From mboxrd@z Thu Jan 1 00:00:00 1970 From: frank.rowand@am.sony.com (Frank Rowand) Date: Wed, 30 Nov 2011 18:57:07 -0800 Subject: [RFC PATCH 4/6] ARM: Remove __ARCH_WANT_INTERRUPTS_ON_CTXSW on ASID-capable CPUs In-Reply-To: <1322569352-23584-5-git-send-email-catalin.marinas@arm.com> References: <1322569352-23584-1-git-send-email-catalin.marinas@arm.com> <1322569352-23584-5-git-send-email-catalin.marinas@arm.com> Message-ID: <4ED6ED03.9080408@am.sony.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 11/29/11 04:22, Catalin Marinas wrote: > Since the ASIDs must be unique to an mm across all the CPUs in a system, > the __new_context() function needs to broadcast a context reset event to > all the CPUs during ASID allocation if a roll-over occurred. Such IPIs > cannot be issued with interrupts disabled and ARM had to define > __ARCH_WANT_INTERRUPTS_ON_CTXSW. > > This patch changes the check_context() function to > check_and_switch_context() called from switch_mm(). In case of > ASID-capable CPUs (ARMv6 onwards), if a new ASID is needed, it defers > the __new_context() and cpu_switch_mm() calls to the post-lock switch > hook where the interrupts are enabled. Setting the reserved TTBR0 was > also moved to check_and_switch_context() from cpu_v7_switch_mm(). > > Signed-off-by: Catalin Marinas > Cc: Russell King > --- > arch/arm/include/asm/mmu_context.h | 81 ++++++++++++++++++++++++++++-------- > arch/arm/include/asm/system.h | 2 + > arch/arm/include/asm/thread_info.h | 1 + > arch/arm/mm/context.c | 4 +- > arch/arm/mm/proc-v7.S | 3 - > 5 files changed, 69 insertions(+), 22 deletions(-) > < snip > > diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S > index 2faff3b..d5334d9 100644 > --- a/arch/arm/mm/proc-v7.S > +++ b/arch/arm/mm/proc-v7.S > @@ -116,9 +116,6 @@ ENTRY(cpu_v7_switch_mm) > #ifdef CONFIG_ARM_ERRATA_430973 > mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB > #endif > - mrc p15, 0, r2, c2, c0, 1 @ load TTB 1 > - mcr p15, 0, r2, c2, c0, 0 @ into TTB 0 > - isb > #ifdef CONFIG_ARM_ERRATA_754322 > dsb > #endif I do not have a tree that matches this version of cpu_v7_switch_mm(). Can you point me at a tree that I can see this in? -Frank