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authorAdrian Huang <ahuang12@lenovo.com>2020-01-09 06:02:50 +0300
committerJoerg Roedel <jroedel@suse.de>2020-01-17 13:05:56 +0300
commit62dcee71608506ad83b0525aa1b53a78b3f1689a (patch)
tree534789a5a1b3ee30048063985e45e73f254783bf /drivers/iommu/amd_iommu_init.c
parentbde9e6b9ba755e35768261a5ea15541a4c4b4de8 (diff)
downloadlinux-62dcee71608506ad83b0525aa1b53a78b3f1689a.tar.xz
iommu/amd: Replace two consecutive readl calls with one readq
Optimize the reigster reading by using readq instead of the two consecutive readl calls. Signed-off-by: Adrian Huang <ahuang12@lenovo.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/amd_iommu_init.c')
-rw-r--r--drivers/iommu/amd_iommu_init.c6
1 files changed, 1 insertions, 5 deletions
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index c5167fe0bd5f..cfdc4b60ccbe 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -1718,7 +1718,6 @@ static const struct attribute_group *amd_iommu_groups[] = {
static int __init iommu_init_pci(struct amd_iommu *iommu)
{
int cap_ptr = iommu->cap_ptr;
- u32 low, high;
int ret;
iommu->dev = pci_get_domain_bus_and_slot(0, PCI_BUS_NUM(iommu->devid),
@@ -1736,10 +1735,7 @@ static int __init iommu_init_pci(struct amd_iommu *iommu)
amd_iommu_iotlb_sup = false;
/* read extended feature bits */
- low = readl(iommu->mmio_base + MMIO_EXT_FEATURES);
- high = readl(iommu->mmio_base + MMIO_EXT_FEATURES + 4);
-
- iommu->features = ((u64)high << 32) | low;
+ iommu->features = readq(iommu->mmio_base + MMIO_EXT_FEATURES);
if (iommu_feature(iommu, FEATURE_GT)) {
int glxval;