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authorYong Wu <yong.wu@mediatek.com>2020-12-07 17:35:53 +0800
committerWill Deacon <will@kernel.org>2020-12-07 10:49:34 +0000
commit093b32a849b336b5b48bdde1041fc06f91ae475c (patch)
tree824c546de9567462e6cfa887d3829e77fb7f9735 /drivers/iommu
parent058236eef606ea53ea7317afc20e9469cf3c3b91 (diff)
iommu: Improve the performance for direct_mapping
Currently direct_mapping always use the smallest pgsize which is SZ_4K normally to mapping. This is unnecessary. we could gather the size, and call iommu_map then, iommu_map could decide how to map better with the just right pgsize. >From the original comment, we should take care overlap, otherwise, iommu_map may return -EEXIST. In this overlap case, we should map the previous region before overlap firstly. then map the left part. Each a iommu device will call this direct_mapping when its iommu initialize, This patch is effective to improve the boot/initialization time especially while it only needs level 1 mapping. Signed-off-by: Anan Sun <anan.sun@mediatek.com> Signed-off-by: Yong Wu <yong.wu@mediatek.com> Link: https://lore.kernel.org/r/20201207093553.8635-1-yong.wu@mediatek.com Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/iommu.c22
1 files changed, 17 insertions, 5 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index dd617ed854a3..ae70a313c090 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -739,6 +739,7 @@ static int iommu_create_device_direct_mappings(struct iommu_group *group,
/* We need to consider overlapping regions for different devices */
list_for_each_entry(entry, &mappings, list) {
dma_addr_t start, end, addr;
+ size_t map_size = 0;
if (domain->ops->apply_resv_region)
domain->ops->apply_resv_region(dev, domain, entry);
@@ -750,16 +751,27 @@ static int iommu_create_device_direct_mappings(struct iommu_group *group,
entry->type != IOMMU_RESV_DIRECT_RELAXABLE)
continue;
- for (addr = start; addr < end; addr += pg_size) {
+ for (addr = start; addr <= end; addr += pg_size) {
phys_addr_t phys_addr;
+ if (addr == end)
+ goto map_end;
+
phys_addr = iommu_iova_to_phys(domain, addr);
- if (phys_addr)
+ if (!phys_addr) {
+ map_size += pg_size;
continue;
+ }
- ret = iommu_map(domain, addr, addr, pg_size, entry->prot);
- if (ret)
- goto out;
+map_end:
+ if (map_size) {
+ ret = iommu_map(domain, addr - map_size,
+ addr - map_size, map_size,
+ entry->prot);
+ if (ret)
+ goto out;
+ map_size = 0;
+ }
}
}