#ifndef _ASM_X86_CACHEFLUSH_H
#define _ASM_X86_CACHEFLUSH_H
/* Caches aren't brain-dead on the intel. */
#include <asm-generic/cacheflush.h>
#include <asm/special_insns.h>
#include <asm/uaccess.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_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
/*
* The set_memory_* API can be used to change various attributes of a virtual
* address range. The attributes include:
* Cachability : UnCached, WriteCombining, WriteBack
* Executability : eXeutable, NoteXecutable
* Read/Write : ReadOnly, ReadWrite
* Presence : NotPresent
* Encryption : Encrypted, Decrypted
*
* Within a category, the attributes are mutually exclusive.
*
* The implementation of this API will take care of various aspects that
* are associated with changing such attributes, such as:
* - Flushing TLBs
* - Flushing CPU caches
* - Making sure aliases of the memory behind the mapping don't violate
* coherency rules as defined by the CPU in the system.
*
* What this API does not do:
* - Provide exclusion between various callers - including callers that
* operation on other mappings of the same physical page
* - Restore default attributes when a page is freed
* - Guarantee that mappings other than the requested one are
* in any state, other than that these do not violate rules for
* the CPU you have. Do not depend on any effects on other mappings,
* CPUs other than the one you have may have more relaxed rules.
* The caller is required to take care of these.
*/
int _set_memory_uc(unsigned long addr, int numpages);
int _set_memory_wc(unsigned long addr, int numpages);
int _set_memory_wb(unsigned long addr, int numpages);
int set_memory_uc(unsigned long addr, int numpages);
int set_memory_wc(unsigned long addr, int numpages);
int set_memory_wb(unsigned long addr, int numpages);
int set_memory_x(unsigned long addr, int numpages);
int set_memory_nx(unsigned long addr, int numpages);
int set_memory_ro(unsigned long addr, int numpages);
int set_memory_rw(unsigned long addr, int numpages);
int set_memory_np(unsigned long addr, int numpages);
int set_memory_4k(unsigned long addr, int numpages);
int set_memory_encrypted(unsigned long addr, int numpages);
int set_memory_decrypted(unsigned long addr, int numpages);
int set_memory_array_uc(unsigned long *addr, int addrinarray);
int set_memory_array_wc(unsigned long *addr, int addrinarray);
int set_memory_array_wb(unsigned long *addr, int addrinarray);
int set_pages_array_uc(struct page **pages, int addrinarray);
int set_pages_array_wc(struct page **pages, int addrinarray);
int set_pages_array_wb(struct page **pages, int addrinarray);
/*
* For legacy compatibility with the old APIs, a few functions
* are provided that work on a "struct page".
* These functions operate ONLY on the 1:1 kernel mapping of the
* memory that the struct page represents, and internally just
* call the set_memory_* function. See the description of the
* set_memory_* function for more details on conventions.
*
* These APIs should be considered *deprecated* and are likely going to
* be removed in the future.
* The reason for this is the implicit operation on the 1:1 mapping only,
* making this not a generally useful API.
*
* Specifically, many users of the old APIs had a virtual address,
* called virt_to_page() or vmalloc_to_page() on that address to
* get a struct page* that the old API required.
* To convert these cases, use set_memory_*() on the original
* virtual address, do not use these functions.
*/
int set_pages_uc(struct page *page, int numpages);
int set_pages_wb(struct page *page, int numpages);
int set_pages_x(struct page *page, int numpages);
int set_pages_nx(struct page *page, int numpages);
int set_pages_ro(struct page *page, int numpages);
int set_pages_rw(struct page *page, int numpages);
void clflush_cache_range(void *addr, unsigned int size);
#define mmio_flush_range(addr, size) clflush_cache_range(addr, size)
#ifdef CONFIG_DEBUG_RODATA
void mark_rodata_ro(void);
extern const int rodata_test_data;
extern int kernel_set_to_readonly;
void set_kernel_text_rw(void);
void set_kernel_text_ro(void);
#else
static inline void set_kernel_text_rw(void) { }
static inline void set_kernel_text_ro(void) { }
#endif
#ifdef CONFIG_X86_64
static inline int set_mce_nospec(unsigned long pfn)
{
unsigned long decoy_addr;
int rc;
/*
* Mark the linear address as UC to make sure we don't log more
* errors because of speculative access to the page.
* We would like to just call:
* set_memory_uc((unsigned long)pfn_to_kaddr(pfn), 1);
* but doing that would radically increase the odds of a
* speculative access to the poison page because we'd have
* the virtual address of the kernel 1:1 mapping sitting
* around in registers.
* Instead we get tricky. We create a non-canonical address
* that looks just like the one we want, but has bit 63 flipped.
* This relies on set_memory_uc() properly sanitizing any __pa()
* results with __PHYSICAL_MASK or PTE_PFN_MASK.
*/
decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
rc = set_memory_uc(decoy_addr, 1);
if (rc)
printk(KERN_WARNING
"Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
return rc;
}
#define set_mce_nospec set_mce_nospec
/* Restore full speculative operation to the pfn. */
static inline int clear_mce_nospec(unsigned long pfn)
{
return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1);
}
#define clear_mce_nospec clear_mce_nospec
#else
/*
* Few people would run a 32-bit kernel on a machine that supports
* recoverable errors because they have too much memory to boot 32-bit.
*/
#endif
#ifdef CONFIG_DEBUG_RODATA_TEST
int rodata_test(void);
#else
static inline int rodata_test(void)
{
return 0;
}
#endif
#endif /* _ASM_X86_CACHEFLUSH_H */
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