[PATCH] [ALTERNATIVE] ARM: fix copypage functions for clang

From: Arnd Bergmann
Date: Wed Oct 17 2018 - 05:06:12 EST


clang points out that a naked function should not pass
the function arguments into the inline assembly:

arch/arm/mm/copypage-feroceon.c:67:9: error: parameter references not allowed in naked functions
arch/arm/mm/copypage-v4mc.c:64:9: error: parameter references not allowed in naked functions
arch/arm/mm/copypage-v4wb.c:47:9: error: parameter references not allowed in naked functions
arch/arm/mm/copypage-v4wt.c:43:9: error: parameter references not allowed in naked functions
arch/arm/mm/copypage-xsc3.c:70:9: error: parameter references not allowed in naked functions
arch/arm/mm/copypage-xscale.c:84:9: error: parameter references not allowed in naked functions

The constraints were originally added in commit 9a40ac86152c ("ARM:
6164/1: Add kto and kfrom to input operands list.") as a gcc-4.5
workaround. Another workaround for the same problem was added in commit
9c695203a7dd ("compiler-gcc.h: gcc-4.5 needs noclone and noinline
on __naked functions") and should have obsoleted the first one. That
workaroud was subsequently reverted in commit d124b44f09ca ("Compiler
Attributes: naked was fixed in gcc 4.6") as we raised the minimum compiler
level to gcc-4.6.

Remove the extraneous references and use the register numbers
consistently as required by clang.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
I've used this on my randconfig build setup, and it makes all
configurations build without warnings, but I have not done
any runtime testing on it.
---
arch/arm/mm/copypage-feroceon.c | 4 ++--
arch/arm/mm/copypage-v4mc.c | 26 +++++++++++++-------------
arch/arm/mm/copypage-v4wb.c | 4 ++--
arch/arm/mm/copypage-v4wt.c | 4 ++--
arch/arm/mm/copypage-xsc3.c | 6 +++---
arch/arm/mm/copypage-xscale.c | 4 ++--
6 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/arch/arm/mm/copypage-feroceon.c b/arch/arm/mm/copypage-feroceon.c
index 49ee0c1a7209..e69bf2f15f32 100644
--- a/arch/arm/mm/copypage-feroceon.c
+++ b/arch/arm/mm/copypage-feroceon.c
@@ -18,7 +18,7 @@ feroceon_copy_user_page(void *kto, const void *kfrom)
{
asm("\
stmfd sp!, {r4-r9, lr} \n\
- mov ip, %2 \n\
+ mov ip, %0 \n\
1: mov lr, r1 \n\
ldmia r1!, {r2 - r9} \n\
pld [lr, #32] \n\
@@ -64,7 +64,7 @@ feroceon_copy_user_page(void *kto, const void *kfrom)
mcr p15, 0, ip, c7, c10, 4 @ drain WB\n\
ldmfd sp!, {r4-r9, pc}"
:
- : "r" (kto), "r" (kfrom), "I" (PAGE_SIZE));
+ : "I" (PAGE_SIZE));
}

void feroceon_copy_user_highpage(struct page *to, struct page *from,
diff --git a/arch/arm/mm/copypage-v4mc.c b/arch/arm/mm/copypage-v4mc.c
index 0224416cba3c..5c70e48ad833 100644
--- a/arch/arm/mm/copypage-v4mc.c
+++ b/arch/arm/mm/copypage-v4mc.c
@@ -45,23 +45,23 @@ mc_copy_user_page(void *from, void *to)
{
asm volatile(
"stmfd sp!, {r4, lr} @ 2\n\
- mov r4, %2 @ 1\n\
- ldmia %0!, {r2, r3, ip, lr} @ 4\n\
-1: mcr p15, 0, %1, c7, c6, 1 @ 1 invalidate D line\n\
- stmia %1!, {r2, r3, ip, lr} @ 4\n\
- ldmia %0!, {r2, r3, ip, lr} @ 4+1\n\
- stmia %1!, {r2, r3, ip, lr} @ 4\n\
- ldmia %0!, {r2, r3, ip, lr} @ 4\n\
- mcr p15, 0, %1, c7, c6, 1 @ 1 invalidate D line\n\
- stmia %1!, {r2, r3, ip, lr} @ 4\n\
- ldmia %0!, {r2, r3, ip, lr} @ 4\n\
+ mov r4, %0 @ 1\n\
+ ldmia r0!, {r2, r3, ip, lr} @ 4\n\
+1: mcr p15, 0, r1, c7, c6, 1 @ 1 invalidate D line\n\
+ stmia r1!, {r2, r3, ip, lr} @ 4\n\
+ ldmia r0!, {r2, r3, ip, lr} @ 4+1\n\
+ stmia r1!, {r2, r3, ip, lr} @ 4\n\
+ ldmia r0!, {r2, r3, ip, lr} @ 4\n\
+ mcr p15, 0, r1, c7, c6, 1 @ 1 invalidate D line\n\
+ stmia r1!, {r2, r3, ip, lr} @ 4\n\
+ ldmia r0!, {r2, r3, ip, lr} @ 4\n\
subs r4, r4, #1 @ 1\n\
- stmia %1!, {r2, r3, ip, lr} @ 4\n\
- ldmneia %0!, {r2, r3, ip, lr} @ 4\n\
+ stmia r1!, {r2, r3, ip, lr} @ 4\n\
+ ldmneia r0!, {r2, r3, ip, lr} @ 4\n\
bne 1b @ 1\n\
ldmfd sp!, {r4, pc} @ 3"
:
- : "r" (from), "r" (to), "I" (PAGE_SIZE / 64));
+ : "I" (PAGE_SIZE / 64));
}

void v4_mc_copy_user_highpage(struct page *to, struct page *from,
diff --git a/arch/arm/mm/copypage-v4wb.c b/arch/arm/mm/copypage-v4wb.c
index 067d0fdd630c..7ea9cf07bd5c 100644
--- a/arch/arm/mm/copypage-v4wb.c
+++ b/arch/arm/mm/copypage-v4wb.c
@@ -27,7 +27,7 @@ v4wb_copy_user_page(void *kto, const void *kfrom)
{
asm("\
stmfd sp!, {r4, lr} @ 2\n\
- mov r2, %2 @ 1\n\
+ mov r2, %0 @ 1\n\
ldmia r1!, {r3, r4, ip, lr} @ 4\n\
1: mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line\n\
stmia r0!, {r3, r4, ip, lr} @ 4\n\
@@ -44,7 +44,7 @@ v4wb_copy_user_page(void *kto, const void *kfrom)
mcr p15, 0, r1, c7, c10, 4 @ 1 drain WB\n\
ldmfd sp!, {r4, pc} @ 3"
:
- : "r" (kto), "r" (kfrom), "I" (PAGE_SIZE / 64));
+ : "I" (PAGE_SIZE / 64));
}

void v4wb_copy_user_highpage(struct page *to, struct page *from,
diff --git a/arch/arm/mm/copypage-v4wt.c b/arch/arm/mm/copypage-v4wt.c
index b85c5da2e510..c742ab24efd6 100644
--- a/arch/arm/mm/copypage-v4wt.c
+++ b/arch/arm/mm/copypage-v4wt.c
@@ -25,7 +25,7 @@ v4wt_copy_user_page(void *kto, const void *kfrom)
{
asm("\
stmfd sp!, {r4, lr} @ 2\n\
- mov r2, %2 @ 1\n\
+ mov r2, %0 @ 1\n\
ldmia r1!, {r3, r4, ip, lr} @ 4\n\
1: stmia r0!, {r3, r4, ip, lr} @ 4\n\
ldmia r1!, {r3, r4, ip, lr} @ 4+1\n\
@@ -40,7 +40,7 @@ v4wt_copy_user_page(void *kto, const void *kfrom)
mcr p15, 0, r2, c7, c7, 0 @ flush ID cache\n\
ldmfd sp!, {r4, pc} @ 3"
:
- : "r" (kto), "r" (kfrom), "I" (PAGE_SIZE / 64));
+ : "I" (PAGE_SIZE / 64));
}

void v4wt_copy_user_highpage(struct page *to, struct page *from,
diff --git a/arch/arm/mm/copypage-xsc3.c b/arch/arm/mm/copypage-xsc3.c
index 03a2042aced5..9944bdb4721d 100644
--- a/arch/arm/mm/copypage-xsc3.c
+++ b/arch/arm/mm/copypage-xsc3.c
@@ -34,8 +34,8 @@ xsc3_mc_copy_user_page(void *kto, const void *kfrom)
{
asm("\
stmfd sp!, {r4, r5, lr} \n\
- mov lr, %2 \n\
- \n\
+ mov lr, %0 \n\
+ \n\
pld [r1, #0] \n\
pld [r1, #32] \n\
1: pld [r1, #64] \n\
@@ -67,7 +67,7 @@ xsc3_mc_copy_user_page(void *kto, const void *kfrom)
\n\
ldmfd sp!, {r4, r5, pc}"
:
- : "r" (kto), "r" (kfrom), "I" (PAGE_SIZE / 64 - 1));
+ : "I" (PAGE_SIZE / 64 - 1));
}

void xsc3_mc_copy_user_highpage(struct page *to, struct page *from,
diff --git a/arch/arm/mm/copypage-xscale.c b/arch/arm/mm/copypage-xscale.c
index 97972379f4d6..ef52a052d9bb 100644
--- a/arch/arm/mm/copypage-xscale.c
+++ b/arch/arm/mm/copypage-xscale.c
@@ -45,7 +45,7 @@ mc_copy_user_page(void *from, void *to)
*/
asm volatile(
"stmfd sp!, {r4, r5, lr} \n\
- mov lr, %2 \n\
+ mov lr, %0 \n\
pld [r0, #0] \n\
pld [r0, #32] \n\
pld [r1, #0] \n\
@@ -81,7 +81,7 @@ mc_copy_user_page(void *from, void *to)
beq 2b \n\
ldmfd sp!, {r4, r5, pc} "
:
- : "r" (from), "r" (to), "I" (PAGE_SIZE / 64 - 1));
+ : "I" (PAGE_SIZE / 64 - 1));
}

void xscale_mc_copy_user_highpage(struct page *to, struct page *from,
--
2.18.0