* Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> [150409 06:49]: > On Thu, Apr 09, 2015 at 12:06:58AM +0100, Russell King - ARM Linux wrote: > > On Tue, Apr 07, 2015 at 08:22:08AM -0700, Tony Lindgren wrote: > > > Works for me. The above needs the following fix folded in to build: > > > > > > --- a/arch/arm/mm/proc-v7.S > > > +++ b/arch/arm/mm/proc-v7.S > > > @@ -532,7 +532,7 @@ __v7_ca9mp_proc_info: > > > __v7_ca8_proc_info: > > > .long 0x410fc080 > > > .long 0xff0ffff0 > > > - __v7_proc __v7_ca8mp_proc_info, proc_fns = ca8_processor_functions > > > + __v7_proc __v7_ca8_proc_info, __v7_setup, proc_fns = ca8_processor_functions > > > .size __v7_ca8_proc_info, . - __v7_ca8_proc_info > > > > > > #endif /* CONFIG_ARM_LPAE */ > > > > Thanks, merged into the original patch. > > Do you want to give me an ack for this, thanks? The patch below works for me: Tested-by: Tony Lindgren <tony@xxxxxxxxxxx> I'm wondering if this and the follow-up patch should be tagged cc: stable? They together fix apps segfaulting both with and without 430973 for some common use cases for distro kernels. Regards, Tony > 8<=== > From: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> > Subject: [PATCH] ARM: proc-v7: avoid errata 430973 workaround for non-Cortex > A8 CPUs > > Avoid the errata 430973 workaround for non-Cortex A8 CPUs. Having this > workaround enabled introduces an additional branch target buffer flush > into the context switching path, something we wish to avoid. To allow > this errata to be enabled in multiplatform kernels while reducing its > impact, rearrange the Cortex-A8 CPU support to avoid impacting on other > Version 7 CPUs. > > Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> > --- > arch/arm/mm/proc-v7-2level.S | 12 ++++++++---- > arch/arm/mm/proc-v7.S | 28 ++++++++++++++++++++++++++++ > 2 files changed, 36 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/mm/proc-v7-2level.S b/arch/arm/mm/proc-v7-2level.S > index bc86be205c04..fa385140715f 100644 > --- a/arch/arm/mm/proc-v7-2level.S > +++ b/arch/arm/mm/proc-v7-2level.S > @@ -37,15 +37,18 @@ > * It is assumed that: > * - we are not using split page tables > */ > -ENTRY(cpu_v7_switch_mm) > +ENTRY(cpu_ca8_switch_mm) > #ifdef CONFIG_MMU > mov r2, #0 > - mmid r1, r1 @ get mm->context.id > - ALT_SMP(orr r0, r0, #TTB_FLAGS_SMP) > - ALT_UP(orr r0, r0, #TTB_FLAGS_UP) > #ifdef CONFIG_ARM_ERRATA_430973 > mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB > #endif > +#endif > +ENTRY(cpu_v7_switch_mm) > +#ifdef CONFIG_MMU > + mmid r1, r1 @ get mm->context.id > + ALT_SMP(orr r0, r0, #TTB_FLAGS_SMP) > + ALT_UP(orr r0, r0, #TTB_FLAGS_UP) > #ifdef CONFIG_PID_IN_CONTEXTIDR > mrc p15, 0, r2, c13, c0, 1 @ read current context ID > lsr r2, r2, #8 @ extract the PID > @@ -61,6 +64,7 @@ ENTRY(cpu_v7_switch_mm) > #endif > bx lr > ENDPROC(cpu_v7_switch_mm) > +ENDPROC(cpu_ca8_switch_mm) > > /* > * cpu_v7_set_pte_ext(ptep, pte) > diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S > index b1d19ea5e1af..003190ae9cd8 100644 > --- a/arch/arm/mm/proc-v7.S > +++ b/arch/arm/mm/proc-v7.S > @@ -153,6 +153,21 @@ ENDPROC(cpu_v7_do_resume) > #endif > > /* > + * Cortex-A8 > + */ > + globl_equ cpu_ca8_proc_init, cpu_v7_proc_init > + globl_equ cpu_ca8_proc_fin, cpu_v7_proc_fin > + globl_equ cpu_ca8_reset, cpu_v7_reset > + globl_equ cpu_ca8_do_idle, cpu_v7_do_idle > + globl_equ cpu_ca8_dcache_clean_area, cpu_v7_dcache_clean_area > + globl_equ cpu_ca8_set_pte_ext, cpu_v7_set_pte_ext > + globl_equ cpu_ca8_suspend_size, cpu_v7_suspend_size > +#ifdef CONFIG_ARM_CPU_SUSPEND > + globl_equ cpu_ca8_do_suspend, cpu_v7_do_suspend > + globl_equ cpu_ca8_do_resume, cpu_v7_do_resume > +#endif > + > +/* > * Cortex-A9 processor functions > */ > globl_equ cpu_ca9mp_proc_init, cpu_v7_proc_init > @@ -471,7 +486,10 @@ __v7_setup_stack: > > @ define struct processor (see <asm/proc-fns.h> and proc-macros.S) > define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 > +#ifndef CONFIG_ARM_LPAE > + define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 > define_processor_functions ca9mp, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 > +#endif > #ifdef CONFIG_CPU_PJ4B > define_processor_functions pj4b, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 > #endif > @@ -527,6 +545,16 @@ __v7_ca9mp_proc_info: > __v7_proc __v7_ca9mp_proc_info, __v7_ca9mp_setup, proc_fns = ca9mp_processor_functions > .size __v7_ca9mp_proc_info, . - __v7_ca9mp_proc_info > > + /* > + * ARM Ltd. Cortex A8 processor. > + */ > + .type __v7_ca8_proc_info, #object > +__v7_ca8_proc_info: > + .long 0x410fc080 > + .long 0xff0ffff0 > + __v7_proc __v7_ca8_proc_info, __v7_setup, proc_fns = ca8_processor_functions > + .size __v7_ca8_proc_info, . - __v7_ca8_proc_info > + > #endif /* CONFIG_ARM_LPAE */ > > /* > -- > 1.8.3.1 > > -- > FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up > according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
