diff options
| author | Longpeng(Mike) <longpeng2@huawei.com> | 2021-10-14 13:38:39 +0800 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2021-10-18 12:31:48 +0200 |
| commit | 9906b9352a35427508d974db3a496eb3c49e2010 (patch) | |
| tree | 3450fd05cf8d7734acb1a3e9b83e6961a27955f8 /drivers/iommu | |
| parent | 37c8041a818dec2cea22ea48a3f90d512a9e1fcd (diff) | |
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>
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/intel/iommu.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 16a35669a9d0..0bde0c8b4126 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -2479,12 +2479,17 @@ __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn, return -ENOMEM; first_pte = pte; + lvl_pages = lvl_to_nr_pages(largepage_lvl); + /* It is large page*/ if (largepage_lvl > 1) { unsigned long end_pfn; + unsigned long pages_to_remove; pteval |= DMA_PTE_LARGE_PAGE; - end_pfn = ((iov_pfn + nr_pages) & level_mask(largepage_lvl)) - 1; + pages_to_remove = min_t(unsigned long, nr_pages, + nr_pte_to_next_page(pte) * lvl_pages); + end_pfn = iov_pfn + pages_to_remove - 1; switch_to_super_page(domain, iov_pfn, end_pfn, largepage_lvl); } else { pteval &= ~(uint64_t)DMA_PTE_LARGE_PAGE; @@ -2506,10 +2511,6 @@ __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn, WARN_ON(1); } - lvl_pages = lvl_to_nr_pages(largepage_lvl); - - BUG_ON(nr_pages < lvl_pages); - nr_pages -= lvl_pages; iov_pfn += lvl_pages; phys_pfn += lvl_pages; |