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authorGerd Hoffmann <kraxel@suse.de>2006-06-26 13:56:16 +0200
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-26 10:48:14 -0700
commitd167a51877e94dda73dd656c51f363502309f713 (patch)
treeeb02c2974b61777f575dfdc07d4c2adf83bde434 /arch
parent240cd6a80642da528bfa382ec2ae4e3cb8991ea7 (diff)
[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 <waldi@debian.org> Signed-off-by: Gerd Hoffmann <kraxel@suse.de> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/i386/kernel/alternative.c118
-rw-r--r--arch/x86_64/kernel/Makefile4
-rw-r--r--arch/x86_64/kernel/module.c38
-rw-r--r--arch/x86_64/kernel/setup.c76
-rw-r--r--arch/x86_64/kernel/smpboot.c4
-rw-r--r--arch/x86_64/kernel/vmlinux.lds.S20
-rw-r--r--arch/x86_64/mm/init.c27
7 files changed, 152 insertions, 135 deletions
diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c
index 5cbd6f99fb2a..50eb0e03777e 100644
--- a/arch/i386/kernel/alternative.c
+++ b/arch/i386/kernel/alternative.c
@@ -4,27 +4,41 @@
#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
+static int no_replacement = 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;
+}
+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);
+
+#define DPRINTK(fmt, args...) if (debug_alternative) \
+ printk(KERN_DEBUG fmt, args)
+
+#ifdef GENERIC_NOP1
/* 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[];
+extern unsigned char intelnops[];
static unsigned char *intel_nops[ASM_NOP_MAX+1] = {
NULL,
intelnops,
@@ -36,6 +50,13 @@ static unsigned char *intel_nops[ASM_NOP_MAX+1] = {
intelnops + 1 + 2 + 3 + 4 + 5 + 6,
intelnops + 1 + 2 + 3 + 4 + 5 + 6 + 7,
};
+#endif
+
+#ifdef K8_NOP1
+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,
@@ -47,6 +68,13 @@ static unsigned char *k8_nops[ASM_NOP_MAX+1] = {
k8nops + 1 + 2 + 3 + 4 + 5 + 6,
k8nops + 1 + 2 + 3 + 4 + 5 + 6 + 7,
};
+#endif
+
+#ifdef K7_NOP1
+asm("\t.data\nk7nops: "
+ K7_NOP1 K7_NOP2 K7_NOP3 K7_NOP4 K7_NOP5 K7_NOP6
+ K7_NOP7 K7_NOP8);
+extern unsigned char k7nops[];
static unsigned char *k7_nops[ASM_NOP_MAX+1] = {
NULL,
k7nops,
@@ -58,6 +86,18 @@ static unsigned char *k7_nops[ASM_NOP_MAX+1] = {
k7nops + 1 + 2 + 3 + 4 + 5 + 6,
k7nops + 1 + 2 + 3 + 4 + 5 + 6 + 7,
};
+#endif
+
+#ifdef CONFIG_X86_64
+
+extern char __vsyscall_0;
+static inline unsigned char** find_nop_table(void)
+{
+ return k8_nops;
+}
+
+#else /* CONFIG_X86_64 */
+
static struct nop {
int cpuid;
unsigned char **noptable;
@@ -67,14 +107,6 @@ static struct nop {
{ -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;
@@ -89,6 +121,14 @@ static unsigned char** find_nop_table(void)
return noptable;
}
+#endif /* CONFIG_X86_64 */
+
+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
@@ -99,6 +139,7 @@ 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;
DPRINTK("%s: alt table %p -> %p\n", __FUNCTION__, start, end);
@@ -106,7 +147,16 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
BUG_ON(a->replacementlen > a->instrlen);
if (!boot_cpu_has(a->cpuid))
continue;
- memcpy(a->instr, a->replacement, a->replacementlen);
+ instr = a->instr;
+#ifdef CONFIG_X86_64
+ /* 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));
+ DPRINTK("%s: vsyscall fixup: %p => %p\n",
+ __FUNCTION__, a->instr, instr);
+ }
+#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) {
@@ -186,14 +236,6 @@ struct smp_alt_module {
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)
@@ -201,6 +243,9 @@ void alternatives_smp_module_add(struct module *mod, char *name,
struct smp_alt_module *smp;
unsigned long flags;
+ if (no_replacement)
+ return;
+
if (smp_alt_once) {
if (boot_cpu_has(X86_FEATURE_UP))
alternatives_smp_unlock(locks, locks_end,
@@ -235,7 +280,7 @@ void alternatives_smp_module_del(struct module *mod)
struct smp_alt_module *item;
unsigned long flags;
- if (smp_alt_once)
+ if (no_replacement || smp_alt_once)
return;
spin_lock_irqsave(&smp_alt, flags);
@@ -256,7 +301,7 @@ void alternatives_smp_switch(int smp)
struct smp_alt_module *mod;
unsigned long flags;
- if (smp_alt_once)
+ if (no_replacement || smp_alt_once)
return;
BUG_ON(!smp && (num_online_cpus() > 1));
@@ -285,6 +330,13 @@ void alternatives_smp_switch(int smp)
void __init alternative_instructions(void)
{
+ 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);
+ return;
+ }
apply_alternatives(__alt_instructions, __alt_instructions_end);
/* switch to patch-once-at-boottime-only mode and free the
diff --git a/arch/x86_64/kernel/Makefile b/arch/x86_64/kernel/Makefile
index 059c88313f4e..381bc6ad743e 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 bac195c74bcc..9d0958ff547f 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 4b7e02216970..64640c8f5eed 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 71a7222cf9ce..06535e7687ce 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 b81f473c4a19..5968c2415da9 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) {
diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c
index 4ba34e95d835..a70a8e3e312d 100644
--- a/arch/x86_64/mm/init.c
+++ b/arch/x86_64/mm/init.c
@@ -644,20 +644,29 @@ void __init mem_init(void)
#endif
}
-void free_initmem(void)
+void free_init_pages(char *what, unsigned long begin, unsigned long end)
{
unsigned long addr;
- addr = (unsigned long)(&__init_begin);
- for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
+ if (begin >= end)
+ return;
+
+ printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
+ for (addr = begin; addr < end; addr += PAGE_SIZE) {
ClearPageReserved(virt_to_page(addr));
init_page_count(virt_to_page(addr));
memset((void *)(addr & ~(PAGE_SIZE-1)), 0xcc, PAGE_SIZE);
free_page(addr);
totalram_pages++;
}
+}
+
+void free_initmem(void)
+{
memset(__initdata_begin, 0xba, __initdata_end - __initdata_begin);
- printk ("Freeing unused kernel memory: %luk freed\n", (__init_end - __init_begin) >> 10);
+ free_init_pages("unused kernel memory",
+ (unsigned long)(&__init_begin),
+ (unsigned long)(&__init_end));
}
#ifdef CONFIG_DEBUG_RODATA
@@ -686,15 +695,7 @@ void mark_rodata_ro(void)
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
- if (start >= end)
- return;
- printk ("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