LXR linux/arch/x86/include/asm/set

   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
  37int _set_memory_uc(unsigned long addr, int numpages);
  38int _set_memory_wc(unsigned long addr, int numpages);
  39int _set_memory_wt(unsigned long addr, int numpages);
  40int _set_memory_wb(unsigned long addr, int numpages);
  41int set_memory_uc(unsigned long addr, int numpages);
  42int set_memory_wc(unsigned long addr, int numpages);
  43int set_memory_wb(unsigned long addr, int numpages);
  44int set_memory_np(unsigned long addr, int numpages);
  45int set_memory_4k(unsigned long addr, int numpages);
  46int set_memory_encrypted(unsigned long addr, int numpages);
  47int set_memory_decrypted(unsigned long addr, int numpages);
  48int set_memory_np_noalias(unsigned long addr, int numpages);
  49
  50int set_pages_array_uc(struct page **pages, int addrinarray);
  51int set_pages_array_wc(struct page **pages, int addrinarray);
  52int set_pages_array_wt(struct page **pages, int addrinarray);
  53int 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
  75int set_pages_uc(struct page *page, int numpages);
  76int set_pages_wb(struct page *page, int numpages);
  77int set_pages_ro(struct page *page, int numpages);
  78int set_pages_rw(struct page *page, int numpages);
  79
  80int set_direct_map_invalid_noflush(struct page *page);
  81int set_direct_map_default_noflush(struct page *page);
  82
  83extern int kernel_set_to_readonly;
  84void set_kernel_text_rw(void);
  85void set_kernel_text_ro(void);
  86
  87#ifdef CONFIG_X86_64
  88static inline int set_mce_nospec(unsigned long pfn)
  89{
  90        unsigned long decoy_addr;
  91        int rc;
  92
  93        /*
  94         * Mark the linear address as UC to make sure we don't log more
  95         * errors because of speculative access to the page.
  96         * We would like to just call:
  97         *      set_memory_uc((unsigned long)pfn_to_kaddr(pfn), 1);
  98         * but doing that would radically increase the odds of a
  99         * speculative access to the poison page because we'd have
 100         * the virtual address of the kernel 1:1 mapping sitting
 101         * around in registers.
 102         * Instead we get tricky.  We create a non-canonical address
 103         * that looks just like the one we want, but has bit 63 flipped.
 104         * This relies on set_memory_uc() properly sanitizing any __pa()
 105         * results with __PHYSICAL_MASK or PTE_PFN_MASK.
 106         */
 107        decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
 108
 109        rc = set_memory_uc(decoy_addr, 1);
 110        if (rc)
 111                pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
 112        return rc;
 113}
 114#define set_mce_nospec set_mce_nospec
 115
 116/* Restore full speculative operation to the pfn. */
 117static inline int clear_mce_nospec(unsigned long pfn)
 118{
 119        return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1);
 120}
 121#define clear_mce_nospec clear_mce_nospec
 122#else
 123/*
 124 * Few people would run a 32-bit kernel on a machine that supports
 125 * recoverable errors because they have too much memory to boot 32-bit.
 126 */
 127#endif
 128
 129#endif /* _ASM_X86_SET_MEMORY_H */
 130