/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_SET_MEMORY_H #define _ASM_X86_SET_MEMORY_H #include #include /* * The set_memory_* API can be used to change various attributes of a virtual * address range. The attributes include: * Cachability : UnCached, WriteCombining, WriteThrough, 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_wt(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_wt(unsigned long addr, int numpages); int set_memory_wb(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_np_noalias(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_wt(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_wt(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); extern int kernel_set_to_readonly; void set_kernel_text_rw(void); void set_kernel_text_ro(void); #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) pr_warn("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 #endif /* _ASM_X86_SET_MEMORY_H */