[PATCH v2 4/7] arm64: clean up symbol aliasing

Mark Rutland
2022-01-25T11:36:28Z

Now that we have SYM_FUNC_ALIAS() and SYM_FUNC_ALIAS_WEAK(), use those
to simplify and more consistently define function aliases across
arch/arm64.

Aliases are now defined in terms of a canonical function name. For
position-independent functions I've made the __pi_<func> name the
canonical name, and defined other alises in terms of this.

The SYM_FUNC_{START,END}_PI(func) macros obscure the __pi_<func> name,
and make this hard to seatch for. The SYM_FUNC_START_WEAK_PI() macro
also obscures the fact that the __pi_<func> fymbol is global and the
<func> symbol is weak. For clarity, I have removed these macros and used
SYM_FUNC_{START,END}() directly with the __pi_<func> name.

For example:

SYM_FUNC_START_WEAK_PI(func)
... asm insns ...
SYM_FUNC_END_PI(func)
EXPORT_SYMBOL(func)

... becomes:

SYM_FUNC_START(__pi_func)
... asm insns ...
SYM_FUNC_END(__pi_func)

SYM_FUNC_ALIAS_WEAK(func, __pi_func)
EXPORT_SYMBOL(func)

For clarity, where there are multiple annotations such as
EXPORT_SYMBOL(), I've tried to keep annotations grouped by symbol. For
example, where a function has a name and an alias which are both
exported, this is organised as:

SYM_FUNC_START(func)
... asm insns ...
SYM_FUNC_END(func)
EXPORT_SYMBOL(func)

SYM_FUNC_ALAIAS(alias, func)
EXPORT_SYMBOL(alias)

For consistency with the other string functions, I've defined strrchr as
a position-independent function, as it can safely be used as such even
though we have no users today.

As we no longer use SYM_FUNC_{START,END}_ALIAS(), our local copies are
removed. The common versions will be removed by a subsequent patch.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
---
arch/arm64/include/asm/linkage.h | 24 ----------------------
arch/arm64/kvm/hyp/nvhe/cache.S | 5 +++--
arch/arm64/lib/clear_page.S | 5 +++--
arch/arm64/lib/copy_page.S | 5 +++--
arch/arm64/lib/memchr.S | 5 +++--
arch/arm64/lib/memcmp.S | 6 +++---
arch/arm64/lib/memcpy.S | 21 ++++++++++---------
arch/arm64/lib/memset.S | 12 ++++++-----
arch/arm64/lib/strchr.S | 6 ++++--
arch/arm64/lib/strcmp.S | 6 +++---
arch/arm64/lib/strlen.S | 6 +++---
arch/arm64/lib/strncmp.S | 6 +++---
arch/arm64/lib/strnlen.S | 6 ++++--
arch/arm64/lib/strrchr.S | 5 +++--
arch/arm64/mm/cache.S | 35 +++++++++++++++++++-------------
15 files changed, 74 insertions(+), 79 deletions(-)

diff --git a/arch/arm64/include/asm/linkage.h b/arch/arm64/include/asm/linkage.h
index b77e9b3f5371c..43f8c25b3fda6 100644
--- a/arch/arm64/include/asm/linkage.h
+++ b/arch/arm64/include/asm/linkage.h
@@ -39,28 +39,4 @@
SYM_START(name, SYM_L_WEAK, SYM_A_NONE) \
bti c ;

-/*
- * Annotate a function as position independent, i.e., safe to be called before
- * the kernel virtual mapping is activated.
- */
-#define SYM_FUNC_START_PI(x) \
- SYM_FUNC_START_ALIAS(__pi_##x); \
- SYM_FUNC_START(x)
-
-#define SYM_FUNC_START_WEAK_PI(x) \
- SYM_FUNC_START_ALIAS(__pi_##x); \
- SYM_FUNC_START_WEAK(x)
-
-#define SYM_FUNC_START_WEAK_ALIAS_PI(x) \
- SYM_FUNC_START_ALIAS(__pi_##x); \
- SYM_START(x, SYM_L_WEAK, SYM_A_ALIGN)
-
-#define SYM_FUNC_END_PI(x) \
- SYM_FUNC_END(x); \
- SYM_FUNC_END_ALIAS(__pi_##x)
-
-#define SYM_FUNC_END_ALIAS_PI(x) \
- SYM_FUNC_END_ALIAS(x); \
- SYM_FUNC_END_ALIAS(__pi_##x)
-
#endif
diff --git a/arch/arm64/kvm/hyp/nvhe/cache.S b/arch/arm64/kvm/hyp/nvhe/cache.S
index 958734f4d6b0e..0c367eb5f4e28 100644
--- a/arch/arm64/kvm/hyp/nvhe/cache.S
+++ b/arch/arm64/kvm/hyp/nvhe/cache.S
@@ -7,7 +7,8 @@
#include <asm/assembler.h>
#include <asm/alternative.h>

-SYM_FUNC_START_PI(dcache_clean_inval_poc)
+SYM_FUNC_START(__pi_dcache_clean_inval_poc)
dcache_by_line_op civac, sy, x0, x1, x2, x3
ret
-SYM_FUNC_END_PI(dcache_clean_inval_poc)
+SYM_FUNC_END(__pi_dcache_clean_inval_poc)
+SYM_FUNC_ALIAS(dcache_clean_inval_poc, __pi_dcache_clean_inval_poc)
diff --git a/arch/arm64/lib/clear_page.S b/arch/arm64/lib/clear_page.S
index 1fd5d790ab800..ebde40e7fa2b2 100644
--- a/arch/arm64/lib/clear_page.S
+++ b/arch/arm64/lib/clear_page.S
@@ -14,7 +14,7 @@
* Parameters:
* x0 - dest
*/
-SYM_FUNC_START_PI(clear_page)
+SYM_FUNC_START(__pi_clear_page)
mrs x1, dczid_el0
tbnz x1, #4, 2f /* Branch if DC ZVA is prohibited */
and w1, w1, #0xf
@@ -35,5 +35,6 @@ SYM_FUNC_START_PI(clear_page)
tst x0, #(PAGE_SIZE - 1)
b.ne 2b
ret
-SYM_FUNC_END_PI(clear_page)
+SYM_FUNC_END(__pi_clear_page)
+SYM_FUNC_ALIAS(clear_page, __pi_clear_page)
EXPORT_SYMBOL(clear_page)
diff --git a/arch/arm64/lib/copy_page.S b/arch/arm64/lib/copy_page.S
index 29144f4cd4492..c336d2ffdec55 100644
--- a/arch/arm64/lib/copy_page.S
+++ b/arch/arm64/lib/copy_page.S
@@ -17,7 +17,7 @@
* x0 - dest
* x1 - src
*/
-SYM_FUNC_START_PI(copy_page)
+SYM_FUNC_START(__pi_copy_page)
alternative_if ARM64_HAS_NO_HW_PREFETCH
// Prefetch three cache lines ahead.
prfm pldl1strm, [x1, #128]
@@ -75,5 +75,6 @@ alternative_else_nop_endif
stnp x16, x17, [x0, #112 - 256]

ret
-SYM_FUNC_END_PI(copy_page)
+SYM_FUNC_END(__pi_copy_page)
+SYM_FUNC_ALIAS(copy_page, __pi_copy_page)
EXPORT_SYMBOL(copy_page)
diff --git a/arch/arm64/lib/memchr.S b/arch/arm64/lib/memchr.S
index 7c2276fdab543..37a9f2a4f7f4b 100644
--- a/arch/arm64/lib/memchr.S
+++ b/arch/arm64/lib/memchr.S
@@ -38,7 +38,7 @@

.p2align 4
nop
-SYM_FUNC_START_WEAK_PI(memchr)
+SYM_FUNC_START(__pi_memchr)
and chrin, chrin, #0xff
lsr wordcnt, cntin, #3
cbz wordcnt, L(byte_loop)
@@ -71,5 +71,6 @@ CPU_LE( rev tmp, tmp)
L(not_found):
mov result, #0
ret
-SYM_FUNC_END_PI(memchr)
+SYM_FUNC_END(__pi_memchr)
+SYM_FUNC_ALIAS_WEAK(memchr, __pi_memchr)
EXPORT_SYMBOL_NOKASAN(memchr)
diff --git a/arch/arm64/lib/memcmp.S b/arch/arm64/lib/memcmp.S
index 7d956384222ff..a5ccf2c55f911 100644
--- a/arch/arm64/lib/memcmp.S
+++ b/arch/arm64/lib/memcmp.S
@@ -32,7 +32,7 @@
#define tmp1 x7
#define tmp2 x8

-SYM_FUNC_START_WEAK_PI(memcmp)
+SYM_FUNC_START(__pi_memcmp)
subs limit, limit, 8
b.lo L(less8)

@@ -134,6 +134,6 @@ L(byte_loop):
b.eq L(byte_loop)
sub result, data1w, data2w
ret
-
-SYM_FUNC_END_PI(memcmp)
+SYM_FUNC_END(__pi_memcmp)
+SYM_FUNC_ALIAS_WEAK(memcmp, __pi_memcmp)
EXPORT_SYMBOL_NOKASAN(memcmp)
diff --git a/arch/arm64/lib/memcpy.S b/arch/arm64/lib/memcpy.S
index b82fd64ee1e1c..4ab48d49c4515 100644
--- a/arch/arm64/lib/memcpy.S
+++ b/arch/arm64/lib/memcpy.S
@@ -57,10 +57,7 @@
The loop tail is handled by always copying 64 bytes from the end.
*/

-SYM_FUNC_START_ALIAS(__memmove)
-SYM_FUNC_START_WEAK_ALIAS_PI(memmove)
-SYM_FUNC_START_ALIAS(__memcpy)
-SYM_FUNC_START_WEAK_PI(memcpy)
+SYM_FUNC_START(__pi_memcpy)
add srcend, src, count
add dstend, dstin, count
cmp count, 128
@@ -241,12 +238,16 @@ L(copy64_from_start):
stp B_l, B_h, [dstin, 16]
stp C_l, C_h, [dstin]
ret
+SYM_FUNC_END(__pi_memcpy)

-SYM_FUNC_END_PI(memcpy)
-EXPORT_SYMBOL(memcpy)
-SYM_FUNC_END_ALIAS(__memcpy)
+SYM_FUNC_ALIAS(__memcpy, __pi_memcpy)
EXPORT_SYMBOL(__memcpy)
-SYM_FUNC_END_ALIAS_PI(memmove)
-EXPORT_SYMBOL(memmove)
-SYM_FUNC_END_ALIAS(__memmove)
+SYM_FUNC_ALIAS_WEAK(memcpy, __memcpy)
+EXPORT_SYMBOL(memcpy)
+
+SYM_FUNC_ALIAS(__pi_memmove, __pi_memcpy)
+
+SYM_FUNC_ALIAS(__memmove, __pi_memmove)
EXPORT_SYMBOL(__memmove)
+SYM_FUNC_ALIAS_WEAK(memmove, __memmove)
+EXPORT_SYMBOL(memmove)
diff --git a/arch/arm64/lib/memset.S b/arch/arm64/lib/memset.S
index a9c1c9a01ea90..a5aebe82ad73b 100644
--- a/arch/arm64/lib/memset.S
+++ b/arch/arm64/lib/memset.S
@@ -42,8 +42,7 @@ dst .req x8
tmp3w .req w9
tmp3 .req x9

-SYM_FUNC_START_ALIAS(__memset)
-SYM_FUNC_START_WEAK_PI(memset)
+SYM_FUNC_START(__pi_memset)
mov dst, dstin /* Preserve return value. */
and A_lw, val, #255
orr A_lw, A_lw, A_lw, lsl #8
@@ -202,7 +201,10 @@ SYM_FUNC_START_WEAK_PI(memset)
ands count, count, zva_bits_x
b.ne .Ltail_maybe_long
ret
-SYM_FUNC_END_PI(memset)
-EXPORT_SYMBOL(memset)
-SYM_FUNC_END_ALIAS(__memset)
+SYM_FUNC_END(__pi_memset)
+
+SYM_FUNC_ALIAS(__memset, __pi_memset)
EXPORT_SYMBOL(__memset)
+
+SYM_FUNC_ALIAS_WEAK(memset, __pi_memset)
+EXPORT_SYMBOL(memset)
diff --git a/arch/arm64/lib/strchr.S b/arch/arm64/lib/strchr.S
index 1f47eae3b0d6d..94ee67a6b212c 100644
--- a/arch/arm64/lib/strchr.S
+++ b/arch/arm64/lib/strchr.S
@@ -18,7 +18,7 @@
* Returns:
* x0 - address of first occurrence of 'c' or 0
*/
-SYM_FUNC_START_WEAK(strchr)
+SYM_FUNC_START(__pi_strchr)
and w1, w1, #0xff
1: ldrb w2, [x0], #1
cmp w2, w1
@@ -28,5 +28,7 @@ SYM_FUNC_START_WEAK(strchr)
cmp w2, w1
csel x0, x0, xzr, eq
ret
-SYM_FUNC_END(strchr)
+SYM_FUNC_END(__pi_strchr)
+
+SYM_FUNC_ALIAS_WEAK(strchr, __pi_strchr)
EXPORT_SYMBOL_NOKASAN(strchr)
diff --git a/arch/arm64/lib/strcmp.S b/arch/arm64/lib/strcmp.S
index 83bcad72ec972..cda7de747efcf 100644
--- a/arch/arm64/lib/strcmp.S
+++ b/arch/arm64/lib/strcmp.S
@@ -41,7 +41,7 @@

/* Start of performance-critical section -- one 64B cache line. */
.align 6
-SYM_FUNC_START_WEAK_PI(strcmp)
+SYM_FUNC_START(__pi_strcmp)
eor tmp1, src1, src2
mov zeroones, #REP8_01
tst tmp1, #7
@@ -171,6 +171,6 @@ L(loop_misaligned):
L(done):
sub result, data1, data2
ret
-
-SYM_FUNC_END_PI(strcmp)
+SYM_FUNC_END(__pi_strcmp)
+SYM_FUNC_ALIAS_WEAK(strcmp, __pi_strcmp)
EXPORT_SYMBOL_NOHWKASAN(strcmp)
diff --git a/arch/arm64/lib/strlen.S b/arch/arm64/lib/strlen.S
index 1648790e91b3c..4919fe81ae540 100644
--- a/arch/arm64/lib/strlen.S
+++ b/arch/arm64/lib/strlen.S
@@ -79,7 +79,7 @@
whether the first fetch, which may be misaligned, crosses a page
boundary. */

-SYM_FUNC_START_WEAK_PI(strlen)
+SYM_FUNC_START(__pi_strlen)
and tmp1, srcin, MIN_PAGE_SIZE - 1
mov zeroones, REP8_01
cmp tmp1, MIN_PAGE_SIZE - 16
@@ -208,6 +208,6 @@ L(page_cross):
csel data1, data1, tmp4, eq
csel data2, data2, tmp2, eq
b L(page_cross_entry)
-
-SYM_FUNC_END_PI(strlen)
+SYM_FUNC_END(__pi_strlen)
+SYM_FUNC_ALIAS_WEAK(strlen, __pi_strlen)
EXPORT_SYMBOL_NOKASAN(strlen)
diff --git a/arch/arm64/lib/strncmp.S b/arch/arm64/lib/strncmp.S
index e42bcfcd37e6f..a848abcec975e 100644
--- a/arch/arm64/lib/strncmp.S
+++ b/arch/arm64/lib/strncmp.S
@@ -44,7 +44,7 @@
#define endloop x15
#define count mask

-SYM_FUNC_START_WEAK_PI(strncmp)
+SYM_FUNC_START(__pi_strncmp)
cbz limit, L(ret0)
eor tmp1, src1, src2
mov zeroones, #REP8_01
@@ -256,6 +256,6 @@ L(done_loop):
L(ret0):
mov result, #0
ret
-
-SYM_FUNC_END_PI(strncmp)
+SYM_FUNC_END(__pi_strncmp)
+SYM_FUNC_ALIAS_WEAK(strncmp, __pi_strncmp)
EXPORT_SYMBOL_NOHWKASAN(strncmp)
diff --git a/arch/arm64/lib/strnlen.S b/arch/arm64/lib/strnlen.S
index b72913a990389..d5ac0e10a01db 100644
--- a/arch/arm64/lib/strnlen.S
+++ b/arch/arm64/lib/strnlen.S
@@ -47,7 +47,7 @@ limit_wd .req x14
#define REP8_7f 0x7f7f7f7f7f7f7f7f
#define REP8_80 0x8080808080808080

-SYM_FUNC_START_WEAK_PI(strnlen)
+SYM_FUNC_START(__pi_strnlen)
cbz limit, .Lhit_limit
mov zeroones, #REP8_01
bic src, srcin, #15
@@ -156,5 +156,7 @@ CPU_LE( lsr tmp2, tmp2, tmp4 ) /* Shift (tmp1 & 63). */
.Lhit_limit:
mov len, limit
ret
-SYM_FUNC_END_PI(strnlen)
+SYM_FUNC_END(__pi_strnlen)
+
+SYM_FUNC_ALIAS_WEAK(strnlen, __pi_strnlen)
EXPORT_SYMBOL_NOKASAN(strnlen)
diff --git a/arch/arm64/lib/strrchr.S b/arch/arm64/lib/strrchr.S
index 13132d1ed6d12..a5123cf0ce125 100644
--- a/arch/arm64/lib/strrchr.S
+++ b/arch/arm64/lib/strrchr.S
@@ -18,7 +18,7 @@
* Returns:
* x0 - address of last occurrence of 'c' or 0
*/
-SYM_FUNC_START_WEAK_PI(strrchr)
+SYM_FUNC_START(__pi_strrchr)
mov x3, #0
and w1, w1, #0xff
1: ldrb w2, [x0], #1
@@ -29,5 +29,6 @@ SYM_FUNC_START_WEAK_PI(strrchr)
b 1b
2: mov x0, x3
ret
-SYM_FUNC_END_PI(strrchr)
+SYM_FUNC_END(__pi_strrchr)
+SYM_FUNC_ALIAS_WEAK(strrchr, __pi_strrchr)
EXPORT_SYMBOL_NOKASAN(strrchr)
diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S
index 7d0563db42014..0ea6cc25dc663 100644
--- a/arch/arm64/mm/cache.S
+++ b/arch/arm64/mm/cache.S
@@ -107,10 +107,11 @@ SYM_FUNC_END(icache_inval_pou)
* - start - virtual start address of region
* - end - virtual end address of region
*/
-SYM_FUNC_START_PI(dcache_clean_inval_poc)
+SYM_FUNC_START(__pi_dcache_clean_inval_poc)
dcache_by_line_op civac, sy, x0, x1, x2, x3
ret
-SYM_FUNC_END_PI(dcache_clean_inval_poc)
+SYM_FUNC_END(__pi_dcache_clean_inval_poc)
+SYM_FUNC_ALIAS(dcache_clean_inval_poc, __pi_dcache_clean_inval_poc)

/*
* dcache_clean_pou(start, end)
@@ -140,7 +141,7 @@ SYM_FUNC_END(dcache_clean_pou)
* - start - kernel start address of region
* - end - kernel end address of region
*/
-SYM_FUNC_START_PI(dcache_inval_poc)
+SYM_FUNC_START(__pi_dcache_inval_poc)
dcache_line_size x2, x3
sub x3, x2, #1
tst x1, x3 // end cache line aligned?
@@ -158,7 +159,8 @@ SYM_FUNC_START_PI(dcache_inval_poc)
b.lo 2b
dsb sy
ret
-SYM_FUNC_END_PI(dcache_inval_poc)
+SYM_FUNC_END(__pi_dcache_inval_poc)
+SYM_FUNC_ALIAS(dcache_inval_poc, __pi_dcache_inval_poc)

/*
* dcache_clean_poc(start, end)
@@ -169,10 +171,11 @@ SYM_FUNC_END_PI(dcache_inval_poc)
* - start - virtual start address of region
* - end - virtual end address of region
*/
-SYM_FUNC_START_PI(dcache_clean_poc)
+SYM_FUNC_START(__pi_dcache_clean_poc)
dcache_by_line_op cvac, sy, x0, x1, x2, x3
ret
-SYM_FUNC_END_PI(dcache_clean_poc)
+SYM_FUNC_END(__pi_dcache_clean_poc)
+SYM_FUNC_ALIAS(dcache_clean_poc, __pi_dcache_clean_poc)

/*
* dcache_clean_pop(start, end)
@@ -183,13 +186,14 @@ SYM_FUNC_END_PI(dcache_clean_poc)
* - start - virtual start address of region
* - end - virtual end address of region
*/
-SYM_FUNC_START_PI(dcache_clean_pop)
+SYM_FUNC_START(__pi_dcache_clean_pop)
alternative_if_not ARM64_HAS_DCPOP
b dcache_clean_poc
alternative_else_nop_endif
dcache_by_line_op cvap, sy, x0, x1, x2, x3
ret
-SYM_FUNC_END_PI(dcache_clean_pop)
+SYM_FUNC_END(__pi_dcache_clean_pop)
+SYM_FUNC_ALIAS(dcache_clean_pop, __pi_dcache_clean_pop)

/*
* __dma_flush_area(start, size)
@@ -199,11 +203,12 @@ SYM_FUNC_END_PI(dcache_clean_pop)
* - start - virtual start address of region
* - size - size in question
*/
-SYM_FUNC_START_PI(__dma_flush_area)
+SYM_FUNC_START(__pi___dma_flush_area)
add x1, x0, x1
dcache_by_line_op civac, sy, x0, x1, x2, x3
ret
-SYM_FUNC_END_PI(__dma_flush_area)
+SYM_FUNC_END(__pi___dma_flush_area)
+SYM_FUNC_ALIAS(__dma_flush_area, __pi___dma_flush_area)

/*
* __dma_map_area(start, size, dir)
@@ -211,12 +216,13 @@ SYM_FUNC_END_PI(__dma_flush_area)
* - size - size of region
* - dir - DMA direction
*/
-SYM_FUNC_START_PI(__dma_map_area)
+SYM_FUNC_START(__pi___dma_map_area)
add x1, x0, x1
cmp w2, #DMA_FROM_DEVICE
b.eq __pi_dcache_inval_poc
b __pi_dcache_clean_poc
-SYM_FUNC_END_PI(__dma_map_area)
+SYM_FUNC_END(__pi___dma_map_area)
+SYM_FUNC_ALIAS(__dma_map_area, __pi___dma_map_area)

/*
* __dma_unmap_area(start, size, dir)
@@ -224,9 +230,10 @@ SYM_FUNC_END_PI(__dma_map_area)
* - size - size of region
* - dir - DMA direction
*/
-SYM_FUNC_START_PI(__dma_unmap_area)
+SYM_FUNC_START(__pi___dma_unmap_area)
add x1, x0, x1
cmp w2, #DMA_TO_DEVICE
b.ne __pi_dcache_inval_poc
ret
-SYM_FUNC_END_PI(__dma_unmap_area)
+SYM_FUNC_END(__pi___dma_unmap_area)
+SYM_FUNC_ALIAS(__dma_unmap_area, __pi___dma_unmap_area)
--
2.30.2