x86/mm: Unexport __cachemode2pte_tbl

Exporting the raw data for a table is generally a bad idea. Move
cachemode2protval() out of line given that it isn't really used in the
fast path, and then mark __cachemode2pte_tbl static.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200408152745.1565832-5-hch@lst.de

arch/x86/include/asm/pgtable_types.h

@@ -467,8 +467,6 @@ static inline pteval_t pte_flags(pte_t pte)
 	return native_pte_val(pte) & PTE_FLAGS_MASK;
 }
 
-extern uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM];
-
 #define __pte2cm_idx(cb)				\
 	((((cb) >> (_PAGE_BIT_PAT - 2)) & 4) |		\
 	 (((cb) >> (_PAGE_BIT_PCD - 1)) & 2) |		\
@@ -478,16 +476,8 @@ extern uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM];
 	 (((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));
-}
+unsigned long cachemode2protval(enum page_cache_mode pcm);
+
 static inline unsigned long protval_4k_2_large(unsigned long val)
 {
 	return (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |

arch/x86/mm/init.c

@@ -49,7 +49,7 @@
  *   Index into __pte2cachemode_tbl[] are the caching attribute bits of the pte
  *   (_PAGE_PWT, _PAGE_PCD, _PAGE_PAT) at index bit positions 0, 1, 2.
  */
-uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM] = {
+static uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM] = {
 	[_PAGE_CACHE_MODE_WB      ]	= 0         | 0        ,
 	[_PAGE_CACHE_MODE_WC      ]	= 0         | _PAGE_PCD,
 	[_PAGE_CACHE_MODE_UC_MINUS]	= 0         | _PAGE_PCD,
@@ -57,7 +57,14 @@ uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM] = {
 	[_PAGE_CACHE_MODE_WT      ]	= 0         | _PAGE_PCD,
 	[_PAGE_CACHE_MODE_WP      ]	= 0         | _PAGE_PCD,
 };
-EXPORT_SYMBOL(__cachemode2pte_tbl);
+
+unsigned long cachemode2protval(enum page_cache_mode pcm)
+{
+	if (likely(pcm == 0))
+		return 0;
+	return __cachemode2pte_tbl[pcm];
+}
+EXPORT_SYMBOL(cachemode2protval);
 
 static uint8_t __pte2cachemode_tbl[8] = {
 	[__pte2cm_idx( 0        | 0         | 0        )] = _PAGE_CACHE_MODE_WB,

arch/x86/mm/pat/set_memory.c

@@ -68,6 +68,11 @@ static DEFINE_SPINLOCK(cpa_lock);
 #define CPA_PAGES_ARRAY 4
 #define CPA_NO_CHECK_ALIAS 8 /* Do not search for aliases */
 
+static inline pgprot_t cachemode2pgprot(enum page_cache_mode pcm)
+{
+	return __pgprot(cachemode2protval(pcm));
+}
+
 #ifdef CONFIG_PROC_FS
 static unsigned long direct_pages_count[PG_LEVEL_NUM];