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-rw-r--r--arch/i386/kernel/Makefile2
-rw-r--r--arch/i386/kernel/alternative.c321
-rw-r--r--arch/i386/kernel/cpu/proc.c2
-rw-r--r--arch/i386/kernel/module.c32
-rw-r--r--arch/i386/kernel/semaphore.c8
-rw-r--r--arch/i386/kernel/setup.c95
-rw-r--r--arch/i386/kernel/smpboot.c3
-rw-r--r--arch/i386/kernel/vmlinux.lds.S20
8 files changed, 372 insertions, 111 deletions
diff --git a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile
index 65656c033d70..5b9ed21216cf 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 000000000000..5cbd6f99fb2a
--- /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 89a85af33d28..5cfbd8011698 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 5149c8a621f0..470cf97e7cd3 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 7455ab643943..967dc74df9ee 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 ab62a9f4701e..5f58f8cb9836 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 7007e1783797..4c470e99a742 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 4710195b6b74..3f21c6f6466d 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 = .;
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