| Message ID | 1395330365-9901-2-git-send-email-ian.campbell@citrix.com |
|---|---|
| State | Superseded |
| Headers | show |
On 03/20/2014 03:45 PM, Ian Campbell wrote: > 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(-) > > diff --git a/xen/arch/arm/arm32/lib/bitops.h b/xen/arch/arm/arm32/lib/bitops.h > index 689f2e8..25784c3 100644 > --- a/xen/arch/arm/arm32/lib/bitops.h > +++ b/xen/arch/arm/arm32/lib/bitops.h > @@ -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 > diff --git a/xen/arch/arm/arm32/lib/changebit.S b/xen/arch/arm/arm32/lib/changebit.S > index 62954bc..11f41d2 100644 > --- a/xen/arch/arm/arm32/lib/changebit.S > +++ b/xen/arch/arm/arm32/lib/changebit.S > @@ -13,6 +13,4 @@ > #include "bitops.h" > .text > fined(CONFIG_SMP) > -ENTRY(_change_bit) > - bitop eor > -ENDPROC(_change_bit) > +bitop _change_bit, eor > diff --git a/xen/arch/arm/arm32/lib/clearbit.S b/xen/arch/arm/arm32/lib/clearbit.S > index 42ce416..1b6a569 100644 > --- a/xen/arch/arm/arm32/lib/clearbit.S > +++ b/xen/arch/arm/arm32/lib/clearbit.S > @@ -14,6 +14,4 @@ > #include "bitops.h" > .text > > -ENTRY(_clear_bit) > - bitop bic > -ENDPROC(_clear_bit) > +bitop _clear_bit, bic > diff --git a/xen/arch/arm/arm32/lib/setbit.S b/xen/arch/arm/arm32/lib/setbit.S > index c828851..1f4ef56 100644 > --- a/xen/arch/arm/arm32/lib/setbit.S > +++ b/xen/arch/arm/arm32/lib/setbit.S > @@ -13,6 +13,4 @@ > #include "bitops.h" > .text > > -ENTRY(_set_bit) > - bitop orr > -ENDPROC(_set_bit) > +bitop _set_bit, orr > diff --git a/xen/arch/arm/arm32/lib/testchangebit.S b/xen/arch/arm/arm32/lib/testchangebit.S > index a7f527c..7f4635c 100644 > --- a/xen/arch/arm/arm32/lib/testchangebit.S > +++ b/xen/arch/arm/arm32/lib/testchangebit.S > @@ -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 > diff --git a/xen/arch/arm/arm32/lib/testclearbit.S b/xen/arch/arm/arm32/lib/testclearbit.S > index 8f39c72..4d4152f 100644 > --- a/xen/arch/arm/arm32/lib/testclearbit.S > +++ b/xen/arch/arm/arm32/lib/testclearbit.S > @@ -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 > diff --git a/xen/arch/arm/arm32/lib/testsetbit.S b/xen/arch/arm/arm32/lib/testsetbit.S > index 1b8d273..54f48f9 100644 > --- a/xen/arch/arm/arm32/lib/testsetbit.S > +++ b/xen/arch/arm/arm32/lib/testsetbit.S > @@ -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 >
diff --git a/xen/arch/arm/arm32/lib/bitops.h b/xen/arch/arm/arm32/lib/bitops.h index 689f2e8..25784c3 100644 --- a/xen/arch/arm/arm32/lib/bitops.h +++ b/xen/arch/arm/arm32/lib/bitops.h @@ -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 diff --git a/xen/arch/arm/arm32/lib/changebit.S b/xen/arch/arm/arm32/lib/changebit.S index 62954bc..11f41d2 100644 --- a/xen/arch/arm/arm32/lib/changebit.S +++ b/xen/arch/arm/arm32/lib/changebit.S @@ -13,6 +13,4 @@ #include "bitops.h" .text -ENTRY(_change_bit) - bitop eor -ENDPROC(_change_bit) +bitop _change_bit, eor diff --git a/xen/arch/arm/arm32/lib/clearbit.S b/xen/arch/arm/arm32/lib/clearbit.S index 42ce416..1b6a569 100644 --- a/xen/arch/arm/arm32/lib/clearbit.S +++ b/xen/arch/arm/arm32/lib/clearbit.S @@ -14,6 +14,4 @@ #include "bitops.h" .text -ENTRY(_clear_bit) - bitop bic -ENDPROC(_clear_bit) +bitop _clear_bit, bic diff --git a/xen/arch/arm/arm32/lib/setbit.S b/xen/arch/arm/arm32/lib/setbit.S index c828851..1f4ef56 100644 --- a/xen/arch/arm/arm32/lib/setbit.S +++ b/xen/arch/arm/arm32/lib/setbit.S @@ -13,6 +13,4 @@ #include "bitops.h" .text -ENTRY(_set_bit) - bitop orr -ENDPROC(_set_bit) +bitop _set_bit, orr diff --git a/xen/arch/arm/arm32/lib/testchangebit.S b/xen/arch/arm/arm32/lib/testchangebit.S index a7f527c..7f4635c 100644 --- a/xen/arch/arm/arm32/lib/testchangebit.S +++ b/xen/arch/arm/arm32/lib/testchangebit.S @@ -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 diff --git a/xen/arch/arm/arm32/lib/testclearbit.S b/xen/arch/arm/arm32/lib/testclearbit.S index 8f39c72..4d4152f 100644 --- a/xen/arch/arm/arm32/lib/testclearbit.S +++ b/xen/arch/arm/arm32/lib/testclearbit.S @@ -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 diff --git a/xen/arch/arm/arm32/lib/testsetbit.S b/xen/arch/arm/arm32/lib/testsetbit.S index 1b8d273..54f48f9 100644 --- a/xen/arch/arm/arm32/lib/testsetbit.S +++ b/xen/arch/arm/arm32/lib/testsetbit.S @@ -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> --- 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(-)