From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean-Philippe Brucker Subject: [PATCH v2 27/40] iommu/arm-smmu-v3: Add SVA feature checking Date: Fri, 11 May 2018 20:06:28 +0100 Message-ID: <20180511190641.23008-28-jean-philippe.brucker@arm.com> References: <20180511190641.23008-1-jean-philippe.brucker@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180511190641.23008-1-jean-philippe.brucker-5wv7dgnIgG8@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org Cc: xuzaibo-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, okaya-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, ashok.raj-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, bharatku-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org, rfranz-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org, rgummal-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org, ilias.apalodimas-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, christian.koenig-5C7GfCeVMHo@public.gmane.org List-Id: iommu@lists.linux-foundation.org Aggregate all sanity-checks for sharing CPU page tables with the SMMU under a single ARM_SMMU_FEAT_SVA bit. For PCIe SVA, users also need to check FEAT_ATS and FEAT_PRI. For platform SVM, they will most likely have to check FEAT_STALLS. Signed-off-by: Jean-Philippe Brucker --- v1->v2: Add 52-bit PA cap and debug message --- drivers/iommu/arm-smmu-v3.c | 72 +++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 073cba33ae6c..2716e4a4d3f7 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -525,6 +525,7 @@ struct arm_smmu_device { #define ARM_SMMU_FEAT_VAX (1 << 14) #define ARM_SMMU_FEAT_E2H (1 << 15) #define ARM_SMMU_FEAT_BTM (1 << 16) +#define ARM_SMMU_FEAT_SVA (1 << 17) u32 features; #define ARM_SMMU_OPT_SKIP_PREFETCH (1 << 0) @@ -2565,6 +2566,74 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass) return 0; } +static bool arm_smmu_supports_sva(struct arm_smmu_device *smmu) +{ + unsigned long reg, fld; + unsigned long oas; + unsigned long asid_bits; + + u32 feat_mask = ARM_SMMU_FEAT_BTM | ARM_SMMU_FEAT_COHERENCY; + + if ((smmu->features & feat_mask) != feat_mask) + return false; + + if (!(smmu->pgsize_bitmap & PAGE_SIZE)) + return false; + + /* + * Get the smallest PA size of all CPUs (sanitized by cpufeature). We're + * not even pretending to support AArch32 here. + */ + reg = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1); + fld = cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR0_PARANGE_SHIFT); + switch (fld) { + case 0x0: + oas = 32; + break; + case 0x1: + oas = 36; + break; + case 0x2: + oas = 40; + break; + case 0x3: + oas = 42; + break; + case 0x4: + oas = 44; + break; + case 0x5: + oas = 48; + break; + case 0x6: + oas = 52; + break; + default: + return false; + } + + /* abort if MMU outputs addresses greater than what we support. */ + if (smmu->oas < oas) + return false; + + /* We can support bigger ASIDs than the CPU, but not smaller */ + fld = cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR0_ASID_SHIFT); + asid_bits = fld ? 16 : 8; + if (smmu->asid_bits < asid_bits) + return false; + + /* + * See max_pinned_asids in arch/arm64/mm/context.c. The following is + * generally the maximum number of bindable processes. + */ + if (IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) + asid_bits--; + dev_dbg(smmu->dev, "%d shared contexts\n", (1 << asid_bits) - + num_possible_cpus() - 2); + + return true; +} + static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu) { u32 reg; @@ -2766,6 +2835,9 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu) smmu->ias = max(smmu->ias, smmu->oas); + if (arm_smmu_supports_sva(smmu)) + smmu->features |= ARM_SMMU_FEAT_SVA; + dev_info(smmu->dev, "ias %lu-bit, oas %lu-bit (features 0x%08x)\n", smmu->ias, smmu->oas, smmu->features); return 0; -- 2.17.0