@@ -1,13 +1,20 @@
#include <xen/config.h>
#if __LINUX_ARM_ARCH__ >= 6
- .macro bitop, instr
+ .macro bitop, name, instr
+ENTRY( \name )
+UNWIND( .fnstart )
ands ip, r1, #3
strneb r1, [ip] @ assert word-aligned
mov r2, #1
and r3, r0, #31 @ Get bit offset
mov r0, r0, lsr #5
add r1, r1, r0, lsl #2 @ Get word offset
+#if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
+ .arch_extension mp
+ ALT_SMP(W(pldw) [r1])
+ ALT_UP(W(nop))
+#endif
mov r3, r2, lsl r3
1: ldrex r2, [r1]
\instr r2, r2, r3
@@ -15,9 +22,13 @@
cmp r0, #0
bne 1b
bx lr
+UNWIND( .fnend )
+ENDPROC(\name )
.endm
- .macro testop, instr, store
+ .macro testop, name, instr, store
+ENTRY( \name )
+UNWIND( .fnstart )
ands ip, r1, #3
strneb r1, [ip] @ assert word-aligned
mov r2, #1
@@ -36,6 +47,8 @@
cmp r0, #0
movne r0, #1
2: bx lr
+UNWIND( .fnend )
+ENDPROC(\name )
.endm
#else
.macro bitop, name, instr
@@ -13,6 +13,4 @@
#include "bitops.h"
.text
-ENTRY(_change_bit)
- bitop eor
-ENDPROC(_change_bit)
+bitop _change_bit, eor
@@ -14,6 +14,4 @@
#include "bitops.h"
.text
-ENTRY(_clear_bit)
- bitop bic
-ENDPROC(_clear_bit)
+bitop _clear_bit, bic
@@ -13,6 +13,4 @@
#include "bitops.h"
.text
-ENTRY(_set_bit)
- bitop orr
-ENDPROC(_set_bit)
+bitop _set_bit, orr
@@ -13,6 +13,4 @@
#include "bitops.h"
.text
-ENTRY(_test_and_change_bit)
- testop eor, str
-ENDPROC(_test_and_change_bit)
+testop _test_and_change_bit, eor, str
@@ -13,6 +13,4 @@
#include "bitops.h"
.text
-ENTRY(_test_and_clear_bit)
- testop bicne, strne
-ENDPROC(_test_and_clear_bit)
+testop _test_and_clear_bit, bicne, strne
@@ -13,6 +13,4 @@
#include "bitops.h"
.text
-ENTRY(_test_and_set_bit)
- testop orreq, streq
-ENDPROC(_test_and_set_bit)
+testop _test_and_set_bit, orreq, streq
This pulls in the following Linux commits: commit c36ef4b1762302a493c6cb754073bded084700e2 Author: Will Deacon <will.deacon@arm.com> Date: Wed Nov 23 11:28:25 2011 +0100 ARM: 7171/1: unwind: add unwind directives to bitops assembly macros The bitops functions (e.g. _test_and_set_bit) on ARM do not have unwind annotations and therefore the kernel cannot backtrace out of them on a fatal error (for example, NULL pointer dereference). This patch annotates the bitops assembly macros with UNWIND annotations so that we can produce a meaningful backtrace on error. Callers of the macros are modified to pass their function name as a macro parameter, enforcing that the macros are used as standalone function implementations. Acked-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> commit d779c07dd72098a7416d907494f958213b7726f3 Author: Will Deacon <will.deacon@arm.com> Date: Thu Jun 27 12:01:51 2013 +0100 ARM: bitops: prefetch the destination word for write prior to strex The cost of changing a cacheline from shared to exclusive state can be significant, especially when this is triggered by an exclusive store, since it may result in having to retry the transaction. This patch prefixes our atomic bitops implementation with prefetchw, to try and grab the line in exclusive state from the start. The testop macro is left alone, since the barrier semantics limit the usefulness of prefetching data. Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> commit b7ec699405f55667caeb46d96229d75bf33a83ad Author: Will Deacon <will.deacon@arm.com> Date: Tue Nov 19 15:46:11 2013 +0100 ARM: 7893/1: bitops: only emit .arch_extension mp if CONFIG_SMP Uwe reported a build failure when targetting a NOMMU platform with my recent prefetch changes: arch/arm/lib/changebit.S: Assembler messages: arch/arm/lib/changebit.S:15: Error: architectural extension `mp' is not allowed for the current base architecture This is due to use of the .arch_extension mp directive immediately prior to an ALT_SMP(...) instruction. Whilst the ALT_SMP macro will expand to nothing if !CONFIG_SMP, gas will still choke on the directive. This patch fixes the issue by only emitting the sequence (including the directive) if CONFIG_SMP=y. Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Julien Grall <julien.grall@linaro.org> --- xen/arch/arm/arm32/lib/bitops.h | 17 +++++++++++++++-- xen/arch/arm/arm32/lib/changebit.S | 4 +--- xen/arch/arm/arm32/lib/clearbit.S | 4 +--- xen/arch/arm/arm32/lib/setbit.S | 4 +--- xen/arch/arm/arm32/lib/testchangebit.S | 4 +--- xen/arch/arm/arm32/lib/testclearbit.S | 4 +--- xen/arch/arm/arm32/lib/testsetbit.S | 4 +--- 7 files changed, 21 insertions(+), 20 deletions(-)