linux/drivers/iommu/intel
Longpeng(Mike) 9906b9352a iommu/vt-d: Avoid duplicate removing in __domain_mapping()
The __domain_mapping() always removes the pages in the range from
'iov_pfn' to 'end_pfn', but the 'end_pfn' is always the last pfn
of the range that the caller wants to map.

This would introduce too many duplicated removing and leads the
map operation take too long, for example:

  Map iova=0x100000,nr_pages=0x7d61800
    iov_pfn: 0x100000, end_pfn: 0x7e617ff
    iov_pfn: 0x140000, end_pfn: 0x7e617ff
    iov_pfn: 0x180000, end_pfn: 0x7e617ff
    iov_pfn: 0x1c0000, end_pfn: 0x7e617ff
    iov_pfn: 0x200000, end_pfn: 0x7e617ff
    ...
  it takes about 50ms in total.

We can reduce the cost by recalculate the 'end_pfn' and limit it
to the boundary of the end of this pte page.

  Map iova=0x100000,nr_pages=0x7d61800
    iov_pfn: 0x100000, end_pfn: 0x13ffff
    iov_pfn: 0x140000, end_pfn: 0x17ffff
    iov_pfn: 0x180000, end_pfn: 0x1bffff
    iov_pfn: 0x1c0000, end_pfn: 0x1fffff
    iov_pfn: 0x200000, end_pfn: 0x23ffff
    ...
  it only need 9ms now.

This also removes a meaningless BUG_ON() in __domain_mapping().

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Tested-by: Liujunjie <liujunjie23@huawei.com>
Link: https://lore.kernel.org/r/20211008000433.1115-1-longpeng2@huawei.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20211014053839.727419-10-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-10-18 12:31:48 +02:00
..
cap_audit.c iommu/vt-d: Check FL and SL capability sanity in scalable mode 2021-10-18 12:31:48 +02:00
cap_audit.h iommu/vt-d: Check FL and SL capability sanity in scalable mode 2021-10-18 12:31:48 +02:00
debugfs.c iommu/vt-d: Expose latency monitor data through debugfs 2021-06-10 09:06:13 +02:00
dmar.c iommu/vt-d: Dump DMAR translation structure when DMA fault occurs 2021-10-18 12:31:48 +02:00
iommu.c iommu/vt-d: Avoid duplicate removing in __domain_mapping() 2021-10-18 12:31:48 +02:00
irq_remapping.c pci-v5.13-changes 2021-05-05 13:24:11 -07:00
Kconfig iommu/vt-d: Dump DMAR translation structure when DMA fault occurs 2021-10-18 12:31:48 +02:00
Makefile iommu/vt-d: Add common code for dmar latency performance monitors 2021-06-10 09:06:13 +02:00
pasid.c Merge branches 'apple/dart', 'arm/smmu', 'iommu/fixes', 'x86/amd', 'x86/vt-d' and 'core' into next 2021-08-20 17:14:35 +02:00
pasid.h Merge branches 'apple/dart', 'arm/smmu', 'iommu/fixes', 'x86/amd', 'x86/vt-d' and 'core' into next 2021-08-20 17:14:35 +02:00
perf.c iommu/vt-d: Drop the kernel doc annotation 2021-08-19 10:41:08 +02:00
perf.h iommu/vt-d: Add common code for dmar latency performance monitors 2021-06-10 09:06:13 +02:00
svm.c iommu/vt-d: Clean up unused PASID updating functions 2021-10-18 12:31:48 +02:00
trace.c