Merge branch 'for-joerg/arm-smmu/updates' of...

Merge branch 'for-joerg/arm-smmu/updates' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into arm/smmu

drivers/acpi/arm64/iort.c

@@ -1028,6 +1028,14 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
 	dev_dbg(dev, "dma_pfn_offset(%#08llx)\n", offset);
 }
 
+static bool iort_pci_rc_supports_ats(struct acpi_iort_node *node)
+{
+	struct acpi_iort_root_complex *pci_rc;
+
+	pci_rc = (struct acpi_iort_root_complex *)node->node_data;
+	return pci_rc->ats_attribute & ACPI_IORT_ATS_SUPPORTED;
+}
+
 /**
  * iort_iommu_configure - Set-up IOMMU configuration for a device.
  *
@@ -1063,6 +1071,9 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev)
 		info.node = node;
 		err = pci_for_each_dma_alias(to_pci_dev(dev),
 					     iort_pci_iommu_init, &info);
+
+		if (!err && iort_pci_rc_supports_ats(node))
+			dev->iommu_fwspec->flags |= IOMMU_FWSPEC_PCI_RC_ATS;
 	} else {
 		int i = 0;
 

drivers/iommu/Kconfig

@@ -359,6 +359,31 @@ config ARM_SMMU
 	  Say Y here if your SoC includes an IOMMU device implementing
 	  the ARM SMMU architecture.
 
+config ARM_SMMU_DISABLE_BYPASS_BY_DEFAULT
+	bool "Default to disabling bypass on ARM SMMU v1 and v2"
+	depends on ARM_SMMU
+	default y
+	help
+	  Say Y here to (by default) disable bypass streams such that
+	  incoming transactions from devices that are not attached to
+	  an iommu domain will report an abort back to the device and
+	  will not be allowed to pass through the SMMU.
+
+	  Any old kernels that existed before this KConfig was
+	  introduced would default to _allowing_ bypass (AKA the
+	  equivalent of NO for this config).  However the default for
+	  this option is YES because the old behavior is insecure.
+
+	  There are few reasons to allow unmatched stream bypass, and
+	  even fewer good ones.  If saying YES here breaks your board
+	  you should work on fixing your board.  This KConfig option
+	  is expected to be removed in the future and we'll simply
+	  hardcode the bypass disable in the code.
+
+	  NOTE: the kernel command line parameter
+	  'arm-smmu.disable_bypass' will continue to override this
+	  config.
+
 config ARM_SMMU_V3
 	bool "ARM Ltd. System MMU Version 3 (SMMUv3) Support"
 	depends on ARM64

drivers/iommu/arm-smmu-regs.h

@@ -147,6 +147,8 @@ enum arm_smmu_s2cr_privcfg {
 #define CBAR_IRPTNDX_SHIFT		24
 #define CBAR_IRPTNDX_MASK		0xff
 
+#define ARM_SMMU_GR1_CBFRSYNRA(n)	(0x400 + ((n) << 2))
+
 #define ARM_SMMU_GR1_CBA2R(n)		(0x800 + ((n) << 2))
 #define CBA2R_RW64_32BIT		(0 << 0)
 #define CBA2R_RW64_64BIT		(1 << 0)

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;
@@ -505,19 +524,6 @@ struct arm_smmu_s2_cfg {
 	u64				vtcr;
 };
 
-struct arm_smmu_strtab_ent {
-	/*
-	 * An STE is "assigned" if the master emitting the corresponding SID
-	 * is attached to a domain. The behaviour of an unassigned STE is
-	 * determined by the disable_bypass parameter, whereas an assigned
-	 * STE behaves according to s1_cfg/s2_cfg, which themselves are
-	 * configured according to the domain type.
-	 */
-	bool				assigned;
-	struct arm_smmu_s1_cfg		*s1_cfg;
-	struct arm_smmu_s2_cfg		*s2_cfg;
-};
-
 struct arm_smmu_strtab_cfg {
 	__le64				*strtab;
 	dma_addr_t			strtab_dma;
@@ -591,9 +597,14 @@ struct arm_smmu_device {
 };
 
 /* SMMU private data for each master */
-struct arm_smmu_master_data {
+struct arm_smmu_master {
 	struct arm_smmu_device		*smmu;
-	struct arm_smmu_strtab_ent	ste;
+	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 */
@@ -618,6 +629,9 @@ struct arm_smmu_domain {
 	};
 
 	struct iommu_domain		domain;
+
+	struct list_head		devices;
+	spinlock_t			devices_lock;
 };
 
 struct arm_smmu_option_prop {
@@ -820,6 +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);
@@ -864,6 +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;
@@ -883,6 +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:
@@ -999,7 +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) &&
@@ -1009,6 +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 */
@@ -1025,7 +1057,6 @@ static u64 arm_smmu_cpu_tcr_to_cd(u64 tcr)
 	val |= ARM_SMMU_TCR2CD(tcr, EPD0);
 	val |= ARM_SMMU_TCR2CD(tcr, EPD1);
 	val |= ARM_SMMU_TCR2CD(tcr, IPS);
-	val |= ARM_SMMU_TCR2CD(tcr, TBI0);
 
 	return val;
 }
@@ -1085,8 +1116,8 @@ static void arm_smmu_sync_ste_for_sid(struct arm_smmu_device *smmu, u32 sid)
 	arm_smmu_cmdq_issue_sync(smmu);
 }
 
-static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid,
-				      __le64 *dst, struct arm_smmu_strtab_ent *ste)
+static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
+				      __le64 *dst)
 {
 	/*
 	 * This is hideously complicated, but we only really care about
@@ -1106,6 +1137,10 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid,
 	 */
 	u64 val = le64_to_cpu(dst[0]);
 	bool ste_live = false;
+	struct arm_smmu_device *smmu = NULL;
+	struct arm_smmu_s1_cfg *s1_cfg = NULL;
+	struct arm_smmu_s2_cfg *s2_cfg = NULL;
+	struct arm_smmu_domain *smmu_domain = NULL;
 	struct arm_smmu_cmdq_ent prefetch_cmd = {
 		.opcode		= CMDQ_OP_PREFETCH_CFG,
 		.prefetch	= {
@@ -1113,6 +1148,25 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid,
 		},
 	};
 
+	if (master) {
+		smmu_domain = master->domain;
+		smmu = master->smmu;
+	}
+
+	if (smmu_domain) {
+		switch (smmu_domain->stage) {
+		case ARM_SMMU_DOMAIN_S1:
+			s1_cfg = &smmu_domain->s1_cfg;
+			break;
+		case ARM_SMMU_DOMAIN_S2:
+		case ARM_SMMU_DOMAIN_NESTED:
+			s2_cfg = &smmu_domain->s2_cfg;
+			break;
+		default:
+			break;
+		}
+	}
+
 	if (val & STRTAB_STE_0_V) {
 		switch (FIELD_GET(STRTAB_STE_0_CFG, val)) {
 		case STRTAB_STE_0_CFG_BYPASS:
@@ -1133,8 +1187,8 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid,
 	val = STRTAB_STE_0_V;
 
 	/* Bypass/fault */
-	if (!ste->assigned || !(ste->s1_cfg || ste->s2_cfg)) {
-		if (!ste->assigned && disable_bypass)
+	if (!smmu_domain || !(s1_cfg || s2_cfg)) {
+		if (!smmu_domain && disable_bypass)
 			val |= FIELD_PREP(STRTAB_STE_0_CFG, STRTAB_STE_0_CFG_ABORT);
 		else
 			val |= FIELD_PREP(STRTAB_STE_0_CFG, STRTAB_STE_0_CFG_BYPASS);
@@ -1152,41 +1206,42 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid,
 		return;
 	}
 
-	if (ste->s1_cfg) {
+	if (s1_cfg) {
 		BUG_ON(ste_live);
 		dst[1] = cpu_to_le64(
 			 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 &&
 		   !(smmu->features & ARM_SMMU_FEAT_STALL_FORCE))
 			dst[1] |= cpu_to_le64(STRTAB_STE_1_S1STALLD);
 
-		val |= (ste->s1_cfg->cdptr_dma & STRTAB_STE_0_S1CTXPTR_MASK) |
+		val |= (s1_cfg->cdptr_dma & STRTAB_STE_0_S1CTXPTR_MASK) |
 			FIELD_PREP(STRTAB_STE_0_CFG, STRTAB_STE_0_CFG_S1_TRANS);
 	}
 
-	if (ste->s2_cfg) {
+	if (s2_cfg) {
 		BUG_ON(ste_live);
 		dst[2] = cpu_to_le64(
-			 FIELD_PREP(STRTAB_STE_2_S2VMID, ste->s2_cfg->vmid) |
-			 FIELD_PREP(STRTAB_STE_2_VTCR, ste->s2_cfg->vtcr) |
+			 FIELD_PREP(STRTAB_STE_2_S2VMID, s2_cfg->vmid) |
+			 FIELD_PREP(STRTAB_STE_2_VTCR, s2_cfg->vtcr) |
 #ifdef __BIG_ENDIAN
 			 STRTAB_STE_2_S2ENDI |
 #endif
 			 STRTAB_STE_2_S2PTW | STRTAB_STE_2_S2AA64 |
 			 STRTAB_STE_2_S2R);
 
-		dst[3] = cpu_to_le64(ste->s2_cfg->vttbr & STRTAB_STE_3_S2TTB_MASK);
+		dst[3] = cpu_to_le64(s2_cfg->vttbr & STRTAB_STE_3_S2TTB_MASK);
 
 		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);
@@ -1199,10 +1254,9 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid,
 static void arm_smmu_init_bypass_stes(u64 *strtab, unsigned int nent)
 {
 	unsigned int i;
-	struct arm_smmu_strtab_ent ste = { .assigned = false };
 
 	for (i = 0; i < nent; ++i) {
-		arm_smmu_write_strtab_ent(NULL, -1, strtab, &ste);
+		arm_smmu_write_strtab_ent(NULL, -1, strtab);
 		strtab += STRTAB_STE_DWORDS;
 	}
 }
@@ -1390,6 +1444,96 @@ 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)
 {
@@ -1493,6 +1637,9 @@ static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
 	}
 
 	mutex_init(&smmu_domain->init_mutex);
+	INIT_LIST_HEAD(&smmu_domain->devices);
+	spin_lock_init(&smmu_domain->devices_lock);
+
 	return &smmu_domain->domain;
 }
 
@@ -1688,55 +1835,97 @@ static __le64 *arm_smmu_get_step_for_sid(struct arm_smmu_device *smmu, u32 sid)
 	return step;
 }
 
-static void arm_smmu_install_ste_for_dev(struct iommu_fwspec *fwspec)
+static void arm_smmu_install_ste_for_dev(struct arm_smmu_master *master)
 {
 	int i, j;
-	struct arm_smmu_master_data *master = fwspec->iommu_priv;
 	struct arm_smmu_device *smmu = master->smmu;
 
-	for (i = 0; i < fwspec->num_ids; ++i) {
-		u32 sid = fwspec->ids[i];
+	for (i = 0; i < master->num_sids; ++i) {
+		u32 sid = master->sids[i];
 		__le64 *step = arm_smmu_get_step_for_sid(smmu, sid);
 
 		/* Bridged PCI devices may end up with duplicated IDs */
 		for (j = 0; j < i; j++)
-			if (fwspec->ids[j] == sid)
+			if (master->sids[j] == sid)
 				break;
 		if (j < i)
 			continue;
 
-		arm_smmu_write_strtab_ent(smmu, sid, step, &master->ste);
+		arm_smmu_write_strtab_ent(master, sid, step);
 	}
 }
 
-static void arm_smmu_detach_dev(struct device *dev)
+static int arm_smmu_enable_ats(struct arm_smmu_master *master)
 {
-	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
-	struct arm_smmu_master_data *master = fwspec->iommu_priv;
+	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;
+	struct arm_smmu_domain *smmu_domain = master->domain;
+
+	if (!smmu_domain)
+		return;
+
+	spin_lock_irqsave(&smmu_domain->devices_lock, flags);
+	list_del(&master->domain_head);
+	spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
 
-	master->ste.assigned = false;
-	arm_smmu_install_ste_for_dev(fwspec);
+	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)
 {
 	int ret = 0;
+	unsigned long flags;
 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 	struct arm_smmu_device *smmu;
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
-	struct arm_smmu_master_data *master;
-	struct arm_smmu_strtab_ent *ste;
+	struct arm_smmu_master *master;
 
 	if (!fwspec)
 		return -ENOENT;
 
 	master = fwspec->iommu_priv;
 	smmu = master->smmu;
-	ste = &master->ste;
 
-	/* Already attached to a different domain? */
-	if (ste->assigned)
-		arm_smmu_detach_dev(dev);
+	arm_smmu_detach_dev(master);
 
 	mutex_lock(&smmu_domain->init_mutex);
 
@@ -1756,21 +1945,19 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 		goto out_unlock;
 	}
 
-	ste->assigned = true;
+	master->domain = smmu_domain;
 
-	if (smmu_domain->stage == ARM_SMMU_DOMAIN_BYPASS) {
-		ste->s1_cfg = NULL;
-		ste->s2_cfg = NULL;
-	} else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
-		ste->s1_cfg = &smmu_domain->s1_cfg;
-		ste->s2_cfg = NULL;
-		arm_smmu_write_ctx_desc(smmu, ste->s1_cfg);
-	} else {
-		ste->s1_cfg = NULL;
-		ste->s2_cfg = &smmu_domain->s2_cfg;
-	}
+	spin_lock_irqsave(&smmu_domain->devices_lock, flags);
+	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);
 
-	arm_smmu_install_ste_for_dev(fwspec);
+	arm_smmu_install_ste_for_dev(master);
 out_unlock:
 	mutex_unlock(&smmu_domain->init_mutex);
 	return ret;
@@ -1790,12 +1977,18 @@ 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)
@@ -1860,7 +2053,7 @@ static int arm_smmu_add_device(struct device *dev)
 {
 	int i, ret;
 	struct arm_smmu_device *smmu;
-	struct arm_smmu_master_data *master;
+	struct arm_smmu_master *master;
 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 	struct iommu_group *group;
 
@@ -1882,13 +2075,16 @@ 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;
 		fwspec->iommu_priv = master;
 	}
 
 	/* Check the SIDs are in range of the SMMU and our stream table */
-	for (i = 0; i < fwspec->num_ids; i++) {
-		u32 sid = fwspec->ids[i];
+	for (i = 0; i < master->num_sids; i++) {
+		u32 sid = master->sids[i];
 
 		if (!arm_smmu_sid_in_range(smmu, sid))
 			return -ERANGE;
@@ -1913,7 +2109,7 @@ static int arm_smmu_add_device(struct device *dev)
 static void arm_smmu_remove_device(struct device *dev)
 {
 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
-	struct arm_smmu_master_data *master;
+	struct arm_smmu_master *master;
 	struct arm_smmu_device *smmu;
 
 	if (!fwspec || fwspec->ops != &arm_smmu_ops)
@@ -1921,8 +2117,7 @@ static void arm_smmu_remove_device(struct device *dev)
 
 	master = fwspec->iommu_priv;
 	smmu = master->smmu;
-	if (master && master->ste.assigned)
-		arm_smmu_detach_dev(dev);
+	arm_smmu_detach_dev(master);
 	iommu_group_remove_device(dev);
 	iommu_device_unlink(&smmu->iommu, dev);
 	kfree(master);
@@ -2454,13 +2649,9 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
 	/* Clear CR0 and sync (disables SMMU and queue processing) */
 	reg = readl_relaxed(smmu->base + ARM_SMMU_CR0);
 	if (reg & CR0_SMMUEN) {
-		if (is_kdump_kernel()) {
-			arm_smmu_update_gbpa(smmu, GBPA_ABORT, 0);
-			arm_smmu_device_disable(smmu);
-			return -EBUSY;
-		}
-
 		dev_warn(smmu->dev, "SMMU currently enabled! Resetting...\n");
+		WARN_ON(is_kdump_kernel() && !disable_bypass);
+		arm_smmu_update_gbpa(smmu, GBPA_ABORT, 0);
 	}
 
 	ret = arm_smmu_device_disable(smmu);
@@ -2547,12 +2738,24 @@ 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");
 		return ret;
 	}
 
+	if (is_kdump_kernel())
+		enables &= ~(CR0_EVTQEN | CR0_PRIQEN);
 
 	/* Enable the SMMU interface, or ensure bypass */
 	if (!bypass || disable_bypass) {

drivers/iommu/arm-smmu.c

@@ -110,7 +110,8 @@ static int force_stage;
 module_param(force_stage, int, S_IRUGO);
 MODULE_PARM_DESC(force_stage,
 	"Force SMMU mappings to be installed at a particular stage of translation. A value of '1' or '2' forces the corresponding stage. All other values are ignored (i.e. no stage is forced). Note that selecting a specific stage will disable support for nested translation.");
-static bool disable_bypass;
+static bool disable_bypass =
+	IS_ENABLED(CONFIG_ARM_SMMU_DISABLE_BYPASS_BY_DEFAULT);
 module_param(disable_bypass, bool, S_IRUGO);
 MODULE_PARM_DESC(disable_bypass,
 	"Disable bypass streams such that incoming transactions from devices that are not attached to an iommu domain will report an abort back to the device and will not be allowed to pass through the SMMU.");
@@ -569,12 +570,13 @@ static const struct iommu_gather_ops arm_smmu_s2_tlb_ops_v1 = {
 
 static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
 {
-	u32 fsr, fsynr;
+	u32 fsr, fsynr, cbfrsynra;
 	unsigned long iova;
 	struct iommu_domain *domain = dev;
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 	struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
 	struct arm_smmu_device *smmu = smmu_domain->smmu;
+	void __iomem *gr1_base = ARM_SMMU_GR1(smmu);
 	void __iomem *cb_base;
 
 	cb_base = ARM_SMMU_CB(smmu, cfg->cbndx);
@@ -585,10 +587,11 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
 
 	fsynr = readl_relaxed(cb_base + ARM_SMMU_CB_FSYNR0);
 	iova = readq_relaxed(cb_base + ARM_SMMU_CB_FAR);
+	cbfrsynra = readl_relaxed(gr1_base + ARM_SMMU_GR1_CBFRSYNRA(cfg->cbndx));
 
 	dev_err_ratelimited(smmu->dev,
-	"Unhandled context fault: fsr=0x%x, iova=0x%08lx, fsynr=0x%x, cb=%d\n",
-			    fsr, iova, fsynr, cfg->cbndx);
+	"Unhandled context fault: fsr=0x%x, iova=0x%08lx, fsynr=0x%x, cbfrsynra=0x%x, cb=%d\n",
+			    fsr, iova, fsynr, cbfrsynra, cfg->cbndx);
 
 	writel(fsr, cb_base + ARM_SMMU_CB_FSR);
 	return IRQ_HANDLED;

include/linux/iommu.h

@@ -392,10 +392,14 @@ struct iommu_fwspec {
 	const struct iommu_ops	*ops;
 	struct fwnode_handle	*iommu_fwnode;
 	void			*iommu_priv;
+	u32			flags;
 	unsigned int		num_ids;
 	u32			ids[1];
 };
 
+/* ATS is supported */
+#define IOMMU_FWSPEC_PCI_RC_ATS			(1 << 0)
+
 int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
 		      const struct iommu_ops *ops);
 void iommu_fwspec_free(struct device *dev);

include/linux/pci.h

@@ -1521,21 +1521,6 @@ static inline void pcie_ecrc_get_policy(char *str) { }
 
 bool pci_ats_disabled(void);
 
-#ifdef CONFIG_PCI_ATS
-/* Address Translation Service */
-void pci_ats_init(struct pci_dev *dev);
-int pci_enable_ats(struct pci_dev *dev, int ps);
-void pci_disable_ats(struct pci_dev *dev);
-int pci_ats_queue_depth(struct pci_dev *dev);
-int pci_ats_page_aligned(struct pci_dev *dev);
-#else
-static inline void pci_ats_init(struct pci_dev *d) { }
-static inline int pci_enable_ats(struct pci_dev *d, int ps) { return -ENODEV; }
-static inline void pci_disable_ats(struct pci_dev *d) { }
-static inline int pci_ats_queue_depth(struct pci_dev *d) { return -ENODEV; }
-static inline int pci_ats_page_aligned(struct pci_dev *dev) { return 0; }
-#endif
-
 #ifdef CONFIG_PCIE_PTM
 int pci_enable_ptm(struct pci_dev *dev, u8 *granularity);
 #else
@@ -1728,8 +1713,24 @@ static inline int pci_irqd_intx_xlate(struct irq_domain *d,
 static inline const struct pci_device_id *pci_match_id(const struct pci_device_id *ids,
 							 struct pci_dev *dev)
 { return NULL; }
+static inline bool pci_ats_disabled(void) { return true; }
 #endif /* CONFIG_PCI */
 
+#ifdef CONFIG_PCI_ATS
+/* Address Translation Service */
+void pci_ats_init(struct pci_dev *dev);
+int pci_enable_ats(struct pci_dev *dev, int ps);
+void pci_disable_ats(struct pci_dev *dev);
+int pci_ats_queue_depth(struct pci_dev *dev);
+int pci_ats_page_aligned(struct pci_dev *dev);
+#else
+static inline void pci_ats_init(struct pci_dev *d) { }
+static inline int pci_enable_ats(struct pci_dev *d, int ps) { return -ENODEV; }
+static inline void pci_disable_ats(struct pci_dev *d) { }
+static inline int pci_ats_queue_depth(struct pci_dev *d) { return -ENODEV; }
+static inline int pci_ats_page_aligned(struct pci_dev *dev) { return 0; }
+#endif
+
 /* Include architecture-dependent settings and functions */
 
 #include <asm/pci.h>