From: Benjamin Gray <bgray@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org, mpe@ellerman.id.au
Cc: Benjamin Gray <bgray@linux.ibm.com>
Subject: [PATCH v1 3/3] powerpc/code-patching: Optimise patch_memcpy() to 4 byte chunks
Date: Fri, 15 Mar 2024 13:57:36 +1100 [thread overview]
Message-ID: <20240315025736.404867-3-bgray@linux.ibm.com> (raw)
In-Reply-To: <20240315025736.404867-1-bgray@linux.ibm.com>
As we are patching instructions, we can assume the length is a multiple
of 4 and the destination address is aligned.
Atomicity of patching a prefixed instruction is not a concern, as the
original implementation doesn't provide it anyway.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
---
arch/powerpc/lib/code-patching.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index c6633759b509..ed450a32918c 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -394,10 +394,10 @@ static int patch_memset32(u32 *addr, u32 val, size_t count)
return -EPERM;
}
-static int patch_memcpy(void *dst, void *src, size_t len)
+static int patch_memcpy32(u32 *dst, u32 *src, size_t count)
{
- for (void *end = src + len; src < end; dst++, src++)
- __put_kernel_nofault(dst, src, u8, failed);
+ for (u32 *end = src + count; src < end; dst++, src++)
+ __put_kernel_nofault(dst, src, u32, failed);
return 0;
@@ -424,7 +424,7 @@ static int __patch_instructions(u32 *patch_addr, u32 *code, size_t len, bool rep
err = patch_memset32(patch_addr, val, len / 4);
}
} else {
- err = patch_memcpy(patch_addr, code, len);
+ err = patch_memcpy32(patch_addr, code, len / 4);
}
smp_wmb(); /* smp write barrier */
--
2.44.0
next prev parent reply other threads:[~2024-03-15 3:00 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-15 2:57 [PATCH v1 1/3] powerpc/code-patching: Test patch_instructions() during boot Benjamin Gray
2024-03-15 2:57 ` [PATCH v1 2/3] powerpc/code-patching: Use dedicated memory routines for patching Benjamin Gray
2024-03-15 3:17 ` Benjamin Gray
2024-03-15 6:36 ` Christophe Leroy
2024-03-17 21:42 ` Benjamin Gray
2024-03-15 2:57 ` Benjamin Gray [this message]
2024-03-15 6:39 ` [PATCH v1 3/3] powerpc/code-patching: Optimise patch_memcpy() to 4 byte chunks Christophe Leroy
2024-03-17 21:44 ` Benjamin Gray
2024-03-15 7:14 ` [PATCH v1 1/3] powerpc/code-patching: Test patch_instructions() during boot Christophe Leroy
2024-03-17 21:38 ` Benjamin Gray
2024-03-17 22:23 ` Benjamin Gray
2024-03-18 2:25 ` Michael Ellerman
2024-03-17 22:24 ` Benjamin Gray
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