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       1                 :            : /* SPDX-License-Identifier: GPL-2.0 */
       2                 :            : #ifndef _ASM_X86_SET_MEMORY_H
       3                 :            : #define _ASM_X86_SET_MEMORY_H
       4                 :            : 
       5                 :            : #include <asm/page.h>
       6                 :            : #include <asm-generic/set_memory.h>
       7                 :            : 
       8                 :            : /*
       9                 :            :  * The set_memory_* API can be used to change various attributes of a virtual
      10                 :            :  * address range. The attributes include:
      11                 :            :  * Cachability   : UnCached, WriteCombining, WriteThrough, WriteBack
      12                 :            :  * Executability : eXeutable, NoteXecutable
      13                 :            :  * Read/Write    : ReadOnly, ReadWrite
      14                 :            :  * Presence      : NotPresent
      15                 :            :  * Encryption    : Encrypted, Decrypted
      16                 :            :  *
      17                 :            :  * Within a category, the attributes are mutually exclusive.
      18                 :            :  *
      19                 :            :  * The implementation of this API will take care of various aspects that
      20                 :            :  * are associated with changing such attributes, such as:
      21                 :            :  * - Flushing TLBs
      22                 :            :  * - Flushing CPU caches
      23                 :            :  * - Making sure aliases of the memory behind the mapping don't violate
      24                 :            :  *   coherency rules as defined by the CPU in the system.
      25                 :            :  *
      26                 :            :  * What this API does not do:
      27                 :            :  * - Provide exclusion between various callers - including callers that
      28                 :            :  *   operation on other mappings of the same physical page
      29                 :            :  * - Restore default attributes when a page is freed
      30                 :            :  * - Guarantee that mappings other than the requested one are
      31                 :            :  *   in any state, other than that these do not violate rules for
      32                 :            :  *   the CPU you have. Do not depend on any effects on other mappings,
      33                 :            :  *   CPUs other than the one you have may have more relaxed rules.
      34                 :            :  * The caller is required to take care of these.
      35                 :            :  */
      36                 :            : 
      37                 :            : int _set_memory_uc(unsigned long addr, int numpages);
      38                 :            : int _set_memory_wc(unsigned long addr, int numpages);
      39                 :            : int _set_memory_wt(unsigned long addr, int numpages);
      40                 :            : int _set_memory_wb(unsigned long addr, int numpages);
      41                 :            : int set_memory_uc(unsigned long addr, int numpages);
      42                 :            : int set_memory_wc(unsigned long addr, int numpages);
      43                 :            : int set_memory_wb(unsigned long addr, int numpages);
      44                 :            : int set_memory_np(unsigned long addr, int numpages);
      45                 :            : int set_memory_4k(unsigned long addr, int numpages);
      46                 :            : int set_memory_encrypted(unsigned long addr, int numpages);
      47                 :            : int set_memory_decrypted(unsigned long addr, int numpages);
      48                 :            : int set_memory_np_noalias(unsigned long addr, int numpages);
      49                 :            : 
      50                 :            : int set_pages_array_uc(struct page **pages, int addrinarray);
      51                 :            : int set_pages_array_wc(struct page **pages, int addrinarray);
      52                 :            : int set_pages_array_wt(struct page **pages, int addrinarray);
      53                 :            : int set_pages_array_wb(struct page **pages, int addrinarray);
      54                 :            : 
      55                 :            : /*
      56                 :            :  * For legacy compatibility with the old APIs, a few functions
      57                 :            :  * are provided that work on a "struct page".
      58                 :            :  * These functions operate ONLY on the 1:1 kernel mapping of the
      59                 :            :  * memory that the struct page represents, and internally just
      60                 :            :  * call the set_memory_* function. See the description of the
      61                 :            :  * set_memory_* function for more details on conventions.
      62                 :            :  *
      63                 :            :  * These APIs should be considered *deprecated* and are likely going to
      64                 :            :  * be removed in the future.
      65                 :            :  * The reason for this is the implicit operation on the 1:1 mapping only,
      66                 :            :  * making this not a generally useful API.
      67                 :            :  *
      68                 :            :  * Specifically, many users of the old APIs had a virtual address,
      69                 :            :  * called virt_to_page() or vmalloc_to_page() on that address to
      70                 :            :  * get a struct page* that the old API required.
      71                 :            :  * To convert these cases, use set_memory_*() on the original
      72                 :            :  * virtual address, do not use these functions.
      73                 :            :  */
      74                 :            : 
      75                 :            : int set_pages_uc(struct page *page, int numpages);
      76                 :            : int set_pages_wb(struct page *page, int numpages);
      77                 :            : int set_pages_ro(struct page *page, int numpages);
      78                 :            : int set_pages_rw(struct page *page, int numpages);
      79                 :            : 
      80                 :            : int set_direct_map_invalid_noflush(struct page *page);
      81                 :            : int set_direct_map_default_noflush(struct page *page);
      82                 :            : 
      83                 :            : extern int kernel_set_to_readonly;
      84                 :            : 
      85                 :            : #ifdef CONFIG_X86_64
      86                 :          0 : static inline int set_mce_nospec(unsigned long pfn)
      87                 :            : {
      88                 :          0 :         unsigned long decoy_addr;
      89                 :          0 :         int rc;
      90                 :            : 
      91                 :            :         /*
      92                 :            :          * Mark the linear address as UC to make sure we don't log more
      93                 :            :          * errors because of speculative access to the page.
      94                 :            :          * We would like to just call:
      95                 :            :          *      set_memory_uc((unsigned long)pfn_to_kaddr(pfn), 1);
      96                 :            :          * but doing that would radically increase the odds of a
      97                 :            :          * speculative access to the poison page because we'd have
      98                 :            :          * the virtual address of the kernel 1:1 mapping sitting
      99                 :            :          * around in registers.
     100                 :            :          * Instead we get tricky.  We create a non-canonical address
     101                 :            :          * that looks just like the one we want, but has bit 63 flipped.
     102                 :            :          * This relies on set_memory_uc() properly sanitizing any __pa()
     103                 :            :          * results with __PHYSICAL_MASK or PTE_PFN_MASK.
     104                 :            :          */
     105                 :          0 :         decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
     106                 :            : 
     107                 :          0 :         rc = set_memory_uc(decoy_addr, 1);
     108         [ #  # ]:          0 :         if (rc)
     109                 :          0 :                 pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
     110                 :          0 :         return rc;
     111                 :            : }
     112                 :            : #define set_mce_nospec set_mce_nospec
     113                 :            : 
     114                 :            : /* Restore full speculative operation to the pfn. */
     115                 :            : static inline int clear_mce_nospec(unsigned long pfn)
     116                 :            : {
     117                 :            :         return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1);
     118                 :            : }
     119                 :            : #define clear_mce_nospec clear_mce_nospec
     120                 :            : #else
     121                 :            : /*
     122                 :            :  * Few people would run a 32-bit kernel on a machine that supports
     123                 :            :  * recoverable errors because they have too much memory to boot 32-bit.
     124                 :            :  */
     125                 :            : #endif
     126                 :            : 
     127                 :            : #endif /* _ASM_X86_SET_MEMORY_H */