]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - arch/i386/kernel/alternative.c
Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
[linux-2.6-omap-h63xx.git] / arch / i386 / kernel / alternative.c
index 583c238e17fb2e9550fbbcb490ba1a41288b97dc..d8cda14fff8bc4713f41a15a0193cb935550c602 100644 (file)
@@ -1,33 +1,46 @@
 #include <linux/module.h>
+#include <linux/sched.h>
 #include <linux/spinlock.h>
 #include <linux/list.h>
 #include <asm/alternative.h>
 #include <asm/sections.h>
 
-static int no_replacement    = 0;
+static int noreplace_smp     = 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;
 }
+__setup("smp-alt-boot", bootonly);
+
 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);
 
+static int __init setup_noreplace_smp(char *str)
+{
+       noreplace_smp = 1;
+       return 1;
+}
+__setup("noreplace-smp", setup_noreplace_smp);
+
+#ifdef CONFIG_PARAVIRT
+static int noreplace_paravirt = 0;
+
+static int __init setup_noreplace_paravirt(char *str)
+{
+       noreplace_paravirt = 1;
+       return 1;
+}
+__setup("noreplace-paravirt", setup_noreplace_paravirt);
+#endif
+
 #define DPRINTK(fmt, args...) if (debug_alternative) \
        printk(KERN_DEBUG fmt, args)
 
@@ -123,12 +136,23 @@ static unsigned char** find_nop_table(void)
 
 #endif /* CONFIG_X86_64 */
 
+static void nop_out(void *insns, unsigned int len)
+{
+       unsigned char **noptable = find_nop_table();
+
+       while (len > 0) {
+               unsigned int noplen = len;
+               if (noplen > ASM_NOP_MAX)
+                       noplen = ASM_NOP_MAX;
+               memcpy(insns, noptable[noplen], noplen);
+               insns += noplen;
+               len -= noplen;
+       }
+}
+
 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
@@ -137,10 +161,9 @@ extern u8 __smp_alt_begin[], __smp_alt_end[];
 
 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;
+       int diff;
 
        DPRINTK("%s: alt table %p -> %p\n", __FUNCTION__, start, end);
        for (a = start; a < end; a++) {
@@ -158,41 +181,12 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
 #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) {
-                       k = diff;
-                       if (k > ASM_NOP_MAX)
-                               k = ASM_NOP_MAX;
-                       memcpy(a->instr + i, noptable[k], k);
-               }
+               nop_out(instr + a->replacementlen, diff);
        }
 }
 
 #ifdef CONFIG_SMP
 
-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;
@@ -208,15 +202,17 @@ static void alternatives_smp_lock(u8 **start, u8 **end, u8 *text, u8 *text_end)
 
 static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end)
 {
-       unsigned char **noptable = find_nop_table();
        u8 **ptr;
 
+       if (noreplace_smp)
+               return;
+
        for (ptr = start; ptr < end; ptr++) {
                if (*ptr < text)
                        continue;
                if (*ptr > text_end)
                        continue;
-               **ptr = noptable[1][0];
+               nop_out(*ptr, 1);
        };
 }
 
@@ -245,7 +241,7 @@ void alternatives_smp_module_add(struct module *mod, char *name,
        struct smp_alt_module *smp;
        unsigned long flags;
 
-       if (no_replacement)
+       if (noreplace_smp)
                return;
 
        if (smp_alt_once) {
@@ -282,7 +278,7 @@ void alternatives_smp_module_del(struct module *mod)
        struct smp_alt_module *item;
        unsigned long flags;
 
-       if (no_replacement || smp_alt_once)
+       if (smp_alt_once || noreplace_smp)
                return;
 
        spin_lock_irqsave(&smp_alt, flags);
@@ -313,7 +309,7 @@ void alternatives_smp_switch(int smp)
        return;
 #endif
 
-       if (no_replacement || smp_alt_once)
+       if (noreplace_smp || smp_alt_once)
                return;
        BUG_ON(!smp && (num_online_cpus() > 1));
 
@@ -322,8 +318,6 @@ void alternatives_smp_switch(int 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);
@@ -331,8 +325,6 @@ void alternatives_smp_switch(int smp)
                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);
@@ -342,17 +334,39 @@ void alternatives_smp_switch(int smp)
 
 #endif
 
-void __init alternative_instructions(void)
+#ifdef CONFIG_PARAVIRT
+void apply_paravirt(struct paravirt_patch_site *start,
+                   struct paravirt_patch_site *end)
 {
-       unsigned long flags;
-       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);
+       struct paravirt_patch_site *p;
+
+       if (noreplace_paravirt)
                return;
+
+       for (p = start; p < end; p++) {
+               unsigned int used;
+
+               used = paravirt_ops.patch(p->instrtype, p->clobbers, p->instr,
+                                         p->len);
+
+               BUG_ON(used > p->len);
+
+               /* Pad the rest with nops */
+               nop_out(p->instr + used, p->len - used);
        }
 
+       /* Sync to be conservative, in case we patched following
+        * instructions */
+       sync_core();
+}
+extern struct paravirt_patch_site __start_parainstructions[],
+       __stop_parainstructions[];
+#endif /* CONFIG_PARAVIRT */
+
+void __init alternative_instructions(void)
+{
+       unsigned long flags;
+
        local_irq_save(flags);
        apply_alternatives(__alt_instructions, __alt_instructions_end);
 
@@ -372,22 +386,19 @@ void __init alternative_instructions(void)
                        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);
+                               (unsigned long)__smp_locks,
+                               (unsigned long)__smp_locks_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);
        }
 #endif
+       apply_paravirt(__parainstructions, __parainstructions_end);
        local_irq_restore(flags);
 }