From: gdavis@mvista.com (George G. Davis)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC/PATCH 7/7] ARM: ARM11 MPCore: cpu_v6_set_pte_ext is not preempt safe
Date: Thu, 6 Oct 2011 08:35:08 -0400 [thread overview]
Message-ID: <232DB229-FDB4-4E59-AA06-D10DFF02604C@mvista.com> (raw)
In-Reply-To: <20111006074647.GA26349@n2100.arm.linux.org.uk>
On Oct 6, 2011, at 3:46 AM, Russell King - ARM Linux wrote:
> On Thu, Oct 06, 2011 at 01:08:34AM -0400, gdavis at mvista.com wrote:
>> diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S
>> index a923aa0..dd2e5e5 100644
>> --- a/arch/arm/mm/proc-v6.S
>> +++ b/arch/arm/mm/proc-v6.S
>> @@ -122,7 +122,18 @@ ENTRY(cpu_v6_switch_mm)
>>
>> ENTRY(cpu_v6_set_pte_ext)
>> #ifdef CONFIG_MMU
>> +#ifdef CONFIG_PREEMPT
>> + ALT_SMP(stmdb sp!, {r4, r10, r11})
>> + ALT_SMP(get_thread_info r10)
>> + ALT_SMP(ldr r4, [r10, #TI_PREEMPT]) @ get preempt count
>> + ALT_SMP(add r11, r4, #1) @ increment it
>> + ALT_SMP(str r11, [r10, #TI_PREEMPT]) @ disable preempt
>> +#endif
>> armv6_set_pte_ext cpu_v6
>> +#ifdef CONFIG_PREEMPT
>> + ALT_SMP(str r4, [r10, #TI_PREEMPT]) @ restore preempt count
>> + ALT_SMP(ldmia sp!, {r4, r10, r11})
>> +#endif
>> #endif
>
> And what effect do you expect the above to have?
My goal was to be proactive, heading off a request to use this macro for
the SMP case since preempt disable is only required on ARM11 MPCore.
I thought this would achieve that goal, only using those instructions on SMP,
not UP machines.
> Do you understand the purpose of the ALT_SMP macro?
Clearly I don't understand the use case.
> Do you understand that it should be paired with ALT_UP ?
No, I did not know that. I'll remove use of ALT_SMP and add CONFIG_SMP
as a conditional compile dependency then. Is that OK?
Thanks!
--
Regards,
George
next prev parent reply other threads:[~2011-10-06 12:35 UTC|newest]
Thread overview: 93+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-20 13:43 parallel load of modules on an ARM multicore EXTERNAL Waechtler Peter (Fa. TCP, CM-AI/PJ-CF31)
2011-06-21 15:50 ` Catalin Marinas
2011-06-23 14:39 ` AW: " EXTERNAL Waechtler Peter (Fa. TCP, CM-AI/PJ-CF31)
2011-06-23 14:52 ` Catalin Marinas
2011-06-23 15:12 ` Russell King - ARM Linux
2011-06-23 15:34 ` Catalin Marinas
2011-06-23 17:02 ` Catalin Marinas
2011-06-23 15:20 ` AW: " EXTERNAL Waechtler Peter (Fa. TCP, CM-AI/PJ-CF31)
2011-07-07 4:25 ` George G. Davis
2011-10-20 4:04 ` George G. Davis
2011-09-22 7:29 ` George G. Davis
2011-09-22 8:52 ` Catalin Marinas
2011-10-06 4:29 ` George G. Davis
2011-10-06 5:08 ` [RFC/PATCH 0/7] ARM: ARM11 MPCore preemption/task migration cache coherency fixups gdavis at mvista.com
2011-10-06 5:08 ` [RFC/PATCH 1/7] ARM: ARM11 MPCore: pgd_alloc is not preempt safe gdavis at mvista.com
2011-10-06 16:35 ` Russell King - ARM Linux
2011-10-06 19:38 ` George G. Davis
2011-10-06 5:08 ` [RFC/PATCH 2/7] ARM: ARM11 MPCore: pte_alloc_one{, _kernel} are " gdavis at mvista.com
2011-10-06 5:08 ` [RFC/PATCH 3/7] ARM: ARM11 MPCore: {clean, flush}_pmd_entry " gdavis at mvista.com
2011-10-06 5:08 ` [RFC/PATCH 4/7] ARM: ARM11 MPCore: clean_dcache_area is " gdavis at mvista.com
2011-10-06 5:08 ` [RFC/PATCH 5/7] ARM: Move get_thread_info macro definition to <asm/assembler.h> gdavis at mvista.com
2011-10-06 5:08 ` [RFC/PATCH 6/7] ARM: ARM11 MPCore: DMA_CACHE_RWFO operations are not preempt safe gdavis at mvista.com
2011-10-06 16:40 ` Russell King - ARM Linux
2011-10-06 19:41 ` George G. Davis
2011-10-06 5:08 ` [RFC/PATCH 7/7] ARM: ARM11 MPCore: cpu_v6_set_pte_ext is " gdavis at mvista.com
2011-10-06 7:46 ` Russell King - ARM Linux
2011-10-06 12:35 ` George G. Davis [this message]
2011-10-07 2:38 ` [RFC/PATCH v2 0/7] ARM11 MPCore: preemption/task migration cache coherency fixups gdavis at mvista.com
2011-10-07 2:38 ` [RFC/PATCH 1/7] ARM: ARM11 MPCore: pgd_alloc is not preempt safe gdavis at mvista.com
2011-10-07 2:38 ` [RFC/PATCH 2/7] ARM: ARM11 MPCore: pte_alloc_one{, _kernel} are " gdavis at mvista.com
2011-10-07 7:47 ` [RFC/PATCH 2/7] ARM: ARM11 MPCore: pte_alloc_one{,_kernel} " Russell King - ARM Linux
2011-10-07 15:31 ` [RFC/PATCH 2/7] ARM: ARM11 MPCore: pte_alloc_one{, _kernel} " George G. Davis
2011-10-07 2:38 ` [RFC/PATCH 3/7] ARM: ARM11 MPCore: {clean, flush}_pmd_entry " gdavis at mvista.com
2011-10-11 9:53 ` [RFC/PATCH 3/7] ARM: ARM11 MPCore: {clean,flush}_pmd_entry " Catalin Marinas
2011-10-12 2:34 ` [RFC/PATCH 3/7] ARM: ARM11 MPCore: {clean, flush}_pmd_entry " George G. Davis
2011-10-13 14:31 ` [RFC/PATCH 3/7] ARM: ARM11 MPCore: {clean,flush}_pmd_entry " Russell King - ARM Linux
2011-10-14 1:34 ` [RFC/PATCH 3/7] ARM: ARM11 MPCore: {clean, flush}_pmd_entry " George G. Davis
2011-10-07 2:38 ` [RFC/PATCH 4/7] ARM: ARM11 MPCore: clean_dcache_area is " gdavis at mvista.com
2011-10-07 2:38 ` [RFC/PATCH 5/7] ARM: Move get_thread_info macro definition to <asm/assembler.h> gdavis at mvista.com
2011-10-11 9:56 ` Catalin Marinas
2011-10-12 6:04 ` gdavis at mvista.com
2011-10-13 14:34 ` Russell King - ARM Linux
2011-10-13 14:49 ` Catalin Marinas
2011-10-13 14:53 ` Russell King - ARM Linux
2011-10-14 1:46 ` George G. Davis
2011-10-14 1:44 ` George G. Davis
2011-10-14 1:42 ` George G. Davis
2011-10-14 2:54 ` Nicolas Pitre
2011-10-14 12:56 ` George G. Davis
2011-10-07 2:38 ` [RFC/PATCH 6/7] ARM: ARM11 MPCore: DMA_CACHE_RWFO operations are not preempt safe gdavis at mvista.com
2011-10-07 2:38 ` [RFC/PATCH 7/7] ARM: ARM11 MPCore: cpu_v6_set_pte_ext is " gdavis at mvista.com
2011-10-07 16:26 ` [RFC/PATCH v3 0/7] ARM11 MPCore: preemption/task migration cache coherency fixups gdavis at mvista.com
2011-10-07 16:26 ` [RFC/PATCH v3 1/7] ARM: ARM11 MPCore: pgd_alloc is not preempt safe gdavis at mvista.com
2011-10-07 16:26 ` [RFC/PATCH v3 2/7] ARM: ARM11 MPCore: pte_alloc_one{, _kernel} are " gdavis at mvista.com
2011-10-07 16:26 ` [RFC/PATCH v3 3/7] ARM: ARM11 MPCore: {clean, flush}_pmd_entry " gdavis at mvista.com
2011-10-07 16:26 ` [RFC/PATCH v3 4/7] ARM: ARM11 MPCore: clean_dcache_area is " gdavis at mvista.com
2011-10-07 16:26 ` [RFC/PATCH v3 5/7] ARM: Move get_thread_info macro definition to <asm/assembler.h> gdavis at mvista.com
2011-10-07 16:26 ` [RFC/PATCH v3 6/7] ARM: ARM11 MPCore: DMA_CACHE_RWFO operations are not preempt safe gdavis at mvista.com
2011-10-07 16:26 ` [RFC/PATCH v3 7/7] ARM: ARM11 MPCore: cpu_v6_set_pte_ext is " gdavis at mvista.com
2011-10-18 13:47 ` [RFC/PATCH v4 0/7] ARM11 MPCore: preemption/task migration cache coherency fixups gdavis at mvista.com
2011-10-18 13:47 ` [RFC/PATCH v4 1/7] ARM: ARM11 MPCore: pgd_alloc is not preempt safe gdavis at mvista.com
2011-10-18 13:47 ` [RFC/PATCH v4 2/7] ARM: ARM11 MPCore: pte_alloc_one{, _kernel} are " gdavis at mvista.com
2011-10-18 13:47 ` [RFC/PATCH v4 3/7] ARM: ARM11 MPCore: {clean, flush}_pmd_entry " gdavis at mvista.com
2011-10-18 13:47 ` [RFC/PATCH v4 4/7] ARM: ARM11 MPCore: clean_dcache_area is " gdavis at mvista.com
2011-10-18 17:08 ` Tony Lindgren
2011-10-18 17:30 ` George G. Davis
2011-10-18 17:43 ` Tony Lindgren
2011-10-18 18:13 ` George G. Davis
2011-10-18 13:47 ` [RFC/PATCH v4 5/7] ARM: Move get_thread_info macro definition to <asm/assembler.h> gdavis at mvista.com
2011-10-18 13:47 ` [RFC/PATCH v4 6/7] ARM: ARM11 MPCore: DMA_CACHE_RWFO operations are not preempt safe gdavis at mvista.com
2011-10-18 21:28 ` Nicolas Pitre
2011-10-18 23:26 ` George G. Davis
2011-10-19 1:09 ` Nicolas Pitre
2011-10-18 13:47 ` [RFC/PATCH v4 7/7] ARM: ARM11 MPCore: cpu_v6_set_pte_ext is " gdavis at mvista.com
2011-10-18 21:52 ` Nicolas Pitre
2011-10-18 23:29 ` George G. Davis
2012-06-12 20:40 ` [RFC/PATCH v5 0/7] ARM11 MPCore: preemption/task migration cache coherency fixups gdavis at mvista.com
2012-06-12 20:40 ` [RFC/PATCH v5 1/7] ARM: ARM11 MPCore: Make pgd_alloc preempt safe gdavis at mvista.com
2012-06-12 20:40 ` [RFC/PATCH v5 2/7] ARM: ARM11 MPCore: Make pte_alloc_one{, _kernel} " gdavis at mvista.com
2012-06-12 20:40 ` [RFC/PATCH v5 3/7] ARM: ARM11 MPCore: Make {clean, flush}_pmd_entry " gdavis at mvista.com
2012-06-12 20:40 ` [RFC/PATCH v5 4/7] ARM: Move get_thread_info macro definition to <asm/assembler.h> gdavis at mvista.com
2012-06-12 20:40 ` [RFC/PATCH v5 5/7] ARM: ARM11 MPCore: cpu_v6_dcache_clean_area needs RFO gdavis at mvista.com
2012-06-13 9:32 ` Catalin Marinas
2012-06-13 9:36 ` Russell King - ARM Linux
2012-06-13 9:41 ` Catalin Marinas
2012-06-13 9:45 ` Russell King - ARM Linux
2012-06-13 9:54 ` Catalin Marinas
2012-06-13 11:36 ` George G. Davis
2012-06-13 11:21 ` George G. Davis
2012-06-12 20:40 ` [RFC/PATCH v5 6/7] ARM: ARM11 MPCore: Make DMA_CACHE_RWFO operations preempt safe gdavis at mvista.com
2012-06-12 20:40 ` [RFC/PATCH v5 7/7] ARM: ARM11 MPCore: Make cpu_v6_set_pte_ext " gdavis at mvista.com
2012-06-13 9:34 ` Catalin Marinas
2012-06-13 11:35 ` George G. Davis
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