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authorChristoph Hellwig <hch@lst.de>2019-11-21 18:13:03 +0100
committerChristoph Hellwig <hch@lst.de>2019-11-21 18:13:03 +0100
commitd7293f79caea45c50c0ab4294847e7af96501ced (patch)
tree04d55fbe33562f4d242e0445baae55690ebb6682 /arch/arm64
parent68a33b1794665ba8a1d1ef1d3bfcc7c587d380a6 (diff)
parentbff3b04460a80f425442fe8e5c6ee8c3ebef611f (diff)
downloadlinux-d7293f79caea45c50c0ab4294847e7af96501ced.tar.bz2
Merge branch 'for-next/zone-dma' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into dma-mapping-for-next
Pull in a stable branch from the arm64 tree that adds the zone_dma_bits variable to avoid creating hard to resolve conflicts with that addition.
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/Kconfig4
-rw-r--r--arch/arm64/mm/init.c77
2 files changed, 57 insertions, 24 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 57606307fe34..ed5706ebf551 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -265,6 +265,10 @@ 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
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 45c00a54909c..d933589c48e8 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -20,6 +20,7 @@
#include <linux/sort.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
+#include <linux/dma-direct.h>
#include <linux/dma-mapping.h>
#include <linux/dma-contiguous.h>
#include <linux/efi.h>
@@ -41,6 +42,8 @@
#include <asm/tlb.h>
#include <asm/alternative.h>
+#define ARM64_ZONE_DMA_BITS 30
+
/*
* We need to be able to catch inadvertent references to memstart_addr
* that occur (potentially in generic code) before arm64_memblock_init()
@@ -56,7 +59,14 @@ 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;
+static phys_addr_t arm64_dma32_phys_limit __ro_after_init;
#ifdef CONFIG_KEXEC_CORE
/*
@@ -81,7 +91,7 @@ static void __init reserve_crashkernel(void)
if (crash_base == 0) {
/* Current arm64 boot protocol requires 2MB alignment */
- crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT,
+ crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit,
crash_size, SZ_2M);
if (crash_base == 0) {
pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
@@ -169,15 +179,16 @@ static void __init reserve_elfcorehdr(void)
{
}
#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_dma_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
@@ -186,8 +197,11 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
{
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(max_zone_dma_phys());
+ max_zone_pfns[ZONE_DMA32] = PFN_DOWN(arm64_dma32_phys_limit);
#endif
max_zone_pfns[ZONE_NORMAL] = max;
@@ -200,16 +214,21 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
{
struct memblock_region *reg;
unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
- unsigned long max_dma = min;
+ unsigned long max_dma32 = min;
+ unsigned long __maybe_unused max_dma = min;
memset(zone_size, 0, sizeof(zone_size));
- /* 4GB maximum for 32-bit only capable devices */
-#ifdef CONFIG_ZONE_DMA32
+#ifdef CONFIG_ZONE_DMA
max_dma = PFN_DOWN(arm64_dma_phys_limit);
- zone_size[ZONE_DMA32] = max_dma - min;
+ 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 - max_dma;
#endif
- zone_size[ZONE_NORMAL] = max - max_dma;
+ zone_size[ZONE_NORMAL] = max - max_dma32;
memcpy(zhole_size, zone_size, sizeof(zhole_size));
@@ -219,16 +238,22 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
if (start >= max)
continue;
-
-#ifdef CONFIG_ZONE_DMA32
+#ifdef CONFIG_ZONE_DMA
if (start < max_dma) {
- unsigned long dma_end = min(end, max_dma);
- zhole_size[ZONE_DMA32] -= dma_end - start;
+ unsigned long dma_end = min_not_zero(end, max_dma);
+ zhole_size[ZONE_DMA] -= dma_end - start;
}
#endif
- if (end > max_dma) {
+#ifdef CONFIG_ZONE_DMA32
+ if (start < max_dma32) {
+ 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) {
unsigned long normal_end = min(end, max);
- unsigned long normal_start = max(start, max_dma);
+ unsigned long normal_start = max(start, max_dma32);
zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
}
}
@@ -418,11 +443,15 @@ 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)) {
+ zone_dma_bits = ARM64_ZONE_DMA_BITS;
+ arm64_dma_phys_limit = max_zone_phys(ARM64_ZONE_DMA_BITS);
+ }
+
if (IS_ENABLED(CONFIG_ZONE_DMA32))
- arm64_dma_phys_limit = max_zone_dma_phys();
+ arm64_dma32_phys_limit = max_zone_phys(32);
else
- arm64_dma_phys_limit = PHYS_MASK + 1;
+ arm64_dma32_phys_limit = PHYS_MASK + 1;
reserve_crashkernel();
@@ -430,7 +459,7 @@ void __init arm64_memblock_init(void)
high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
- dma_contiguous_reserve(arm64_dma_phys_limit);
+ dma_contiguous_reserve(arm64_dma32_phys_limit);
}
void __init bootmem_init(void)
@@ -534,7 +563,7 @@ static void __init free_unused_memmap(void)
void __init mem_init(void)
{
if (swiotlb_force == SWIOTLB_FORCE ||
- max_pfn > (arm64_dma_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;