diff options
Diffstat (limited to 'arch/i386')
| -rw-r--r-- | arch/i386/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/i386/kernel/alternative.c | 321 | ||||
| -rw-r--r-- | arch/i386/kernel/cpu/proc.c | 2 | ||||
| -rw-r--r-- | arch/i386/kernel/module.c | 32 | ||||
| -rw-r--r-- | arch/i386/kernel/semaphore.c | 8 | ||||
| -rw-r--r-- | arch/i386/kernel/setup.c | 95 | ||||
| -rw-r--r-- | arch/i386/kernel/smpboot.c | 3 | ||||
| -rw-r--r-- | arch/i386/kernel/vmlinux.lds.S | 20 | ||||
| -rw-r--r-- | arch/i386/mm/init.c | 45 |
9 files changed, 394 insertions, 134 deletions
diff --git a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile index 65656c033d7..5b9ed21216c 100644 --- a/arch/i386/kernel/Makefile +++ b/arch/i386/kernel/Makefile @@ -7,7 +7,7 @@ extra-y := head.o init_task.o vmlinux.lds obj-y := process.o semaphore.o signal.o entry.o traps.o irq.o \ ptrace.o time.o ioport.o ldt.o setup.o i8259.o sys_i386.o \ pci-dma.o i386_ksyms.o i387.o dmi_scan.o bootflag.o \ - quirks.o i8237.o topology.o + quirks.o i8237.o topology.o alternative.o obj-y += cpu/ obj-y += timers/ diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c new file mode 100644 index 00000000000..5cbd6f99fb2 --- /dev/null +++ b/arch/i386/kernel/alternative.c @@ -0,0 +1,321 @@ +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/list.h> +#include <asm/alternative.h> +#include <asm/sections.h> + +#define DEBUG 0 +#if DEBUG +# define DPRINTK(fmt, args...) printk(fmt, args) +#else +# define DPRINTK(fmt, args...) +#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\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[]; +static unsigned char *intel_nops[ASM_NOP_MAX+1] = { + NULL, + intelnops, + intelnops + 1, + intelnops + 1 + 2, + intelnops + 1 + 2 + 3, + intelnops + 1 + 2 + 3 + 4, + intelnops + 1 + 2 + 3 + 4 + 5, + intelnops + 1 + 2 + 3 + 4 + 5 + 6, + intelnops + 1 + 2 + 3 + 4 + 5 + 6 + 7, +}; +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, +}; +static unsigned char *k7_nops[ASM_NOP_MAX+1] = { + NULL, + k7nops, + k7nops + 1, + k7nops + 1 + 2, + k7nops + 1 + 2 + 3, + k7nops + 1 + 2 + 3 + 4, + k7nops + 1 + 2 + 3 + 4 + 5, + k7nops + 1 + 2 + 3 + 4 + 5 + 6, + k7nops + 1 + 2 + 3 + 4 + 5 + 6 + 7, +}; +static struct nop { + int cpuid; + unsigned char **noptable; +} noptypes[] = { + { X86_FEATURE_K8, k8_nops }, + { X86_FEATURE_K7, k7_nops }, + { -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; + int i; + + for (i = 0; noptypes[i].cpuid >= 0; i++) { + if (boot_cpu_has(noptypes[i].cpuid)) { + noptable = noptypes[i].noptable; + break; + } + } + return noptable; +} + +/* 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. + Tough. Make sure you disable such features by hand. */ + +void apply_alternatives(struct alt_instr *start, struct alt_instr *end) +{ + unsigned char **noptable = find_nop_table(); + struct alt_instr *a; + int diff, i, k; + + DPRINTK("%s: alt table %p -> %p\n", __FUNCTION__, start, end); + for (a = start; a < end; a++) { + BUG_ON(a->replacementlen > a->instrlen); + if (!boot_cpu_has(a->cpuid)) + continue; + memcpy(a->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; + memcpy(a->instr + i, noptable[k], k); + } + } +} + +static void alternatives_smp_save(struct alt_instr *start, struct alt_instr *end) +{ + struct alt_instr *a; + + DPRINTK("%s: alt table %p-%p\n", __FUNCTION__, start, end); + for (a = start; a < end; a++) { + memcpy(a->replacement + a->replacementlen, + a->instr, + a->instrlen); + } +} + +static void alternatives_smp_apply(struct alt_instr *start, struct alt_instr *end) +{ + struct alt_instr *a; + + for (a = start; a < end; a++) { + memcpy(a->instr, + a->replacement + a->replacementlen, + a->instrlen); + } +} + +static void alternatives_smp_lock(u8 **start, u8 **end, u8 *text, u8 *text_end) +{ + u8 **ptr; + + for (ptr = start; ptr < end; ptr++) { + if (*ptr < text) + continue; + if (*ptr > text_end) + continue; + **ptr = 0xf0; /* lock prefix */ + }; +} + +static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end) +{ + unsigned char **noptable = find_nop_table(); + u8 **ptr; + + for (ptr = start; ptr < end; ptr++) { + if (*ptr < text) + continue; + if (*ptr > text_end) + continue; + **ptr = noptable[1][0]; + }; +} + +struct smp_alt_module { + /* what is this ??? */ + struct module *mod; + char *name; + + /* ptrs to lock prefixes */ + u8 **locks; + u8 **locks_end; + + /* .text segment, needed to avoid patching init code ;) */ + u8 *text; + u8 *text_end; + + struct list_head next; +}; +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) +{ + struct smp_alt_module *smp; + unsigned long flags; + + if (smp_alt_once) { + if (boot_cpu_has(X86_FEATURE_UP)) + alternatives_smp_unlock(locks, locks_end, + text, text_end); + return; + } + + smp = kzalloc(sizeof(*smp), GFP_KERNEL); + if (NULL == smp) + return; /* we'll run the (safe but slow) SMP code then ... */ + + smp->mod = mod; + smp->name = name; + smp->locks = locks; + smp->locks_end = locks_end; + smp->text = text; + smp->text_end = text_end; + DPRINTK("%s: locks %p -> %p, text %p -> %p, name %s\n", + __FUNCTION__, smp->locks, smp->locks_end, + smp->text, smp->text_end, smp->name); + + spin_lock_irqsave(&smp_alt, flags); + list_add_tail(&smp->next, &smp_alt_modules); + if (boot_cpu_has(X86_FEATURE_UP)) + alternatives_smp_unlock(smp->locks, smp->locks_end, + smp->text, smp->text_end); + spin_unlock_irqrestore(&smp_alt, flags); +} + +void alternatives_smp_module_del(struct module *mod) +{ + struct smp_alt_module *item; + unsigned long flags; + + if (smp_alt_once) + return; + + spin_lock_irqsave(&smp_alt, flags); + list_for_each_entry(item, &smp_alt_modules, next) { + if (mod != item->mod) + continue; + list_del(&item->next); + spin_unlock_irqrestore(&smp_alt, flags); + DPRINTK("%s: %s\n", __FUNCTION__, item->name); + kfree(item); + return; + } + spin_unlock_irqrestore(&smp_alt, flags); +} + +void alternatives_smp_switch(int smp) +{ + struct smp_alt_module *mod; + unsigned long flags; + + if (smp_alt_once) + return; + BUG_ON(!smp && (num_online_cpus() > 1)); + + spin_lock_irqsave(&smp_alt, flags); + if (smp) { + printk(KERN_INFO "SMP alternatives: switching to SMP code\n"); + clear_bit(X86_FEATURE_UP, boot_cpu_data.x86_capability); + clear_bit(X86_FEATURE_UP, cpu_data[0].x86_capability); + alternatives_smp_apply(__smp_alt_instructions, + __smp_alt_instructions_end); + list_for_each_entry(mod, &smp_alt_modules, next) + alternatives_smp_lock(mod->locks, mod->locks_end, + mod->text, mod->text_end); + } else { + printk(KERN_INFO "SMP alternatives: switching to UP code\n"); + set_bit(X86_FEATURE_UP, boot_cpu_data.x86_capability); + set_bit(X86_FEATURE_UP, cpu_data[0].x86_capability); + apply_alternatives(__smp_alt_instructions, + __smp_alt_instructions_end); + list_for_each_entry(mod, &smp_alt_modules, next) + alternatives_smp_unlock(mod->locks, mod->locks_end, + mod->text, mod->text_end); + } + spin_unlock_irqrestore(&smp_alt, flags); +} + +void __init alternative_instructions(void) +{ + apply_alternatives(__alt_instructions, __alt_instructions_end); + + /* switch to patch-once-at-boottime-only mode and free the + * tables in case we know the number of CPUs will never ever + * change */ +#ifdef CONFIG_HOTPLUG_CPU + if (num_possible_cpus() < 2) + smp_alt_once = 1; +#else + smp_alt_once = 1; +#endif + + if (smp_alt_once) { + if (1 == num_possible_cpus()) { + printk(KERN_INFO "SMP alternatives: switching to UP code\n"); + set_bit(X86_FEATURE_UP, boot_cpu_data.x86_capability); + set_bit(X86_FEATURE_UP, cpu_data[0].x86_capability); + apply_alternatives(__smp_alt_instructions, + __smp_alt_instructions_end); + alternatives_smp_unlock(__smp_locks, __smp_locks_end, + _text, _etext); + } + free_init_pages("SMP alternatives", + (unsigned long)__smp_alt_begin, + (unsigned long)__smp_alt_end); + } else { + alternatives_smp_save(__smp_alt_instructions, + __smp_alt_instructions_end); + alternatives_smp_module_add(NULL, "core kernel", + __smp_locks, __smp_locks_end, + _text, _etext); + alternatives_smp_switch(0); + } +} diff --git a/arch/i386/kernel/cpu/proc.c b/arch/i386/kernel/cpu/proc.c index 89a85af33d2..5cfbd801169 100644 --- a/arch/i386/kernel/cpu/proc.c +++ b/arch/i386/kernel/cpu/proc.c @@ -40,7 +40,7 @@ static int show_cpuinfo(struct seq_file *m, void *v) /* Other (Linux-defined) */ "cxmmx", "k6_mtrr", "cyrix_arr", "centaur_mcr", NULL, NULL, NULL, NULL, - "constant_tsc", NULL, NULL, NULL, NULL, NULL, NULL, NULL, + "constant_tsc", "up", 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/i386/kernel/module.c b/arch/i386/kernel/module.c index 5149c8a621f..470cf97e7cd 100644 --- a/arch/i386/kernel/module.c +++ b/arch/i386/kernel/module.c @@ -104,26 +104,38 @@ int apply_relocate_add(Elf32_Shdr *sechdrs, return -ENOEXEC; } -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 *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); - } + 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/i386/kernel/semaphore.c b/arch/i386/kernel/semaphore.c index 7455ab64394..967dc74df9e 100644 --- a/arch/i386/kernel/semaphore.c +++ b/arch/i386/kernel/semaphore.c @@ -110,11 +110,11 @@ asm( ".align 4\n" ".globl __write_lock_failed\n" "__write_lock_failed:\n\t" - LOCK "addl $" RW_LOCK_BIAS_STR ",(%eax)\n" + LOCK_PREFIX "addl $" RW_LOCK_BIAS_STR ",(%eax)\n" "1: rep; nop\n\t" "cmpl $" RW_LOCK_BIAS_STR ",(%eax)\n\t" "jne 1b\n\t" - LOCK "subl $" RW_LOCK_BIAS_STR ",(%eax)\n\t" + LOCK_PREFIX "subl $" RW_LOCK_BIAS_STR ",(%eax)\n\t" "jnz __write_lock_failed\n\t" "ret" ); @@ -124,11 +124,11 @@ asm( ".align 4\n" ".globl __read_lock_failed\n" "__read_lock_failed:\n\t" - LOCK "incl (%eax)\n" + LOCK_PREFIX "incl (%eax)\n" "1: rep; nop\n\t" "cmpl $1,(%eax)\n\t" "js 1b\n\t" - LOCK "decl (%eax)\n\t" + LOCK_PREFIX "decl (%eax)\n\t" "js __read_lock_failed\n\t" "ret" ); diff --git a/arch/i386/kernel/setup.c b/arch/i386/kernel/setup.c index ab62a9f4701..5f58f8cb983 100644 --- a/arch/i386/kernel/setup.c +++ b/arch/i386/kernel/setup.c @@ -1377,101 +1377,6 @@ static void __init register_memory(void) pci_mem_start, gapstart, gapsize); } -/* 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[]; -static unsigned char *intel_nops[ASM_NOP_MAX+1] = { - NULL, - intelnops, - intelnops + 1, - intelnops + 1 + 2, - intelnops + 1 + 2 + 3, - intelnops + 1 + 2 + 3 + 4, - intelnops + 1 + 2 + 3 + 4 + 5, - intelnops + 1 + 2 + 3 + 4 + 5 + 6, - intelnops + 1 + 2 + 3 + 4 + 5 + 6 + 7, -}; -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, -}; -static unsigned char *k7_nops[ASM_NOP_MAX+1] = { - NULL, - k7nops, - k7nops + 1, - k7nops + 1 + 2, - k7nops + 1 + 2 + 3, - k7nops + 1 + 2 + 3 + 4, - k7nops + 1 + 2 + 3 + 4 + 5, - k7nops + 1 + 2 + 3 + 4 + 5 + 6, - k7nops + 1 + 2 + 3 + 4 + 5 + 6 + 7, -}; -static struct nop { - int cpuid; - unsigned char **noptable; -} noptypes[] = { - { X86_FEATURE_K8, k8_nops }, - { X86_FEATURE_K7, k7_nops }, - { -1, NULL } -}; - -/* 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. - Tough. Make sure you disable such features by hand. */ -void apply_alternatives(void *start, void *end) -{ - struct alt_instr *a; - int diff, i, k; - unsigned char **noptable = intel_nops; - for (i = 0; noptypes[i].cpuid >= 0; i++) { - if (boot_cpu_has(noptypes[i].cpuid)) { - noptable = noptypes[i].noptable; - break; - } - } - for (a = start; (void *)a < end; a++) { - if (!boot_cpu_has(a->cpuid)) - continue; - BUG_ON(a->replacementlen > a->instrlen); - memcpy(a->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; - memcpy(a->instr + i, noptable[k], k); - } - } -} - -void __init alternative_instructions(void) -{ - extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; - apply_alternatives(__alt_instructions, __alt_instructions_end); -} - static char * __init machine_specific_memory_setup(void); #ifdef CONFIG_MCA diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c index 7007e178379..4c470e99a74 100644 --- a/arch/i386/kernel/smpboot.c +++ b/arch/i386/kernel/smpboot.c @@ -899,6 +899,7 @@ static int __devinit do_boot_cpu(int apicid, int cpu) unsigned short nmi_high = 0, nmi_low = 0; ++cpucount; + alternatives_smp_switch(1); /* * We can't use kernel_thread since we must avoid to @@ -1368,6 +1369,8 @@ 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/i386/kernel/vmlinux.lds.S b/arch/i386/kernel/vmlinux.lds.S index 4710195b6b7..3f21c6f6466 100644 --- a/arch/i386/kernel/vmlinux.lds.S +++ b/arch/i386/kernel/vmlinux.lds.S @@ -68,6 +68,26 @@ SECTIONS *(.data.init_task) } + /* 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(4); + __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 = .; + /* will be freed after init */ . = ALIGN(4096); /* Init code and data */ __init_begin = .; diff --git a/arch/i386/mm/init.c b/arch/i386/mm/init.c index 7ba55a6e2db..9f66ac582a8 100644 --- a/arch/i386/mm/init.c +++ b/arch/i386/mm/init.c @@ -720,21 +720,6 @@ static int noinline do_test_wp_bit(void) return flag; } -void free_initmem(void) -{ - unsigned long addr; - - addr = (unsigned long)(&__init_begin); - for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { - ClearPageReserved(virt_to_page(addr)); - init_page_count(virt_to_page(addr)); - memset((void *)addr, 0xcc, PAGE_SIZE); - free_page(addr); - totalram_pages++; - } - printk (KERN_INFO "Freeing unused kernel memory: %dk freed\n", (__init_end - __init_begin) >> 10); -} - #ifdef CONFIG_DEBUG_RODATA extern char __start_rodata, __end_rodata; @@ -758,17 +743,31 @@ void mark_rodata_ro(void) } #endif +void free_init_pages(char *what, unsigned long begin, unsigned long end) +{ + unsigned long addr; + + for (addr = begin; addr < end; addr += PAGE_SIZE) { + ClearPageReserved(virt_to_page(addr)); + init_page_count(virt_to_page(addr)); + memset((void *)addr, 0xcc, PAGE_SIZE); + free_page(addr); + totalram_pages++; + } + printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10); +} + +void free_initmem(void) +{ + free_init_pages("unused kernel memory", + (unsigned long)(&__init_begin), + (unsigned long)(&__init_end)); +} #ifdef CONFIG_BLK_DEV_INITRD void free_initrd_mem(unsigned long start, unsigned long end) { - if (start < end) - printk (KERN_INFO "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 + |