提交 1f6f655e 编写于 作者: C Christoph Hellwig 提交者: Borislav Petkov

x86/mm: Add a x86_has_pat_wp() helper

Abstract the ioremap code away from the caching mode internals.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200408152745.1565832-2-hch@lst.de
上级 ae83d0b4
......@@ -24,4 +24,6 @@ extern void memtype_free_io(resource_size_t start, resource_size_t end);
extern bool pat_pfn_immune_to_uc_mtrr(unsigned long pfn);
bool x86_has_pat_wp(void);
#endif /* _ASM_X86_MEMTYPE_H */
......@@ -71,6 +71,12 @@ uint8_t __pte2cachemode_tbl[8] = {
};
EXPORT_SYMBOL(__pte2cachemode_tbl);
/* Check that the write-protect PAT entry is set for write-protect */
bool x86_has_pat_wp(void)
{
return __pte2cachemode_tbl[_PAGE_CACHE_MODE_WP] == _PAGE_CACHE_MODE_WP;
}
static unsigned long __initdata pgt_buf_start;
static unsigned long __initdata pgt_buf_end;
static unsigned long __initdata pgt_buf_top;
......
......@@ -778,10 +778,8 @@ void __init *early_memremap_encrypted(resource_size_t phys_addr,
void __init *early_memremap_encrypted_wp(resource_size_t phys_addr,
unsigned long size)
{
/* Be sure the write-protect PAT entry is set for write-protect */
if (__pte2cachemode_tbl[_PAGE_CACHE_MODE_WP] != _PAGE_CACHE_MODE_WP)
if (!x86_has_pat_wp())
return NULL;
return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC_WP);
}
......@@ -799,10 +797,8 @@ void __init *early_memremap_decrypted(resource_size_t phys_addr,
void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
unsigned long size)
{
/* Be sure the write-protect PAT entry is set for write-protect */
if (__pte2cachemode_tbl[_PAGE_CACHE_MODE_WP] != _PAGE_CACHE_MODE_WP)
if (!x86_has_pat_wp())
return NULL;
return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_NOENC_WP);
}
#endif /* CONFIG_AMD_MEM_ENCRYPT */
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册