From d167a51877e94dda73dd656c51f363502309f713 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Mon, 26 Jun 2006 13:56:16 +0200 Subject: [PATCH] [PATCH] x86_64: x86_64 version of the smp alternative patch. Changes are largely identical to the i386 version: * alternative #define are moved to the new alternative.h file. * one new elf section with pointers to the lock prefixes which can be nop'ed out for non-smp. * two new elf sections simliar to the "classic" alternatives to replace SMP code with simpler UP code. * fixup headers to use alternative.h instead of defining their own LOCK / LOCK_PREFIX macros. The patch reuses the i386 version of the alternatives code to avoid code duplication. The code in alternatives.c was shuffled around a bit to reduce the number of #ifdefs needed. It also got some tweaks needed for x86_64 (vsyscall page handling) and new features (noreplacement option which was x86_64 only up to now). Debug printk's are changed from compile-time to runtime. Loosely based on a early version from Bastian Blank Signed-off-by: Gerd Hoffmann Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/i386/kernel/alternative.c | 118 ++++++++++++++++++------- arch/x86_64/kernel/Makefile | 4 +- arch/x86_64/kernel/module.c | 38 +++++--- arch/x86_64/kernel/setup.c | 76 +--------------- arch/x86_64/kernel/smpboot.c | 4 + arch/x86_64/kernel/vmlinux.lds.S | 20 +++++ arch/x86_64/mm/init.c | 27 +++--- include/asm-i386/alternative.h | 2 + include/asm-x86_64/alternative.h | 146 +++++++++++++++++++++++++++++++ include/asm-x86_64/atomic.h | 42 ++++----- include/asm-x86_64/bitops.h | 7 +- include/asm-x86_64/cpufeature.h | 2 + include/asm-x86_64/mutex.h | 4 +- include/asm-x86_64/rwlock.h | 8 +- include/asm-x86_64/semaphore.h | 8 +- include/asm-x86_64/spinlock.h | 10 ++- include/asm-x86_64/system.h | 86 +----------------- 17 files changed, 344 insertions(+), 258 deletions(-) create mode 100644 include/asm-x86_64/alternative.h diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c index 5cbd6f99fb2a..50eb0e03777e 100644 --- a/arch/i386/kernel/alternative.c +++ b/arch/i386/kernel/alternative.c @@ -4,27 +4,41 @@ #include #include -#define DEBUG 0 -#if DEBUG -# define DPRINTK(fmt, args...) printk(fmt, args) -#else -# define DPRINTK(fmt, args...) -#endif +static int no_replacement = 0; +static int smp_alt_once = 0; +static int debug_alternative = 0; + +static int __init noreplacement_setup(char *s) +{ + no_replacement = 1; + return 1; +} +static int __init bootonly(char *str) +{ + smp_alt_once = 1; + return 1; +} +static int __init debug_alt(char *str) +{ + debug_alternative = 1; + return 1; +} +__setup("noreplacement", noreplacement_setup); +__setup("smp-alt-boot", bootonly); +__setup("debug-alternative", debug_alt); + +#define DPRINTK(fmt, args...) if (debug_alternative) \ + printk(KERN_DEBUG fmt, args) + +#ifdef GENERIC_NOP1 /* Use inline assembly to define this because the nops are defined as inline assembly strings in the include files and we cannot get them easily into strings. */ asm("\t.data\nintelnops: " GENERIC_NOP1 GENERIC_NOP2 GENERIC_NOP3 GENERIC_NOP4 GENERIC_NOP5 GENERIC_NOP6 GENERIC_NOP7 GENERIC_NOP8); -asm("\t.data\nk8nops: " - K8_NOP1 K8_NOP2 K8_NOP3 K8_NOP4 K8_NOP5 K8_NOP6 - K8_NOP7 K8_NOP8); -asm("\t.data\nk7nops: " - K7_NOP1 K7_NOP2 K7_NOP3 K7_NOP4 K7_NOP5 K7_NOP6 - K7_NOP7 K7_NOP8); - -extern unsigned char intelnops[], k8nops[], k7nops[]; +extern unsigned char intelnops[]; static unsigned char *intel_nops[ASM_NOP_MAX+1] = { NULL, intelnops, @@ -36,6 +50,13 @@ static unsigned char *intel_nops[ASM_NOP_MAX+1] = { intelnops + 1 + 2 + 3 + 4 + 5 + 6, intelnops + 1 + 2 + 3 + 4 + 5 + 6 + 7, }; +#endif + +#ifdef K8_NOP1 +asm("\t.data\nk8nops: " + K8_NOP1 K8_NOP2 K8_NOP3 K8_NOP4 K8_NOP5 K8_NOP6 + K8_NOP7 K8_NOP8); +extern unsigned char k8nops[]; static unsigned char *k8_nops[ASM_NOP_MAX+1] = { NULL, k8nops, @@ -47,6 +68,13 @@ static unsigned char *k8_nops[ASM_NOP_MAX+1] = { k8nops + 1 + 2 + 3 + 4 + 5 + 6, k8nops + 1 + 2 + 3 + 4 + 5 + 6 + 7, }; +#endif + +#ifdef K7_NOP1 +asm("\t.data\nk7nops: " + K7_NOP1 K7_NOP2 K7_NOP3 K7_NOP4 K7_NOP5 K7_NOP6 + K7_NOP7 K7_NOP8); +extern unsigned char k7nops[]; static unsigned char *k7_nops[ASM_NOP_MAX+1] = { NULL, k7nops, @@ -58,6 +86,18 @@ static unsigned char *k7_nops[ASM_NOP_MAX+1] = { k7nops + 1 + 2 + 3 + 4 + 5 + 6, k7nops + 1 + 2 + 3 + 4 + 5 + 6 + 7, }; +#endif + +#ifdef CONFIG_X86_64 + +extern char __vsyscall_0; +static inline unsigned char** find_nop_table(void) +{ + return k8_nops; +} + +#else /* CONFIG_X86_64 */ + static struct nop { int cpuid; unsigned char **noptable; @@ -67,14 +107,6 @@ static struct nop { { -1, NULL } }; - -extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; -extern struct alt_instr __smp_alt_instructions[], __smp_alt_instructions_end[]; -extern u8 *__smp_locks[], *__smp_locks_end[]; - -extern u8 __smp_alt_begin[], __smp_alt_end[]; - - static unsigned char** find_nop_table(void) { unsigned char **noptable = intel_nops; @@ -89,6 +121,14 @@ static unsigned char** find_nop_table(void) return noptable; } +#endif /* CONFIG_X86_64 */ + +extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; +extern struct alt_instr __smp_alt_instructions[], __smp_alt_instructions_end[]; +extern u8 *__smp_locks[], *__smp_locks_end[]; + +extern u8 __smp_alt_begin[], __smp_alt_end[]; + /* Replace instructions with better alternatives for this CPU type. This runs before SMP is initialized to avoid SMP problems with self modifying code. This implies that assymetric systems where @@ -99,6 +139,7 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end) { unsigned char **noptable = find_nop_table(); struct alt_instr *a; + u8 *instr; int diff, i, k; DPRINTK("%s: alt table %p -> %p\n", __FUNCTION__, start, end); @@ -106,7 +147,16 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end) BUG_ON(a->replacementlen > a->instrlen); if (!boot_cpu_has(a->cpuid)) continue; - memcpy(a->instr, a->replacement, a->replacementlen); + instr = a->instr; +#ifdef CONFIG_X86_64 + /* vsyscall code is not mapped yet. resolve it manually. */ + if (instr >= (u8 *)VSYSCALL_START && instr < (u8*)VSYSCALL_END) { + instr = __va(instr - (u8*)VSYSCALL_START + (u8*)__pa_symbol(&__vsyscall_0)); + DPRINTK("%s: vsyscall fixup: %p => %p\n", + __FUNCTION__, a->instr, instr); + } +#endif + memcpy(instr, a->replacement, a->replacementlen); diff = a->instrlen - a->replacementlen; /* Pad the rest with nops */ for (i = a->replacementlen; diff > 0; diff -= k, i += k) { @@ -186,14 +236,6 @@ struct smp_alt_module { static LIST_HEAD(smp_alt_modules); static DEFINE_SPINLOCK(smp_alt); -static int smp_alt_once = 0; -static int __init bootonly(char *str) -{ - smp_alt_once = 1; - return 1; -} -__setup("smp-alt-boot", bootonly); - void alternatives_smp_module_add(struct module *mod, char *name, void *locks, void *locks_end, void *text, void *text_end) @@ -201,6 +243,9 @@ void alternatives_smp_module_add(struct module *mod, char *name, struct smp_alt_module *smp; unsigned long flags; + if (no_replacement) + return; + if (smp_alt_once) { if (boot_cpu_has(X86_FEATURE_UP)) alternatives_smp_unlock(locks, locks_end, @@ -235,7 +280,7 @@ void alternatives_smp_module_del(struct module *mod) struct smp_alt_module *item; unsigned long flags; - if (smp_alt_once) + if (no_replacement || smp_alt_once) return; spin_lock_irqsave(&smp_alt, flags); @@ -256,7 +301,7 @@ void alternatives_smp_switch(int smp) struct smp_alt_module *mod; unsigned long flags; - if (smp_alt_once) + if (no_replacement || smp_alt_once) return; BUG_ON(!smp && (num_online_cpus() > 1)); @@ -285,6 +330,13 @@ void alternatives_smp_switch(int smp) void __init alternative_instructions(void) { + if (no_replacement) { + printk(KERN_INFO "(SMP-)alternatives turned off\n"); + free_init_pages("SMP alternatives", + (unsigned long)__smp_alt_begin, + (unsigned long)__smp_alt_end); + return; + } apply_alternatives(__alt_instructions, __alt_instructions_end); /* switch to patch-once-at-boottime-only mode and free the diff --git a/arch/x86_64/kernel/Makefile b/arch/x86_64/kernel/Makefile index 059c88313f4e..381bc6ad743e 100644 --- a/arch/x86_64/kernel/Makefile +++ b/arch/x86_64/kernel/Makefile @@ -8,7 +8,7 @@ obj-y := process.o signal.o entry.o traps.o irq.o \ ptrace.o time.o ioport.o ldt.o setup.o i8259.o sys_x86_64.o \ x8664_ksyms.o i387.o syscall.o vsyscall.o \ setup64.o bootflag.o e820.o reboot.o quirks.o i8237.o \ - pci-dma.o pci-nommu.o + pci-dma.o pci-nommu.o alternative.o obj-$(CONFIG_X86_MCE) += mce.o obj-$(CONFIG_X86_MCE_INTEL) += mce_intel.o @@ -49,3 +49,5 @@ intel_cacheinfo-y += ../../i386/kernel/cpu/intel_cacheinfo.o quirks-y += ../../i386/kernel/quirks.o i8237-y += ../../i386/kernel/i8237.o msr-$(subst m,y,$(CONFIG_X86_MSR)) += ../../i386/kernel/msr.o +alternative-y += ../../i386/kernel/alternative.o + diff --git a/arch/x86_64/kernel/module.c b/arch/x86_64/kernel/module.c index bac195c74bcc..9d0958ff547f 100644 --- a/arch/x86_64/kernel/module.c +++ b/arch/x86_64/kernel/module.c @@ -145,26 +145,38 @@ int apply_relocate(Elf_Shdr *sechdrs, return -ENOSYS; } -extern void apply_alternatives(void *start, void *end); - int module_finalize(const Elf_Ehdr *hdr, - const Elf_Shdr *sechdrs, - struct module *me) + const Elf_Shdr *sechdrs, + struct module *me) { - const Elf_Shdr *s; + const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL; char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; - /* look for .altinstructions to patch */ - for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { - void *seg; - if (strcmp(".altinstructions", secstrings + s->sh_name)) - continue; - seg = (void *)s->sh_addr; - apply_alternatives(seg, seg + s->sh_size); - } + for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { + if (!strcmp(".text", secstrings + s->sh_name)) + text = s; + if (!strcmp(".altinstructions", secstrings + s->sh_name)) + alt = s; + if (!strcmp(".smp_locks", secstrings + s->sh_name)) + locks= s; + } + + if (alt) { + /* patch .altinstructions */ + void *aseg = (void *)alt->sh_addr; + apply_alternatives(aseg, aseg + alt->sh_size); + } + if (locks && text) { + void *lseg = (void *)locks->sh_addr; + void *tseg = (void *)text->sh_addr; + alternatives_smp_module_add(me, me->name, + lseg, lseg + locks->sh_size, + tseg, tseg + text->sh_size); + } return 0; } void module_arch_cleanup(struct module *mod) { + alternatives_smp_module_del(mod); } diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c index 4b7e02216970..64640c8f5eed 100644 --- a/arch/x86_64/kernel/setup.c +++ b/arch/x86_64/kernel/setup.c @@ -473,80 +473,6 @@ contig_initmem_init(unsigned long start_pfn, unsigned long end_pfn) } #endif -/* Use inline assembly to define this because the nops are defined - as inline assembly strings in the include files and we cannot - get them easily into strings. */ -asm("\t.data\nk8nops: " - K8_NOP1 K8_NOP2 K8_NOP3 K8_NOP4 K8_NOP5 K8_NOP6 - K8_NOP7 K8_NOP8); - -extern unsigned char k8nops[]; -static unsigned char *k8_nops[ASM_NOP_MAX+1] = { - NULL, - k8nops, - k8nops + 1, - k8nops + 1 + 2, - k8nops + 1 + 2 + 3, - k8nops + 1 + 2 + 3 + 4, - k8nops + 1 + 2 + 3 + 4 + 5, - k8nops + 1 + 2 + 3 + 4 + 5 + 6, - k8nops + 1 + 2 + 3 + 4 + 5 + 6 + 7, -}; - -extern char __vsyscall_0; - -/* Replace instructions with better alternatives for this CPU type. - - This runs before SMP is initialized to avoid SMP problems with - self modifying code. This implies that assymetric systems where - APs have less capabilities than the boot processor are not handled. - In this case boot with "noreplacement". */ -void apply_alternatives(void *start, void *end) -{ - struct alt_instr *a; - int diff, i, k; - for (a = start; (void *)a < end; a++) { - u8 *instr; - - if (!boot_cpu_has(a->cpuid)) - continue; - - BUG_ON(a->replacementlen > a->instrlen); - instr = a->instr; - /* vsyscall code is not mapped yet. resolve it manually. */ - if (instr >= (u8 *)VSYSCALL_START && instr < (u8*)VSYSCALL_END) - instr = __va(instr - (u8*)VSYSCALL_START + (u8*)__pa_symbol(&__vsyscall_0)); - __inline_memcpy(instr, a->replacement, a->replacementlen); - diff = a->instrlen - a->replacementlen; - - /* Pad the rest with nops */ - for (i = a->replacementlen; diff > 0; diff -= k, i += k) { - k = diff; - if (k > ASM_NOP_MAX) - k = ASM_NOP_MAX; - __inline_memcpy(instr + i, k8_nops[k], k); - } - } -} - -static int no_replacement __initdata = 0; - -void __init alternative_instructions(void) -{ - extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; - if (no_replacement) - return; - apply_alternatives(__alt_instructions, __alt_instructions_end); -} - -static int __init noreplacement_setup(char *s) -{ - no_replacement = 1; - return 1; -} - -__setup("noreplacement", noreplacement_setup); - #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE) struct edd edd; #ifdef CONFIG_EDD_MODULE @@ -1303,7 +1229,7 @@ static int show_cpuinfo(struct seq_file *m, void *v) /* Other (Linux-defined) */ "cxmmx", NULL, "cyrix_arr", "centaur_mcr", NULL, "constant_tsc", NULL, NULL, - NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, + "up", NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c index 71a7222cf9ce..06535e7687ce 100644 --- a/arch/x86_64/kernel/smpboot.c +++ b/arch/x86_64/kernel/smpboot.c @@ -797,6 +797,8 @@ static int __cpuinit do_boot_cpu(int cpu, int apicid) } + alternatives_smp_switch(1); + c_idle.idle = get_idle_for_cpu(cpu); if (c_idle.idle) { @@ -1259,6 +1261,8 @@ void __cpu_die(unsigned int cpu) /* They ack this in play_dead by setting CPU_DEAD */ if (per_cpu(cpu_state, cpu) == CPU_DEAD) { printk ("CPU %d is now offline\n", cpu); + if (1 == num_online_cpus()) + alternatives_smp_switch(0); return; } msleep(100); diff --git a/arch/x86_64/kernel/vmlinux.lds.S b/arch/x86_64/kernel/vmlinux.lds.S index b81f473c4a19..5968c2415da9 100644 --- a/arch/x86_64/kernel/vmlinux.lds.S +++ b/arch/x86_64/kernel/vmlinux.lds.S @@ -131,6 +131,26 @@ SECTIONS *(.data.page_aligned) } + /* might get freed after init */ + . = ALIGN(4096); + __smp_alt_begin = .; + __smp_alt_instructions = .; + .smp_altinstructions : AT(ADDR(.smp_altinstructions) - LOAD_OFFSET) { + *(.smp_altinstructions) + } + __smp_alt_instructions_end = .; + . = ALIGN(8); + __smp_locks = .; + .smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) { + *(.smp_locks) + } + __smp_locks_end = .; + .smp_altinstr_replacement : AT(ADDR(.smp_altinstr_replacement) - LOAD_OFFSET) { + *(.smp_altinstr_replacement) + } + . = ALIGN(4096); + __smp_alt_end = .; + . = ALIGN(4096); /* Init code and data */ __init_begin = .; .init.text : AT(ADDR(.init.text) - LOAD_OFFSET) { diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c index 4ba34e95d835..a70a8e3e312d 100644 --- a/arch/x86_64/mm/init.c +++ b/arch/x86_64/mm/init.c @@ -644,20 +644,29 @@ void __init mem_init(void) #endif } -void free_initmem(void) +void free_init_pages(char *what, unsigned long begin, unsigned long end) { unsigned long addr; - addr = (unsigned long)(&__init_begin); - for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { + if (begin >= end) + return; + + printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10); + for (addr = begin; addr < end; addr += PAGE_SIZE) { ClearPageReserved(virt_to_page(addr)); init_page_count(virt_to_page(addr)); memset((void *)(addr & ~(PAGE_SIZE-1)), 0xcc, PAGE_SIZE); free_page(addr); totalram_pages++; } +} + +void free_initmem(void) +{ memset(__initdata_begin, 0xba, __initdata_end - __initdata_begin); - printk ("Freeing unused kernel memory: %luk freed\n", (__init_end - __init_begin) >> 10); + free_init_pages("unused kernel memory", + (unsigned long)(&__init_begin), + (unsigned long)(&__init_end)); } #ifdef CONFIG_DEBUG_RODATA @@ -686,15 +695,7 @@ void mark_rodata_ro(void) #ifdef CONFIG_BLK_DEV_INITRD void free_initrd_mem(unsigned long start, unsigned long end) { - if (start >= end) - return; - printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); - for (; start < end; start += PAGE_SIZE) { - ClearPageReserved(virt_to_page(start)); - init_page_count(virt_to_page(start)); - free_page(start); - totalram_pages++; - } + free_init_pages("initrd memory", start, end); } #endif diff --git a/include/asm-i386/alternative.h b/include/asm-i386/alternative.h index d79e9ee10fd7..c61bd1a17f37 100644 --- a/include/asm-i386/alternative.h +++ b/include/asm-i386/alternative.h @@ -5,6 +5,8 @@ #include +#include + struct alt_instr { u8 *instr; /* original instruction */ u8 *replacement; diff --git a/include/asm-x86_64/alternative.h b/include/asm-x86_64/alternative.h new file mode 100644 index 000000000000..387c8f66af7d --- /dev/null +++ b/include/asm-x86_64/alternative.h @@ -0,0 +1,146 @@ +#ifndef _X86_64_ALTERNATIVE_H +#define _X86_64_ALTERNATIVE_H + +#ifdef __KERNEL__ + +#include + +struct alt_instr { + u8 *instr; /* original instruction */ + u8 *replacement; + u8 cpuid; /* cpuid bit set for replacement */ + u8 instrlen; /* length of original instruction */ + u8 replacementlen; /* length of new instruction, <= instrlen */ + u8 pad[5]; +}; + +extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); + +struct module; +extern void alternatives_smp_module_add(struct module *mod, char *name, + void *locks, void *locks_end, + void *text, void *text_end); +extern void alternatives_smp_module_del(struct module *mod); +extern void alternatives_smp_switch(int smp); + +#endif + +/* + * Alternative instructions for different CPU types or capabilities. + * + * This allows to use optimized instructions even on generic binary + * kernels. + * + * length of oldinstr must be longer or equal the length of newinstr + * It can be padded with nops as needed. + * + * For non barrier like inlines please define new variants + * without volatile and memory clobber. + */ +#define alternative(oldinstr, newinstr, feature) \ + asm volatile ("661:\n\t" oldinstr "\n662:\n" \ + ".section .altinstructions,\"a\"\n" \ + " .align 8\n" \ + " .quad 661b\n" /* label */ \ + " .quad 663f\n" /* new instruction */ \ + " .byte %c0\n" /* feature bit */ \ + " .byte 662b-661b\n" /* sourcelen */ \ + " .byte 664f-663f\n" /* replacementlen */ \ + ".previous\n" \ + ".section .altinstr_replacement,\"ax\"\n" \ + "663:\n\t" newinstr "\n664:\n" /* replacement */ \ + ".previous" :: "i" (feature) : "memory") + +/* + * Alternative inline assembly with input. + * + * Pecularities: + * No memory clobber here. + * Argument numbers start with 1. + * Best is to use constraints that are fixed size (like (%1) ... "r") + * If you use variable sized constraints like "m" or "g" in the + * replacement make sure to pad to the worst case length. + */ +#define alternative_input(oldinstr, newinstr, feature, input...) \ + asm volatile ("661:\n\t" oldinstr "\n662:\n" \ + ".section .altinstructions,\"a\"\n" \ + " .align 8\n" \ + " .quad 661b\n" /* label */ \ + " .quad 663f\n" /* new instruction */ \ + " .byte %c0\n" /* feature bit */ \ + " .byte 662b-661b\n" /* sourcelen */ \ + " .byte 664f-663f\n" /* replacementlen */ \ + ".previous\n" \ + ".section .altinstr_replacement,\"ax\"\n" \ + "663:\n\t" newinstr "\n664:\n" /* replacement */ \ + ".previous" :: "i" (feature), ##input) + +/* Like alternative_input, but with a single output argument */ +#define alternative_io(oldinstr, newinstr, feature, output, input...) \ + asm volatile ("661:\n\t" oldinstr "\n662:\n" \ + ".section .altinstructions,\"a\"\n" \ + " .align 8\n" \ + " .quad 661b\n" /* label */ \ + " .quad 663f\n" /* new instruction */ \ + " .byte %c[feat]\n" /* feature bit */ \ + " .byte 662b-661b\n" /* sourcelen */ \ + " .byte 664f-663f\n" /* replacementlen */ \ + ".previous\n" \ + ".section .altinstr_replacement,\"ax\"\n" \ + "663:\n\t" newinstr "\n664:\n" /* replacement */ \ + ".previous" : output : [feat] "i" (feature), ##input) + +/* + * Alternative inline assembly for SMP. + * + * alternative_smp() takes two versions (SMP first, UP second) and is + * for more complex stuff such as spinlocks. + * + * The LOCK_PREFIX macro defined here replaces the LOCK and + * LOCK_PREFIX macros used everywhere in the source tree. + * + * SMP alternatives use the same data structures as the other + * alternatives and the X86_FEATURE_UP flag to indicate the case of a + * UP system running a SMP kernel. The existing apply_alternatives() + * works fine for patching a SMP kernel for UP. + * + * The SMP alternative tables can be kept after boot and contain both + * UP and SMP versions of the instructions to allow switching back to + * SMP at runtime, when hotplugging in a new CPU, which is especially + * useful in virtualized environments. + * + * The very common lock prefix is handled as special case in a + * separate table which is a pure address list without replacement ptr + * and size information. That keeps the table sizes small. + */ + +#ifdef CONFIG_SMP +#define alternative_smp(smpinstr, upinstr, args...) \ + asm volatile ("661:\n\t" smpinstr "\n662:\n" \ + ".section .smp_altinstructions,\"a\"\n" \ + " .align 8\n" \ + " .quad 661b\n" /* label */ \ + " .quad 663f\n" /* new instruction */ \ + " .byte 0x66\n" /* X86_FEATURE_UP */ \ + " .byte 662b-661b\n" /* sourcelen */ \ + " .byte 664f-663f\n" /* replacementlen */ \ + ".previous\n" \ + ".section .smp_altinstr_replacement,\"awx\"\n" \ + "663:\n\t" upinstr "\n" /* replacement */ \ + "664:\n\t.fill 662b-661b,1,0x42\n" /* space for original */ \ + ".previous" : args) + +#define LOCK_PREFIX \ + ".section .smp_locks,\"a\"\n" \ + " .align 8\n" \ + " .quad 661f\n" /* address */ \ + ".previous\n" \ + "661:\n\tlock; " + +#else /* ! CONFIG_SMP */ +#define alternative_smp(smpinstr, upinstr, args...) \ + asm volatile (upinstr : args) +#define LOCK_PREFIX "" +#endif + +#endif /* _X86_64_ALTERNATIVE_H */ diff --git a/include/asm-x86_64/atomic.h b/include/asm-x86_64/atomic.h index bd3fa67ed835..007e88d6d43f 100644 --- a/include/asm-x86_64/atomic.h +++ b/include/asm-x86_64/atomic.h @@ -1,7 +1,7 @@ #ifndef __ARCH_X86_64_ATOMIC__ #define __ARCH_X86_64_ATOMIC__ -#include +#include /* atomic_t should be 32 bit signed type */ @@ -52,7 +52,7 @@ typedef struct { volatile int counter; } atomic_t; static __inline__ void atomic_add(int i, atomic_t *v) { __asm__ __volatile__( - LOCK "addl %1,%0" + LOCK_PREFIX "addl %1,%0" :"=m" (v->counter) :"ir" (i), "m" (v->counter)); } @@ -67,7 +67,7 @@ static __inline__ void atomic_add(int i, atomic_t *v) static __inline__ void atomic_sub(int i, atomic_t *v) { __asm__ __volatile__( - LOCK "subl %1,%0" + LOCK_PREFIX "subl %1,%0" :"=m" (v->counter) :"ir" (i), "m" (v->counter)); } @@ -86,7 +86,7 @@ static __inline__ int atomic_sub_and_test(int i, atomic_t *v) unsigned char c; __asm__ __volatile__( - LOCK "subl %2,%0; sete %1" + LOCK_PREFIX "subl %2,%0; sete %1" :"=m" (v->counter), "=qm" (c) :"ir" (i), "m" (v->counter) : "memory"); return c; @@ -101,7 +101,7 @@ static __inline__ int atomic_sub_and_test(int i, atomic_t *v) static __inline__ void atomic_inc(atomic_t *v) { __asm__ __volatile__( - LOCK "incl %0" + LOCK_PREFIX "incl %0" :"=m" (v->counter) :"m" (v->counter)); } @@ -115,7 +115,7 @@ static __inline__ void atomic_inc(atomic_t *v) static __inline__ void atomic_dec(atomic_t *v) { __asm__ __volatile__( - LOCK "decl %0" + LOCK_PREFIX "decl %0" :"=m" (v->counter) :"m" (v->counter)); } @@ -133,7 +133,7 @@ static __inline__ int atomic_dec_and_test(atomic_t *v) unsigned char c; __asm__ __volatile__( - LOCK "decl %0; sete %1" + LOCK_PREFIX "decl %0; sete %1" :"=m" (v->counter), "=qm" (c) :"m" (v->counter) : "memory"); return c != 0; @@ -152,7 +152,7 @@ static __inline__ int atomic_inc_and_test(atomic_t *v) unsigned char c; __asm__ __volatile__( - LOCK "incl %0; sete %1" + LOCK_PREFIX "incl %0; sete %1" :"=m" (v->counter), "=qm" (c) :"m" (v->counter) : "memory"); return c != 0; @@ -172,7 +172,7 @@ static __inline__ int atomic_add_negative(int i, atomic_t *v) unsigned char c; __asm__ __volatile__( - LOCK "addl %2,%0; sets %1" + LOCK_PREFIX "addl %2,%0; sets %1" :"=m" (v->counter), "=qm" (c) :"ir" (i), "m" (v->counter) : "memory"); return c; @@ -189,7 +189,7 @@ static __inline__ int atomic_add_return(int i, atomic_t *v) { int __i = i; __asm__ __volatile__( - LOCK "xaddl %0, %1;" + LOCK_PREFIX "xaddl %0, %1;" :"=r"(i) :"m"(v->counter), "0"(i)); return i + __i; @@ -237,7 +237,7 @@ typedef struct { volatile long counter; } atomic64_t; static __inline__ void atomic64_add(long i, atomic64_t *v) { __asm__ __volatile__( - LOCK "addq %1,%0" + LOCK_PREFIX "addq %1,%0" :"=m" (v->counter) :"ir" (i), "m" (v->counter)); } @@ -252,7 +252,7 @@ static __inline__ void atomic64_add(long i, atomic64_t *v) static __inline__ void atomic64_sub(long i, atomic64_t *v) { __asm__ __volatile__( - LOCK "subq %1,%0" + LOCK_PREFIX "subq %1,%0" :"=m" (v->counter) :"ir" (i), "m" (v->counter)); } @@ -271,7 +271,7 @@ static __inline__ int atomic64_sub_and_test(long i, atomic64_t *v) unsigned char c; __asm__ __volatile__( - LOCK "subq %2,%0; sete %1" + LOCK_PREFIX "subq %2,%0; sete %1" :"=m" (v->counter), "=qm" (c) :"ir" (i), "m" (v->counter) : "memory"); return c; @@ -286,7 +286,7 @@ static __inline__ int atomic64_sub_and_test(long i, atomic64_t *v) static __inline__ void atomic64_inc(atomic64_t *v) { __asm__ __volatile__( - LOCK "incq %0" + LOCK_PREFIX "incq %0" :"=m" (v->counter) :"m" (v->counter)); } @@ -300,7 +300,7 @@ static __inline__ void atomic64_inc(atomic64_t *v) static __inline__ void atomic64_dec(atomic64_t *v) { __asm__ __volatile__( - LOCK "decq %0" + LOCK_PREFIX "decq %0" :"=m" (v->counter) :"m" (v->counter)); } @@ -318,7 +318,7 @@ static __inline__ int atomic64_dec_and_test(atomic64_t *v) unsigned char c; __asm__ __volatile__( - LOCK "decq %0; sete %1" + LOCK_PREFIX "decq %0; sete %1" :"=m" (v->counter), "=qm" (c) :"m" (v->counter) : "memory"); return c != 0; @@ -337,7 +337,7 @@ static __inline__ int atomic64_inc_and_test(atomic64_t *v) unsigned char c; __asm__ __volatile__( - LOCK "incq %0; sete %1" + LOCK_PREFIX "incq %0; sete %1" :"=m" (v->counter), "=qm" (c) :"m" (v->counter) : "memory"); return c != 0; @@ -357,7 +357,7 @@ static __inline__ int atomic64_add_negative(long i, atomic64_t *v) unsigned char c; __asm__ __volatile__( - LOCK "addq %2,%0; sets %1" + LOCK_PREFIX "addq %2,%0; sets %1" :"=m" (v->counter), "=qm" (c) :"ir" (i), "m" (v->counter) : "memory"); return c; @@ -374,7 +374,7 @@ static __inline__ long atomic64_add_return(long i, atomic64_t *v) { long __i = i; __asm__ __volatile__( - LOCK "xaddq %0, %1;" + LOCK_PREFIX "xaddq %0, %1;" :"=r"(i) :"m"(v->counter), "0"(i)); return i + __i; @@ -418,11 +418,11 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t *v) /* These are x86-specific, used by some header files */ #define atomic_clear_mask(mask, addr) \ -__asm__ __volatile__(LOCK "andl %0,%1" \ +__asm__ __volatile__(LOCK_PREFIX "andl %0,%1" \ : : "r" (~(mask)),"m" (*addr) : "memory") #define atomic_set_mask(mask, addr) \ -__asm__ __volatile__(LOCK "orl %0,%1" \ +__asm__ __volatile__(LOCK_PREFIX "orl %0,%1" \ : : "r" ((unsigned)mask),"m" (*(addr)) : "memory") /* Atomic operations are already serializing on x86 */ diff --git a/include/asm-x86_64/bitops.h b/include/asm-x86_64/bitops.h index e9bf933d25d0..f7ba57b1cc08 100644 --- a/include/asm-x86_64/bitops.h +++ b/include/asm-x86_64/bitops.h @@ -5,12 +5,7 @@ * Copyright 1992, Linus Torvalds. */ - -#ifdef CONFIG_SMP -#define LOCK_PREFIX "lock ; " -#else -#define LOCK_PREFIX "" -#endif +#include #define ADDR (*(volatile long *) addr) diff --git a/include/asm-x86_64/cpufeature.h b/include/asm-x86_64/cpufeature.h index 662964b74e34..afc44e557400 100644 --- a/include/asm-x86_64/cpufeature.h +++ b/include/asm-x86_64/cpufeature.h @@ -65,6 +65,8 @@ #define X86_FEATURE_CONSTANT_TSC (3*32+5) /* TSC runs at constant rate */ #define X86_FEATURE_SYNC_RDTSC (3*32+6) /* RDTSC syncs CPU core */ #define X86_FEATURE_FXSAVE_LEAK (3*32+7) /* FIP/FOP/FDP leaks through FXSAVE */ +#define X86_FEATURE_UP (3*32+8) /* SMP kernel running on UP */ + /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */ #define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */ diff --git a/include/asm-x86_64/mutex.h b/include/asm-x86_64/mutex.h index 11fbee2bd6c0..06fab6de2a88 100644 --- a/include/asm-x86_64/mutex.h +++ b/include/asm-x86_64/mutex.h @@ -24,7 +24,7 @@ do { \ typecheck_fn(fastcall void (*)(atomic_t *), fail_fn); \ \ __asm__ __volatile__( \ - LOCK " decl (%%rdi) \n" \ + LOCK_PREFIX " decl (%%rdi) \n" \ " js 2f \n" \ "1: \n" \ \ @@ -74,7 +74,7 @@ do { \ typecheck_fn(fastcall void (*)(atomic_t *), fail_fn); \ \ __asm__ __volatile__( \ - LOCK " incl (%%rdi) \n" \ + LOCK_PREFIX " incl (%%rdi) \n" \ " jle 2f \n" \ "1: \n" \ \ diff --git a/include/asm-x86_64/rwlock.h b/include/asm-x86_64/rwlock.h index 9942cc393064..dea0e9459264 100644 --- a/include/asm-x86_64/rwlock.h +++ b/include/asm-x86_64/rwlock.h @@ -24,7 +24,7 @@ #define RW_LOCK_BIAS_STR "0x01000000" #define __build_read_lock_ptr(rw, helper) \ - asm volatile(LOCK "subl $1,(%0)\n\t" \ + asm volatile(LOCK_PREFIX "subl $1,(%0)\n\t" \ "js 2f\n" \ "1:\n" \ LOCK_SECTION_START("") \ @@ -34,7 +34,7 @@ ::"a" (rw) : "memory") #define __build_read_lock_const(rw, helper) \ - asm volatile(LOCK "subl $1,%0\n\t" \ + asm volatile(LOCK_PREFIX "subl $1,%0\n\t" \ "js 2f\n" \ "1:\n" \ LOCK_SECTION_START("") \ @@ -54,7 +54,7 @@ } while (0) #define __build_write_lock_ptr(rw, helper) \ - asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \ + asm volatile(LOCK_PREFIX "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \ "jnz 2f\n" \ "1:\n" \ LOCK_SECTION_START("") \ @@ -64,7 +64,7 @@ ::"a" (rw) : "memory") #define __build_write_lock_const(rw, helper) \ - asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",%0\n\t" \ + asm volatile(LOCK_PREFIX "subl $" RW_LOCK_BIAS_STR ",%0\n\t" \ "jnz 2f\n" \ "1:\n" \ LOCK_SECTION_START("") \ diff --git a/include/asm-x86_64/semaphore.h b/include/asm-x86_64/semaphore.h index a389aa6fe80f..064df08b9a0f 100644 --- a/include/asm-x86_64/semaphore.h +++ b/include/asm-x86_64/semaphore.h @@ -106,7 +106,7 @@ static inline void down(struct semaphore * sem) __asm__ __volatile__( "# atomic down operation\n\t" - LOCK "decl %0\n\t" /* --sem->count */ + LOCK_PREFIX "decl %0\n\t" /* --sem->count */ "js 2f\n" "1:\n" LOCK_SECTION_START("") @@ -130,7 +130,7 @@ static inline int down_interruptible(struct semaphore * sem) __asm__ __volatile__( "# atomic interruptible down operation\n\t" - LOCK "decl %1\n\t" /* --sem->count */ + LOCK_PREFIX "decl %1\n\t" /* --sem->count */ "js 2f\n\t" "xorl %0,%0\n" "1:\n" @@ -154,7 +154,7 @@ static inline int down_trylock(struct semaphore * sem) __asm__ __volatile__( "# atomic interruptible down operation\n\t" - LOCK "decl %1\n\t" /* --sem->count */ + LOCK_PREFIX "decl %1\n\t" /* --sem->count */ "js 2f\n\t" "xorl %0,%0\n" "1:\n" @@ -178,7 +178,7 @@ static inline void up(struct semaphore * sem) { __asm__ __volatile__( "# atomic up operation\n\t" - LOCK "incl %0\n\t" /* ++sem->count */ + LOCK_PREFIX "incl %0\n\t" /* ++sem->count */ "jle 2f\n" "1:\n" LOCK_SECTION_START("") diff --git a/include/asm-x86_64/spinlock.h b/include/asm-x86_64/spinlock.h index 5d8a5e3589ff..8d3421996f94 100644 --- a/include/asm-x86_64/spinlock.h +++ b/include/asm-x86_64/spinlock.h @@ -31,15 +31,19 @@ "jmp 1b\n" \ LOCK_SECTION_END +#define __raw_spin_lock_string_up \ + "\n\tdecl %0" + #define __raw_spin_unlock_string \ "movl $1,%0" \ :"=m" (lock->slock) : : "memory" static inline void __raw_spin_lock(raw_spinlock_t *lock) { - __asm__ __volatile__( - __raw_spin_lock_string - :"=m" (lock->slock) : : "memory"); + alternative_smp( + __raw_spin_lock_string, + __raw_spin_lock_string_up, + "=m" (lock->slock) : : "memory"); } #define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock) diff --git a/include/asm-x86_64/system.h b/include/asm-x86_64/system.h index f48e0dad8b3d..68e559f3631c 100644 --- a/include/asm-x86_64/system.h +++ b/include/asm-x86_64/system.h @@ -3,15 +3,10 @@ #include #include +#include #ifdef __KERNEL__ -#ifdef CONFIG_SMP -#define LOCK_PREFIX "lock ; " -#else -#define LOCK_PREFIX "" -#endif - #define __STR(x) #x #define STR(x) __STR(x) @@ -34,7 +29,7 @@ "thread_return:\n\t" \ "movq %%gs:%P[pda_pcurrent],%%rsi\n\t" \ "movq %P[thread_info](%%rsi),%%r8\n\t" \ - LOCK "btr %[tif_fork],%P[ti_flags](%%r8)\n\t" \ + LOCK_PREFIX "btr %[tif_fork],%P[ti_flags](%%r8)\n\t" \ "movq %%rax,%%rdi\n\t" \ "jc ret_from_fork\n\t" \ RESTORE_CONTEXT \ @@ -69,82 +64,6 @@ extern void load_gs_index(unsigned); ".previous" \ : :"r" (value), "r" (0)) -#ifdef __KERNEL__ -struct alt_instr { - __u8 *instr; /* original instruction */ - __u8 *replacement; - __u8 cpuid; /* cpuid bit set for replacement */ - __u8 instrlen; /* length of original instruction */ - __u8 replacementlen; /* length of new instruction, <= instrlen */ - __u8 pad[5]; -}; -#endif - -/* - * Alternative instructions for different CPU types or capabilities. - * - * This allows to use optimized instructions even on generic binary - * kernels. - * - * length of oldinstr must be longer or equal the length of newinstr - * It can be padded with nops as needed. - * - * For non barrier like inlines please define new variants - * without volatile and memory clobber. - */ -#define alternative(oldinstr, newinstr, feature) \ - asm volatile ("661:\n\t" oldinstr "\n662:\n" \ - ".section .altinstructions,\"a\"\n" \ - " .align 8\n" \ - " .quad 661b\n" /* label */ \ - " .quad 663f\n" /* new instruction */ \ - " .byte %c0\n" /* feature bit */ \ - " .byte 662b-661b\n" /* sourcelen */ \ - " .byte 664f-663f\n" /* replacementlen */ \ - ".previous\n" \ - ".section .altinstr_replacement,\"ax\"\n" \ - "663:\n\t" newinstr "\n664:\n" /* replacement */ \ - ".previous" :: "i" (feature) : "memory") - -/* - * Alternative inline assembly with input. - * - * Peculiarities: - * No memory clobber here. - * Argument numbers start with 1. - * Best is to use constraints that are fixed size (like (%1) ... "r") - * If you use variable sized constraints like "m" or "g" in the - * replacement make sure to pad to the worst case length. - */ -#define alternative_input(oldinstr, newinstr, feature, input...) \ - asm volatile ("661:\n\t" oldinstr "\n662:\n" \ - ".section .altinstructions,\"a\"\n" \ - " .align 8\n" \ - " .quad 661b\n" /* label */ \ - " .quad 663f\n" /* new instruction */ \ - " .byte %c0\n" /* feature bit */ \ - " .byte 662b-661b\n" /* sourcelen */ \ - " .byte 664f-663f\n" /* replacementlen */ \ - ".previous\n" \ - ".section .altinstr_replacement,\"ax\"\n" \ - "663:\n\t" newinstr "\n664:\n" /* replacement */ \ - ".previous" :: "i" (feature), ##input) - -/* Like alternative_input, but with a single output argument */ -#define alternative_io(oldinstr, newinstr, feature, output, input...) \ - asm volatile ("661:\n\t" oldinstr "\n662:\n" \ - ".section .altinstructions,\"a\"\n" \ - " .align 8\n" \ - " .quad 661b\n" /* label */ \ - " .quad 663f\n" /* new instruction */ \ - " .byte %c[feat]\n" /* feature bit */ \ - " .byte 662b-661b\n" /* sourcelen */ \ - " .byte 664f-663f\n" /* replacementlen */ \ - ".previous\n" \ - ".section .altinstr_replacement,\"ax\"\n" \ - "663:\n\t" newinstr "\n664:\n" /* replacement */ \ - ".previous" : output : [feat] "i" (feature), ##input) - /* * Clear and set 'TS' bit respectively */ @@ -366,5 +285,6 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, void cpu_idle_wait(void); extern unsigned long arch_align_stack(unsigned long sp); +extern void free_init_pages(char *what, unsigned long begin, unsigned long end); #endif -- 2.20.1