From d167a51877e94dda73dd656c51f363502309f713 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Mon, 26 Jun 2006 13:56:16 +0200 Subject: [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/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 +++++++++++ 5 files changed, 53 insertions(+), 89 deletions(-) (limited to 'arch/x86_64/kernel') diff --git a/arch/x86_64/kernel/Makefile b/arch/x86_64/kernel/Makefile index 059c88313f4..381bc6ad743 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 bac195c74bc..9d0958ff547 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 4b7e0221697..64640c8f5ee 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 71a7222cf9c..06535e7687c 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 b81f473c4a1..5968c2415da 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) { -- cgit v1.2.3-70-g09d2