Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
authorLinus Torvalds <torvalds@linux-foundation.org>
Tue, 18 May 2010 15:35:37 +0000 (08:35 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 18 May 2010 15:35:37 +0000 (08:35 -0700)
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Use .cfi_sections for assembly code
  x86-64: Reduce SMP locks table size
  x86, asm: Introduce and use percpu_inc()

arch/x86/Makefile
arch/x86/include/asm/alternative-asm.h
arch/x86/include/asm/alternative.h
arch/x86/include/asm/dwarf2.h
arch/x86/include/asm/hardirq.h
arch/x86/include/asm/percpu.h
arch/x86/kernel/alternative.c
arch/x86/kernel/cpu/mcheck/mce.c

index 0a43dc515e4c10dcd38f2d5adbd7e42b614069f4..8aa1b59b9074586e1fe9930b85d0cf945f14a695 100644 (file)
@@ -95,8 +95,9 @@ sp-$(CONFIG_X86_64) := rsp
 cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_endproc,-DCONFIG_AS_CFI=1)
 # is .cfi_signal_frame supported too?
 cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1)
-KBUILD_AFLAGS += $(cfi) $(cfi-sigframe)
-KBUILD_CFLAGS += $(cfi) $(cfi-sigframe)
+cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTIONS=1)
+KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections)
+KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections)
 
 LDFLAGS := -m elf_$(UTS_MACHINE)
 
index b97f786a48d597ce4c718667a19c0d8c2b45c9c7..a63a68be1cce2258daf9cadf0d465b291296c930 100644 (file)
@@ -6,8 +6,8 @@
        .macro LOCK_PREFIX
 1:     lock
        .section .smp_locks,"a"
-       _ASM_ALIGN
-       _ASM_PTR 1b
+       .balign 4
+       .long 1b - .
        .previous
        .endm
 #else
index b09ec55650b3806f91f4909558a61688a39404ee..714bf24172845313b62f08519d1c2ce49d9dc5da 100644 (file)
@@ -30,8 +30,8 @@
 #ifdef CONFIG_SMP
 #define LOCK_PREFIX \
                ".section .smp_locks,\"a\"\n"   \
-               _ASM_ALIGN "\n"                 \
-               _ASM_PTR "661f\n" /* address */ \
+               ".balign 4\n"                   \
+               ".long 661f - .\n" /* offset */ \
                ".previous\n"                   \
                "661:\n\tlock; "
 
index ae6253ab90294c89d4d009f370a6a0046431971b..733f7e91e7a99f45435a6b46c831ff3e6e9c05da 100644 (file)
 #define CFI_SIGNAL_FRAME
 #endif
 
+#if defined(CONFIG_AS_CFI_SECTIONS) && defined(__ASSEMBLY__)
+       /*
+        * Emit CFI data in .debug_frame sections, not .eh_frame sections.
+        * The latter we currently just discard since we don't do DWARF
+        * unwinding at runtime.  So only the offline DWARF information is
+        * useful to anyone.  Note we should not use this directive if this
+        * file is used in the vDSO assembly, or if vmlinux.lds.S gets
+        * changed so it doesn't discard .eh_frame.
+        */
+       .cfi_sections .debug_frame
+#endif
+
 #else
 
 /*
index 0f8576427cfefff4ada5dfdaac118e01428d8997..aeab29aee617240fbf479d2945572879be4525ec 100644 (file)
@@ -35,7 +35,7 @@ DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
 
 #define __ARCH_IRQ_STAT
 
-#define inc_irq_stat(member)   percpu_add(irq_stat.member, 1)
+#define inc_irq_stat(member)   percpu_inc(irq_stat.member)
 
 #define local_softirq_pending()        percpu_read(irq_stat.__softirq_pending)
 
index 66a272dfd8b8aa0d5fcb788ace9bec17da31e236..0ec6d12d84e68b377909da90f18ec0e3488f4526 100644 (file)
@@ -190,6 +190,29 @@ do {                                                                       \
        pfo_ret__;                                      \
 })
 
+#define percpu_unary_op(op, var)                       \
+({                                                     \
+       switch (sizeof(var)) {                          \
+       case 1:                                         \
+               asm(op "b "__percpu_arg(0)              \
+                   : "+m" (var));                      \
+               break;                                  \
+       case 2:                                         \
+               asm(op "w "__percpu_arg(0)              \
+                   : "+m" (var));                      \
+               break;                                  \
+       case 4:                                         \
+               asm(op "l "__percpu_arg(0)              \
+                   : "+m" (var));                      \
+               break;                                  \
+       case 8:                                         \
+               asm(op "q "__percpu_arg(0)              \
+                   : "+m" (var));                      \
+               break;                                  \
+       default: __bad_percpu_size();                   \
+       }                                               \
+})
+
 /*
  * percpu_read() makes gcc load the percpu variable every time it is
  * accessed while percpu_read_stable() allows the value to be cached.
@@ -207,6 +230,7 @@ do {                                                                        \
 #define percpu_and(var, val)           percpu_to_op("and", var, val)
 #define percpu_or(var, val)            percpu_to_op("or", var, val)
 #define percpu_xor(var, val)           percpu_to_op("xor", var, val)
+#define percpu_inc(var)                percpu_unary_op("inc", var)
 
 #define __this_cpu_read_1(pcp)         percpu_from_op("mov", (pcp), "m"(pcp))
 #define __this_cpu_read_2(pcp)         percpu_from_op("mov", (pcp), "m"(pcp))
index 1a160d5d44d0bd0f47b0b88b9e6a98f4b9b7f2b3..936738427223e40e9a48ba254aee7b7e5a71a143 100644 (file)
@@ -194,7 +194,7 @@ static void __init_or_module add_nops(void *insns, unsigned int len)
 }
 
 extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
-extern u8 *__smp_locks[], *__smp_locks_end[];
+extern s32 __smp_locks[], __smp_locks_end[];
 static void *text_poke_early(void *addr, const void *opcode, size_t len);
 
 /* Replace instructions with better alternatives for this CPU type.
@@ -235,37 +235,39 @@ void __init_or_module apply_alternatives(struct alt_instr *start,
 
 #ifdef CONFIG_SMP
 
-static void alternatives_smp_lock(u8 **start, u8 **end, u8 *text, u8 *text_end)
+static void alternatives_smp_lock(const s32 *start, const s32 *end,
+                                 u8 *text, u8 *text_end)
 {
-       u8 **ptr;
+       const s32 *poff;
 
        mutex_lock(&text_mutex);
-       for (ptr = start; ptr < end; ptr++) {
-               if (*ptr < text)
-                       continue;
-               if (*ptr > text_end)
+       for (poff = start; poff < end; poff++) {
+               u8 *ptr = (u8 *)poff + *poff;
+
+               if (!*poff || ptr < text || ptr >= text_end)
                        continue;
                /* turn DS segment override prefix into lock prefix */
-               text_poke(*ptr, ((unsigned char []){0xf0}), 1);
+               text_poke(ptr, ((unsigned char []){0xf0}), 1);
        };
        mutex_unlock(&text_mutex);
 }
 
-static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end)
+static void alternatives_smp_unlock(const s32 *start, const s32 *end,
+                                   u8 *text, u8 *text_end)
 {
-       u8 **ptr;
+       const s32 *poff;
 
        if (noreplace_smp)
                return;
 
        mutex_lock(&text_mutex);
-       for (ptr = start; ptr < end; ptr++) {
-               if (*ptr < text)
-                       continue;
-               if (*ptr > text_end)
+       for (poff = start; poff < end; poff++) {
+               u8 *ptr = (u8 *)poff + *poff;
+
+               if (!*poff || ptr < text || ptr >= text_end)
                        continue;
                /* turn lock prefix into DS segment override prefix */
-               text_poke(*ptr, ((unsigned char []){0x3E}), 1);
+               text_poke(ptr, ((unsigned char []){0x3E}), 1);
        };
        mutex_unlock(&text_mutex);
 }
@@ -276,8 +278,8 @@ struct smp_alt_module {
        char            *name;
 
        /* ptrs to lock prefixes */
-       u8              **locks;
-       u8              **locks_end;
+       const s32       *locks;
+       const s32       *locks_end;
 
        /* .text segment, needed to avoid patching init code ;) */
        u8              *text;
@@ -398,16 +400,19 @@ void alternatives_smp_switch(int smp)
 int alternatives_text_reserved(void *start, void *end)
 {
        struct smp_alt_module *mod;
-       u8 **ptr;
+       const s32 *poff;
        u8 *text_start = start;
        u8 *text_end = end;
 
        list_for_each_entry(mod, &smp_alt_modules, next) {
                if (mod->text > text_end || mod->text_end < text_start)
                        continue;
-               for (ptr = mod->locks; ptr < mod->locks_end; ptr++)
-                       if (text_start <= *ptr && text_end >= *ptr)
+               for (poff = mod->locks; poff < mod->locks_end; poff++) {
+                       const u8 *ptr = (const u8 *)poff + *poff;
+
+                       if (text_start <= ptr && text_end > ptr)
                                return 1;
+               }
        }
 
        return 0;
index 8a6f0afa767ec804c0a1ffa2f6bfee6e87168cb1..7a355ddcc64b98707fef017c084937b82219aa89 100644 (file)
@@ -539,7 +539,7 @@ void machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
        struct mce m;
        int i;
 
-       __get_cpu_var(mce_poll_count)++;
+       percpu_inc(mce_poll_count);
 
        mce_setup(&m);
 
@@ -934,7 +934,7 @@ void do_machine_check(struct pt_regs *regs, long error_code)
 
        atomic_inc(&mce_entry);
 
-       __get_cpu_var(mce_exception_count)++;
+       percpu_inc(mce_exception_count);
 
        if (notify_die(DIE_NMI, "machine check", regs, error_code,
                           18, SIGKILL) == NOTIFY_STOP)