+ return -1;
+}
+static inline void set_page_memtype(struct page *pg,
+ enum page_cache_mode memtype)
+{
+}
+#endif
+
enum {
PAT_UC = 0, /* uncached */
PAT_WC = 1, /* Write combining */
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