From ca4744084772e1fee999391bee0fcdca5d91a757 Mon Sep 17 00:00:00 2001 From: Santosh Shilimkar Date: Thu, 6 Feb 2014 19:50:35 +0100 Subject: ARM: 7952/1: mm: Fix the memblock allocation for LPAE machines Commit ad6492b8 added much needed memblock_virt_alloc_low() and further commit 07bacb3 {memblock, bootmem: restore goal for alloc_low} fixed the issue with low memory limit thanks to Yinghai. But even after all these fixes, there is still one case where the limit check done with ARCH_LOW_ADDRESS_LIMIT for low memory fails. Russell pointed out the issue with 32 bit LPAE machines in below thread. https://lkml.org/lkml/2014/1/28/364 Since on some LPAE machines where memory start address is beyond 4GB, the low memory marker in memblock will be set to default ARCH_LOW_ADDRESS_LIMIT which is wrong. We can fix this by letting architectures set the ARCH_LOW_ADDRESS_LIMIT using another export similar to memblock_set_current_limit() but am not sure whether its worth the trouble. Tell me if you think otherwise. Rather am just trying to fix that one broken case using memblock_virt_alloc() in setup code since the memblock.current_limit is updated appropriately makes it work on all ARM 32 bit machines. Cc: Yinghai Lu Cc: Strashko, Grygorii Cc: Andrew Morton Signed-off-by: Santosh Shilimkar Signed-off-by: Russell King --- arch/arm/kernel/setup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index b0df9761de6d..1e8b030dbefd 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -731,7 +731,7 @@ static void __init request_standard_resources(const struct machine_desc *mdesc) kernel_data.end = virt_to_phys(_end - 1); for_each_memblock(memory, region) { - res = memblock_virt_alloc_low(sizeof(*res), 0); + res = memblock_virt_alloc(sizeof(*res), 0); res->name = "System RAM"; res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region)); res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1; -- cgit From b3634575930857724d5c3987a2739b0637999b4e Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Tue, 18 Feb 2014 17:02:54 +0100 Subject: ARM: 7980/1: kernel: improve error message when LPAE config doesn't match CPU Currently, when the kernel is configured with LPAE support, but the CPU doesn't support it, the error message is fairly cryptic: Error: unrecognized/unsupported processor variant (0x561f5811). This messages is normally shown when there is an issue when comparing the processor ID (CP15 0, c0, c0) with the values/masks described in proc-v7.S. However, the same message is displayed when LPAE support is enabled in the kernel configuration, but not available in the CPU, after looking at ID_MMFR0 (CP15 0, c0, c1, 4). Having the same error message is highly misleading. This commit improves this by showing a different error message when this situation occurs: Error: Kernel with LPAE support, but CPU does not support LPAE. Signed-off-by: Thomas Petazzoni Signed-off-by: Russell King --- arch/arm/kernel/head-common.S | 12 ++++++++++++ arch/arm/kernel/head.S | 2 +- 2 files changed, 13 insertions(+), 1 deletion(-) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S index 47cd974e57ea..c96ecacb2021 100644 --- a/arch/arm/kernel/head-common.S +++ b/arch/arm/kernel/head-common.S @@ -177,6 +177,18 @@ __lookup_processor_type_data: .long __proc_info_end .size __lookup_processor_type_data, . - __lookup_processor_type_data +__error_lpae: +#ifdef CONFIG_DEBUG_LL + adr r0, str_lpae + bl printascii + b __error +str_lpae: .asciz "\nError: Kernel with LPAE support, but CPU does not support LPAE.\n" +#else + b __error +#endif + .align +ENDPROC(__error_lpae) + __error_p: #ifdef CONFIG_DEBUG_LL adr r0, str_p1 diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 914616e0bdcd..f5f381d91556 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -102,7 +102,7 @@ ENTRY(stext) and r3, r3, #0xf @ extract VMSA support cmp r3, #5 @ long-descriptor translation table format? THUMB( it lo ) @ force fixup-able long branch encoding - blo __error_p @ only classic page table format + blo __error_lpae @ only classic page table format #endif #ifndef CONFIG_XIP_KERNEL -- cgit