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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/x86/include/asm/special_insns.h | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/include/asm/special_insns.h')
-rw-r--r-- | arch/x86/include/asm/special_insns.h | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h new file mode 100644 index 0000000000..d6cd9344f6 --- /dev/null +++ b/arch/x86/include/asm/special_insns.h @@ -0,0 +1,301 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_SPECIAL_INSNS_H +#define _ASM_X86_SPECIAL_INSNS_H + + +#ifdef __KERNEL__ + +#include <asm/nops.h> +#include <asm/processor-flags.h> +#include <linux/irqflags.h> +#include <linux/jump_label.h> + +/* + * The compiler should not reorder volatile asm statements with respect to each + * other: they should execute in program order. However GCC 4.9.x and 5.x have + * a bug (which was fixed in 8.1, 7.3 and 6.5) where they might reorder + * volatile asm. The write functions are not affected since they have memory + * clobbers preventing reordering. To prevent reads from being reordered with + * respect to writes, use a dummy memory operand. + */ + +#define __FORCE_ORDER "m"(*(unsigned int *)0x1000UL) + +void native_write_cr0(unsigned long val); + +static inline unsigned long native_read_cr0(void) +{ + unsigned long val; + asm volatile("mov %%cr0,%0\n\t" : "=r" (val) : __FORCE_ORDER); + return val; +} + +static __always_inline unsigned long native_read_cr2(void) +{ + unsigned long val; + asm volatile("mov %%cr2,%0\n\t" : "=r" (val) : __FORCE_ORDER); + return val; +} + +static __always_inline void native_write_cr2(unsigned long val) +{ + asm volatile("mov %0,%%cr2": : "r" (val) : "memory"); +} + +static inline unsigned long __native_read_cr3(void) +{ + unsigned long val; + asm volatile("mov %%cr3,%0\n\t" : "=r" (val) : __FORCE_ORDER); + return val; +} + +static inline void native_write_cr3(unsigned long val) +{ + asm volatile("mov %0,%%cr3": : "r" (val) : "memory"); +} + +static inline unsigned long native_read_cr4(void) +{ + unsigned long val; +#ifdef CONFIG_X86_32 + /* + * This could fault if CR4 does not exist. Non-existent CR4 + * is functionally equivalent to CR4 == 0. Keep it simple and pretend + * that CR4 == 0 on CPUs that don't have CR4. + */ + asm volatile("1: mov %%cr4, %0\n" + "2:\n" + _ASM_EXTABLE(1b, 2b) + : "=r" (val) : "0" (0), __FORCE_ORDER); +#else + /* CR4 always exists on x86_64. */ + asm volatile("mov %%cr4,%0\n\t" : "=r" (val) : __FORCE_ORDER); +#endif + return val; +} + +void native_write_cr4(unsigned long val); + +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +static inline u32 rdpkru(void) +{ + u32 ecx = 0; + u32 edx, pkru; + + /* + * "rdpkru" instruction. Places PKRU contents in to EAX, + * clears EDX and requires that ecx=0. + */ + asm volatile(".byte 0x0f,0x01,0xee\n\t" + : "=a" (pkru), "=d" (edx) + : "c" (ecx)); + return pkru; +} + +static inline void wrpkru(u32 pkru) +{ + u32 ecx = 0, edx = 0; + + /* + * "wrpkru" instruction. Loads contents in EAX to PKRU, + * requires that ecx = edx = 0. + */ + asm volatile(".byte 0x0f,0x01,0xef\n\t" + : : "a" (pkru), "c"(ecx), "d"(edx)); +} + +#else +static inline u32 rdpkru(void) +{ + return 0; +} + +static inline void wrpkru(u32 pkru) +{ +} +#endif + +static __always_inline void native_wbinvd(void) +{ + asm volatile("wbinvd": : :"memory"); +} + +static inline unsigned long __read_cr4(void) +{ + return native_read_cr4(); +} + +#ifdef CONFIG_PARAVIRT_XXL +#include <asm/paravirt.h> +#else + +static inline unsigned long read_cr0(void) +{ + return native_read_cr0(); +} + +static inline void write_cr0(unsigned long x) +{ + native_write_cr0(x); +} + +static __always_inline unsigned long read_cr2(void) +{ + return native_read_cr2(); +} + +static __always_inline void write_cr2(unsigned long x) +{ + native_write_cr2(x); +} + +/* + * Careful! CR3 contains more than just an address. You probably want + * read_cr3_pa() instead. + */ +static inline unsigned long __read_cr3(void) +{ + return __native_read_cr3(); +} + +static inline void write_cr3(unsigned long x) +{ + native_write_cr3(x); +} + +static inline void __write_cr4(unsigned long x) +{ + native_write_cr4(x); +} + +static __always_inline void wbinvd(void) +{ + native_wbinvd(); +} + +#endif /* CONFIG_PARAVIRT_XXL */ + +static __always_inline void clflush(volatile void *__p) +{ + asm volatile("clflush %0" : "+m" (*(volatile char __force *)__p)); +} + +static inline void clflushopt(volatile void *__p) +{ + alternative_io(".byte 0x3e; clflush %P0", + ".byte 0x66; clflush %P0", + X86_FEATURE_CLFLUSHOPT, + "+m" (*(volatile char __force *)__p)); +} + +static inline void clwb(volatile void *__p) +{ + volatile struct { char x[64]; } *p = __p; + + asm volatile(ALTERNATIVE_2( + ".byte 0x3e; clflush (%[pax])", + ".byte 0x66; clflush (%[pax])", /* clflushopt (%%rax) */ + X86_FEATURE_CLFLUSHOPT, + ".byte 0x66, 0x0f, 0xae, 0x30", /* clwb (%%rax) */ + X86_FEATURE_CLWB) + : [p] "+m" (*p) + : [pax] "a" (p)); +} + +#ifdef CONFIG_X86_USER_SHADOW_STACK +static inline int write_user_shstk_64(u64 __user *addr, u64 val) +{ + asm_volatile_goto("1: wrussq %[val], (%[addr])\n" + _ASM_EXTABLE(1b, %l[fail]) + :: [addr] "r" (addr), [val] "r" (val) + :: fail); + return 0; +fail: + return -EFAULT; +} +#endif /* CONFIG_X86_USER_SHADOW_STACK */ + +#define nop() asm volatile ("nop") + +static inline void serialize(void) +{ + /* Instruction opcode for SERIALIZE; supported in binutils >= 2.35. */ + asm volatile(".byte 0xf, 0x1, 0xe8" ::: "memory"); +} + +/* The dst parameter must be 64-bytes aligned */ +static inline void movdir64b(void __iomem *dst, const void *src) +{ + const struct { char _[64]; } *__src = src; + struct { char _[64]; } __iomem *__dst = dst; + + /* + * MOVDIR64B %(rdx), rax. + * + * Both __src and __dst must be memory constraints in order to tell the + * compiler that no other memory accesses should be reordered around + * this one. + * + * Also, both must be supplied as lvalues because this tells + * the compiler what the object is (its size) the instruction accesses. + * I.e., not the pointers but what they point to, thus the deref'ing '*'. + */ + asm volatile(".byte 0x66, 0x0f, 0x38, 0xf8, 0x02" + : "+m" (*__dst) + : "m" (*__src), "a" (__dst), "d" (__src)); +} + +/** + * enqcmds - Enqueue a command in supervisor (CPL0) mode + * @dst: destination, in MMIO space (must be 512-bit aligned) + * @src: 512 bits memory operand + * + * The ENQCMDS instruction allows software to write a 512-bit command to + * a 512-bit-aligned special MMIO region that supports the instruction. + * A return status is loaded into the ZF flag in the RFLAGS register. + * ZF = 0 equates to success, and ZF = 1 indicates retry or error. + * + * This function issues the ENQCMDS instruction to submit data from + * kernel space to MMIO space, in a unit of 512 bits. Order of data access + * is not guaranteed, nor is a memory barrier performed afterwards. It + * returns 0 on success and -EAGAIN on failure. + * + * Warning: Do not use this helper unless your driver has checked that the + * ENQCMDS instruction is supported on the platform and the device accepts + * ENQCMDS. + */ +static inline int enqcmds(void __iomem *dst, const void *src) +{ + const struct { char _[64]; } *__src = src; + struct { char _[64]; } __iomem *__dst = dst; + bool zf; + + /* + * ENQCMDS %(rdx), rax + * + * See movdir64b()'s comment on operand specification. + */ + asm volatile(".byte 0xf3, 0x0f, 0x38, 0xf8, 0x02, 0x66, 0x90" + CC_SET(z) + : CC_OUT(z) (zf), "+m" (*__dst) + : "m" (*__src), "a" (__dst), "d" (__src)); + + /* Submission failure is indicated via EFLAGS.ZF=1 */ + if (zf) + return -EAGAIN; + + return 0; +} + +static __always_inline void tile_release(void) +{ + /* + * Instruction opcode for TILERELEASE; supported in binutils + * version >= 2.36. + */ + asm volatile(".byte 0xc4, 0xe2, 0x78, 0x49, 0xc0"); +} + +#endif /* __KERNEL__ */ + +#endif /* _ASM_X86_SPECIAL_INSNS_H */ |