diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/string_64.h | 5 | ||||
| -rw-r--r-- | arch/x86/include/asm/uaccess_64.h | 11 | ||||
| -rw-r--r-- | arch/x86/lib/usercopy_64.c | 128 |
4 files changed, 145 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 4ccfacc7232a..bb273b2f50b5 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -54,6 +54,7 @@ config X86 select ARCH_HAS_KCOV if X86_64 select ARCH_HAS_MMIO_FLUSH select ARCH_HAS_PMEM_API if X86_64 + select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 select ARCH_HAS_SET_MEMORY select ARCH_HAS_SG_CHAIN select ARCH_HAS_STRICT_KERNEL_RWX diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h index 733bae07fb29..1f22bc277c45 100644 --- a/arch/x86/include/asm/string_64.h +++ b/arch/x86/include/asm/string_64.h @@ -109,6 +109,11 @@ memcpy_mcsafe(void *dst, const void *src, size_t cnt) return 0; } +#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE +#define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1 +void memcpy_flushcache(void *dst, const void *src, size_t cnt); +#endif + #endif /* __KERNEL__ */ #endif /* _ASM_X86_STRING_64_H */ diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index c5504b9a472e..b16f6a1d8b26 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -171,6 +171,10 @@ unsigned long raw_copy_in_user(void __user *dst, const void __user *src, unsigne extern long __copy_user_nocache(void *dst, const void __user *src, unsigned size, int zerorest); +extern long __copy_user_flushcache(void *dst, const void __user *src, unsigned size); +extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset, + size_t len); + static inline int __copy_from_user_inatomic_nocache(void *dst, const void __user *src, unsigned size) @@ -179,6 +183,13 @@ __copy_from_user_inatomic_nocache(void *dst, const void __user *src, return __copy_user_nocache(dst, src, size, 0); } +static inline int +__copy_from_user_flushcache(void *dst, const void __user *src, unsigned size) +{ + kasan_check_write(dst, size); + return __copy_user_flushcache(dst, src, size); +} + unsigned long copy_user_handle_tail(char *to, char *from, unsigned len); diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c index 3b7c40a2e3e1..f42d2fd86ca3 100644 --- a/arch/x86/lib/usercopy_64.c +++ b/arch/x86/lib/usercopy_64.c @@ -7,6 +7,7 @@ */ #include <linux/export.h> #include <linux/uaccess.h> +#include <linux/highmem.h> /* * Zero Userspace @@ -73,3 +74,130 @@ copy_user_handle_tail(char *to, char *from, unsigned len) clac(); return len; } + +#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE +/** + * clean_cache_range - write back a cache range with CLWB + * @vaddr: virtual start address + * @size: number of bytes to write back + * + * Write back a cache range using the CLWB (cache line write back) + * instruction. Note that @size is internally rounded up to be cache + * line size aligned. + */ +static void clean_cache_range(void *addr, size_t size) +{ + u16 x86_clflush_size = boot_cpu_data.x86_clflush_size; + unsigned long clflush_mask = x86_clflush_size - 1; + void *vend = addr + size; + void *p; + + for (p = (void *)((unsigned long)addr & ~clflush_mask); + p < vend; p += x86_clflush_size) + clwb(p); +} + +long __copy_user_flushcache(void *dst, const void __user *src, unsigned size) +{ + unsigned long flushed, dest = (unsigned long) dst; + long rc = __copy_user_nocache(dst, src, size, 0); + + /* + * __copy_user_nocache() uses non-temporal stores for the bulk + * of the transfer, but we need to manually flush if the + * transfer is unaligned. A cached memory copy is used when + * destination or size is not naturally aligned. That is: + * - Require 8-byte alignment when size is 8 bytes or larger. + * - Require 4-byte alignment when size is 4 bytes. + */ + if (size < 8) { + if (!IS_ALIGNED(dest, 4) || size != 4) + clean_cache_range(dst, 1); + } else { + if (!IS_ALIGNED(dest, 8)) { + dest = ALIGN(dest, boot_cpu_data.x86_clflush_size); + clean_cache_range(dst, 1); + } + + flushed = dest - (unsigned long) dst; + if (size > flushed && !IS_ALIGNED(size - flushed, 8)) + clean_cache_range(dst + size - 1, 1); + } + + return rc; +} + +void memcpy_flushcache(void *_dst, const void *_src, size_t size) +{ + unsigned long dest = (unsigned long) _dst; + unsigned long source = (unsigned long) _src; + + /* cache copy and flush to align dest */ + if (!IS_ALIGNED(dest, 8)) { + unsigned len = min_t(unsigned, size, ALIGN(dest, 8) - dest); + + memcpy((void *) dest, (void *) source, len); + clean_cache_range((void *) dest, len); + dest += len; + source += len; + size -= len; + if (!size) + return; + } + + /* 4x8 movnti loop */ + while (size >= 32) { + asm("movq (%0), %%r8\n" + "movq 8(%0), %%r9\n" + "movq 16(%0), %%r10\n" + "movq 24(%0), %%r11\n" + "movnti %%r8, (%1)\n" + "movnti %%r9, 8(%1)\n" + "movnti %%r10, 16(%1)\n" + "movnti %%r11, 24(%1)\n" + :: "r" (source), "r" (dest) + : "memory", "r8", "r9", "r10", "r11"); + dest += 32; + source += 32; + size -= 32; + } + + /* 1x8 movnti loop */ + while (size >= 8) { + asm("movq (%0), %%r8\n" + "movnti %%r8, (%1)\n" + :: "r" (source), "r" (dest) + : "memory", "r8"); + dest += 8; + source += 8; + size -= 8; + } + + /* 1x4 movnti loop */ + while (size >= 4) { + asm("movl (%0), %%r8d\n" + "movnti %%r8d, (%1)\n" + :: "r" (source), "r" (dest) + : "memory", "r8"); + dest += 4; + source += 4; + size -= 4; + } + + /* cache copy for remaining bytes */ + if (size) { + memcpy((void *) dest, (void *) source, size); + clean_cache_range((void *) dest, size); + } +} +EXPORT_SYMBOL_GPL(memcpy_flushcache); + +void memcpy_page_flushcache(char *to, struct page *page, size_t offset, + size_t len) +{ + char *from = kmap_atomic(page); + + memcpy_flushcache(to, from + offset, len); + kunmap_atomic(from); +} +#endif |