diff options
| author | Weidong Han <weidong.han@intel.com> | 2008-12-08 15:34:06 +0800 |
|---|---|---|
| committer | Joerg Roedel <joerg.roedel@amd.com> | 2009-01-03 14:02:18 +0100 |
| commit | 1b5736839ae13dadc5947940144f95dd0f4a4a8c (patch) | |
| tree | 2b6ce6b68850d905e4ce5d38b6872b82f6328208 /drivers/pci/intel-iommu.c | |
| parent | 8c11e798eee2ce4475134eaf61302b28ea4f205d (diff) | |
calculate agaw for each iommu
"SAGAW" capability may be different across iommus. Use a default agaw, but if default agaw is not supported in some iommus, choose a less supported agaw.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Diffstat (limited to 'drivers/pci/intel-iommu.c')
| -rw-r--r-- | drivers/pci/intel-iommu.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index 9dca689215e..3ecfa2304c2 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -362,6 +362,28 @@ void free_iova_mem(struct iova *iova) kmem_cache_free(iommu_iova_cache, iova); } + +static inline int width_to_agaw(int width); + +/* calculate agaw for each iommu. + * "SAGAW" may be different across iommus, use a default agaw, and + * get a supported less agaw for iommus that don't support the default agaw. + */ +int iommu_calculate_agaw(struct intel_iommu *iommu) +{ + unsigned long sagaw; + int agaw = -1; + + sagaw = cap_sagaw(iommu->cap); + for (agaw = width_to_agaw(DEFAULT_DOMAIN_ADDRESS_WIDTH); + agaw >= 0; agaw--) { + if (test_bit(agaw, &sagaw)) + break; + } + + return agaw; +} + /* in native case, each domain is related to only one iommu */ static struct intel_iommu *domain_get_iommu(struct dmar_domain *domain) { |