From c8358ceb90c90a11c98e14d1ccfcbf528141f325 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Mon, 31 Jan 2011 13:50:44 +0000 Subject: [PATCH] ARM: LPAE: Add context switching support With LPAE, TTBRx registers are 64-bit. The ASID is stored in TTBR0 rather than a separate Context ID register. This patch makes the necessary changes to handle context switching on LPAE. Signed-off-by: Catalin Marinas --- arch/arm/mm/context.c | 19 +++++++++++++++++-- arch/arm/mm/proc-v7.S | 10 ++++++++-- 2 files changed, 25 insertions(+), 4 deletions(-) diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c index b0ee9ba3cfab..fcdb1017cdc6 100644 --- a/arch/arm/mm/context.c +++ b/arch/arm/mm/context.c @@ -22,6 +22,21 @@ unsigned int cpu_last_asid = ASID_FIRST_VERSION; DEFINE_PER_CPU(struct mm_struct *, current_mm); #endif +#ifdef CONFIG_ARM_LPAE +#define cpu_set_asid(asid) { \ + unsigned long ttbl, ttbh; \ + asm volatile( \ + " mrrc p15, 0, %0, %1, c2 @ read TTBR0\n" \ + " mov %1, %2, lsl #(48 - 32) @ set ASID\n" \ + " mcrr p15, 0, %0, %1, c2 @ set TTBR0\n" \ + : "=&r" (ttbl), "=&r" (ttbh) \ + : "r" (asid & ~ASID_MASK)); \ +} +#else +#define cpu_set_asid(asid) \ + asm(" mcr p15, 0, %0, c13, c0, 1\n" : : "r" (asid)) +#endif + /* * We fork()ed a process, and we need a new context for the child * to run in. We reserve version 0 for initial tasks so we will @@ -37,7 +52,7 @@ void __init_new_context(struct task_struct *tsk, struct mm_struct *mm) static void flush_context(void) { /* set the reserved ASID before flushing the TLB */ - asm("mcr p15, 0, %0, c13, c0, 1\n" : : "r" (0)); + cpu_set_asid(0); isb(); local_flush_tlb_all(); if (icache_is_vivt_asid_tagged()) { @@ -99,7 +114,7 @@ static void reset_context(void *info) set_mm_context(mm, asid); /* set the new ASID */ - asm("mcr p15, 0, %0, c13, c0, 1\n" : : "r" (mm->context.id)); + cpu_set_asid(mm->context.id); isb(); } diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S index 3c3867850a30..ac72d89683df 100644 --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -101,8 +101,13 @@ ENDPROC(cpu_v7_dcache_clean_area) */ ENTRY(cpu_v7_switch_mm) #ifdef CONFIG_MMU - mov r2, #0 ldr r1, [r1, #MM_CONTEXT_ID] @ get mm->context.id + mov r2, #0 +#ifdef CONFIG_ARM_LPAE + and r3, r1, #0xff + mov r3, r3, lsl #(48 - 32) @ ASID + mcrr p15, 0, r0, r3, c2 @ set TTB 0 +#else /* !CONFIG_ARM_LPAE */ ALT_SMP(orr r0, r0, #TTB_FLAGS_SMP) ALT_UP(orr r0, r0, #TTB_FLAGS_UP) #ifdef CONFIG_ARM_ERRATA_430973 @@ -113,12 +118,13 @@ ENTRY(cpu_v7_switch_mm) #endif mcr p15, 0, r2, c13, c0, 1 @ set reserved context ID isb -1: mcr p15, 0, r0, c2, c0, 0 @ set TTB 0 + mcr p15, 0, r0, c2, c0, 0 @ set TTB 0 isb #ifdef CONFIG_ARM_ERRATA_754322 dsb #endif mcr p15, 0, r1, c13, c0, 1 @ set context ID +#endif /* CONFIG_ARM_LPAE */ isb #endif mov pc, lr -- 2.39.5