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powerpc: Fixup lwsync at runtime 

To allow for a single kernel image on e500 v1/v2/mc we need to fixup lwsync
at runtime.  On e500v1/v2 lwsync causes an illop so we need to patch up
the code.  We default to 'sync' since that is always safe and if the cpu
is capable we will replace 'sync' with 'lwsync'.

We introduce CPU_FTR_LWSYNC as a way to determine at runtime if this is
needed.  This flag could be moved elsewhere since we dont really use it
for the normal CPU_FTR purpose.

Finally we only store the relative offset in the fixup section to keep it
as small as possible rather than using a full fixup_entry.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
hifive-unleashed-5.1
Kumar Gala 2008-07-02 01:16:40 +10:00 committed by Paul Mackerras
parent 5888da1876
commit 2d1b202762
13 changed files with 133 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
arch/powerpc/kernel/module.c
View File

@ -86,6 +86,12 @@ int module_finalize(const Elf_Ehdr *hdr,
(void *)sect->sh_addr + sect->sh_size);
#endif
sect = find_section(hdr, sechdrs, "__lwsync_fixup");
if (sect != NULL)
do_lwsync_fixups(cur_cpu_spec->cpu_features,
(void *)sect->sh_addr,
(void *)sect->sh_addr + sect->sh_size);
return 0;
}

4
arch/powerpc/kernel/setup_32.c
View File

@ -101,6 +101,10 @@ unsigned long __init early_init(unsigned long dt_ptr)
PTRRELOC(&__start___ftr_fixup),
PTRRELOC(&__stop___ftr_fixup));
do_lwsync_fixups(spec->cpu_features,
PTRRELOC(&__start___lwsync_fixup),
PTRRELOC(&__stop___lwsync_fixup));
return KERNELBASE + offset;
}

2
arch/powerpc/kernel/setup_64.c
View File

@ -363,6 +363,8 @@ void __init setup_system(void)
&__start___ftr_fixup, &__stop___ftr_fixup);
do_feature_fixups(powerpc_firmware_features,
&__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
do_lwsync_fixups(cur_cpu_spec->cpu_features,
&__start___lwsync_fixup, &__stop___lwsync_fixup);
/*
* Unflatten the device-tree passed by prom_init or kexec

10
arch/powerpc/kernel/vdso.c
View File

@ -571,6 +571,11 @@ static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
if (start64)
do_feature_fixups(powerpc_firmware_features,
start64, start64 + size64);
start64 = find_section64(v64->hdr, "__lwsync_fixup", &size64);
if (start64)
do_lwsync_fixups(cur_cpu_spec->cpu_features,
start64, start64 + size64);
#endif /* CONFIG_PPC64 */
start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
@ -585,6 +590,11 @@ static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
start32, start32 + size32);
#endif /* CONFIG_PPC64 */
start32 = find_section32(v32->hdr, "__lwsync_fixup", &size32);
if (start32)
do_lwsync_fixups(cur_cpu_spec->cpu_features,
start32, start32 + size32);
return 0;
}

3
arch/powerpc/kernel/vdso32/vdso32.lds.S
View File

@ -33,6 +33,9 @@ SECTIONS
. = ALIGN(8);
__ftr_fixup : { *(__ftr_fixup) }
. = ALIGN(8);
__lwsync_fixup : { *(__lwsync_fixup) }
#ifdef CONFIG_PPC64
. = ALIGN(8);
__fw_ftr_fixup : { *(__fw_ftr_fixup) }

3
arch/powerpc/kernel/vdso64/vdso64.lds.S
View File

@ -34,6 +34,9 @@ SECTIONS
. = ALIGN(8);
__ftr_fixup : { *(__ftr_fixup) }
. = ALIGN(8);
__lwsync_fixup : { *(__lwsync_fixup) }
. = ALIGN(8);
__fw_ftr_fixup : { *(__fw_ftr_fixup) }

6
arch/powerpc/kernel/vmlinux.lds.S
View File

@ -127,6 +127,12 @@ SECTIONS
*(__ftr_fixup)
__stop___ftr_fixup = .;
}
. = ALIGN(8);
__lwsync_fixup : AT(ADDR(__lwsync_fixup) - LOAD_OFFSET) {
__start___lwsync_fixup = .;
*(__lwsync_fixup)
__stop___lwsync_fixup = .;
}
#ifdef CONFIG_PPC64
. = ALIGN(8);
__fw_ftr_fixup : AT(ADDR(__fw_ftr_fixup) - LOAD_OFFSET) {

15
arch/powerpc/lib/feature-fixups-test.S
View File

@ -10,6 +10,7 @@
#include <asm/feature-fixups.h>
#include <asm/ppc_asm.h>
#include <asm/synch.h>
.text
@ -725,3 +726,17 @@ MAKE_MACRO_TEST_EXPECTED(FTR);
MAKE_MACRO_TEST(FW_FTR);
MAKE_MACRO_TEST_EXPECTED(FW_FTR);
#endif
globl(lwsync_fixup_test)
1: or 1,1,1
LWSYNC
globl(end_lwsync_fixup_test)
globl(lwsync_fixup_test_expected_LWSYNC)
1: or 1,1,1
lwsync
globl(lwsync_fixup_test_expected_SYNC)
1: or 1,1,1
sync

36
arch/powerpc/lib/feature-fixups.c
View File

@ -110,6 +110,22 @@ void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end)
}
}
void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)
{
unsigned int *start, *end, *dest;
if (!(value & CPU_FTR_LWSYNC))
return ;
start = fixup_start;
end = fixup_end;
for (; start < end; start++) {
dest = (void *)start + *start;
patch_instruction(dest, PPC_LWSYNC_INSTR);
}
}
#ifdef CONFIG_FTR_FIXUP_SELFTEST
#define check(x) \
@ -295,6 +311,25 @@ static void test_fw_macros(void)
#endif
}
static void test_lwsync_macros(void)
{
extern void lwsync_fixup_test;
extern void end_lwsync_fixup_test;
extern void lwsync_fixup_test_expected_LWSYNC;
extern void lwsync_fixup_test_expected_SYNC;
unsigned long size = &end_lwsync_fixup_test -
&lwsync_fixup_test;
/* The fixups have already been done for us during boot */
if (cur_cpu_spec->cpu_features & CPU_FTR_LWSYNC) {
check(memcmp(&lwsync_fixup_test,
&lwsync_fixup_test_expected_LWSYNC, size) == 0);
} else {
check(memcmp(&lwsync_fixup_test,
&lwsync_fixup_test_expected_SYNC, size) == 0);
}
}
static int __init test_feature_fixups(void)
{
printk(KERN_DEBUG "Running feature fixup self-tests ...\n");
@ -307,6 +342,7 @@ static int __init test_feature_fixups(void)
test_alternative_case_with_external_branch();
test_cpu_macros();
test_fw_macros();
test_lwsync_macros();
return 0;
}

3
include/asm-powerpc/code-patching.h
View File

@ -12,7 +12,8 @@
#include <asm/types.h>
#define PPC_NOP_INSTR 0x60000000
#define PPC_NOP_INSTR 0x60000000
#define PPC_LWSYNC_INSTR 0x7c2004ac
/* Flags for create_branch:
* "b" == create_branch(addr, target, 0);

21
include/asm-powerpc/cputable.h
View File

@ -156,6 +156,7 @@ extern void do_feature_fixups(unsigned long value, void *fixup_start,
#define CPU_FTR_UNIFIED_ID_CACHE ASM_CONST(0x0000000001000000)
#define CPU_FTR_SPE ASM_CONST(0x0000000002000000)
#define CPU_FTR_NEED_PAIRED_STWCX ASM_CONST(0x0000000004000000)
#define CPU_FTR_LWSYNC ASM_CONST(0x0000000008000000)
/*
* Add the 64-bit processor unique features in the top half of the word;
@ -369,43 +370,43 @@ extern void do_feature_fixups(unsigned long value, void *fixup_start,
CPU_FTR_NODSISRALIGN)
#define CPU_FTRS_E500MC (CPU_FTR_MAYBE_CAN_DOZE | CPU_FTR_USE_TB | \
CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_BIG_PHYS | CPU_FTR_NODSISRALIGN | \
CPU_FTR_L2CSR)
CPU_FTR_L2CSR | CPU_FTR_LWSYNC)
#define CPU_FTRS_GENERIC_32 (CPU_FTR_COMMON | CPU_FTR_NODSISRALIGN)
/* 64-bit CPUs */
#define CPU_FTRS_POWER3 (CPU_FTR_USE_TB | \
#define CPU_FTRS_POWER3 (CPU_FTR_USE_TB | CPU_FTR_LWSYNC | \
CPU_FTR_HPTE_TABLE | CPU_FTR_IABR | CPU_FTR_PPC_LE)
#define CPU_FTRS_RS64 (CPU_FTR_USE_TB | \
#define CPU_FTRS_RS64 (CPU_FTR_USE_TB | CPU_FTR_LWSYNC | \
CPU_FTR_HPTE_TABLE | CPU_FTR_IABR | \
CPU_FTR_MMCRA | CPU_FTR_CTRL)
#define CPU_FTRS_POWER4 (CPU_FTR_USE_TB | \
#define CPU_FTRS_POWER4 (CPU_FTR_USE_TB | CPU_FTR_LWSYNC | \
CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
CPU_FTR_MMCRA)
#define CPU_FTRS_PPC970 (CPU_FTR_USE_TB | \
#define CPU_FTRS_PPC970 (CPU_FTR_USE_TB | CPU_FTR_LWSYNC | \
CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
CPU_FTR_ALTIVEC_COMP | CPU_FTR_CAN_NAP | CPU_FTR_MMCRA)
#define CPU_FTRS_POWER5 (CPU_FTR_USE_TB | \
#define CPU_FTRS_POWER5 (CPU_FTR_USE_TB | CPU_FTR_LWSYNC | \
CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
CPU_FTR_MMCRA | CPU_FTR_SMT | \
CPU_FTR_COHERENT_ICACHE | CPU_FTR_LOCKLESS_TLBIE | \
CPU_FTR_PURR)
#define CPU_FTRS_POWER6 (CPU_FTR_USE_TB | \
#define CPU_FTRS_POWER6 (CPU_FTR_USE_TB | CPU_FTR_LWSYNC | \
CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
CPU_FTR_MMCRA | CPU_FTR_SMT | \
CPU_FTR_COHERENT_ICACHE | CPU_FTR_LOCKLESS_TLBIE | \
CPU_FTR_PURR | CPU_FTR_SPURR | CPU_FTR_REAL_LE | \
CPU_FTR_DSCR)
#define CPU_FTRS_POWER7 (CPU_FTR_USE_TB | \
#define CPU_FTRS_POWER7 (CPU_FTR_USE_TB | CPU_FTR_LWSYNC | \
CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
CPU_FTR_MMCRA | CPU_FTR_SMT | \
CPU_FTR_COHERENT_ICACHE | CPU_FTR_LOCKLESS_TLBIE | \
CPU_FTR_PURR | CPU_FTR_SPURR | CPU_FTR_REAL_LE | \
CPU_FTR_DSCR)
#define CPU_FTRS_CELL (CPU_FTR_USE_TB | \
#define CPU_FTRS_CELL (CPU_FTR_USE_TB | CPU_FTR_LWSYNC | \
CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
CPU_FTR_ALTIVEC_COMP | CPU_FTR_MMCRA | CPU_FTR_SMT | \
CPU_FTR_PAUSE_ZERO | CPU_FTR_CI_LARGE_PAGE | CPU_FTR_CELL_TB_BUG)
#define CPU_FTRS_PA6T (CPU_FTR_USE_TB | \
#define CPU_FTRS_PA6T (CPU_FTR_USE_TB | CPU_FTR_LWSYNC | \
CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | \
CPU_FTR_ALTIVEC_COMP | CPU_FTR_CI_LARGE_PAGE | \
CPU_FTR_PURR | CPU_FTR_REAL_LE | CPU_FTR_NO_SLBIE_B)

10
include/asm-powerpc/feature-fixups.h
View File

@ -113,4 +113,14 @@ label##5: \
#endif /* __ASSEMBLY__ */
/* LWSYNC feature sections */
#define START_LWSYNC_SECTION(label) label##1:
#define MAKE_LWSYNC_SECTION_ENTRY(label, sect) \
label##2: \
.pushsection sect,"a"; \
.align 2; \
label##3: \
.long label##1b-label##3b; \
.popsection;
#endif /* __ASM_POWERPC_FEATURE_FIXUPS_H */

42
include/asm-powerpc/synch.h
View File

@ -3,24 +3,12 @@
#ifdef __KERNEL__
#include <linux/stringify.h>
#include <asm/feature-fixups.h>
#if defined(__powerpc64__) || defined(CONFIG_PPC_E500MC)
#define __SUBARCH_HAS_LWSYNC
#endif
#ifdef __SUBARCH_HAS_LWSYNC
# define LWSYNC lwsync
#else
# define LWSYNC sync
#endif
#ifdef CONFIG_SMP
#define ISYNC_ON_SMP "\n\tisync\n"
#define LWSYNC_ON_SMP __stringify(LWSYNC) "\n"
#else
#define ISYNC_ON_SMP
#define LWSYNC_ON_SMP
#endif
#ifndef __ASSEMBLY__
extern unsigned int __start___lwsync_fixup, __stop___lwsync_fixup;
extern void do_lwsync_fixups(unsigned long value, void *fixup_start,
void *fixup_end);
static inline void eieio(void)
{
@ -31,6 +19,26 @@ static inline void isync(void)
{
__asm__ __volatile__ ("isync" : : : "memory");
}
#endif /* __ASSEMBLY__ */
#if defined(__powerpc64__)
# define LWSYNC lwsync
#elif defined(CONFIG_E500)
# define LWSYNC \
START_LWSYNC_SECTION(96); \
sync; \
MAKE_LWSYNC_SECTION_ENTRY(96, __lwsync_fixup);
#else
# define LWSYNC sync
#endif
#ifdef CONFIG_SMP
#define ISYNC_ON_SMP "\n\tisync\n"
#define LWSYNC_ON_SMP stringify_in_c(LWSYNC) "\n"
#else
#define ISYNC_ON_SMP
#define LWSYNC_ON_SMP
#endif
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_SYNCH_H */