1 files changed, 195 insertions, 6 deletions

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 3e7198ee9530..3bde137a3755 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -29,6 +29,7 @@
 #include <linux/of_iommu.h>
 #include <linux/of_platform.h>
 #include <linux/pci.h>
+#include <linux/pci-ats.h>
 #include <linux/platform_device.h>
 
 #include <linux/amba/bus.h>
@@ -86,6 +87,7 @@
 #define IDR5_VAX_52_BIT			1
 
 #define ARM_SMMU_CR0			0x20
+#define CR0_ATSCHK			(1 << 4)
 #define CR0_CMDQEN			(1 << 3)
 #define CR0_EVTQEN			(1 << 2)
 #define CR0_PRIQEN			(1 << 1)
@@ -294,6 +296,7 @@
 #define CMDQ_ERR_CERROR_NONE_IDX	0
 #define CMDQ_ERR_CERROR_ILL_IDX		1
 #define CMDQ_ERR_CERROR_ABT_IDX		2
+#define CMDQ_ERR_CERROR_ATC_INV_IDX	3
 
 #define CMDQ_0_OP			GENMASK_ULL(7, 0)
 #define CMDQ_0_SSV			(1UL << 11)
@@ -312,6 +315,12 @@
 #define CMDQ_TLBI_1_VA_MASK		GENMASK_ULL(63, 12)
 #define CMDQ_TLBI_1_IPA_MASK		GENMASK_ULL(51, 12)
 
+#define CMDQ_ATC_0_SSID			GENMASK_ULL(31, 12)
+#define CMDQ_ATC_0_SID			GENMASK_ULL(63, 32)
+#define CMDQ_ATC_0_GLOBAL		(1UL << 9)
+#define CMDQ_ATC_1_SIZE			GENMASK_ULL(5, 0)
+#define CMDQ_ATC_1_ADDR_MASK		GENMASK_ULL(63, 12)
+
 #define CMDQ_PRI_0_SSID			GENMASK_ULL(31, 12)
 #define CMDQ_PRI_0_SID			GENMASK_ULL(63, 32)
 #define CMDQ_PRI_1_GRPID		GENMASK_ULL(8, 0)
@@ -433,6 +442,16 @@ struct arm_smmu_cmdq_ent {
 			u64			addr;
 		} tlbi;
 
+		#define CMDQ_OP_ATC_INV		0x40
+		#define ATC_INV_SIZE_ALL	52
+		struct {
+			u32			sid;
+			u32			ssid;
+			u64			addr;
+			u8			size;
+			bool			global;
+		} atc;
+
 		#define CMDQ_OP_PRI_RESP	0x41
 		struct {
 			u32			sid;
@@ -580,10 +599,12 @@ struct arm_smmu_device {
 /* SMMU private data for each master */
 struct arm_smmu_master {
 	struct arm_smmu_device		*smmu;
+	struct device			*dev;
 	struct arm_smmu_domain		*domain;
 	struct list_head		domain_head;
 	u32				*sids;
 	unsigned int			num_sids;
+	bool				ats_enabled		:1;
 };
 
 /* SMMU private data for an IOMMU domain */
@@ -813,6 +834,14 @@ static int arm_smmu_cmdq_build_cmd(u64 *cmd, struct arm_smmu_cmdq_ent *ent)
 	case CMDQ_OP_TLBI_S12_VMALL:
 		cmd[0] |= FIELD_PREP(CMDQ_TLBI_0_VMID, ent->tlbi.vmid);
 		break;
+	case CMDQ_OP_ATC_INV:
+		cmd[0] |= FIELD_PREP(CMDQ_0_SSV, ent->substream_valid);
+		cmd[0] |= FIELD_PREP(CMDQ_ATC_0_GLOBAL, ent->atc.global);
+		cmd[0] |= FIELD_PREP(CMDQ_ATC_0_SSID, ent->atc.ssid);
+		cmd[0] |= FIELD_PREP(CMDQ_ATC_0_SID, ent->atc.sid);
+		cmd[1] |= FIELD_PREP(CMDQ_ATC_1_SIZE, ent->atc.size);
+		cmd[1] |= ent->atc.addr & CMDQ_ATC_1_ADDR_MASK;
+		break;
 	case CMDQ_OP_PRI_RESP:
 		cmd[0] |= FIELD_PREP(CMDQ_0_SSV, ent->substream_valid);
 		cmd[0] |= FIELD_PREP(CMDQ_PRI_0_SSID, ent->pri.ssid);
@@ -857,6 +886,7 @@ static void arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu)
 		[CMDQ_ERR_CERROR_NONE_IDX]	= "No error",
 		[CMDQ_ERR_CERROR_ILL_IDX]	= "Illegal command",
 		[CMDQ_ERR_CERROR_ABT_IDX]	= "Abort on command fetch",
+		[CMDQ_ERR_CERROR_ATC_INV_IDX]	= "ATC invalidate timeout",
 	};
 
 	int i;
@@ -876,6 +906,14 @@ static void arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu)
 		dev_err(smmu->dev, "retrying command fetch\n");
 	case CMDQ_ERR_CERROR_NONE_IDX:
 		return;
+	case CMDQ_ERR_CERROR_ATC_INV_IDX:
+		/*
+		 * ATC Invalidation Completion timeout. CONS is still pointing
+		 * at the CMD_SYNC. Attempt to complete other pending commands
+		 * by repeating the CMD_SYNC, though we might well end up back
+		 * here since the ATC invalidation may still be pending.
+		 */
+		return;
 	case CMDQ_ERR_CERROR_ILL_IDX:
 		/* Fallthrough */
 	default:
@@ -992,7 +1030,7 @@ static int __arm_smmu_cmdq_issue_sync(struct arm_smmu_device *smmu)
 	return ret;
 }
 
-static void arm_smmu_cmdq_issue_sync(struct arm_smmu_device *smmu)
+static int arm_smmu_cmdq_issue_sync(struct arm_smmu_device *smmu)
 {
 	int ret;
 	bool msi = (smmu->features & ARM_SMMU_FEAT_MSI) &&
@@ -1002,6 +1040,7 @@ static void arm_smmu_cmdq_issue_sync(struct arm_smmu_device *smmu)
 		  : __arm_smmu_cmdq_issue_sync(smmu);
 	if (ret)
 		dev_err_ratelimited(smmu->dev, "CMD_SYNC timeout\n");
+	return ret;
 }
 
 /* Context descriptor manipulation functions */
@@ -1174,9 +1213,6 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
 			 FIELD_PREP(STRTAB_STE_1_S1CIR, STRTAB_STE_1_S1C_CACHE_WBRA) |
 			 FIELD_PREP(STRTAB_STE_1_S1COR, STRTAB_STE_1_S1C_CACHE_WBRA) |
 			 FIELD_PREP(STRTAB_STE_1_S1CSH, ARM_SMMU_SH_ISH) |
-#ifdef CONFIG_PCI_ATS
-			 FIELD_PREP(STRTAB_STE_1_EATS, STRTAB_STE_1_EATS_TRANS) |
-#endif
 			 FIELD_PREP(STRTAB_STE_1_STRW, STRTAB_STE_1_STRW_NSEL1));
 
 		if (smmu->features & ARM_SMMU_FEAT_STALLS &&
@@ -1203,6 +1239,10 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
 		val |= FIELD_PREP(STRTAB_STE_0_CFG, STRTAB_STE_0_CFG_S2_TRANS);
 	}
 
+	if (master->ats_enabled)
+		dst[1] |= cpu_to_le64(FIELD_PREP(STRTAB_STE_1_EATS,
+						 STRTAB_STE_1_EATS_TRANS));
+
 	arm_smmu_sync_ste_for_sid(smmu, sid);
 	dst[0] = cpu_to_le64(val);
 	arm_smmu_sync_ste_for_sid(smmu, sid);
@@ -1405,6 +1445,96 @@ static irqreturn_t arm_smmu_combined_irq_handler(int irq, void *dev)
 	return IRQ_WAKE_THREAD;
 }
 
+static void
+arm_smmu_atc_inv_to_cmd(int ssid, unsigned long iova, size_t size,
+			struct arm_smmu_cmdq_ent *cmd)
+{
+	size_t log2_span;
+	size_t span_mask;
+	/* ATC invalidates are always on 4096-bytes pages */
+	size_t inval_grain_shift = 12;
+	unsigned long page_start, page_end;
+
+	*cmd = (struct arm_smmu_cmdq_ent) {
+		.opcode			= CMDQ_OP_ATC_INV,
+		.substream_valid	= !!ssid,
+		.atc.ssid		= ssid,
+	};
+
+	if (!size) {
+		cmd->atc.size = ATC_INV_SIZE_ALL;
+		return;
+	}
+
+	page_start	= iova >> inval_grain_shift;
+	page_end	= (iova + size - 1) >> inval_grain_shift;
+
+	/*
+	 * In an ATS Invalidate Request, the address must be aligned on the
+	 * range size, which must be a power of two number of page sizes. We
+	 * thus have to choose between grossly over-invalidating the region, or
+	 * splitting the invalidation into multiple commands. For simplicity
+	 * we'll go with the first solution, but should refine it in the future
+	 * if multiple commands are shown to be more efficient.
+	 *
+	 * Find the smallest power of two that covers the range. The most
+	 * significant differing bit between the start and end addresses,
+	 * fls(start ^ end), indicates the required span. For example:
+	 *
+	 * We want to invalidate pages [8; 11]. This is already the ideal range:
+	 *		x = 0b1000 ^ 0b1011 = 0b11
+	 *		span = 1 << fls(x) = 4
+	 *
+	 * To invalidate pages [7; 10], we need to invalidate [0; 15]:
+	 *		x = 0b0111 ^ 0b1010 = 0b1101
+	 *		span = 1 << fls(x) = 16
+	 */
+	log2_span	= fls_long(page_start ^ page_end);
+	span_mask	= (1ULL << log2_span) - 1;
+
+	page_start	&= ~span_mask;
+
+	cmd->atc.addr	= page_start << inval_grain_shift;
+	cmd->atc.size	= log2_span;
+}
+
+static int arm_smmu_atc_inv_master(struct arm_smmu_master *master,
+				   struct arm_smmu_cmdq_ent *cmd)
+{
+	int i;
+
+	if (!master->ats_enabled)
+		return 0;
+
+	for (i = 0; i < master->num_sids; i++) {
+		cmd->atc.sid = master->sids[i];
+		arm_smmu_cmdq_issue_cmd(master->smmu, cmd);
+	}
+
+	return arm_smmu_cmdq_issue_sync(master->smmu);
+}
+
+static int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain,
+				   int ssid, unsigned long iova, size_t size)
+{
+	int ret = 0;
+	unsigned long flags;
+	struct arm_smmu_cmdq_ent cmd;
+	struct arm_smmu_master *master;
+
+	if (!(smmu_domain->smmu->features & ARM_SMMU_FEAT_ATS))
+		return 0;
+
+	arm_smmu_atc_inv_to_cmd(ssid, iova, size, &cmd);
+
+	spin_lock_irqsave(&smmu_domain->devices_lock, flags);
+	list_for_each_entry(master, &smmu_domain->devices, domain_head)
+		ret |= arm_smmu_atc_inv_master(master, &cmd);
+	spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
+
+	return ret ? -ETIMEDOUT : 0;
+}
+
 /* IO_PGTABLE API */
 static void arm_smmu_tlb_sync(void *cookie)
 {
@@ -1726,6 +1856,42 @@ static void arm_smmu_install_ste_for_dev(struct arm_smmu_master *master)
 	}
 }
 
+static int arm_smmu_enable_ats(struct arm_smmu_master *master)
+{
+	int ret;
+	size_t stu;
+	struct pci_dev *pdev;
+	struct arm_smmu_device *smmu = master->smmu;
+	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(master->dev);
+
+	if (!(smmu->features & ARM_SMMU_FEAT_ATS) || !dev_is_pci(master->dev) ||
+	    !(fwspec->flags & IOMMU_FWSPEC_PCI_RC_ATS) || pci_ats_disabled())
+		return -ENXIO;
+
+	pdev = to_pci_dev(master->dev);
+	if (pdev->untrusted)
+		return -EPERM;
+
+	/* Smallest Translation Unit: log2 of the smallest supported granule */
+	stu = __ffs(smmu->pgsize_bitmap);
+
+	ret = pci_enable_ats(pdev, stu);
+	if (ret)
+		return ret;
+
+	master->ats_enabled = true;
+	return 0;
+}
+
+static void arm_smmu_disable_ats(struct arm_smmu_master *master)
+{
+	if (!master->ats_enabled || !dev_is_pci(master->dev))
+		return;
+
+	pci_disable_ats(to_pci_dev(master->dev));
+	master->ats_enabled = false;
+}
+
 static void arm_smmu_detach_dev(struct arm_smmu_master *master)
 {
 	unsigned long flags;
@@ -1740,6 +1906,9 @@ static void arm_smmu_detach_dev(struct arm_smmu_master *master)
 
 	master->domain = NULL;
 	arm_smmu_install_ste_for_dev(master);
+
+	/* Disabling ATS invalidates all ATC entries */
+	arm_smmu_disable_ats(master);
 }
 
 static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
@@ -1783,6 +1952,9 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 	list_add(&master->domain_head, &smmu_domain->devices);
 	spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
 
+	if (smmu_domain->stage != ARM_SMMU_DOMAIN_BYPASS)
+		arm_smmu_enable_ats(master);
+
 	if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1)
 		arm_smmu_write_ctx_desc(smmu, &smmu_domain->s1_cfg);
 
@@ -1806,12 +1978,18 @@ static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
 static size_t
 arm_smmu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size)
 {
-	struct io_pgtable_ops *ops = to_smmu_domain(domain)->pgtbl_ops;
+	int ret;
+	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+	struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops;
 
 	if (!ops)
 		return 0;
 
-	return ops->unmap(ops, iova, size);
+	ret = ops->unmap(ops, iova, size);
+	if (ret && arm_smmu_atc_inv_domain(smmu_domain, 0, iova, size))
+		return 0;
+
+	return ret;
 }
 
 static void arm_smmu_flush_iotlb_all(struct iommu_domain *domain)
@@ -1898,6 +2076,7 @@ static int arm_smmu_add_device(struct device *dev)
 		if (!master)
 			return -ENOMEM;
 
+		master->dev = dev;
 		master->smmu = smmu;
 		master->sids = fwspec->ids;
 		master->num_sids = fwspec->num_ids;
@@ -2564,6 +2743,16 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
 		}
 	}
 
+	if (smmu->features & ARM_SMMU_FEAT_ATS) {
+		enables |= CR0_ATSCHK;
+		ret = arm_smmu_write_reg_sync(smmu, enables, ARM_SMMU_CR0,
+					      ARM_SMMU_CR0ACK);
+		if (ret) {
+			dev_err(smmu->dev, "failed to enable ATS check\n");
+			return ret;
+		}
+	}
+
 	ret = arm_smmu_setup_irqs(smmu);
 	if (ret) {
 		dev_err(smmu->dev, "failed to setup irqs\n");