Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932609Ab0KLSC4 (ORCPT ); Fri, 12 Nov 2010 13:02:56 -0500 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:50926 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932423Ab0KLSBN (ORCPT ); Fri, 12 Nov 2010 13:01:13 -0500 From: Catalin Marinas To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 13/20] ARM: LPAE: Add SMP support for the 3-level page table format Date: Fri, 12 Nov 2010 18:00:33 +0000 Message-Id: <1289584840-18097-14-git-send-email-catalin.marinas@arm.com> X-Mailer: git-send-email 1.7.3.2.164.g6f10c In-Reply-To: <1289584840-18097-1-git-send-email-catalin.marinas@arm.com> References: <1289584840-18097-1-git-send-email-catalin.marinas@arm.com> X-OriginalArrivalTime: 12 Nov 2010 18:00:52.0438 (UTC) FILETIME=[8B9DF760:01CB8293] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4086 Lines: 129 With 3-level page tables, starting secondary CPUs required allocating the pgd as well. Since LPAE Linux uses TTBR1 for the kernel page tables, this patch reorders the CPU setup call in the head.S file so that the swapper_pg_dir is used. TTBR0 is set to the value generated by the primary CPU. Signed-off-by: Catalin Marinas --- arch/arm/kernel/head.S | 10 +++++----- arch/arm/kernel/smp.c | 39 +++++++++++++++++++++++++++++++++++++-- 2 files changed, 42 insertions(+), 7 deletions(-) diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index fd8a29e..b54d00e 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -321,6 +321,10 @@ ENTRY(secondary_startup) moveq r0, #'p' @ yes, error 'p' beq __error_p + pgtbl r4 + add r12, r10, #BSYM(PROCINFO_INITFUNC) + blx r12 @ initialise processor + @ (return control reg) /* * Use the page tables supplied from __cpu_up. */ @@ -328,12 +332,8 @@ ENTRY(secondary_startup) ldmia r4, {r5, r7, r12} @ address to jump to after sub r4, r4, r5 @ mmu has been enabled ldr r4, [r7, r4] @ get secondary_data.pgdir - adr lr, BSYM(__enable_mmu) @ return address mov r13, r12 @ __secondary_switched address - ARM( add pc, r10, #PROCINFO_INITFUNC ) @ initialise processor - @ (return control reg) - THUMB( add r12, r10, #PROCINFO_INITFUNC ) - THUMB( mov pc, r12 ) + b __enable_mmu ENDPROC(secondary_startup) /* diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 40b386c..089e2ae 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -82,8 +82,10 @@ static inline void identity_mapping_add(pgd_t *pgd, unsigned long start, pmd = pmd_offset(pgd + pgd_index(addr), addr); pmd[0] = __pmd(addr | prot); addr += SECTION_SIZE; +#ifndef CONFIG_ARM_LPAE pmd[1] = __pmd(addr | prot); addr += SECTION_SIZE; +#endif flush_pmd_entry(pmd); outer_clean_range(__pa(pmd), __pa(pmd + 1)); } @@ -98,7 +100,9 @@ static inline void identity_mapping_del(pgd_t *pgd, unsigned long start, for (addr = start & PMD_MASK; addr < end; addr += PMD_SIZE) { pmd = pmd_offset(pgd + pgd_index(addr), addr); pmd[0] = __pmd(0); +#ifndef CONFIG_ARM_LPAE pmd[1] = __pmd(0); +#endif clean_pmd_entry(pmd); outer_clean_range(__pa(pmd), __pa(pmd + 1)); } @@ -109,6 +113,10 @@ int __cpuinit __cpu_up(unsigned int cpu) struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu); struct task_struct *idle = ci->idle; pgd_t *pgd; +#ifdef CONFIG_ARM_LPAE + pgd_t *pgd_phys; + pmd_t *pmd; +#endif int ret; /* @@ -137,8 +145,30 @@ int __cpuinit __cpu_up(unsigned int cpu) * a 1:1 mapping for the physical address of the kernel. */ pgd = pgd_alloc(&init_mm); - if (!pgd) - return -ENOMEM; + if (!pgd) { + ret = -ENOMEM; + goto out; + } + +#ifdef CONFIG_ARM_LPAE + /* + * Check for overlapping between PHYS_OFFSET and PAGE_OFFSET and + * duplicate the pmd to avoid overriding valid kernel mappings in the + * init_mm page tables. The code assumes that the kernel text and data + * sections are within 1GB of PHYS_OFFSET (maximum range convered by + * a PMD table with LPAE). + */ + pgd_phys = pgd + pgd_index(PHYS_OFFSET); + pmd = pmd_alloc_one(NULL, PHYS_OFFSET); + if (!pmd) { + ret = -ENOMEM; + goto nopmd; + } + if (pgd_present(*pgd_phys)) + memcpy(pmd, pmd_offset(pgd_phys, 0), + PTRS_PER_PMD * sizeof(pmd_t)); + pgd_populate(NULL, pgd_phys, pmd); +#endif if (PHYS_OFFSET != PAGE_OFFSET) { #ifndef CONFIG_HOTPLUG_CPU @@ -192,8 +222,13 @@ int __cpuinit __cpu_up(unsigned int cpu) identity_mapping_del(pgd, __pa(_sdata), __pa(_edata)); } +#ifdef CONFIG_ARM_LPAE + pmd_free(&init_mm, pmd_offset(pgd_phys, 0)); +nopmd: +#endif pgd_free(&init_mm, pgd); +out: if (ret) { printk(KERN_CRIT "CPU%u: processor failed to boot\n", cpu); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/