From: Andrew Morton <akpm@osdl.org>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
sfr@canb.auug.org.au, Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH] lockdep: annotate i386 apm
Date: Wed, 11 Oct 2006 14:18:13 -0700 [thread overview]
Message-ID: <20061011141813.79fb278f.akpm@osdl.org> (raw)
In-Reply-To: <1160574022.2006.82.camel@taijtu>
On Wed, 11 Oct 2006 15:40:22 +0200
Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
>
> Lockdep doesn't like to enable interrupts when they are enabled already.
>
> ...
>
> --- linux-2.6.18.noarch.orig/arch/i386/kernel/apm.c
> +++ linux-2.6.18.noarch/arch/i386/kernel/apm.c
> @@ -539,11 +539,22 @@ static inline void apm_restore_cpus(cpum
> * Also, we KNOW that for the non error case of apm_bios_call, there
> * is no useful data returned in the low order 8 bits of eax.
> */
> -#define APM_DO_CLI \
> - if (apm_info.allow_ints) \
> - local_irq_enable(); \
> - else \
> - local_irq_disable();
> +#define APM_DO_CLI \
> + do { \
> + if (apm_info.allow_ints) { \
> + if (irqs_disabled_flags(flags)) \
> + local_irq_enable(); \
> + } else \
> + local_irq_disable(); \
> + } while (0)
> +
> +#define APM_DO_STI \
> + do { \
> + if (irqs_disabled_flags(flags)) \
> + local_irq_disable(); \
> + else if (irqs_disabled()) \
> + local_irq_enable(); \
> + } while (0)
>
> #ifdef APM_ZERO_SEGS
> # define APM_DECL_SEGS \
> @@ -600,7 +611,7 @@ static u8 apm_bios_call(u32 func, u32 eb
> APM_DO_SAVE_SEGS;
> apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi);
> APM_DO_RESTORE_SEGS;
> - local_irq_restore(flags);
> + APM_DO_STI;
> gdt[0x40 / 8] = save_desc_40;
> put_cpu();
> apm_restore_cpus(cpus);
> @@ -644,7 +655,7 @@ static u8 apm_bios_call_simple(u32 func,
> APM_DO_SAVE_SEGS;
> error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax);
> APM_DO_RESTORE_SEGS;
> - local_irq_restore(flags);
> + APM_DO_STI;
> gdt[0x40 / 8] = save_desc_40;
> put_cpu();
> apm_restore_cpus(cpus);
ick.
Does this work?
--- a/arch/i386/kernel/apm.c~lockdep-annotate-i386-apm
+++ a/arch/i386/kernel/apm.c
@@ -540,12 +540,6 @@ static inline void apm_restore_cpus(cpum
* Also, we KNOW that for the non error case of apm_bios_call, there
* is no useful data returned in the low order 8 bits of eax.
*/
-#define APM_DO_CLI \
- if (apm_info.allow_ints) \
- local_irq_enable(); \
- else \
- local_irq_disable();
-
#ifdef APM_ZERO_SEGS
# define APM_DECL_SEGS \
unsigned int saved_fs; unsigned int saved_gs;
@@ -596,8 +590,9 @@ static u8 apm_bios_call(u32 func, u32 eb
save_desc_40 = gdt[0x40 / 8];
gdt[0x40 / 8] = bad_bios_desc;
- local_save_flags(flags);
- APM_DO_CLI;
+ local_irq_save(flags);
+ if (apm_info.allow_ints)
+ local_irq_enable();
APM_DO_SAVE_SEGS;
apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi);
APM_DO_RESTORE_SEGS;
@@ -640,8 +635,9 @@ static u8 apm_bios_call_simple(u32 func,
save_desc_40 = gdt[0x40 / 8];
gdt[0x40 / 8] = bad_bios_desc;
- local_save_flags(flags);
- APM_DO_CLI;
+ local_irq_save(flags);
+ if (apm_info.allow_ints)
+ local_irq_enable();
APM_DO_SAVE_SEGS;
error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax);
APM_DO_RESTORE_SEGS;
_
next prev parent reply other threads:[~2006-10-11 21:19 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-10-11 13:40 Peter Zijlstra
2006-10-11 21:18 ` Andrew Morton [this message]
2006-10-12 6:06 ` Peter Zijlstra
2006-10-12 6:39 ` Andrew Morton
2006-10-12 6:50 ` Peter Zijlstra
2006-10-12 7:29 ` Andrew Morton
2006-10-12 8:13 ` Peter Zijlstra
2006-10-12 8:02 ` Ingo Molnar
2006-10-12 8:26 ` Peter Zijlstra
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