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arm64: Increase the swiotlb buffer size 64MB

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With commit 3690951fc6 (arm64: Use swiotlb late initialisation), the
swiotlb buffer size is limited to MAX_ORDER_NR_PAGES. However, there are
platforms with 32-bit only devices that require bounce buffering via
swiotlb. This patch changes the swiotlb initialisation to an early 64MB
memblock allocation. In order to get the swiotlb buffer correctly
allocated (via memblock_virt_alloc_low_nopanic), this patch also defines
ARCH_LOW_ADDRESS_LIMIT to the maximum physical address capable of 32-bit
DMA.

Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Catalin Marinas
2015-02-05 18:01:53 +00:00
parent f6242cac10
commit a1e50a8225
3 changed files with 14 additions and 19 deletions
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14
arch/arm64/mm/init.c
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@@ -33,6 +33,7 @@
#include <linux/dma-mapping.h>
#include <linux/dma-contiguous.h>
#include <linux/efi.h>
#include <linux/swiotlb.h>
#include <asm/fixmap.h>
#include <asm/memory.h>
@@ -45,6 +46,7 @@
#include "mm.h"
phys_addr_t memstart_addr __read_mostly = 0;
phys_addr_t arm64_dma_phys_limit __read_mostly;
#ifdef CONFIG_BLK_DEV_INITRD
static int __init early_initrd(char *p)
@@ -85,7 +87,7 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
/* 4GB maximum for 32-bit only capable devices */
if (IS_ENABLED(CONFIG_ZONE_DMA)) {
max_dma = PFN_DOWN(max_zone_dma_phys());
max_dma = PFN_DOWN(arm64_dma_phys_limit);
zone_size[ZONE_DMA] = max_dma - min;
}
zone_size[ZONE_NORMAL] = max - max_dma;
@@ -156,8 +158,6 @@ early_param("mem", early_mem);
void __init arm64_memblock_init(void)
{
phys_addr_t dma_phys_limit = 0;
memblock_enforce_memory_limit(memory_limit);
/*
@@ -174,8 +174,10 @@ void __init arm64_memblock_init(void)
/* 4GB maximum for 32-bit only capable devices */
if (IS_ENABLED(CONFIG_ZONE_DMA))
dma_phys_limit = max_zone_dma_phys();
dma_contiguous_reserve(dma_phys_limit);
arm64_dma_phys_limit = max_zone_dma_phys();
else
arm64_dma_phys_limit = PHYS_MASK + 1;
dma_contiguous_reserve(arm64_dma_phys_limit);
memblock_allow_resize();
memblock_dump_all();
@@ -276,6 +278,8 @@ static void __init free_unused_memmap(void)
*/
void __init mem_init(void)
{
swiotlb_init(1);
set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
#ifndef CONFIG_SPARSEMEM_VMEMMAP