Commit 0f61f6be authored by Mark Rutland's avatar Mark Rutland Committed by Will Deacon
Browse files

arm64: clean up symbol aliasing 



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_ALIAS(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: default avatarMark Rutland <mark.rutland@arm.com>
Acked-by: default avatarArd Biesheuvel <ardb@kernel.org>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Acked-by: default avatarMark Brown <broonie@kernel.org>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Will Deacon <will@kernel.org>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220216162229.1076788-3-mark.rutland@arm.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent e0891269

arch/arm64/include/asm/linkage.h

+0 −24
Original line number Diff line number Diff line
@@ -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

arch/arm64/kvm/hyp/nvhe/cache.S

+3 −2
Original line number Diff line number Diff line
@@ -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)

arch/arm64/lib/clear_page.S

+3 −2
Original line number Diff line number Diff line
@@ -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)

arch/arm64/lib/copy_page.S

+3 −2
Original line number Diff line number Diff line
@@ -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)

arch/arm64/lib/memchr.S

+3 −2
Original line number Diff line number Diff line
@@ -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)