142 lines
5.4 KiB
C
142 lines
5.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_X86_SET_MEMORY_H
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#define _ASM_X86_SET_MEMORY_H
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#include <asm/page.h>
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#include <asm-generic/set_memory.h>
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/*
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* The set_memory_* API can be used to change various attributes of a virtual
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* address range. The attributes include:
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* Cachability : UnCached, WriteCombining, WriteThrough, WriteBack
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* Executability : eXeutable, NoteXecutable
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* Read/Write : ReadOnly, ReadWrite
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* Presence : NotPresent
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* Encryption : Encrypted, Decrypted
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*
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* Within a category, the attributes are mutually exclusive.
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*
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* The implementation of this API will take care of various aspects that
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* are associated with changing such attributes, such as:
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* - Flushing TLBs
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* - Flushing CPU caches
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* - Making sure aliases of the memory behind the mapping don't violate
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* coherency rules as defined by the CPU in the system.
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*
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* What this API does not do:
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* - Provide exclusion between various callers - including callers that
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* operation on other mappings of the same physical page
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* - Restore default attributes when a page is freed
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* - Guarantee that mappings other than the requested one are
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* in any state, other than that these do not violate rules for
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* the CPU you have. Do not depend on any effects on other mappings,
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* CPUs other than the one you have may have more relaxed rules.
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* The caller is required to take care of these.
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*/
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int _set_memory_uc(unsigned long addr, int numpages);
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int _set_memory_wc(unsigned long addr, int numpages);
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int _set_memory_wt(unsigned long addr, int numpages);
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int _set_memory_wb(unsigned long addr, int numpages);
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int set_memory_uc(unsigned long addr, int numpages);
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int set_memory_wc(unsigned long addr, int numpages);
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int set_memory_wt(unsigned long addr, int numpages);
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int set_memory_wb(unsigned long addr, int numpages);
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int set_memory_np(unsigned long addr, int numpages);
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int set_memory_4k(unsigned long addr, int numpages);
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int set_memory_encrypted(unsigned long addr, int numpages);
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int set_memory_decrypted(unsigned long addr, int numpages);
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int set_memory_np_noalias(unsigned long addr, int numpages);
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int set_memory_array_uc(unsigned long *addr, int addrinarray);
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int set_memory_array_wc(unsigned long *addr, int addrinarray);
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int set_memory_array_wt(unsigned long *addr, int addrinarray);
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int set_memory_array_wb(unsigned long *addr, int addrinarray);
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int set_pages_array_uc(struct page **pages, int addrinarray);
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int set_pages_array_wc(struct page **pages, int addrinarray);
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int set_pages_array_wt(struct page **pages, int addrinarray);
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int set_pages_array_wb(struct page **pages, int addrinarray);
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/*
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* For legacy compatibility with the old APIs, a few functions
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* are provided that work on a "struct page".
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* These functions operate ONLY on the 1:1 kernel mapping of the
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* memory that the struct page represents, and internally just
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* call the set_memory_* function. See the description of the
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* set_memory_* function for more details on conventions.
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*
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* These APIs should be considered *deprecated* and are likely going to
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* be removed in the future.
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* The reason for this is the implicit operation on the 1:1 mapping only,
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* making this not a generally useful API.
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*
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* Specifically, many users of the old APIs had a virtual address,
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* called virt_to_page() or vmalloc_to_page() on that address to
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* get a struct page* that the old API required.
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* To convert these cases, use set_memory_*() on the original
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* virtual address, do not use these functions.
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*/
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int set_pages_uc(struct page *page, int numpages);
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int set_pages_wb(struct page *page, int numpages);
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int set_pages_x(struct page *page, int numpages);
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int set_pages_nx(struct page *page, int numpages);
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int set_pages_ro(struct page *page, int numpages);
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int set_pages_rw(struct page *page, int numpages);
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extern int kernel_set_to_readonly;
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void set_kernel_text_rw(void);
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void set_kernel_text_ro(void);
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#ifdef CONFIG_X86_64
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/*
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* Prevent speculative access to the page by either unmapping
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* it (if we do not require access to any part of the page) or
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* marking it uncacheable (if we want to try to retrieve data
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* from non-poisoned lines in the page).
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*/
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static inline int set_mce_nospec(unsigned long pfn, bool unmap)
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{
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unsigned long decoy_addr;
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int rc;
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/*
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* We would like to just call:
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* set_memory_XX((unsigned long)pfn_to_kaddr(pfn), 1);
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* but doing that would radically increase the odds of a
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* speculative access to the poison page because we'd have
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* the virtual address of the kernel 1:1 mapping sitting
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* around in registers.
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* Instead we get tricky. We create a non-canonical address
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* that looks just like the one we want, but has bit 63 flipped.
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* This relies on set_memory_XX() properly sanitizing any __pa()
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* results with __PHYSICAL_MASK or PTE_PFN_MASK.
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*/
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decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
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if (unmap)
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rc = set_memory_np(decoy_addr, 1);
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else
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rc = set_memory_uc(decoy_addr, 1);
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if (rc)
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pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
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return rc;
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}
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#define set_mce_nospec set_mce_nospec
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/* Restore full speculative operation to the pfn. */
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static inline int clear_mce_nospec(unsigned long pfn)
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{
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return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1);
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}
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#define clear_mce_nospec clear_mce_nospec
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#else
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/*
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* Few people would run a 32-bit kernel on a machine that supports
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* recoverable errors because they have too much memory to boot 32-bit.
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*/
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#endif
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#endif /* _ASM_X86_SET_MEMORY_H */
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