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Subject[patch] SMP alternatives
Gerd Knorr wrote:
> Gerd Knorr wrote:
>
>> i.e. something like this (as basic idea, patch is far away from doing
>> anything useful ...)?
>
> Adapting $subject to the actual topic, so other lkml readers can catch
> up ;)
>
> Ok, here new version of the SMP alternatives patch. It features:

Now, some days hacking & debugging and kernel crashing later I have
something more than just proof-of-concept ;)

Modules are supported now, fully modularized distro kernel works fine
with it. If you have a kernel with HOTPLUG_CPU compiled you can
shutdown the second CPU of your dual-processor system via sysfs (echo 0
> /sys/devices/system/cpu/cpu1/online) and watch the kernel switch over
to UP code without lock-prefixed instructions and simplified spinlocks,
then power up the second CPU again (echo 1 > /sys/...) and watch it
patching back in the SMP locking.

For testing & benchmarking purposes I've put also in two (temporary)
sysrq's to switch between UP and SMP bits without booting/shutting down
the second CPU. That one breaks non-i386 builds which are trivially
fixable by just dropping the drivers/char/sysrq.c changes ;)

enjoy,

Gerd
diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/arch/i386/kernel/Makefile work-2.6.14/arch/i386/kernel/Makefile
--- linux-2.6.14/arch/i386/kernel/Makefile 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/arch/i386/kernel/Makefile 2005-11-21 09:19:52.000000000 +0100
@@ -7,7 +7,7 @@
obj-y := process.o semaphore.o signal.o entry.o traps.o irq.o vm86.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 \
- doublefault.o quirks.o i8237.o
+ doublefault.o quirks.o i8237.o alternative.o

obj-y += cpu/
obj-y += timers/
diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/arch/i386/kernel/alternative.c work-2.6.14/arch/i386/kernel/alternative.c
--- linux-2.6.14/arch/i386/kernel/alternative.c 1970-01-01 01:00:00.000000000 +0100
+++ work-2.6.14/arch/i386/kernel/alternative.c 2005-11-22 16:58:59.000000000 +0100
@@ -0,0 +1,285 @@
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <asm/alternative.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 }
+};
+
+/* 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,
+ __u8 *tstart, __u8 *tend)
+{
+ unsigned char **noptable = intel_nops;
+ struct alt_instr *a;
+ int diff, i, k;
+
+ DPRINTK("%s: alts %p-%p, text %p-%p\n", __FUNCTION__,
+ start, end, tstart, tend);
+ for (i = 0; noptypes[i].cpuid >= 0; i++) {
+ if (boot_cpu_has(noptypes[i].cpuid)) {
+ noptable = noptypes[i].noptable;
+ break;
+ }
+ }
+ for (a = start; a < end; a++) {
+ BUG_ON(a->replacementlen > a->instrlen);
+ if (!boot_cpu_has(a->cpuid))
+ continue;
+ if (tstart && a->instr < tstart)
+ continue;
+ if (tend && a->instr > tend)
+ 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);
+ }
+ }
+
+ /* Paranoia */
+ asm volatile ("jmp 1f\n1:");
+ mb();
+}
+
+struct smp_alt_module {
+ /* what is this ??? */
+ struct module *mod;
+ char *name;
+
+ /* our SMP alternatives table */
+ struct alt_instr *astart;
+ struct alt_instr *aend;
+
+ /* .text segment, needed to avoid patching init code ;) */
+ __u8 *tstart;
+ __u8 *tend;
+
+ struct list_head next;
+};
+static LIST_HEAD(smp_alt_modules);
+static DEFINE_SPINLOCK(smp_alt);
+static enum {
+ ALT_UP, ALT_SMP
+} smp_alt_state = ALT_SMP;
+
+static void save_alternatives_smp(struct smp_alt_module *mod)
+{
+ struct alt_instr *a;
+
+ DPRINTK("%s: alts %p-%p, text %p-%p, name %s\n", __FUNCTION__,
+ mod->astart, mod->aend, mod->tstart, mod->tend, mod->name);
+ for (a = mod->astart; a < mod->aend; a++) {
+ if (a->instr < mod->tstart)
+ continue;
+ if (a->instr > mod->tend)
+ continue;
+ memcpy(a->replacement + a->replacementlen,
+ a->instr,
+ a->instrlen);
+ }
+}
+
+static void apply_alternatives_smp(struct smp_alt_module *mod)
+{
+ struct alt_instr *a;
+
+ DPRINTK("%s: alts %p-%p, text %p-%p, name %s\n", __FUNCTION__,
+ mod->astart, mod->aend, mod->tstart, mod->tend, mod->name);
+ for (a = mod->astart; a < mod->aend; a++) {
+ if (a->instr < mod->tstart)
+ continue;
+ if (a->instr > mod->tend)
+ continue;
+ memcpy(a->instr,
+ a->replacement + a->replacementlen,
+ a->instrlen);
+ }
+
+ /* Paranoia */
+ asm volatile ("jmp 1f\n1:");
+ mb();
+}
+
+extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
+extern struct alt_instr __smp_alt_instructions[], __smp_alt_instructions_end[];
+extern __u8 _text[], _etext[];
+
+void alternatives_smp_module_add(struct module *mod, char *name,
+ void *astart, void *aend,
+ void *tstart, void *tend)
+{
+ struct smp_alt_module *smp;
+ unsigned long flags;
+
+ smp = kmalloc(sizeof(*smp), GFP_KERNEL);
+ if (NULL == smp)
+ return; /* we'll run the (safe but slow) SMP code then ... */
+
+ memset(smp,0,sizeof(*smp));
+ smp->mod = mod;
+ smp->name = name;
+ smp->astart = astart;
+ smp->aend = aend;
+ smp->tstart = tstart;
+ smp->tend = tend;
+ DPRINTK("%s: alts %p-%p, text %p-%p, name %s\n", __FUNCTION__,
+ smp->astart, smp->aend, smp->tstart, smp->tend, smp->name);
+
+ spin_lock_irqsave(&smp_alt, flags);
+ list_add_tail(&smp->next, &smp_alt_modules);
+ save_alternatives_smp(smp);
+ if (ALT_UP == smp_alt_state)
+ apply_alternatives(smp->astart, smp->aend,
+ smp->tstart, smp->tend);
+ spin_unlock_irqrestore(&smp_alt, flags);
+
+}
+
+void alternatives_smp_module_del(struct module *mod)
+{
+ struct smp_alt_module *item;
+ unsigned long flags;
+
+ 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 switch_alternatives_up(void)
+{
+ struct smp_alt_module *mod;
+ unsigned long flags;
+
+ if (num_online_cpus() > 1) {
+ /* shouldn't happen in theory ... */
+ printk("%s: Uh, oh, %d cpus active, NOT patching ...\n",
+ __FUNCTION__, num_online_cpus());
+ dump_stack();
+ return;
+ }
+
+ spin_lock_irqsave(&smp_alt, flags);
+
+ if (ALT_UP == smp_alt_state)
+ goto out;
+ smp_alt_state = ALT_UP;
+ printk(KERN_INFO "alternatives: switching to UP code\n");
+
+ set_bit(X86_FEATURE_UP, boot_cpu_data.x86_capability);
+ list_for_each_entry(mod, &smp_alt_modules, next)
+ apply_alternatives(mod->astart, mod->aend,
+ mod->tstart, mod->tend);
+
+ out:
+ spin_unlock_irqrestore(&smp_alt, flags);
+}
+
+void switch_alternatives_smp(void)
+{
+ struct smp_alt_module *mod;
+ unsigned long flags;
+
+ spin_lock_irqsave(&smp_alt, flags);
+
+ if (ALT_SMP == smp_alt_state)
+ goto out;
+ smp_alt_state = ALT_SMP;
+ printk(KERN_INFO "alternatives: switching to SMP code\n");
+
+ clear_bit(X86_FEATURE_UP, boot_cpu_data.x86_capability);
+ list_for_each_entry(mod, &smp_alt_modules, next)
+ apply_alternatives_smp(mod);
+
+ out:
+ spin_unlock_irqrestore(&smp_alt, flags);
+}
+
+void __init alternative_instructions(void)
+{
+ apply_alternatives(__alt_instructions, __alt_instructions_end,
+ NULL, NULL);
+ alternatives_smp_module_add(NULL, "core kernel",
+ __smp_alt_instructions,
+ __smp_alt_instructions_end,
+ _text, _etext);
+ switch_alternatives_up();
+}
+
diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/arch/i386/kernel/module.c work-2.6.14/arch/i386/kernel/module.c
--- linux-2.6.14/arch/i386/kernel/module.c 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/arch/i386/kernel/module.c 2005-11-22 15:59:19.000000000 +0100
@@ -104,26 +104,39 @@
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, *smpalt = 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 (0 == strcmp(".text", secstrings + s->sh_name))
+ text = s;
+ if (0 == strcmp(".altinstructions", secstrings + s->sh_name))
+ alt = s;
+ if (0 == strcmp(".smp_altinstructions", secstrings + s->sh_name))
+ smpalt = s;
+ }
+
+ if (alt) {
+ /* patch .altinstructions */
+ void *aseg = (void *)alt->sh_addr;
+ apply_alternatives(aseg, aseg + alt->sh_size, NULL, NULL);
+ }
+ if (smpalt && text) {
+ void *aseg = (void *)smpalt->sh_addr;
+ void *tseg = (void *)text->sh_addr;
+ alternatives_smp_module_add(me, me->name,
+ aseg, aseg + smpalt->sh_size,
+ tseg, tseg + text->sh_size);
+ }
+
return 0;
}

void module_arch_cleanup(struct module *mod)
{
+ alternatives_smp_module_del(mod);
}
diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/arch/i386/kernel/semaphore.c work-2.6.14/arch/i386/kernel/semaphore.c
--- linux-2.6.14/arch/i386/kernel/semaphore.c 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/arch/i386/kernel/semaphore.c 2005-11-17 11:17:58.000000000 +0100
@@ -110,11 +110,11 @@
".align 4\n"
".globl __write_lock_failed\n"
"__write_lock_failed:\n\t"
- LOCK "addl $" RW_LOCK_BIAS_STR ",(%eax)\n"
+ LOCK_PRE "addl $" RW_LOCK_BIAS_STR ",(%eax)" LOCK_POST "\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_PRE "subl $" RW_LOCK_BIAS_STR ",(%eax)" LOCK_POST "\n\t"
"jnz __write_lock_failed\n\t"
"ret"
);
@@ -124,11 +124,11 @@
".align 4\n"
".globl __read_lock_failed\n"
"__read_lock_failed:\n\t"
- LOCK "incl (%eax)\n"
+ LOCK_PRE "incl (%eax)" LOCK_POST "\n"
"1: rep; nop\n\t"
"cmpl $1,(%eax)\n\t"
"js 1b\n\t"
- LOCK "decl (%eax)\n\t"
+ LOCK_PRE "decl (%eax)" LOCK_POST "\n\t"
"js __read_lock_failed\n\t"
"ret"
);
diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/arch/i386/kernel/setup.c work-2.6.14/arch/i386/kernel/setup.c
--- linux-2.6.14/arch/i386/kernel/setup.c 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/arch/i386/kernel/setup.c 2005-11-21 09:10:40.000000000 +0100
@@ -1361,101 +1361,6 @@
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 -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/arch/i386/kernel/smpboot.c work-2.6.14/arch/i386/kernel/smpboot.c
--- linux-2.6.14/arch/i386/kernel/smpboot.c 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/arch/i386/kernel/smpboot.c 2005-11-18 14:56:37.000000000 +0100
@@ -874,6 +874,7 @@
unsigned short nmi_high = 0, nmi_low = 0;

++cpucount;
+ switch_alternatives_smp();

/*
* We can't use kernel_thread since we must avoid to
@@ -1315,6 +1316,9 @@
fixup_irqs(map);
/* It's now safe to remove this processor from the online map */
cpu_clear(cpu, cpu_online_map);
+
+ if (1 == num_online_cpus())
+ switch_alternatives_up();
return 0;
}

diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/arch/i386/kernel/vmlinux.lds.S work-2.6.14/arch/i386/kernel/vmlinux.lds.S
--- linux-2.6.14/arch/i386/kernel/vmlinux.lds.S 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/arch/i386/kernel/vmlinux.lds.S 2005-11-16 09:50:35.000000000 +0100
@@ -68,6 +68,16 @@
*(.data.init_task)
}

+ . = ALIGN(4);
+ __smp_alt_instructions = .;
+ .smp_altinstructions : AT(ADDR(.smp_altinstructions) - LOAD_OFFSET) {
+ *(.smp_altinstructions)
+ }
+ __smp_alt_instructions_end = .;
+ .smp_altinstr_replacement : AT(ADDR(.smp_altinstr_replacement) - LOAD_OFFSET) {
+ *(.smp_altinstr_replacement)
+ }
+
/* will be freed after init */
. = ALIGN(4096); /* Init code and data */
__init_begin = .;
diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/drivers/char/sysrq.c work-2.6.14/drivers/char/sysrq.c
--- linux-2.6.14/drivers/char/sysrq.c 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/drivers/char/sysrq.c 2005-11-21 09:26:30.000000000 +0100
@@ -271,6 +271,34 @@
.enable_mask = SYSRQ_ENABLE_RTNICE,
};

+#ifdef CONFIG_SMP
+/* handy for testing & benchmarking, probably temporary though.
+ * -- kraxel */
+static void sysrq_handle_up(int key, struct pt_regs *pt_regs,
+ struct tty_struct *tty)
+{
+ switch_alternatives_up();
+}
+static struct sysrq_key_op sysrq_up_op = {
+ .handler = sysrq_handle_up,
+ .help_msg = "UP(x)",
+ .action_msg = "switch smp alternatives to UP",
+ .enable_mask = SYSRQ_ENABLE_LOG,
+};
+
+static void sysrq_handle_smp(int key, struct pt_regs *pt_regs,
+ struct tty_struct *tty)
+{
+ switch_alternatives_smp();
+}
+static struct sysrq_key_op sysrq_smp_op = {
+ .handler = sysrq_handle_smp,
+ .help_msg = "SMP(y)",
+ .action_msg = "switch smp alternatives to SMP",
+ .enable_mask = SYSRQ_ENABLE_LOG,
+};
+#endif
+
/* Key Operations table and lock */
static DEFINE_SPINLOCK(sysrq_key_table_lock);
#define SYSRQ_KEY_TABLE_LENGTH 36
@@ -323,8 +351,13 @@
/* u */ &sysrq_mountro_op,
/* v */ NULL, /* May be assigned at init time by SMP VOYAGER */
/* w */ NULL,
+#ifdef CONFIG_SMP
+/* x */ &sysrq_up_op,
+/* y */ &sysrq_smp_op,
+#else
/* x */ NULL,
/* y */ NULL,
+#endif
/* z */ NULL
};

diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/include/asm-i386/alternative.h work-2.6.14/include/asm-i386/alternative.h
--- linux-2.6.14/include/asm-i386/alternative.h 1970-01-01 01:00:00.000000000 +0100
+++ work-2.6.14/include/asm-i386/alternative.h 2005-11-22 15:30:36.000000000 +0100
@@ -0,0 +1,150 @@
+#ifndef _I386_ALTERNATIVE_H
+#define _I386_ALTERNATIVE_H
+
+#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;
+};
+
+extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end,
+ __u8 *tstart, __u8 *tend);
+
+struct module;
+extern void alternatives_smp_module_add(struct module *mod, char *name,
+ void *astart, void *aend,
+ void *tstart, void *tend);
+extern void alternatives_smp_module_del(struct module *mod);
+
+extern void switch_alternatives_up(void);
+extern void switch_alternatives_smp(void);
+
+#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 4\n" \
+ " .long 661b\n" /* label */ \
+ " .long 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 maake 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 4\n" \
+ " .long 661b\n" /* label */ \
+ " .long 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)
+
+/*
+ * Alternative inline assembly for SMP.
+ *
+ * alternative_smp() takes two versions (SMP first, UP second) and is
+ * for more complex stuff such as spinlocks.
+ *
+ * alternative_smp_lock() just puts an lock in front of the
+ * instruction which will be nop'ed out for UP.
+ *
+ * The LOCK_PRE and LOCK_POST macros can be placed around the
+ * instruction to be locked in places where the simple
+ * alternative_smp_lock() doesn't work (inline asm also using section
+ * tricks, lock instruction in the middle of a longer sequence,
+ * whatever else ... )
+ *
+ * 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 are 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.
+ */
+
+#ifdef CONFIG_SMP
+#define alternative_smp(smpinstr, upinstr, args...) \
+ asm volatile ("661:\n\t" smpinstr "\n662:\n" \
+ ".section .smp_altinstructions,\"a\"\n" \
+ " .align 4\n" \
+ " .long 661b\n" /* label */ \
+ " .long 663f\n" /* new instruction */ \
+ " .byte 0x68\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_PRE \
+ "661:\n\tlock; "
+#define LOCK_POST \
+ "\n" \
+ ".section .smp_altinstructions,\"a\"\n" \
+ " .align 4\n" \
+ " .long 661b\n" /* label */ \
+ " .long 663f\n" /* new instruction */ \
+ " .byte 0x68\n" /* X86_FEATURE_UP */ \
+ " .byte 1\n" /* sourcelen */ \
+ " .byte 0\n" /* replacementlen */ \
+ ".previous\n" \
+ ".section .smp_altinstr_replacement,\"awx\"\n" \
+ "663:\n" /* replacement */ \
+ "664:\n\tlock\n" /* space for original */ \
+ ".previous\n"
+
+#define alternative_smp_lock(lockinstr, args...) \
+ asm volatile (LOCK_PRE lockinstr LOCK_POST : args)
+
+#else /* ! CONFIG_SMP */
+#define alternative_smp(smpinstr, upinstr, args...) \
+ asm volatile (upinstr : args)
+#define alternative_smp_lock(lockinstr, args...) \
+ asm volatile (lockinstr : args)
+#define LOCK_PRE ""
+#define LOCK_POST ""
+#endif
+
+#endif /* _I386_ALTERNATIVE_H */
diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/include/asm-i386/atomic.h work-2.6.14/include/asm-i386/atomic.h
--- linux-2.6.14/include/asm-i386/atomic.h 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/include/asm-i386/atomic.h 2005-11-16 18:18:42.000000000 +0100
@@ -10,12 +10,6 @@
* resource counting etc..
*/

-#ifdef CONFIG_SMP
-#define LOCK "lock ; "
-#else
-#define LOCK ""
-#endif
-
/*
* Make sure gcc doesn't try to be clever and move things around
* on us. We need to use _exactly_ the address the user gave us,
@@ -51,9 +45,9 @@
*/
static __inline__ void atomic_add(int i, atomic_t *v)
{
- __asm__ __volatile__(
- LOCK "addl %1,%0"
- :"=m" (v->counter)
+ alternative_smp_lock(
+ "addl %1,%0",
+ "=m" (v->counter)
:"ir" (i), "m" (v->counter));
}

@@ -66,9 +60,9 @@
*/
static __inline__ void atomic_sub(int i, atomic_t *v)
{
- __asm__ __volatile__(
- LOCK "subl %1,%0"
- :"=m" (v->counter)
+ alternative_smp_lock(
+ "subl %1,%0",
+ "=m" (v->counter)
:"ir" (i), "m" (v->counter));
}

@@ -85,9 +79,9 @@
{
unsigned char c;

- __asm__ __volatile__(
- LOCK "subl %2,%0; sete %1"
- :"=m" (v->counter), "=qm" (c)
+ alternative_smp_lock(
+ "subl %2,%0; sete %1",
+ "=m" (v->counter), "=qm" (c)
:"ir" (i), "m" (v->counter) : "memory");
return c;
}
@@ -100,9 +94,9 @@
*/
static __inline__ void atomic_inc(atomic_t *v)
{
- __asm__ __volatile__(
- LOCK "incl %0"
- :"=m" (v->counter)
+ alternative_smp_lock(
+ "incl %0",
+ "=m" (v->counter)
:"m" (v->counter));
}

@@ -114,9 +108,9 @@
*/
static __inline__ void atomic_dec(atomic_t *v)
{
- __asm__ __volatile__(
- LOCK "decl %0"
- :"=m" (v->counter)
+ alternative_smp_lock(
+ "decl %0",
+ "=m" (v->counter)
:"m" (v->counter));
}

@@ -132,9 +126,9 @@
{
unsigned char c;

- __asm__ __volatile__(
- LOCK "decl %0; sete %1"
- :"=m" (v->counter), "=qm" (c)
+ alternative_smp_lock(
+ "decl %0; sete %1",
+ "=m" (v->counter), "=qm" (c)
:"m" (v->counter) : "memory");
return c != 0;
}
@@ -151,9 +145,9 @@
{
unsigned char c;

- __asm__ __volatile__(
- LOCK "incl %0; sete %1"
- :"=m" (v->counter), "=qm" (c)
+ alternative_smp_lock(
+ "incl %0; sete %1",
+ "=m" (v->counter), "=qm" (c)
:"m" (v->counter) : "memory");
return c != 0;
}
@@ -171,9 +165,9 @@
{
unsigned char c;

- __asm__ __volatile__(
- LOCK "addl %2,%0; sets %1"
- :"=m" (v->counter), "=qm" (c)
+ alternative_smp_lock(
+ "addl %2,%0; sets %1",
+ "=m" (v->counter), "=qm" (c)
:"ir" (i), "m" (v->counter) : "memory");
return c;
}
@@ -194,9 +188,9 @@
#endif
/* Modern 486+ processor */
__i = i;
- __asm__ __volatile__(
- LOCK "xaddl %0, %1;"
- :"=r"(i)
+ alternative_smp_lock(
+ "xaddl %0, %1;",
+ "=r"(i)
:"m"(v->counter), "0"(i));
return i + __i;

@@ -220,12 +214,12 @@

/* These are x86-specific, used by some header files */
#define atomic_clear_mask(mask, addr) \
-__asm__ __volatile__(LOCK "andl %0,%1" \
-: : "r" (~(mask)),"m" (*addr) : "memory")
+alternative_smp_lock("andl %0,%1", \
+: "r" (~(mask)),"m" (*addr) : "memory")

#define atomic_set_mask(mask, addr) \
-__asm__ __volatile__(LOCK "orl %0,%1" \
-: : "r" (mask),"m" (*(addr)) : "memory")
+alternative_smp_lock("orl %0,%1", \
+: "r" (mask),"m" (*(addr)) : "memory")

/* Atomic operations are already serializing on x86 */
#define smp_mb__before_atomic_dec() barrier()
diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/include/asm-i386/bitops.h work-2.6.14/include/asm-i386/bitops.h
--- linux-2.6.14/include/asm-i386/bitops.h 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/include/asm-i386/bitops.h 2005-11-17 09:55:40.000000000 +0100
@@ -7,6 +7,7 @@

#include <linux/config.h>
#include <linux/compiler.h>
+#include <asm/alternative.h>

/*
* These have to be done with inline assembly: that way the bit-setting
@@ -16,12 +17,6 @@
* bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
*/

-#ifdef CONFIG_SMP
-#define LOCK_PREFIX "lock ; "
-#else
-#define LOCK_PREFIX ""
-#endif
-
#define ADDR (*(volatile long *) addr)

/**
@@ -41,9 +36,9 @@
*/
static inline void set_bit(int nr, volatile unsigned long * addr)
{
- __asm__ __volatile__( LOCK_PREFIX
- "btsl %1,%0"
- :"=m" (ADDR)
+ alternative_smp_lock(
+ "btsl %1,%0",
+ "=m" (ADDR)
:"Ir" (nr));
}

@@ -76,9 +71,9 @@
*/
static inline void clear_bit(int nr, volatile unsigned long * addr)
{
- __asm__ __volatile__( LOCK_PREFIX
- "btrl %1,%0"
- :"=m" (ADDR)
+ alternative_smp_lock(
+ "btrl %1,%0",
+ "=m" (ADDR)
:"Ir" (nr));
}

@@ -121,9 +116,9 @@
*/
static inline void change_bit(int nr, volatile unsigned long * addr)
{
- __asm__ __volatile__( LOCK_PREFIX
- "btcl %1,%0"
- :"=m" (ADDR)
+ alternative_smp_lock(
+ "btcl %1,%0",
+ "=m" (ADDR)
:"Ir" (nr));
}

@@ -140,9 +135,9 @@
{
int oldbit;

- __asm__ __volatile__( LOCK_PREFIX
- "btsl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
+ alternative_smp_lock(
+ "btsl %2,%1\n\tsbbl %0,%0",
+ "=r" (oldbit),"=m" (ADDR)
:"Ir" (nr) : "memory");
return oldbit;
}
@@ -180,9 +175,9 @@
{
int oldbit;

- __asm__ __volatile__( LOCK_PREFIX
- "btrl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
+ alternative_smp_lock(
+ "btrl %2,%1\n\tsbbl %0,%0",
+ "=r" (oldbit),"=m" (ADDR)
:"Ir" (nr) : "memory");
return oldbit;
}
@@ -231,9 +226,9 @@
{
int oldbit;

- __asm__ __volatile__( LOCK_PREFIX
- "btcl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
+ alternative_smp_lock(
+ "btcl %2,%1\n\tsbbl %0,%0",
+ "=r" (oldbit),"=m" (ADDR)
:"Ir" (nr) : "memory");
return oldbit;
}
diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/include/asm-i386/cpufeature.h work-2.6.14/include/asm-i386/cpufeature.h
--- linux-2.6.14/include/asm-i386/cpufeature.h 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/include/asm-i386/cpufeature.h 2005-11-16 09:43:47.000000000 +0100
@@ -70,6 +70,8 @@
#define X86_FEATURE_P3 (3*32+ 6) /* P3 */
#define X86_FEATURE_P4 (3*32+ 7) /* P4 */

+#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 */
#define X86_FEATURE_MWAIT (4*32+ 3) /* Monitor/Mwait support */
diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/include/asm-i386/futex.h work-2.6.14/include/asm-i386/futex.h
--- linux-2.6.14/include/asm-i386/futex.h 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/include/asm-i386/futex.h 2005-11-17 11:19:13.000000000 +0100
@@ -28,7 +28,7 @@
"1: movl %2, %0\n\
movl %0, %3\n" \
insn "\n" \
-"2: " LOCK_PREFIX "cmpxchgl %3, %2\n\
+"2: " LOCK_PRE "cmpxchgl %3, %2" LOCK_POST "\n\
jnz 1b\n\
3: .section .fixup,\"ax\"\n\
4: mov %5, %1\n\
@@ -68,7 +68,7 @@
#endif
switch (op) {
case FUTEX_OP_ADD:
- __futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret,
+ __futex_atomic_op1(LOCK_PRE "xaddl %0, %2" LOCK_POST, ret,
oldval, uaddr, oparg);
break;
case FUTEX_OP_OR:
diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/include/asm-i386/rwlock.h work-2.6.14/include/asm-i386/rwlock.h
--- linux-2.6.14/include/asm-i386/rwlock.h 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/include/asm-i386/rwlock.h 2005-11-17 09:44:53.000000000 +0100
@@ -21,21 +21,23 @@
#define RW_LOCK_BIAS_STR "0x01000000"

#define __build_read_lock_ptr(rw, helper) \
- asm volatile(LOCK "subl $1,(%0)\n\t" \
- "jns 1f\n" \
- "call " helper "\n\t" \
- "1:\n" \
- ::"a" (rw) : "memory")
+ alternative_smp("lock; subl $1,(%0)\n\t" \
+ "jns 1f\n" \
+ "call " helper "\n\t" \
+ "1:\n", \
+ "subl $1,(%0)\n\t", \
+ :"a" (rw) : "memory")

#define __build_read_lock_const(rw, helper) \
- asm volatile(LOCK "subl $1,%0\n\t" \
- "jns 1f\n" \
- "pushl %%eax\n\t" \
- "leal %0,%%eax\n\t" \
- "call " helper "\n\t" \
- "popl %%eax\n\t" \
- "1:\n" \
- :"=m" (*(volatile int *)rw) : : "memory")
+ alternative_smp("lock; subl $1,%0\n\t" \
+ "jns 1f\n" \
+ "pushl %%eax\n\t" \
+ "leal %0,%%eax\n\t" \
+ "call " helper "\n\t" \
+ "popl %%eax\n\t" \
+ "1:\n", \
+ "subl $1,%0\n\t", \
+ "=m" (*(volatile int *)rw) : : "memory")

#define __build_read_lock(rw, helper) do { \
if (__builtin_constant_p(rw)) \
@@ -45,21 +47,23 @@
} while (0)

#define __build_write_lock_ptr(rw, helper) \
- asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
- "jz 1f\n" \
- "call " helper "\n\t" \
- "1:\n" \
- ::"a" (rw) : "memory")
+ alternative_smp("lock; subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
+ "jz 1f\n" \
+ "call " helper "\n\t" \
+ "1:\n", \
+ "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t", \
+ :"a" (rw) : "memory")

#define __build_write_lock_const(rw, helper) \
- asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",%0\n\t" \
- "jz 1f\n" \
- "pushl %%eax\n\t" \
- "leal %0,%%eax\n\t" \
- "call " helper "\n\t" \
- "popl %%eax\n\t" \
- "1:\n" \
- :"=m" (*(volatile int *)rw) : : "memory")
+ alternative_smp("lock; subl $" RW_LOCK_BIAS_STR ",%0\n\t" \
+ "jz 1f\n" \
+ "pushl %%eax\n\t" \
+ "leal %0,%%eax\n\t" \
+ "call " helper "\n\t" \
+ "popl %%eax\n\t" \
+ "1:\n", \
+ "subl $" RW_LOCK_BIAS_STR ",%0\n\t", \
+ "=m" (*(volatile int *)rw) : : "memory")

#define __build_write_lock(rw, helper) do { \
if (__builtin_constant_p(rw)) \
diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/include/asm-i386/rwsem.h work-2.6.14/include/asm-i386/rwsem.h
--- linux-2.6.14/include/asm-i386/rwsem.h 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/include/asm-i386/rwsem.h 2005-11-17 11:14:45.000000000 +0100
@@ -99,7 +99,7 @@
{
__asm__ __volatile__(
"# beginning down_read\n\t"
-LOCK_PREFIX " incl (%%eax)\n\t" /* adds 0x00000001, returns the old value */
+LOCK_PRE " incl (%%eax)" LOCK_POST "\n\t" /* adds 0x00000001, returns the old value */
" js 2f\n\t" /* jump if we weren't granted the lock */
"1:\n\t"
LOCK_SECTION_START("")
@@ -130,7 +130,7 @@
" movl %1,%2\n\t"
" addl %3,%2\n\t"
" jle 2f\n\t"
-LOCK_PREFIX " cmpxchgl %2,%0\n\t"
+LOCK_PRE " cmpxchgl %2,%0" LOCK_POST "\n\t"
" jnz 1b\n\t"
"2:\n\t"
"# ending __down_read_trylock\n\t"
@@ -150,7 +150,7 @@
tmp = RWSEM_ACTIVE_WRITE_BIAS;
__asm__ __volatile__(
"# beginning down_write\n\t"
-LOCK_PREFIX " xadd %%edx,(%%eax)\n\t" /* subtract 0x0000ffff, returns the old value */
+LOCK_PRE " xadd %%edx,(%%eax)" LOCK_POST "\n\t" /* subtract 0x0000ffff, returns the old value */
" testl %%edx,%%edx\n\t" /* was the count 0 before? */
" jnz 2f\n\t" /* jump if we weren't granted the lock */
"1:\n\t"
@@ -188,7 +188,7 @@
__s32 tmp = -RWSEM_ACTIVE_READ_BIAS;
__asm__ __volatile__(
"# beginning __up_read\n\t"
-LOCK_PREFIX " xadd %%edx,(%%eax)\n\t" /* subtracts 1, returns the old value */
+LOCK_PRE " xadd %%edx,(%%eax)" LOCK_POST "\n\t" /* subtracts 1, returns the old value */
" js 2f\n\t" /* jump if the lock is being waited upon */
"1:\n\t"
LOCK_SECTION_START("")
@@ -214,7 +214,7 @@
__asm__ __volatile__(
"# beginning __up_write\n\t"
" movl %2,%%edx\n\t"
-LOCK_PREFIX " xaddl %%edx,(%%eax)\n\t" /* tries to transition 0xffff0001 -> 0x00000000 */
+LOCK_PRE " xaddl %%edx,(%%eax)" LOCK_POST "\n\t" /* tries to transition 0xffff0001 -> 0x00000000 */
" jnz 2f\n\t" /* jump if the lock is being waited upon */
"1:\n\t"
LOCK_SECTION_START("")
@@ -239,7 +239,7 @@
{
__asm__ __volatile__(
"# beginning __downgrade_write\n\t"
-LOCK_PREFIX " addl %2,(%%eax)\n\t" /* transitions 0xZZZZ0001 -> 0xYYYY0001 */
+LOCK_PRE " addl %2,(%%eax)" LOCK_POST "\n\t" /* transitions 0xZZZZ0001 -> 0xYYYY0001 */
" js 2f\n\t" /* jump if the lock is being waited upon */
"1:\n\t"
LOCK_SECTION_START("")
@@ -262,9 +262,9 @@
*/
static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
{
- __asm__ __volatile__(
-LOCK_PREFIX "addl %1,%0"
- : "=m"(sem->count)
+ alternative_smp_lock(
+ "addl %1,%0",
+ "=m"(sem->count)
: "ir"(delta), "m"(sem->count));
}

@@ -275,9 +275,9 @@
{
int tmp = delta;

- __asm__ __volatile__(
-LOCK_PREFIX "xadd %0,(%2)"
- : "+r"(tmp), "=m"(sem->count)
+ alternative_smp_lock(
+ "xadd %0,(%2)",
+ "+r"(tmp), "=m"(sem->count)
: "r"(sem), "m"(sem->count)
: "memory");

diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/include/asm-i386/semaphore.h work-2.6.14/include/asm-i386/semaphore.h
--- linux-2.6.14/include/asm-i386/semaphore.h 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/include/asm-i386/semaphore.h 2005-11-17 11:15:49.000000000 +0100
@@ -102,7 +102,7 @@
might_sleep();
__asm__ __volatile__(
"# atomic down operation\n\t"
- LOCK "decl %0\n\t" /* --sem->count */
+ LOCK_PRE "decl %0" LOCK_POST "\n\t" /* --sem->count */
"js 2f\n"
"1:\n"
LOCK_SECTION_START("")
@@ -126,7 +126,7 @@
might_sleep();
__asm__ __volatile__(
"# atomic interruptible down operation\n\t"
- LOCK "decl %1\n\t" /* --sem->count */
+ LOCK_PRE "decl %1" LOCK_POST "\n\t" /* --sem->count */
"js 2f\n\t"
"xorl %0,%0\n"
"1:\n"
@@ -151,7 +151,7 @@

__asm__ __volatile__(
"# atomic interruptible down operation\n\t"
- LOCK "decl %1\n\t" /* --sem->count */
+ LOCK_PRE "decl %1" LOCK_POST "\n\t" /* --sem->count */
"js 2f\n\t"
"xorl %0,%0\n"
"1:\n"
@@ -176,7 +176,7 @@
{
__asm__ __volatile__(
"# atomic up operation\n\t"
- LOCK "incl %0\n\t" /* ++sem->count */
+ LOCK_PRE "incl %0" LOCK_POST "\n\t" /* ++sem->count */
"jle 2f\n"
"1:\n"
LOCK_SECTION_START("")
diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/include/asm-i386/spinlock.h work-2.6.14/include/asm-i386/spinlock.h
--- linux-2.6.14/include/asm-i386/spinlock.h 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/include/asm-i386/spinlock.h 2005-11-16 16:22:12.000000000 +0100
@@ -48,18 +48,23 @@
"jmp 1b\n" \
"4:\n\t"

+#define __raw_spin_lock_string_up \
+ "\n\tdecb %0"
+
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");
}

static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
{
- __asm__ __volatile__(
- __raw_spin_lock_string_flags
- :"=m" (lock->slock) : "r" (flags) : "memory");
+ alternative_smp(
+ __raw_spin_lock_string_flags,
+ __raw_spin_lock_string_up,
+ "=m" (lock->slock) : "r" (flags) : "memory");
}

static inline int __raw_spin_trylock(raw_spinlock_t *lock)
@@ -178,13 +183,16 @@

static inline void __raw_read_unlock(raw_rwlock_t *rw)
{
- asm volatile("lock ; incl %0" :"=m" (rw->lock) : : "memory");
+ alternative_smp_lock(
+ "incl %0",
+ "=m" (rw->lock) : : "memory");
}

static inline void __raw_write_unlock(raw_rwlock_t *rw)
{
- asm volatile("lock ; addl $" RW_LOCK_BIAS_STR ", %0"
- : "=m" (rw->lock) : : "memory");
+ alternative_smp_lock(
+ "addl $" RW_LOCK_BIAS_STR ", %0",
+ "=m" (rw->lock) : : "memory");
}

#endif /* __ASM_SPINLOCK_H */
diff -urN -x 'build-*' -x '*~' -x Make -x scripts linux-2.6.14/include/asm-i386/system.h work-2.6.14/include/asm-i386/system.h
--- linux-2.6.14/include/asm-i386/system.h 2005-10-28 02:02:08.000000000 +0200
+++ work-2.6.14/include/asm-i386/system.h 2005-11-17 09:28:29.000000000 +0100
@@ -267,20 +267,20 @@
unsigned long prev;
switch (size) {
case 1:
- __asm__ __volatile__(LOCK_PREFIX "cmpxchgb %b1,%2"
- : "=a"(prev)
+ alternative_smp_lock("cmpxchgb %b1,%2",
+ "=a"(prev)
: "q"(new), "m"(*__xg(ptr)), "0"(old)
: "memory");
return prev;
case 2:
- __asm__ __volatile__(LOCK_PREFIX "cmpxchgw %w1,%2"
- : "=a"(prev)
+ alternative_smp_lock("cmpxchgw %w1,%2",
+ "=a"(prev)
: "q"(new), "m"(*__xg(ptr)), "0"(old)
: "memory");
return prev;
case 4:
- __asm__ __volatile__(LOCK_PREFIX "cmpxchgl %1,%2"
- : "=a"(prev)
+ alternative_smp_lock("cmpxchgl %1,%2",
+ "=a"(prev)
: "q"(new), "m"(*__xg(ptr)), "0"(old)
: "memory");
return prev;
@@ -292,67 +292,6 @@
((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
(unsigned long)(n),sizeof(*(ptr))))

-#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;
-};
-#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 4\n" \
- " .long 661b\n" /* label */ \
- " .long 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 maake 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 4\n" \
- " .long 661b\n" /* label */ \
- " .long 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)
-
/*
* Force strict CPU ordering.
* And yes, this is required on UP too when we're talking
\
 
 \ /
  Last update: 2005-11-22 18:51    [W:0.216 / U:4.588 seconds]
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