From: Adrian Huang Date: Thu, 9 Jan 2020 03:02:50 +0000 (+0800) Subject: iommu/amd: Replace two consecutive readl calls with one readq X-Git-Tag: v5.6-rc1~53^2^3~2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=62dcee71608506ad83b0525aa1b53a78b3f1689a;p=thirdparty%2Fkernel%2Flinux.git 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 Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c index c5167fe0bd5fd..cfdc4b60ccbef 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;