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- /* 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 inline void native_wbinvd(void)
- {
- asm volatile("wbinvd": : :"memory");
- }
- extern asmlinkage void asm_load_gs_index(unsigned int selector);
- static inline void native_load_gs_index(unsigned int selector)
- {
- unsigned long flags;
- local_irq_save(flags);
- asm_load_gs_index(selector);
- local_irq_restore(flags);
- }
- 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 inline void wbinvd(void)
- {
- native_wbinvd();
- }
- static inline void load_gs_index(unsigned int selector)
- {
- #ifdef CONFIG_X86_64
- native_load_gs_index(selector);
- #else
- loadsegment(gs, selector);
- #endif
- }
- #endif /* CONFIG_PARAVIRT_XXL */
- static 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));
- }
- #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 */
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