[69/90] sparc: Use popc if possible for hweight routines.

From: Greg KH
Date: Sun Aug 14 2011 - 12:14:41 EST


3.0-stable review patch. If anyone has any objections, please let us know.

------------------


From: "David S. Miller" <davem@xxxxxxxxxxxxx>

[ Upstream commit ef7c4d4675d2a9206f913f26ca1a5cd41bff9d41 ]

Just like powerpc, we code patch at boot time.

Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
arch/sparc/include/asm/bitops_64.h | 42 ++----------------------------
arch/sparc/kernel/entry.h | 7 +++++
arch/sparc/kernel/setup_64.c | 27 +++++++++++++++++++
arch/sparc/kernel/sparc_ksyms_64.c | 7 +++++
arch/sparc/kernel/vmlinux.lds.S | 6 +++-
arch/sparc/lib/Makefile | 2 -
arch/sparc/lib/hweight.S | 51 +++++++++++++++++++++++++++++++++++++
7 files changed, 102 insertions(+), 40 deletions(-)
create mode 100644 arch/sparc/lib/hweight.S

--- a/arch/sparc/include/asm/bitops_64.h
+++ b/arch/sparc/include/asm/bitops_64.h
@@ -42,45 +42,11 @@ extern void change_bit(unsigned long nr,
* of bits set) of a N-bit word
*/

-#ifdef ULTRA_HAS_POPULATION_COUNT
+extern unsigned long __arch_hweight64(__u64 w);
+extern unsigned int __arch_hweight32(unsigned int w);
+extern unsigned int __arch_hweight16(unsigned int w);
+extern unsigned int __arch_hweight8(unsigned int w);

-static inline unsigned int __arch_hweight64(unsigned long w)
-{
- unsigned int res;
-
- __asm__ ("popc %1,%0" : "=r" (res) : "r" (w));
- return res;
-}
-
-static inline unsigned int __arch_hweight32(unsigned int w)
-{
- unsigned int res;
-
- __asm__ ("popc %1,%0" : "=r" (res) : "r" (w & 0xffffffff));
- return res;
-}
-
-static inline unsigned int __arch_hweight16(unsigned int w)
-{
- unsigned int res;
-
- __asm__ ("popc %1,%0" : "=r" (res) : "r" (w & 0xffff));
- return res;
-}
-
-static inline unsigned int __arch_hweight8(unsigned int w)
-{
- unsigned int res;
-
- __asm__ ("popc %1,%0" : "=r" (res) : "r" (w & 0xff));
- return res;
-}
-
-#else
-
-#include <asm-generic/bitops/arch_hweight.h>
-
-#endif
#include <asm-generic/bitops/const_hweight.h>
#include <asm-generic/bitops/lock.h>
#endif /* __KERNEL__ */
--- a/arch/sparc/kernel/entry.h
+++ b/arch/sparc/kernel/entry.h
@@ -42,6 +42,13 @@ extern void fpsave(unsigned long *fpregs
extern void fpload(unsigned long *fpregs, unsigned long *fsr);

#else /* CONFIG_SPARC32 */
+struct popc_3insn_patch_entry {
+ unsigned int addr;
+ unsigned int insns[3];
+};
+extern struct popc_3insn_patch_entry __popc_3insn_patch,
+ __popc_3insn_patch_end;
+
extern void __init per_cpu_patch(void);
extern void __init sun4v_patch(void);
extern void __init boot_cpu_id_too_large(int cpu);
--- a/arch/sparc/kernel/setup_64.c
+++ b/arch/sparc/kernel/setup_64.c
@@ -272,6 +272,30 @@ void __init sun4v_patch(void)
sun4v_hvapi_init();
}

+static void __init popc_patch(void)
+{
+ struct popc_3insn_patch_entry *p3;
+
+ p3 = &__popc_3insn_patch;
+ while (p3 < &__popc_3insn_patch_end) {
+ unsigned long addr = p3->addr;
+
+ *(unsigned int *) (addr + 0) = p3->insns[0];
+ wmb();
+ __asm__ __volatile__("flush %0" : : "r" (addr + 0));
+
+ *(unsigned int *) (addr + 4) = p3->insns[1];
+ wmb();
+ __asm__ __volatile__("flush %0" : : "r" (addr + 4));
+
+ *(unsigned int *) (addr + 8) = p3->insns[2];
+ wmb();
+ __asm__ __volatile__("flush %0" : : "r" (addr + 4));
+
+ p3++;
+ }
+}
+
#ifdef CONFIG_SMP
void __init boot_cpu_id_too_large(int cpu)
{
@@ -424,6 +448,9 @@ static void __init init_sparc64_elf_hwca
sparc64_elf_hwcap = cap | mdesc_caps;

report_hwcaps(sparc64_elf_hwcap);
+
+ if (sparc64_elf_hwcap & AV_SPARC_POPC)
+ popc_patch();
}

void __init setup_arch(char **cmdline_p)
--- a/arch/sparc/kernel/sparc_ksyms_64.c
+++ b/arch/sparc/kernel/sparc_ksyms_64.c
@@ -8,6 +8,7 @@
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
+#include <linux/bitops.h>

#include <asm/system.h>
#include <asm/cpudata.h>
@@ -38,5 +39,11 @@ EXPORT_SYMBOL(sun4v_niagara_setperf);
EXPORT_SYMBOL(sun4v_niagara2_getperf);
EXPORT_SYMBOL(sun4v_niagara2_setperf);

+/* from hweight.S */
+EXPORT_SYMBOL(__arch_hweight8);
+EXPORT_SYMBOL(__arch_hweight16);
+EXPORT_SYMBOL(__arch_hweight32);
+EXPORT_SYMBOL(__arch_hweight64);
+
/* Exporting a symbol from /init/main.c */
EXPORT_SYMBOL(saved_command_line);
--- a/arch/sparc/kernel/vmlinux.lds.S
+++ b/arch/sparc/kernel/vmlinux.lds.S
@@ -107,7 +107,11 @@ SECTIONS
*(.sun4v_2insn_patch)
__sun4v_2insn_patch_end = .;
}
-
+ .popc_3insn_patch : {
+ __popc_3insn_patch = .;
+ *(.popc_3insn_patch)
+ __popc_3insn_patch_end = .;
+ }
PERCPU_SECTION(SMP_CACHE_BYTES)

. = ALIGN(PAGE_SIZE);
--- a/arch/sparc/lib/Makefile
+++ b/arch/sparc/lib/Makefile
@@ -37,7 +37,7 @@ lib-$(CONFIG_SPARC64) += GENmemcpy.o GEN
lib-$(CONFIG_SPARC64) += GENpatch.o GENpage.o GENbzero.o

lib-$(CONFIG_SPARC64) += copy_in_user.o user_fixup.o memmove.o
-lib-$(CONFIG_SPARC64) += mcount.o ipcsum.o xor.o
+lib-$(CONFIG_SPARC64) += mcount.o ipcsum.o xor.o hweight.o

obj-y += iomap.o
obj-$(CONFIG_SPARC32) += atomic32.o
--- /dev/null
+++ b/arch/sparc/lib/hweight.S
@@ -0,0 +1,51 @@
+#include <linux/linkage.h>
+
+ .text
+ .align 32
+ENTRY(__arch_hweight8)
+ ba,pt %xcc, __sw_hweight8
+ nop
+ nop
+ENDPROC(__arch_hweight8)
+ .section .popc_3insn_patch, "ax"
+ .word __arch_hweight8
+ sllx %o0, 64-8, %g1
+ retl
+ popc %g1, %o0
+ .previous
+
+ENTRY(__arch_hweight16)
+ ba,pt %xcc, __sw_hweight16
+ nop
+ nop
+ENDPROC(__arch_hweight16)
+ .section .popc_3insn_patch, "ax"
+ .word __arch_hweight16
+ sllx %o0, 64-16, %g1
+ retl
+ popc %g1, %o0
+ .previous
+
+ENTRY(__arch_hweight32)
+ ba,pt %xcc, __sw_hweight32
+ nop
+ nop
+ENDPROC(__arch_hweight32)
+ .section .popc_3insn_patch, "ax"
+ .word __arch_hweight32
+ sllx %o0, 64-32, %g1
+ retl
+ popc %g1, %o0
+ .previous
+
+ENTRY(__arch_hweight64)
+ ba,pt %xcc, __sw_hweight64
+ nop
+ nop
+ENDPROC(__arch_hweight64)
+ .section .popc_3insn_patch, "ax"
+ .word __arch_hweight64
+ retl
+ popc %o0, %o0
+ nop
+ .previous


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