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Message-Id: <dfa7b35e27e01964fcda84bf1ed8b2b31cf93826.1575273217.git.christophe.leroy@c-s.fr>
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From:   Christophe Leroy <christophe.leroy@c-s.fr>
Subject: [PATCH v4 5/8] powerpc/vdso32: Don't read cache line size from the
 datapage on PPC32.
To:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        arnd@arndb.de
Date:   Mon,  2 Dec 2019 07:57:31 +0000 (UTC)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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@c-s.fr>
---
 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