From d582203578a1f3d408e27bb9042e8635954cd320 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Wed, 2 May 2007 19:27:14 +0200 Subject: [PATCH] [PATCH] i386: PARAVIRT: Use patch site IDs computed from offset in paravirt_ops structure Use patch type identifiers derived from the offset of the operation in the paravirt_ops structure. This avoids having to maintain a separate enum for patch site types. Also, since the identifier is derived from the offset into paravirt_ops, the offset can be derived from the identifier. This is used to remove replicated information in the various callsite macros, which has been a source of bugs in the past. This patch also drops the fused save_fl+cli operation, which doesn't really add much and makes things more complex - specifically because it breaks the 1:1 relationship between identifiers and offsets. If this operation turns out to be particularly beneficial, then the right answer is to define a new entrypoint for it. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Andi Kleen Cc: Rusty Russell Cc: Zachary Amsden --- arch/i386/kernel/paravirt.c | 14 ++- arch/i386/kernel/vmi.c | 39 ++------ include/asm-i386/paravirt.h | 177 +++++++++++++++++++----------------- 3 files changed, 104 insertions(+), 126 deletions(-) diff --git a/arch/i386/kernel/paravirt.c b/arch/i386/kernel/paravirt.c index 54cc14d99740..f2982832d3b9 100644 --- a/arch/i386/kernel/paravirt.c +++ b/arch/i386/kernel/paravirt.c @@ -58,7 +58,6 @@ DEF_NATIVE(cli, "cli"); DEF_NATIVE(sti, "sti"); DEF_NATIVE(popf, "push %eax; popf"); DEF_NATIVE(pushf, "pushf; pop %eax"); -DEF_NATIVE(pushf_cli, "pushf; pop %eax; cli"); DEF_NATIVE(iret, "iret"); DEF_NATIVE(sti_sysexit, "sti; sysexit"); @@ -66,13 +65,12 @@ static const struct native_insns { const char *start, *end; } native_insns[] = { - [PARAVIRT_IRQ_DISABLE] = { start_cli, end_cli }, - [PARAVIRT_IRQ_ENABLE] = { start_sti, end_sti }, - [PARAVIRT_RESTORE_FLAGS] = { start_popf, end_popf }, - [PARAVIRT_SAVE_FLAGS] = { start_pushf, end_pushf }, - [PARAVIRT_SAVE_FLAGS_IRQ_DISABLE] = { start_pushf_cli, end_pushf_cli }, - [PARAVIRT_INTERRUPT_RETURN] = { start_iret, end_iret }, - [PARAVIRT_STI_SYSEXIT] = { start_sti_sysexit, end_sti_sysexit }, + [PARAVIRT_PATCH(irq_disable)] = { start_cli, end_cli }, + [PARAVIRT_PATCH(irq_enable)] = { start_sti, end_sti }, + [PARAVIRT_PATCH(restore_fl)] = { start_popf, end_popf }, + [PARAVIRT_PATCH(save_fl)] = { start_pushf, end_pushf }, + [PARAVIRT_PATCH(iret)] = { start_iret, end_iret }, + [PARAVIRT_PATCH(irq_enable_sysexit)] = { start_sti_sysexit, end_sti_sysexit }, }; static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len) diff --git a/arch/i386/kernel/vmi.c b/arch/i386/kernel/vmi.c index ea77d93f59dd..b8d01c3cbff4 100644 --- a/arch/i386/kernel/vmi.c +++ b/arch/i386/kernel/vmi.c @@ -83,11 +83,6 @@ extern struct paravirt_patch __start_parainstructions[], #define MNEM_JMP 0xe9 #define MNEM_RET 0xc3 -static char irq_save_disable_callout[] = { - MNEM_CALL, 0, 0, 0, 0, - MNEM_CALL, 0, 0, 0, 0, - MNEM_RET -}; #define IRQ_PATCH_INT_MASK 0 #define IRQ_PATCH_DISABLE 5 @@ -135,33 +130,17 @@ static unsigned patch_internal(int call, unsigned len, void *insns) static unsigned vmi_patch(u8 type, u16 clobbers, void *insns, unsigned len) { switch (type) { - case PARAVIRT_IRQ_DISABLE: + case PARAVIRT_PATCH(irq_disable): return patch_internal(VMI_CALL_DisableInterrupts, len, insns); - case PARAVIRT_IRQ_ENABLE: + case PARAVIRT_PATCH(irq_enable): return patch_internal(VMI_CALL_EnableInterrupts, len, insns); - case PARAVIRT_RESTORE_FLAGS: + case PARAVIRT_PATCH(restore_fl): return patch_internal(VMI_CALL_SetInterruptMask, len, insns); - case PARAVIRT_SAVE_FLAGS: + case PARAVIRT_PATCH(save_fl): return patch_internal(VMI_CALL_GetInterruptMask, len, insns); - case PARAVIRT_SAVE_FLAGS_IRQ_DISABLE: - if (len >= 10) { - patch_internal(VMI_CALL_GetInterruptMask, len, insns); - patch_internal(VMI_CALL_DisableInterrupts, len-5, insns+5); - return 10; - } else { - /* - * You bastards didn't leave enough room to - * patch save_flags_irq_disable inline. Patch - * to a helper - */ - BUG_ON(len < 5); - *(char *)insns = MNEM_CALL; - patch_offset(insns, irq_save_disable_callout); - return 5; - } - case PARAVIRT_INTERRUPT_RETURN: + case PARAVIRT_PATCH(iret): return patch_internal(VMI_CALL_IRET, len, insns); - case PARAVIRT_STI_SYSEXIT: + case PARAVIRT_PATCH(irq_enable_sysexit): return patch_internal(VMI_CALL_SYSEXIT, len, insns); default: break; @@ -796,12 +775,6 @@ static inline int __init activate_vmi(void) para_fill(irq_disable, DisableInterrupts); para_fill(irq_enable, EnableInterrupts); - /* irq_save_disable !!! sheer pain */ - patch_offset(&irq_save_disable_callout[IRQ_PATCH_INT_MASK], - (char *)paravirt_ops.save_fl); - patch_offset(&irq_save_disable_callout[IRQ_PATCH_DISABLE], - (char *)paravirt_ops.irq_disable); - para_fill(wbinvd, WBINVD); para_fill(read_tsc, RDTSC); diff --git a/include/asm-i386/paravirt.h b/include/asm-i386/paravirt.h index b4cc2fc4031e..1dbc01f4ed4d 100644 --- a/include/asm-i386/paravirt.h +++ b/include/asm-i386/paravirt.h @@ -4,19 +4,8 @@ * para-virtualization: those hooks are defined here. */ #ifdef CONFIG_PARAVIRT -#include #include -/* These are the most performance critical ops, so we want to be able to patch - * callers */ -#define PARAVIRT_IRQ_DISABLE 0 -#define PARAVIRT_IRQ_ENABLE 1 -#define PARAVIRT_RESTORE_FLAGS 2 -#define PARAVIRT_SAVE_FLAGS 3 -#define PARAVIRT_SAVE_FLAGS_IRQ_DISABLE 4 -#define PARAVIRT_INTERRUPT_RETURN 5 -#define PARAVIRT_STI_SYSEXIT 6 - /* Bitmask of what can be clobbered: usually at least eax. */ #define CLBR_NONE 0x0 #define CLBR_EAX 0x1 @@ -191,6 +180,28 @@ struct paravirt_ops extern struct paravirt_ops paravirt_ops; +#define PARAVIRT_PATCH(x) \ + (offsetof(struct paravirt_ops, x) / sizeof(void *)) + +#define paravirt_type(type) \ + [paravirt_typenum] "i" (PARAVIRT_PATCH(type)) +#define paravirt_clobber(clobber) \ + [paravirt_clobber] "i" (clobber) + +#define PARAVIRT_CALL "call *paravirt_ops+%c[paravirt_typenum]*4;" + +#define _paravirt_alt(insn_string, type, clobber) \ + "771:\n\t" insn_string "\n" "772:\n" \ + ".pushsection .parainstructions,\"a\"\n" \ + " .long 771b\n" \ + " .byte " type "\n" \ + " .byte 772b-771b\n" \ + " .short " clobber "\n" \ + ".popsection\n" + +#define paravirt_alt(insn_string) \ + _paravirt_alt(insn_string, "%c[paravirt_typenum]", "%c[paravirt_clobber]") + #define paravirt_enabled() (paravirt_ops.paravirt_enabled) static inline void load_esp0(struct tss_struct *tss, @@ -515,93 +526,89 @@ struct paravirt_patch_site { extern struct paravirt_patch_site __parainstructions[], __parainstructions_end[]; -#define paravirt_alt(insn_string, typenum, clobber) \ - "771:\n\t" insn_string "\n" "772:\n" \ - ".pushsection .parainstructions,\"a\"\n" \ - " .long 771b\n" \ - " .byte " __stringify(typenum) "\n" \ - " .byte 772b-771b\n" \ - " .short " __stringify(clobber) "\n" \ - ".popsection" - static inline unsigned long __raw_local_save_flags(void) { unsigned long f; - __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;" - "call *%1;" - "popl %%edx; popl %%ecx", - PARAVIRT_SAVE_FLAGS, CLBR_NONE) - : "=a"(f): "m"(paravirt_ops.save_fl) - : "memory", "cc"); + asm volatile(paravirt_alt("pushl %%ecx; pushl %%edx;" + PARAVIRT_CALL + "popl %%edx; popl %%ecx") + : "=a"(f) + : paravirt_type(save_fl), + paravirt_clobber(CLBR_NONE) + : "memory", "cc"); return f; } static inline void raw_local_irq_restore(unsigned long f) { - __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;" - "call *%1;" - "popl %%edx; popl %%ecx", - PARAVIRT_RESTORE_FLAGS, CLBR_EAX) - : "=a"(f) : "m" (paravirt_ops.restore_fl), "0"(f) - : "memory", "cc"); + asm volatile(paravirt_alt("pushl %%ecx; pushl %%edx;" + PARAVIRT_CALL + "popl %%edx; popl %%ecx") + : "=a"(f) + : "0"(f), + paravirt_type(restore_fl), + paravirt_clobber(CLBR_EAX) + : "memory", "cc"); } static inline void raw_local_irq_disable(void) { - __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;" - "call *%0;" - "popl %%edx; popl %%ecx", - PARAVIRT_IRQ_DISABLE, CLBR_EAX) - : : "m" (paravirt_ops.irq_disable) - : "memory", "eax", "cc"); + asm volatile(paravirt_alt("pushl %%ecx; pushl %%edx;" + PARAVIRT_CALL + "popl %%edx; popl %%ecx") + : + : paravirt_type(irq_disable), + paravirt_clobber(CLBR_EAX) + : "memory", "eax", "cc"); } static inline void raw_local_irq_enable(void) { - __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;" - "call *%0;" - "popl %%edx; popl %%ecx", - PARAVIRT_IRQ_ENABLE, CLBR_EAX) - : : "m" (paravirt_ops.irq_enable) - : "memory", "eax", "cc"); + asm volatile(paravirt_alt("pushl %%ecx; pushl %%edx;" + PARAVIRT_CALL + "popl %%edx; popl %%ecx") + : + : paravirt_type(irq_enable), + paravirt_clobber(CLBR_EAX) + : "memory", "eax", "cc"); } static inline unsigned long __raw_local_irq_save(void) { unsigned long f; - __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;" - "call *%1; pushl %%eax;" - "call *%2; popl %%eax;" - "popl %%edx; popl %%ecx", - PARAVIRT_SAVE_FLAGS_IRQ_DISABLE, - CLBR_NONE) - : "=a"(f) - : "m" (paravirt_ops.save_fl), - "m" (paravirt_ops.irq_disable) - : "memory", "cc"); + f = __raw_local_save_flags(); + raw_local_irq_disable(); return f; } -#define CLI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;" \ - "call *paravirt_ops+%c[irq_disable];" \ - "popl %%edx; popl %%ecx", \ - PARAVIRT_IRQ_DISABLE, CLBR_EAX) +#define CLI_STRING \ + _paravirt_alt("pushl %%ecx; pushl %%edx;" \ + "call *paravirt_ops+%c[paravirt_cli_type]*4;" \ + "popl %%edx; popl %%ecx", \ + "%c[paravirt_cli_type]", "%c[paravirt_clobber]") + +#define STI_STRING \ + _paravirt_alt("pushl %%ecx; pushl %%edx;" \ + "call *paravirt_ops+%c[paravirt_sti_type]*4;" \ + "popl %%edx; popl %%ecx", \ + "%c[paravirt_sti_type]", "%c[paravirt_clobber]") -#define STI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;" \ - "call *paravirt_ops+%c[irq_enable];" \ - "popl %%edx; popl %%ecx", \ - PARAVIRT_IRQ_ENABLE, CLBR_EAX) #define CLI_STI_CLOBBERS , "%eax" -#define CLI_STI_INPUT_ARGS \ +#define CLI_STI_INPUT_ARGS \ , \ - [irq_disable] "i" (offsetof(struct paravirt_ops, irq_disable)), \ - [irq_enable] "i" (offsetof(struct paravirt_ops, irq_enable)) + [paravirt_cli_type] "i" (PARAVIRT_PATCH(irq_disable)), \ + [paravirt_sti_type] "i" (PARAVIRT_PATCH(irq_enable)), \ + paravirt_clobber(CLBR_EAX) + +#undef PARAVIRT_CALL #else /* __ASSEMBLY__ */ -#define PARA_PATCH(ptype, clobbers, ops) \ +#define PARA_PATCH(off) ((off) / 4) + +#define PARA_SITE(ptype, clobbers, ops) \ 771:; \ ops; \ 772:; \ @@ -612,25 +619,25 @@ static inline unsigned long __raw_local_irq_save(void) .short clobbers; \ .popsection -#define INTERRUPT_RETURN \ - PARA_PATCH(PARAVIRT_INTERRUPT_RETURN, CLBR_ANY, \ - jmp *%cs:paravirt_ops+PARAVIRT_iret) - -#define DISABLE_INTERRUPTS(clobbers) \ - PARA_PATCH(PARAVIRT_IRQ_DISABLE, clobbers, \ - pushl %ecx; pushl %edx; \ - call *paravirt_ops+PARAVIRT_irq_disable; \ - popl %edx; popl %ecx) \ - -#define ENABLE_INTERRUPTS(clobbers) \ - PARA_PATCH(PARAVIRT_IRQ_ENABLE, clobbers, \ - pushl %ecx; pushl %edx; \ - call *%cs:paravirt_ops+PARAVIRT_irq_enable; \ - popl %edx; popl %ecx) - -#define ENABLE_INTERRUPTS_SYSEXIT \ - PARA_PATCH(PARAVIRT_STI_SYSEXIT, CLBR_ANY, \ - jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit) +#define INTERRUPT_RETURN \ + PARA_SITE(PARA_PATCH(PARAVIRT_iret), CLBR_ANY, \ + jmp *%cs:paravirt_ops+PARAVIRT_iret) + +#define DISABLE_INTERRUPTS(clobbers) \ + PARA_SITE(PARA_PATCH(PARAVIRT_irq_disable), clobbers, \ + pushl %ecx; pushl %edx; \ + call *%cs:paravirt_ops+PARAVIRT_irq_disable; \ + popl %edx; popl %ecx) \ + +#define ENABLE_INTERRUPTS(clobbers) \ + PARA_SITE(PARA_PATCH(PARAVIRT_irq_enable), clobbers, \ + pushl %ecx; pushl %edx; \ + call *%cs:paravirt_ops+PARAVIRT_irq_enable; \ + popl %edx; popl %ecx) + +#define ENABLE_INTERRUPTS_SYSEXIT \ + PARA_SITE(PARA_PATCH(PARAVIRT_irq_enable_sysexit), CLBR_ANY, \ + jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit) #define GET_CR0_INTO_EAX \ call *paravirt_ops+PARAVIRT_read_cr0 -- 2.30.2