[PATCH v4 5/8] powerpc/vdso32: Don't read cache line size from the datapage on PPC32.

From: Christophe Leroy
Date: Mon Dec 02 2019 - 02:57:54 EST


On PPC32, the cache lines have a fixed size known at build time.

Don't read it from the datapage.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
arch/powerpc/include/asm/vdso_datapage.h | 4 ----
arch/powerpc/kernel/asm-offsets.c | 2 +-
arch/powerpc/kernel/vdso.c | 5 -----
arch/powerpc/kernel/vdso32/cacheflush.S | 23 +++++++++++++++++++++++
4 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h
index ee5319a6f4e3..b9ef6cf50ea5 100644
--- a/arch/powerpc/include/asm/vdso_datapage.h
+++ b/arch/powerpc/include/asm/vdso_datapage.h
@@ -108,10 +108,6 @@ struct vdso_data {
__u32 stamp_sec_fraction; /* fractional seconds of stamp_xtime */
__u32 hrtimer_res; /* hrtimer resolution */
__u32 syscall_map_32[SYSCALL_MAP_SIZE]; /* map of syscalls */
- __u32 dcache_block_size; /* L1 d-cache block size */
- __u32 icache_block_size; /* L1 i-cache block size */
- __u32 dcache_log_block_size; /* L1 d-cache log block size */
- __u32 icache_log_block_size; /* L1 i-cache log block size */
};

#endif /* CONFIG_PPC64 */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 3d47aec7becf..0013197d89a6 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -389,11 +389,11 @@ int main(void)
OFFSET(STAMP_XTIME_NSEC, vdso_data, stamp_xtime_nsec);
OFFSET(STAMP_SEC_FRAC, vdso_data, stamp_sec_fraction);
OFFSET(CLOCK_HRTIMER_RES, vdso_data, hrtimer_res);
+#ifdef CONFIG_PPC64
OFFSET(CFG_ICACHE_BLOCKSZ, vdso_data, icache_block_size);
OFFSET(CFG_DCACHE_BLOCKSZ, vdso_data, dcache_block_size);
OFFSET(CFG_ICACHE_LOGBLOCKSZ, vdso_data, icache_log_block_size);
OFFSET(CFG_DCACHE_LOGBLOCKSZ, vdso_data, dcache_log_block_size);
-#ifdef CONFIG_PPC64
OFFSET(CFG_SYSCALL_MAP64, vdso_data, syscall_map_64);
OFFSET(TVAL64_TV_SEC, __kernel_old_timeval, tv_sec);
OFFSET(TVAL64_TV_USEC, __kernel_old_timeval, tv_usec);
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index eae9ddaecbcf..b9a108411c0d 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -728,11 +728,6 @@ static int __init vdso_init(void)
*/
vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
-#else
- vdso_data->dcache_block_size = L1_CACHE_BYTES;
- vdso_data->dcache_log_block_size = L1_CACHE_SHIFT;
- vdso_data->icache_block_size = L1_CACHE_BYTES;
- vdso_data->icache_log_block_size = L1_CACHE_SHIFT;
#endif /* CONFIG_PPC64 */


diff --git a/arch/powerpc/kernel/vdso32/cacheflush.S b/arch/powerpc/kernel/vdso32/cacheflush.S
index d178ec8c279d..3440ddf21c8b 100644
--- a/arch/powerpc/kernel/vdso32/cacheflush.S
+++ b/arch/powerpc/kernel/vdso32/cacheflush.S
@@ -10,6 +10,7 @@
#include <asm/vdso.h>
#include <asm/vdso_datapage.h>
#include <asm/asm-offsets.h>
+#include <asm/cache.h>

.text

@@ -23,28 +24,44 @@
*/
V_FUNCTION_BEGIN(__kernel_sync_dicache)
.cfi_startproc
+#ifdef CONFIG_PPC64
mflr r12
.cfi_register lr,r12
get_datapage r10, r0
mtlr r12
+#endif

+#ifdef CONFIG_PPC64
lwz r7,CFG_DCACHE_BLOCKSZ(r10)
addi r5,r7,-1
+#else
+ li r5, L1_CACHE_BYTES - 1
+#endif
andc r6,r3,r5 /* round low to line bdy */
subf r8,r6,r4 /* compute length */
add r8,r8,r5 /* ensure we get enough */
+#ifdef CONFIG_PPC64
lwz r9,CFG_DCACHE_LOGBLOCKSZ(r10)
srw. r8,r8,r9 /* compute line count */
+#else
+ srwi. r8, r8, L1_CACHE_SHIFT
+ mr r7, r6
+#endif
crclr cr0*4+so
beqlr /* nothing to do? */
mtctr r8
1: dcbst 0,r6
+#ifdef CONFIG_PPC64
add r6,r6,r7
+#else
+ addi r6, r6, L1_CACHE_BYTES
+#endif
bdnz 1b
sync

/* Now invalidate the instruction cache */

+#ifdef CONFIG_PPC64
lwz r7,CFG_ICACHE_BLOCKSZ(r10)
addi r5,r7,-1
andc r6,r3,r5 /* round low to line bdy */
@@ -54,9 +71,15 @@ V_FUNCTION_BEGIN(__kernel_sync_dicache)
srw. r8,r8,r9 /* compute line count */
crclr cr0*4+so
beqlr /* nothing to do? */
+#endif
mtctr r8
+#ifdef CONFIG_PPC64
2: icbi 0,r6
add r6,r6,r7
+#else
+2: icbi 0, r7
+ addi r7, r7, L1_CACHE_BYTES
+#endif
bdnz 2b
isync
li r3,0
--
2.13.3