diff options
| author | Yong Wu <yong.wu@mediatek.com> | 2020-12-07 17:35:53 +0800 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-12-07 10:49:34 +0000 |
| commit | 093b32a849b336b5b48bdde1041fc06f91ae475c (patch) | |
| tree | 824c546de9567462e6cfa887d3829e77fb7f9735 /drivers/iommu | |
| parent | 058236eef606ea53ea7317afc20e9469cf3c3b91 (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.c | 22 |
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; + } } } |