diff options
Diffstat (limited to 'target/linux/bcm27xx/patches-5.4/950-0447-arm64-use-both-ZONE_DMA-and-ZONE_DMA32.patch')
| -rw-r--r-- | target/linux/bcm27xx/patches-5.4/950-0447-arm64-use-both-ZONE_DMA-and-ZONE_DMA32.patch | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.4/950-0447-arm64-use-both-ZONE_DMA-and-ZONE_DMA32.patch b/target/linux/bcm27xx/patches-5.4/950-0447-arm64-use-both-ZONE_DMA-and-ZONE_DMA32.patch new file mode 100644 index 0000000000..2397c71af7 --- /dev/null +++ b/target/linux/bcm27xx/patches-5.4/950-0447-arm64-use-both-ZONE_DMA-and-ZONE_DMA32.patch @@ -0,0 +1,174 @@ +From 1fb65f4bc30fbadd0c89521985ff8142693c9631 Mon Sep 17 00:00:00 2001 +From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> +Date: Wed, 11 Sep 2019 20:25:45 +0200 +Subject: [PATCH] arm64: use both ZONE_DMA and ZONE_DMA32 + +commit 1a8e1cef7603e218339ac63cb3178b25554524e5 upstream. + +So far all arm64 devices have supported 32 bit DMA masks for their +peripherals. This is not true anymore for the Raspberry Pi 4 as most of +it's peripherals can only address the first GB of memory on a total of +up to 4 GB. + +This goes against ZONE_DMA32's intent, as it's expected for ZONE_DMA32 +to be addressable with a 32 bit mask. So it was decided to re-introduce +ZONE_DMA in arm64. + +ZONE_DMA will contain the lower 1G of memory, which is currently the +memory area addressable by any peripheral on an arm64 device. +ZONE_DMA32 will contain the rest of the 32 bit addressable memory. + +Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> +Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> +Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> +--- + arch/arm64/Kconfig | 4 +++ + arch/arm64/include/asm/page.h | 2 ++ + arch/arm64/mm/init.c | 54 +++++++++++++++++++++++++---------- + 3 files changed, 45 insertions(+), 15 deletions(-) + +--- a/arch/arm64/Kconfig ++++ b/arch/arm64/Kconfig +@@ -267,6 +267,10 @@ config GENERIC_CSUM + config GENERIC_CALIBRATE_DELAY + def_bool y + ++config ZONE_DMA ++ bool "Support DMA zone" if EXPERT ++ default y ++ + config ZONE_DMA32 + bool "Support DMA32 zone" if EXPERT + default y +--- a/arch/arm64/include/asm/page.h ++++ b/arch/arm64/include/asm/page.h +@@ -38,4 +38,6 @@ extern int pfn_valid(unsigned long); + + #include <asm-generic/getorder.h> + ++#define ARCH_ZONE_DMA_BITS 30 ++ + #endif +--- a/arch/arm64/mm/init.c ++++ b/arch/arm64/mm/init.c +@@ -56,6 +56,13 @@ EXPORT_SYMBOL(physvirt_offset); + struct page *vmemmap __ro_after_init; + EXPORT_SYMBOL(vmemmap); + ++/* ++ * We create both ZONE_DMA and ZONE_DMA32. ZONE_DMA covers the first 1G of ++ * memory as some devices, namely the Raspberry Pi 4, have peripherals with ++ * this limited view of the memory. ZONE_DMA32 will cover the rest of the 32 ++ * bit addressable memory area. ++ */ ++phys_addr_t arm64_dma_phys_limit __ro_after_init; + phys_addr_t arm64_dma32_phys_limit __ro_after_init; + + #ifdef CONFIG_KEXEC_CORE +@@ -169,15 +176,16 @@ static void __init reserve_elfcorehdr(vo + { + } + #endif /* CONFIG_CRASH_DUMP */ ++ + /* +- * Return the maximum physical address for ZONE_DMA32 (DMA_BIT_MASK(32)). It +- * currently assumes that for memory starting above 4G, 32-bit devices will +- * use a DMA offset. ++ * Return the maximum physical address for a zone with a given address size ++ * limit. It currently assumes that for memory starting above 4G, 32-bit ++ * devices will use a DMA offset. + */ +-static phys_addr_t __init max_zone_dma32_phys(void) ++static phys_addr_t __init max_zone_phys(unsigned int zone_bits) + { +- phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32); +- return min(offset + (1ULL << 32), memblock_end_of_DRAM()); ++ phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, zone_bits); ++ return min(offset + (1ULL << zone_bits), memblock_end_of_DRAM()); + } + + #ifdef CONFIG_NUMA +@@ -186,6 +194,9 @@ static void __init zone_sizes_init(unsig + { + unsigned long max_zone_pfns[MAX_NR_ZONES] = {0}; + ++#ifdef CONFIG_ZONE_DMA ++ max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit); ++#endif + #ifdef CONFIG_ZONE_DMA32 + max_zone_pfns[ZONE_DMA32] = PFN_DOWN(arm64_dma32_phys_limit); + #endif +@@ -201,13 +212,18 @@ static void __init zone_sizes_init(unsig + struct memblock_region *reg; + unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES]; + unsigned long max_dma32 = min; ++ unsigned long max_dma = min; + + memset(zone_size, 0, sizeof(zone_size)); + +- /* 4GB maximum for 32-bit only capable devices */ ++#ifdef CONFIG_ZONE_DMA ++ max_dma = PFN_DOWN(arm64_dma_phys_limit); ++ zone_size[ZONE_DMA] = max_dma - min; ++ max_dma32 = max_dma; ++#endif + #ifdef CONFIG_ZONE_DMA32 + max_dma32 = PFN_DOWN(arm64_dma32_phys_limit); +- zone_size[ZONE_DMA32] = max_dma32 - min; ++ zone_size[ZONE_DMA32] = max_dma32 - max_dma; + #endif + zone_size[ZONE_NORMAL] = max - max_dma32; + +@@ -219,11 +235,17 @@ static void __init zone_sizes_init(unsig + + if (start >= max) + continue; +- ++#ifdef CONFIG_ZONE_DMA ++ if (start < max_dma) { ++ unsigned long dma_end = min_not_zero(end, max_dma); ++ zhole_size[ZONE_DMA] -= dma_end - start; ++ } ++#endif + #ifdef CONFIG_ZONE_DMA32 + if (start < max_dma32) { +- unsigned long dma_end = min(end, max_dma32); +- zhole_size[ZONE_DMA32] -= dma_end - start; ++ unsigned long dma32_end = min(end, max_dma32); ++ unsigned long dma32_start = max(start, max_dma); ++ zhole_size[ZONE_DMA32] -= dma32_end - dma32_start; + } + #endif + if (end > max_dma32) { +@@ -418,9 +440,11 @@ void __init arm64_memblock_init(void) + + early_init_fdt_scan_reserved_mem(); + +- /* 4GB maximum for 32-bit only capable devices */ ++ if (IS_ENABLED(CONFIG_ZONE_DMA)) ++ arm64_dma_phys_limit = max_zone_phys(ARCH_ZONE_DMA_BITS); ++ + if (IS_ENABLED(CONFIG_ZONE_DMA32)) +- arm64_dma32_phys_limit = max_zone_dma32_phys(); ++ arm64_dma32_phys_limit = max_zone_phys(32); + else + arm64_dma32_phys_limit = PHYS_MASK + 1; + +@@ -430,7 +454,7 @@ void __init arm64_memblock_init(void) + + high_memory = __va(memblock_end_of_DRAM() - 1) + 1; + +- dma_contiguous_reserve(arm64_dma32_phys_limit); ++ dma_contiguous_reserve(arm64_dma_phys_limit ? : arm64_dma32_phys_limit); + } + + void __init bootmem_init(void) +@@ -534,7 +558,7 @@ static void __init free_unused_memmap(vo + void __init mem_init(void) + { + if (swiotlb_force == SWIOTLB_FORCE || +- max_pfn > (arm64_dma32_phys_limit >> PAGE_SHIFT)) ++ max_pfn > PFN_DOWN(arm64_dma_phys_limit ? : arm64_dma32_phys_limit)) + swiotlb_init(1); + else + swiotlb_force = SWIOTLB_NO_FORCE; |