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Add Tegra241 (Grace) CMDQV Support (part 1/2)

PATCH Superseded Nicolin Chen 1 participant 11 messages Aug 16, 2024

Subsystems (4)

v12 of 14 Superseded Latest is v14 →

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#0 lore raw

v12 cover Add Tegra241 (Grace) CMDQV Support (part 1/2)

NVIDIA's Tegra241 (Grace) SoC has a CMDQ-Virtualization (CMDQV) hardware that extends standard ARM SMMUv3 to support multiple command queues with virtualization capabilities. Though this is similar to the ECMDQ in SMMU v3.3, CMDQV provides additional Virtual Interfaces (VINTFs) allowing VMs to have their own VINTFs and Virtual Command Queues (VCMDQs). The VCMDQs can only execute a limited set of commands, mainly invalidation commands when exclusively used by the VMs, compared to the standard SMMUv3 CMDQ.

Thus, there are two parts of patch series to add its support: the basic in-kernel support as part 1, and the user-space support as part 2.

The in-kernel support is to detect/configure the CMDQV hardware and then allocate a VINTF with some VCMDQs for the kernel/hypervisor to use. Like ECMDQ, CMDQV also allows the kernel to use multiple VCMDQs, giving some limited performance improvement: up to 20% reduction of TLB invalidation time was measured by a multi-threaded DMA unmap benchmark, compared to a single queue.

The user-space support is to provide uAPIs (via IOMMUFD) for hypervisors in user space to passthrough VCMDQs to VMs, allowing these VMs to access the VCMDQs directly without trappings, i.e. no VM Exits. This gives huge performance improvements: 70% to 90% reductions of TLB invalidation time were measured by various DMA unmap tests running in a guest OS, compared to a nested SMMU CMDQ (with trappings).

This is the part-1 series:
- Preparatory changes to share the existing SMMU functions
- A new CMDQV driver and extending the SMMUv3 driver to interact with the new driver
- Limit the commands for a guest kernel.

It's available on Github:
https://github.com/nicolinc/iommufd/commits/vcmdq_in_kernel-v12

And the part-2 RFC series is also sent for discussion:
https://lore.kernel.org/all/[email protected]/

Note that this in-kernel support isn't confined to host kernels running on Grace-powered servers, but is also used by guest kernels running on VMs virtualized on those servers. So, those VMs must install the driver, ideally before the part 2 is merged. So, later those servers would only need to upgrade their host kernels without bothering the VMs.

Thank you!

Changelog
v12:
* Rebased on 6.11-rc3
* Added Jason's Reviewed-by
* Added an arm_smmu_impl_probe helper
* Added an arm_smmu_get_iort_node helper
* Slightly updated the CMDQV acpi probe()
* Added a static_assert() for smmu in struct tegra241_cmdqv
v11:
https://lore.kernel.org/all/[email protected]/
* Rebased on 6.11-rc2
* Fixed "vtinfs" typo in kdoc
* Maxed out the max_n_shift to hardware allowed value
v10:
https://lore.kernel.org/all/[email protected]/
* Rebased on 6.11-rc1
* Added impl design mimicing arm-smmu (v2) driver
* Replaced the CS_NONE quirk with a new smmu option
* Fixed misaligned 64-bit register reading in the isr()
* Explicitly assign opcode to arm_smmu_cmdq_batch_init() where cmd/ent might potentially not be initialized.
v9:
https://lore.kernel.org/all/[email protected]/
* Rebased on 6.10-rc3
* Replaced "base + offset" in write_config() with REG helpers
* Added "Reviewed-by" line from Jason, to the remaining PATCH-5
v8:
https://lore.kernel.org/all/[email protected]/
* Added "Reviewed-by" lines from Jason
* Replaced memset with a simple "cmd[1] = 0"
* Replaced MMIO read/write helpers with REG_* macros
* Dropped the racy static string in lvcmdq_error_header()
* Added a few lines of comments to arm_smmu_get_cmdq at the line calling tegra241_cmdqv_get_cmdq()
v7:
https://lore.kernel.org/all/[email protected]/
* Moved all public symbols into one single patch
* Enforced a command batch to use the same cmdq
* Enforced the use of arm_smmu_cmdq_build_sync_cmd()
* Reworked the tegra241-cmdqv driver patch
- Dropped logging macros, cmdqv->dev, and atomic
- Dropped devm_* and added tegra241_cmdqv_device_remove()
- Moved all structure allocations to cmdqv's probe() from device_reset() where only register configurations remains
- Switched the config macros to inline functions
- Optimized ISR routine with 64-bit reading MMIO
- Scan once per batch against command list
- Reorganized function locations
- Minor readability changes
v6:
https://lore.kernel.org/all/[email protected]/
* Reordered the patch sequence to fix git-bisect break
* Added a status cache to cmdqv/vintf/vcmdq structure
* Added gerror/gerrorn value match in hw_deinit()
* Minimized changes in __arm_smmu_cmdq_skip_err()
* Preallocated VCMDQs to VINTFs for stablility
v5:
https://lore.kernel.org/all/[email protected]/
* Improved print/mmio helpers
* Added proper register reset routines
* Reorganized init/deinit functions to share with VIOMMU callbacks in the upcoming part-2 user-space series (RFC)
v4:
https://lore.kernel.org/all/[email protected]/
* Rebased on v6.9-rc1
* Renamed to "tegra241-cmdqv", following other Grace kernel patches
* Added a set of print and MMIO helpers
* Reworked the guest limitation patch
v3:
https://lore.kernel.org/all/[email protected]/
* Dropped VMID and mdev patches to redesign later based on IOMMUFD
* Separated HYP_OWN part for guest support into a new patch
* Added new preparatory changes
v2:
https://lore.kernel.org/all/[email protected]/
* Added mdev interface support for hypervisor and VMs
* Added preparatory changes for mdev interface implementation
* PATCH-12 Changed ->issue_cmdlist() to ->get_cmdq() for a better integration with recently merged ECMDQ-related changes
v1:
https://lore.kernel.org/all/[email protected]/

Jason Gunthorpe (2):
iommu/arm-smmu-v3: Add an arm_smmu_get_iort_node helper iommu/arm-smmu-v3: Add struct arm_smmu_impl_ops

Nate Watterson (1):
iommu/arm-smmu-v3: Add in-kernel support for NVIDIA Tegra241 (Grace)
CMDQV

Nicolin Chen (7):
iommu/arm-smmu-v3: Issue a batch of commands to the same cmdq iommu/arm-smmu-v3: Enforce arm_smmu_cmdq_build_sync_cmd iommu/arm-smmu-v3: Pass in cmdq pointer to
arm_smmu_cmdq_build_sync_cmd
iommu/arm-smmu-v3: Pass in cmdq pointer to arm_smmu_cmdq_init iommu/arm-smmu-v3: Make symbols public for CONFIG_TEGRA241_CMDQV iommu/arm-smmu-v3: Add ARM_SMMU_OPT_SECONDARY_CMDQ_CS_NONE_ONLY iommu/tegra241-cmdqv: Limit CMDs for guest owned VINTF

 MAINTAINERS                                   |   1 +
 drivers/iommu/Kconfig                         |  11 +
 drivers/iommu/arm/arm-smmu-v3/Makefile        |   1 +
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   | 188 ++--
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  51 +-
 .../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c    | 905 ++++++++++++++++++
 6 files changed, 1090 insertions(+), 67 deletions(-)
 create mode 100644 drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
Signature · 1 line
2.43.0
#1 lore raw

PATCH v12 1/10 iommu/arm-smmu-v3: Issue a batch of commands to the same cmdq

The driver calls in different places the arm_smmu_get_cmdq() helper, and it's fine to do so since the helper always returns the single SMMU CMDQ. However, with NVIDIA CMDQV extension or SMMU ECMDQ, there can be multiple cmdqs in the system to select one from. And either case requires a batch of commands to be issued to the same cmdq. Thus, a cmdq has to be decided in the higher-level callers.

Add a cmdq pointer in arm_smmu_cmdq_batch structure, and decide the cmdq when initializing the batch. Pass its pointer down to the bottom function. Update __arm_smmu_cmdq_issue_cmd() accordingly for single command issuers.

---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 44 +++++++++++++--------
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h |  1 +
 2 files changed, 29 insertions(+), 16 deletions(-)
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +28 -16
index a31460f9f3d4..f409ead589ff 100644
@@ -592,11 +592,11 @@ static void arm_smmu_cmdq_poll_valid_map(struct arm_smmu_cmdq *cmdq,
 
 /* Wait for the command queue to become non-full */
 static int arm_smmu_cmdq_poll_until_not_full(struct arm_smmu_device *smmu,
+					     struct arm_smmu_cmdq *cmdq,
 					     struct arm_smmu_ll_queue *llq)
 {
 	unsigned long flags;
 	struct arm_smmu_queue_poll qp;
-	struct arm_smmu_cmdq *cmdq = arm_smmu_get_cmdq(smmu);
 	int ret = 0;
 
 	/*
@@ -627,11 +627,11 @@ static int arm_smmu_cmdq_poll_until_not_full(struct arm_smmu_device *smmu,
  * Must be called with the cmdq lock held in some capacity.
  */
 static int __arm_smmu_cmdq_poll_until_msi(struct arm_smmu_device *smmu,
+					  struct arm_smmu_cmdq *cmdq,
 					  struct arm_smmu_ll_queue *llq)
 {
 	int ret = 0;
 	struct arm_smmu_queue_poll qp;
-	struct arm_smmu_cmdq *cmdq = arm_smmu_get_cmdq(smmu);
 	u32 *cmd = (u32 *)(Q_ENT(&cmdq->q, llq->prod));
 
 	queue_poll_init(smmu, &qp);
@@ -651,10 +651,10 @@ static int __arm_smmu_cmdq_poll_until_msi(struct arm_smmu_device *smmu,
  * Must be called with the cmdq lock held in some capacity.
  */
 static int __arm_smmu_cmdq_poll_until_consumed(struct arm_smmu_device *smmu,
+					       struct arm_smmu_cmdq *cmdq,
 					       struct arm_smmu_ll_queue *llq)
 {
 	struct arm_smmu_queue_poll qp;
-	struct arm_smmu_cmdq *cmdq = arm_smmu_get_cmdq(smmu);
 	u32 prod = llq->prod;
 	int ret = 0;
 
@@ -701,12 +701,13 @@ static int __arm_smmu_cmdq_poll_until_consumed(struct arm_smmu_device *smmu,
 }
 
 static int arm_smmu_cmdq_poll_until_sync(struct arm_smmu_device *smmu,
+					 struct arm_smmu_cmdq *cmdq,
 					 struct arm_smmu_ll_queue *llq)
 {
 	if (smmu->options & ARM_SMMU_OPT_MSIPOLL)
-		return __arm_smmu_cmdq_poll_until_msi(smmu, llq);
+		return __arm_smmu_cmdq_poll_until_msi(smmu, cmdq, llq);
 
-	return __arm_smmu_cmdq_poll_until_consumed(smmu, llq);
+	return __arm_smmu_cmdq_poll_until_consumed(smmu, cmdq, llq);
 }
 
 static void arm_smmu_cmdq_write_entries(struct arm_smmu_cmdq *cmdq, u64 *cmds,
@@ -743,13 +744,13 @@ static void arm_smmu_cmdq_write_entries(struct arm_smmu_cmdq *cmdq, u64 *cmds,
  *   CPU will appear before any of the commands from the other CPU.
  */
 static int arm_smmu_cmdq_issue_cmdlist(struct arm_smmu_device *smmu,
+				       struct arm_smmu_cmdq *cmdq,
 				       u64 *cmds, int n, bool sync)
 {
 	u64 cmd_sync[CMDQ_ENT_DWORDS];
 	u32 prod;
 	unsigned long flags;
 	bool owner;
-	struct arm_smmu_cmdq *cmdq = arm_smmu_get_cmdq(smmu);
 	struct arm_smmu_ll_queue llq, head;
 	int ret = 0;
 
@@ -763,7 +764,7 @@ static int arm_smmu_cmdq_issue_cmdlist(struct arm_smmu_device *smmu,
 
 		while (!queue_has_space(&llq, n + sync)) {
 			local_irq_restore(flags);
-			if (arm_smmu_cmdq_poll_until_not_full(smmu, &llq))
+			if (arm_smmu_cmdq_poll_until_not_full(smmu, cmdq, &llq))
 				dev_err_ratelimited(smmu->dev, "CMDQ timeout\n");
 			local_irq_save(flags);
 		}
@@ -839,7 +840,7 @@ static int arm_smmu_cmdq_issue_cmdlist(struct arm_smmu_device *smmu,
 	/* 5. If we are inserting a CMD_SYNC, we must wait for it to complete */
 	if (sync) {
 		llq.prod = queue_inc_prod_n(&llq, n);
-		ret = arm_smmu_cmdq_poll_until_sync(smmu, &llq);
+		ret = arm_smmu_cmdq_poll_until_sync(smmu, cmdq, &llq);
 		if (ret) {
 			dev_err_ratelimited(smmu->dev,
 					    "CMD_SYNC timeout at 0x%08x [hwprod 0x%08x, hwcons 0x%08x]\n",
@@ -874,7 +875,8 @@ static int __arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu,
 		return -EINVAL;
 	}
 
-	return arm_smmu_cmdq_issue_cmdlist(smmu, cmd, 1, sync);
+	return arm_smmu_cmdq_issue_cmdlist(
+		smmu, arm_smmu_get_cmdq(smmu), cmd, 1, sync);
 }
 
 static int arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu,
@@ -889,6 +891,13 @@ static int arm_smmu_cmdq_issue_cmd_with_sync(struct arm_smmu_device *smmu,
 	return __arm_smmu_cmdq_issue_cmd(smmu, ent, true);
 }
 
+static void arm_smmu_cmdq_batch_init(struct arm_smmu_device *smmu,
+				     struct arm_smmu_cmdq_batch *cmds)
+{
+	cmds->num = 0;
+	cmds->cmdq = arm_smmu_get_cmdq(smmu);
+}
+
 static void arm_smmu_cmdq_batch_add(struct arm_smmu_device *smmu,
 				    struct arm_smmu_cmdq_batch *cmds,
 				    struct arm_smmu_cmdq_ent *cmd)
@@ -897,12 +906,14 @@ static void arm_smmu_cmdq_batch_add(struct arm_smmu_device *smmu,
 
 	if (cmds->num == CMDQ_BATCH_ENTRIES - 1 &&
 	    (smmu->options & ARM_SMMU_OPT_CMDQ_FORCE_SYNC)) {
-		arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmds, cmds->num, true);
+		arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmdq, cmds->cmds,
+					    cmds->num, true);
 		cmds->num = 0;
 	}
 
 	if (cmds->num == CMDQ_BATCH_ENTRIES) {
-		arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmds, cmds->num, false);
+		arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmdq, cmds->cmds,
+					    cmds->num, false);
 		cmds->num = 0;
 	}
 
@@ -919,7 +930,8 @@ static void arm_smmu_cmdq_batch_add(struct arm_smmu_device *smmu,
 static int arm_smmu_cmdq_batch_submit(struct arm_smmu_device *smmu,
 				      struct arm_smmu_cmdq_batch *cmds)
 {
-	return arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmds, cmds->num, true);
+	return arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmdq, cmds->cmds,
+					   cmds->num, true);
 }
 
 static void arm_smmu_page_response(struct device *dev, struct iopf_fault *unused,
@@ -1170,7 +1182,7 @@ static void arm_smmu_sync_cd(struct arm_smmu_master *master,
 		},
 	};
 
-	cmds.num = 0;
+	arm_smmu_cmdq_batch_init(smmu, &cmds);
 	for (i = 0; i < master->num_streams; i++) {
 		cmd.cfgi.sid = master->streams[i].id;
 		arm_smmu_cmdq_batch_add(smmu, &cmds, &cmd);
@@ -2021,7 +2033,7 @@ static int arm_smmu_atc_inv_master(struct arm_smmu_master *master,
 
 	arm_smmu_atc_inv_to_cmd(ssid, 0, 0, &cmd);
 
-	cmds.num = 0;
+	arm_smmu_cmdq_batch_init(master->smmu, &cmds);
 	for (i = 0; i < master->num_streams; i++) {
 		cmd.atc.sid = master->streams[i].id;
 		arm_smmu_cmdq_batch_add(master->smmu, &cmds, &cmd);
@@ -2059,7 +2071,7 @@ int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain,
 	if (!atomic_read(&smmu_domain->nr_ats_masters))
 		return 0;
 
-	cmds.num = 0;
+	arm_smmu_cmdq_batch_init(smmu_domain->smmu, &cmds);
 
 	spin_lock_irqsave(&smmu_domain->devices_lock, flags);
 	list_for_each_entry(master_domain, &smmu_domain->devices,
@@ -2141,7 +2153,7 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd,
 			num_pages++;
 	}
 
-	cmds.num = 0;
+	arm_smmu_cmdq_batch_init(smmu, &cmds);
 
 	while (iova < end) {
 		if (smmu->features & ARM_SMMU_FEAT_RANGE_INV) {
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +1 -0
index 14bca41a981b..c1454e9758c4 100644
@@ -570,6 +570,7 @@ struct arm_smmu_cmdq {
 
 struct arm_smmu_cmdq_batch {
 	u64				cmds[CMDQ_BATCH_ENTRIES * CMDQ_ENT_DWORDS];
+	struct arm_smmu_cmdq		*cmdq;
 	int				num;
 };
 
Signature · 1 line
2.43.0
#2 lore raw

PATCH v12 2/10 iommu/arm-smmu-v3: Enforce arm_smmu_cmdq_build_sync_cmd

In reply to Nicolin Chen

There is an existing arm_smmu_cmdq_build_sync_cmd() so the driver should call it at all places other than going through arm_smmu_cmdq_build_cmd() separately. This helps the following patch that adds a CS_NONE option.

Note that this changes the type of CMD_SYNC in __arm_smmu_cmdq_skip_err, in ARM_SMMU_OPT_MSIPOLL=true case, from previously a non-MSI one to now an MSI one that is proven to still work using a hacking test:
nvme: Adding to iommu group 10
nvme: --------hacking-----------
arm-smmu-v3: unexpected global error reported (0x00000001),
this could be serious
arm-smmu-v3: CMDQ error (cons 0x01000022): Illegal command
arm-smmu-v3: skipping command in error state:
arm-smmu-v3: 0x0000000000000000
arm-smmu-v3: 0x0000000000000000
nvme: -------recovered----------
nvme nvme0: 72/0/0 default/read/poll queues
nvme0n1: p1 p2

---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 36 ++++++++-------------
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h |  3 --
 2 files changed, 13 insertions(+), 26 deletions(-)
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +13 -23
index f409ead589ff..f481d7be3d4e 100644
@@ -329,16 +329,6 @@ static int arm_smmu_cmdq_build_cmd(u64 *cmd, struct arm_smmu_cmdq_ent *ent)
 		cmd[0] |= FIELD_PREP(CMDQ_RESUME_0_RESP, ent->resume.resp);
 		cmd[1] |= FIELD_PREP(CMDQ_RESUME_1_STAG, ent->resume.stag);
 		break;
-	case CMDQ_OP_CMD_SYNC:
-		if (ent->sync.msiaddr) {
-			cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_CS, CMDQ_SYNC_0_CS_IRQ);
-			cmd[1] |= ent->sync.msiaddr & CMDQ_SYNC_1_MSIADDR_MASK;
-		} else {
-			cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_CS, CMDQ_SYNC_0_CS_SEV);
-		}
-		cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_MSH, ARM_SMMU_SH_ISH);
-		cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_MSIATTR, ARM_SMMU_MEMATTR_OIWB);
-		break;
 	default:
 		return -ENOENT;
 	}
@@ -354,20 +344,23 @@ static struct arm_smmu_cmdq *arm_smmu_get_cmdq(struct arm_smmu_device *smmu)
 static void arm_smmu_cmdq_build_sync_cmd(u64 *cmd, struct arm_smmu_device *smmu,
 					 struct arm_smmu_queue *q, u32 prod)
 {
-	struct arm_smmu_cmdq_ent ent = {
-		.opcode = CMDQ_OP_CMD_SYNC,
-	};
+	cmd[1] = 0;
+	cmd[0] = FIELD_PREP(CMDQ_0_OP, CMDQ_OP_CMD_SYNC) |
+		 FIELD_PREP(CMDQ_SYNC_0_MSH, ARM_SMMU_SH_ISH) |
+		 FIELD_PREP(CMDQ_SYNC_0_MSIATTR, ARM_SMMU_MEMATTR_OIWB);
+
+	if (!(smmu->options & ARM_SMMU_OPT_MSIPOLL)) {
+		cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_CS, CMDQ_SYNC_0_CS_SEV);
+		return;
+	}
 
 	/*
 	 * Beware that Hi16xx adds an extra 32 bits of goodness to its MSI
 	 * payload, so the write will zero the entire command on that platform.
 	 */
-	if (smmu->options & ARM_SMMU_OPT_MSIPOLL) {
-		ent.sync.msiaddr = q->base_dma + Q_IDX(&q->llq, prod) *
-				   q->ent_dwords * 8;
-	}
-
-	arm_smmu_cmdq_build_cmd(cmd, &ent);
+	cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_CS, CMDQ_SYNC_0_CS_IRQ);
+	cmd[1] |= (q->base_dma + Q_IDX(&q->llq, prod) * q->ent_dwords * 8) &
+		  CMDQ_SYNC_1_MSIADDR_MASK;
 }
 
 static void __arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu,
@@ -384,9 +377,6 @@ static void __arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu,
 	u64 cmd[CMDQ_ENT_DWORDS];
 	u32 cons = readl_relaxed(q->cons_reg);
 	u32 idx = FIELD_GET(CMDQ_CONS_ERR, cons);
-	struct arm_smmu_cmdq_ent cmd_sync = {
-		.opcode = CMDQ_OP_CMD_SYNC,
-	};
 
 	dev_err(smmu->dev, "CMDQ error (cons 0x%08x): %s\n", cons,
 		idx < ARRAY_SIZE(cerror_str) ?  cerror_str[idx] : "Unknown");
@@ -420,7 +410,7 @@ static void __arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu,
 		dev_err(smmu->dev, "\t0x%016llx\n", (unsigned long long)cmd[i]);
 
 	/* Convert the erroneous command into a CMD_SYNC */
-	arm_smmu_cmdq_build_cmd(cmd, &cmd_sync);
+	arm_smmu_cmdq_build_sync_cmd(cmd, smmu, q, cons);
 
 	queue_write(Q_ENT(q, cons), cmd, q->ent_dwords);
 }
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +0 -3
index c1454e9758c4..6c5739f6b90f 100644
@@ -518,9 +518,6 @@ struct arm_smmu_cmdq_ent {
 		} resume;
 
 		#define CMDQ_OP_CMD_SYNC	0x46
-		struct {
-			u64			msiaddr;
-		} sync;
 	};
 };
 
Signature · 1 line
2.43.0
#3 lore raw

PATCH v12 3/10 iommu/arm-smmu-v3: Pass in cmdq pointer to arm_smmu_cmdq_build_sync_cmd

In reply to Nicolin Chen

The CMDQV extension on NVIDIA Tegra241 SoC only supports CS_NONE in the CS field of CMD_SYNC, v.s. standard SMMU CMDQ. Pass in the cmdq pointer directly, so the function can identify a different cmdq implementation.

---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +8 -5
index f481d7be3d4e..d11362e9fc8a 100644
@@ -342,8 +342,10 @@ static struct arm_smmu_cmdq *arm_smmu_get_cmdq(struct arm_smmu_device *smmu)
 }
 
 static void arm_smmu_cmdq_build_sync_cmd(u64 *cmd, struct arm_smmu_device *smmu,
-					 struct arm_smmu_queue *q, u32 prod)
+					 struct arm_smmu_cmdq *cmdq, u32 prod)
 {
+	struct arm_smmu_queue *q = &cmdq->q;
+
 	cmd[1] = 0;
 	cmd[0] = FIELD_PREP(CMDQ_0_OP, CMDQ_OP_CMD_SYNC) |
 		 FIELD_PREP(CMDQ_SYNC_0_MSH, ARM_SMMU_SH_ISH) |
@@ -364,7 +366,7 @@ static void arm_smmu_cmdq_build_sync_cmd(u64 *cmd, struct arm_smmu_device *smmu,
 }
 
 static void __arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu,
-				     struct arm_smmu_queue *q)
+				     struct arm_smmu_cmdq *cmdq)
 {
 	static const char * const cerror_str[] = {
 		[CMDQ_ERR_CERROR_NONE_IDX]	= "No error",
@@ -372,6 +374,7 @@ static void __arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu,
 		[CMDQ_ERR_CERROR_ABT_IDX]	= "Abort on command fetch",
 		[CMDQ_ERR_CERROR_ATC_INV_IDX]	= "ATC invalidate timeout",
 	};
+	struct arm_smmu_queue *q = &cmdq->q;
 
 	int i;
 	u64 cmd[CMDQ_ENT_DWORDS];
@@ -410,14 +413,14 @@ static void __arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu,
 		dev_err(smmu->dev, "\t0x%016llx\n", (unsigned long long)cmd[i]);
 
 	/* Convert the erroneous command into a CMD_SYNC */
-	arm_smmu_cmdq_build_sync_cmd(cmd, smmu, q, cons);
+	arm_smmu_cmdq_build_sync_cmd(cmd, smmu, cmdq, cons);
 
 	queue_write(Q_ENT(q, cons), cmd, q->ent_dwords);
 }
 
 static void arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu)
 {
-	__arm_smmu_cmdq_skip_err(smmu, &smmu->cmdq.q);
+	__arm_smmu_cmdq_skip_err(smmu, &smmu->cmdq);
 }
 
 /*
@@ -780,7 +783,7 @@ static int arm_smmu_cmdq_issue_cmdlist(struct arm_smmu_device *smmu,
 	arm_smmu_cmdq_write_entries(cmdq, cmds, llq.prod, n);
 	if (sync) {
 		prod = queue_inc_prod_n(&llq, n);
-		arm_smmu_cmdq_build_sync_cmd(cmd_sync, smmu, &cmdq->q, prod);
+		arm_smmu_cmdq_build_sync_cmd(cmd_sync, smmu, cmdq, prod);
 		queue_write(Q_ENT(&cmdq->q, prod), cmd_sync, CMDQ_ENT_DWORDS);
 
 		/*
Signature · 1 line
2.43.0
#4 lore raw

PATCH v12 4/10 iommu/arm-smmu-v3: Pass in cmdq pointer to arm_smmu_cmdq_init

In reply to Nicolin Chen

So that this function can be used by other cmdqs than &smmu->cmdq only.

---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +3 -3
index d11362e9fc8a..e664c40b14ae 100644
@@ -3555,9 +3555,9 @@ static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
 	return 0;
 }
 
-static int arm_smmu_cmdq_init(struct arm_smmu_device *smmu)
+static int arm_smmu_cmdq_init(struct arm_smmu_device *smmu,
+			      struct arm_smmu_cmdq *cmdq)
 {
-	struct arm_smmu_cmdq *cmdq = &smmu->cmdq;
 	unsigned int nents = 1 << cmdq->q.llq.max_n_shift;
 
 	atomic_set(&cmdq->owner_prod, 0);
@@ -3582,7 +3582,7 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
 	if (ret)
 		return ret;
 
-	ret = arm_smmu_cmdq_init(smmu);
+	ret = arm_smmu_cmdq_init(smmu, &smmu->cmdq);
 	if (ret)
 		return ret;
 
Signature · 1 line
2.43.0
#5 lore raw

PATCH v12 5/10 iommu/arm-smmu-v3: Make symbols public for CONFIG_TEGRA241_CMDQV

In reply to Nicolin Chen

The symbols __arm_smmu_cmdq_skip_err(), arm_smmu_init_one_queue(), and arm_smmu_cmdq_init() need to be used by the tegra241-cmdqv compilation unit in a following patch.

Remove the static and put prototypes in the header.

---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 18 ++++++++----------
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h |  9 +++++++++
 2 files changed, 17 insertions(+), 10 deletions(-)
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +8 -10
index e664c40b14ae..df1149095860 100644
@@ -365,8 +365,8 @@ static void arm_smmu_cmdq_build_sync_cmd(u64 *cmd, struct arm_smmu_device *smmu,
 		  CMDQ_SYNC_1_MSIADDR_MASK;
 }
 
-static void __arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu,
-				     struct arm_smmu_cmdq *cmdq)
+void __arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu,
+			      struct arm_smmu_cmdq *cmdq)
 {
 	static const char * const cerror_str[] = {
 		[CMDQ_ERR_CERROR_NONE_IDX]	= "No error",
@@ -3512,12 +3512,10 @@ static struct iommu_dirty_ops arm_smmu_dirty_ops = {
 };
 
 /* Probing and initialisation functions */
-static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
-				   struct arm_smmu_queue *q,
-				   void __iomem *page,
-				   unsigned long prod_off,
-				   unsigned long cons_off,
-				   size_t dwords, const char *name)
+int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
+			    struct arm_smmu_queue *q, void __iomem *page,
+			    unsigned long prod_off, unsigned long cons_off,
+			    size_t dwords, const char *name)
 {
 	size_t qsz;
 
@@ -3555,8 +3553,8 @@ static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
 	return 0;
 }
 
-static int arm_smmu_cmdq_init(struct arm_smmu_device *smmu,
-			      struct arm_smmu_cmdq *cmdq)
+int arm_smmu_cmdq_init(struct arm_smmu_device *smmu,
+		       struct arm_smmu_cmdq *cmdq)
 {
 	unsigned int nents = 1 << cmdq->q.llq.max_n_shift;
 
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +9 -0
index 6c5739f6b90f..6c5dc2f10a33 100644
@@ -813,6 +813,15 @@ void arm_smmu_tlb_inv_range_asid(unsigned long iova, size_t size, int asid,
 int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain,
 			    unsigned long iova, size_t size);
 
+void __arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu,
+			      struct arm_smmu_cmdq *cmdq);
+int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
+			    struct arm_smmu_queue *q, void __iomem *page,
+			    unsigned long prod_off, unsigned long cons_off,
+			    size_t dwords, const char *name);
+int arm_smmu_cmdq_init(struct arm_smmu_device *smmu,
+		       struct arm_smmu_cmdq *cmdq);
+
 #ifdef CONFIG_ARM_SMMU_V3_SVA
 bool arm_smmu_sva_supported(struct arm_smmu_device *smmu);
 bool arm_smmu_master_sva_supported(struct arm_smmu_master *master);
Signature · 1 line
2.43.0
#6 lore raw

PATCH v12 6/10 iommu/arm-smmu-v3: Add ARM_SMMU_OPT_SECONDARY_CMDQ_CS_NONE_ONLY

In reply to Nicolin Chen

The CMDQV extension in NVIDIA Tegra241 SoC only supports CS_NONE in the CS field of CMD_SYNC. Add a new SMMU option to accommodate that.

---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 17 ++++++++++++++++-
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h |  9 +++++----
 2 files changed, 21 insertions(+), 5 deletions(-)
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +16 -1
index df1149095860..e764236a9216 100644
@@ -341,6 +341,15 @@ static struct arm_smmu_cmdq *arm_smmu_get_cmdq(struct arm_smmu_device *smmu)
 	return &smmu->cmdq;
 }
 
+static bool arm_smmu_cmdq_needs_busy_polling(struct arm_smmu_device *smmu,
+					     struct arm_smmu_cmdq *cmdq)
+{
+	if (cmdq == &smmu->cmdq)
+		return false;
+
+	return smmu->options & ARM_SMMU_OPT_SECONDARY_CMDQ_CS_NONE_ONLY;
+}
+
 static void arm_smmu_cmdq_build_sync_cmd(u64 *cmd, struct arm_smmu_device *smmu,
 					 struct arm_smmu_cmdq *cmdq, u32 prod)
 {
@@ -351,6 +360,11 @@ static void arm_smmu_cmdq_build_sync_cmd(u64 *cmd, struct arm_smmu_device *smmu,
 		 FIELD_PREP(CMDQ_SYNC_0_MSH, ARM_SMMU_SH_ISH) |
 		 FIELD_PREP(CMDQ_SYNC_0_MSIATTR, ARM_SMMU_MEMATTR_OIWB);
 
+	if (arm_smmu_cmdq_needs_busy_polling(smmu, cmdq)) {
+		cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_CS, CMDQ_SYNC_0_CS_NONE);
+		return;
+	}
+
 	if (!(smmu->options & ARM_SMMU_OPT_MSIPOLL)) {
 		cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_CS, CMDQ_SYNC_0_CS_SEV);
 		return;
@@ -697,7 +711,8 @@ static int arm_smmu_cmdq_poll_until_sync(struct arm_smmu_device *smmu,
 					 struct arm_smmu_cmdq *cmdq,
 					 struct arm_smmu_ll_queue *llq)
 {
-	if (smmu->options & ARM_SMMU_OPT_MSIPOLL)
+	if (smmu->options & ARM_SMMU_OPT_MSIPOLL &&
+	    !arm_smmu_cmdq_needs_busy_polling(smmu, cmdq))
 		return __arm_smmu_cmdq_poll_until_msi(smmu, cmdq, llq);
 
 	return __arm_smmu_cmdq_poll_until_consumed(smmu, cmdq, llq);
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +5 -4
index 6c5dc2f10a33..71818f586036 100644
@@ -658,10 +658,11 @@ struct arm_smmu_device {
 #define ARM_SMMU_FEAT_HD		(1 << 22)
 	u32				features;
 
-#define ARM_SMMU_OPT_SKIP_PREFETCH	(1 << 0)
-#define ARM_SMMU_OPT_PAGE0_REGS_ONLY	(1 << 1)
-#define ARM_SMMU_OPT_MSIPOLL		(1 << 2)
-#define ARM_SMMU_OPT_CMDQ_FORCE_SYNC	(1 << 3)
+#define ARM_SMMU_OPT_SKIP_PREFETCH			(1 << 0)
+#define ARM_SMMU_OPT_PAGE0_REGS_ONLY			(1 << 1)
+#define ARM_SMMU_OPT_MSIPOLL				(1 << 2)
+#define ARM_SMMU_OPT_CMDQ_FORCE_SYNC			(1 << 3)
+#define ARM_SMMU_OPT_SECONDARY_CMDQ_CS_NONE_ONLY	(1 << 4)
 	u32				options;
 
 	struct arm_smmu_cmdq		cmdq;
Signature · 1 line
2.43.0
#7 lore raw

PATCH v12 7/10 iommu/arm-smmu-v3: Add an arm_smmu_get_iort_node helper

In reply to Nicolin Chen

From: Jason Gunthorpe <[email protected]>

This will be later used by Tegra241 CMDQV driver too.

---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 5 +----
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 8 ++++++++
 2 files changed, 9 insertions(+), 4 deletions(-)
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +1 -4
index e764236a9216..6df3cb0bc406 100644
@@ -4350,11 +4350,8 @@ static void acpi_smmu_get_options(u32 model, struct arm_smmu_device *smmu)
 static int arm_smmu_device_acpi_probe(struct platform_device *pdev,
 				      struct arm_smmu_device *smmu)
 {
+	struct acpi_iort_node *node = arm_smmu_get_iort_node(smmu);
 	struct acpi_iort_smmu_v3 *iort_smmu;
-	struct device *dev = smmu->dev;
-	struct acpi_iort_node *node;
-
-	node = *(struct acpi_iort_node **)dev_get_platdata(dev);
 
 	/* Retrieve SMMUv3 specific data */
 	iort_smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +8 -0
index 71818f586036..9f5d156b73af 100644
@@ -14,6 +14,8 @@
 #include <linux/mmzone.h>
 #include <linux/sizes.h>
 
+struct acpi_iort_node;
+
 /* MMIO registers */
 #define ARM_SMMU_IDR0			0x0
 #define IDR0_ST_LVL			GENMASK(28, 27)
@@ -791,6 +793,12 @@ static inline struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
 extern struct xarray arm_smmu_asid_xa;
 extern struct mutex arm_smmu_asid_lock;
 
+static inline struct acpi_iort_node *
+arm_smmu_get_iort_node(struct arm_smmu_device *smmu)
+{
+	return *(struct acpi_iort_node **)dev_get_platdata(smmu->dev);
+}
+
 struct arm_smmu_domain *arm_smmu_domain_alloc(void);
 
 void arm_smmu_clear_cd(struct arm_smmu_master *master, ioasid_t ssid);
Signature · 1 line
2.43.0
#8 lore raw

PATCH v12 8/10 iommu/arm-smmu-v3: Add struct arm_smmu_impl_ops

In reply to Nicolin Chen

From: Jason Gunthorpe <[email protected]>

NVIDIA Tegra241 implemented SMMU in a slightly different way that supports a CMDQV extension feature as a secondary CMDQ for virtualization cases.

Mimicing the arm-smmu (v2) driver, introduce a struct arm_smmu_impl_ops to accommodate impl routines.

---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 51 ++++++++++++++++++++-
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h |  9 ++++
 2 files changed, 59 insertions(+), 1 deletion(-)
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +50 -1
index 6df3cb0bc406..2159455cd781 100644
@@ -338,7 +338,12 @@ static int arm_smmu_cmdq_build_cmd(u64 *cmd, struct arm_smmu_cmdq_ent *ent)
 
 static struct arm_smmu_cmdq *arm_smmu_get_cmdq(struct arm_smmu_device *smmu)
 {
-	return &smmu->cmdq;
+	struct arm_smmu_cmdq *cmdq = NULL;
+
+	if (smmu->impl_ops && smmu->impl_ops->get_secondary_cmdq)
+		cmdq = smmu->impl_ops->get_secondary_cmdq(smmu);
+
+	return cmdq ?: &smmu->cmdq;
 }
 
 static bool arm_smmu_cmdq_needs_busy_polling(struct arm_smmu_device *smmu,
@@ -4044,6 +4049,14 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu)
 		return ret;
 	}
 
+	if (smmu->impl_ops && smmu->impl_ops->device_reset) {
+		ret = smmu->impl_ops->device_reset(smmu);
+		if (ret) {
+			dev_err(smmu->dev, "failed to reset impl\n");
+			return ret;
+		}
+	}
+
 	return 0;
 }
 
@@ -4450,6 +4463,38 @@ static void arm_smmu_rmr_install_bypass_ste(struct arm_smmu_device *smmu)
 	iort_put_rmr_sids(dev_fwnode(smmu->dev), &rmr_list);
 }
 
+static void arm_smmu_impl_remove(void *data)
+{
+	struct arm_smmu_device *smmu = data;
+
+	if (smmu->impl_ops && smmu->impl_ops->device_remove)
+		smmu->impl_ops->device_remove(smmu);
+}
+
+/*
+ * Probe all the compiled in implementations. Each one checks to see if it
+ * matches this HW and if so returns a devm_krealloc'd arm_smmu_device which
+ * replaces the callers. Otherwise the original is returned or ERR_PTR.
+ */
+static struct arm_smmu_device *arm_smmu_impl_probe(struct arm_smmu_device *smmu)
+{
+	struct arm_smmu_device *new_smmu = ERR_PTR(-ENODEV);
+	int ret;
+
+	/* Add impl probe */
+
+	if (new_smmu == ERR_PTR(-ENODEV))
+		return smmu;
+	if (IS_ERR(new_smmu))
+		return new_smmu;
+
+	ret = devm_add_action_or_reset(new_smmu->dev, arm_smmu_impl_remove,
+				       new_smmu);
+	if (ret)
+		return ERR_PTR(ret);
+	return new_smmu;
+}
+
 static int arm_smmu_device_probe(struct platform_device *pdev)
 {
 	int irq, ret;
@@ -4471,6 +4516,10 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	smmu = arm_smmu_impl_probe(smmu);
+	if (IS_ERR(smmu))
+		return PTR_ERR(smmu);
+
 	/* Base address */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +9 -0
index 9f5d156b73af..475517729307 100644
@@ -15,6 +15,7 @@
 #include <linux/sizes.h>
 
 struct acpi_iort_node;
+struct arm_smmu_device;
 
 /* MMIO registers */
 #define ARM_SMMU_IDR0			0x0
@@ -629,9 +630,17 @@ struct arm_smmu_strtab_cfg {
 	u32				strtab_base_cfg;
 };
 
+struct arm_smmu_impl_ops {
+	int (*device_reset)(struct arm_smmu_device *smmu);
+	void (*device_remove)(struct arm_smmu_device *smmu);
+	struct arm_smmu_cmdq *(*get_secondary_cmdq)(struct arm_smmu_device *smmu);
+};
+
 /* An SMMUv3 instance */
 struct arm_smmu_device {
 	struct device			*dev;
+	const struct arm_smmu_impl_ops	*impl_ops;
+
 	void __iomem			*base;
 	void __iomem			*page1;
 
Signature · 1 line
2.43.0
#9 lore raw

PATCH v12 9/10 iommu/arm-smmu-v3: Add in-kernel support for NVIDIA Tegra241 (Grace) CMDQV

In reply to Nicolin Chen

From: Nate Watterson <[email protected]>

NVIDIA's Tegra241 Soc has a CMDQ-Virtualization (CMDQV) hardware, extending the standard ARM SMMU v3 IP to support multiple VCMDQs with virtualization capabilities. In terms of command queue, they are very like a standard SMMU CMDQ (or ECMDQs), but only support CS_NONE in the CS field of CMD_SYNC.

Add a new tegra241-cmdqv driver, and insert its structure pointer into the existing arm_smmu_device, and then add related function calls in the SMMUv3 driver to interact with the CMDQV driver.

In the CMDQV driver, add a minimal part for the in-kernel support: reserve VINTF0 for in-kernel use, and assign some of the VCMDQs to the VINTF0, and select one VCMDQ based on the current CPU ID to execute supported commands. This multi-queue design for in-kernel use gives some limited improvements:
up to 20% reduction of invalidation time was measured by a multi-threaded DMA unmap benchmark, compared to a single queue.

The other part of the CMDQV driver will be user-space support that gives a hypervisor running on the host OS to talk to the driver for virtualization use cases, allowing VMs to use VCMDQs without trappings, i.e. no VM Exits. This is designed based on IOMMUFD, and its RFC series is also under review. It will provide a guest OS a bigger improvement: 70% to 90% reductions of TLB invalidation time were measured by DMA unmap tests running in a guest, compared to nested SMMU CMDQ (with trappings).

As the initial version, the CMDQV driver only supports ACPI configurations.

---
 MAINTAINERS                                   |   1 +
 drivers/iommu/Kconfig                         |  11 +
 drivers/iommu/arm/arm-smmu-v3/Makefile        |   1 +
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   |   2 +-
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  11 +
 .../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c    | 872 ++++++++++++++++++
 6 files changed, 897 insertions(+), 1 deletion(-)
 create mode 100644 drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
MAINTAINERS +1 -0
index f328373463b0..dad28b828143 100644
@@ -22474,6 +22474,7 @@ M:	Thierry Reding <[email protected]>
 R:	Krishna Reddy <[email protected]>
 L:	[email protected]
 S:	Supported
+F:	drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
 F:	drivers/iommu/arm/arm-smmu/arm-smmu-nvidia.c
 F:	drivers/iommu/tegra*
 
drivers/iommu/Kconfig +11 -0
index a82f10054aec..22addaedf64d 100644
@@ -424,6 +424,17 @@ config ARM_SMMU_V3_KUNIT_TEST
 	  Enable this option to unit-test arm-smmu-v3 driver functions.
 
 	  If unsure, say N.
+
+config TEGRA241_CMDQV
+	bool "NVIDIA Tegra241 CMDQ-V extension support for ARM SMMUv3"
+	depends on ACPI
+	help
+	  Support for NVIDIA CMDQ-Virtualization extension for ARM SMMUv3. The
+	  CMDQ-V extension is similar to v3.3 ECMDQ for multi command queues
+	  support, except with virtualization capabilities.
+
+	  Say Y here if your system is NVIDIA Tegra241 (Grace) or it has the same
+	  CMDQ-V extension.
 endif
 
 config S390_IOMMU
drivers/iommu/arm/arm-smmu-v3/Makefile +1 -0
index 355173d1441d..dc98c88b48c8 100644
@@ -2,5 +2,6 @@
 obj-$(CONFIG_ARM_SMMU_V3) += arm_smmu_v3.o
 arm_smmu_v3-y := arm-smmu-v3.o
 arm_smmu_v3-$(CONFIG_ARM_SMMU_V3_SVA) += arm-smmu-v3-sva.o
+arm_smmu_v3-$(CONFIG_TEGRA241_CMDQV) += tegra241-cmdqv.o
 
 obj-$(CONFIG_ARM_SMMU_V3_KUNIT_TEST) += arm-smmu-v3-test.o
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +1 -1
index 2159455cd781..839db3bdcfc9 100644
@@ -4481,7 +4481,7 @@ static struct arm_smmu_device *arm_smmu_impl_probe(struct arm_smmu_device *smmu)
 	struct arm_smmu_device *new_smmu = ERR_PTR(-ENODEV);
 	int ret;
 
-	/* Add impl probe */
+	new_smmu = tegra241_cmdqv_acpi_dsdt_probe(smmu);
 
 	if (new_smmu == ERR_PTR(-ENODEV))
 		return smmu;
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +11 -0
index 475517729307..7f1bd95f3f25 100644
@@ -891,4 +891,15 @@ static inline void arm_smmu_sva_remove_dev_pasid(struct iommu_domain *domain,
 {
 }
 #endif /* CONFIG_ARM_SMMU_V3_SVA */
+
+#ifdef CONFIG_TEGRA241_CMDQV
+struct arm_smmu_device *
+tegra241_cmdqv_acpi_dsdt_probe(struct arm_smmu_device *smmu);
+#else /* CONFIG_TEGRA241_CMDQV */
+static inline struct arm_smmu_device *
+tegra241_cmdqv_acpi_dsdt_probe(struct arm_smmu_device *smmu)
+{
+	return ERR_PTR(-ENODEV);
+}
+#endif /* CONFIG_TEGRA241_CMDQV */
 #endif /* _ARM_SMMU_V3_H */
drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c new file +872 -0

872 lines not on this page · raw message

Signature · 1 line
2.43.0
#10 lore raw

PATCH v12 10/10 iommu/tegra241-cmdqv: Limit CMDs for guest owned VINTF

In reply to Nicolin Chen

When VCMDQs are assigned to a VINTF owned by a guest (HYP_OWN bit unset), only TLB and ATC invalidation commands are supported by the VCMDQ HW. So, add a new helper to scan the input cmd to make sure it is supported when selecting a queue, though this assumes that SMMUv3 driver will only add the same type of commands into an arm_smmu_cmdq_batch as it does today.

Note that the guest VM shouldn't have HYP_OWN bit being set regardless of guest kernel driver writing it or not, i.e. the hypervisor running in the host OS should wire this bit to zero when trapping a write access to this VINTF_CONFIG register from a guest kernel.

---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   | 22 +++++++-----
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  3 +-
 .../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c    | 35 ++++++++++++++++++-
 3 files changed, 49 insertions(+), 11 deletions(-)
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +13 -9
index 839db3bdcfc9..4628fc456759 100644
@@ -336,12 +336,13 @@ static int arm_smmu_cmdq_build_cmd(u64 *cmd, struct arm_smmu_cmdq_ent *ent)
 	return 0;
 }
 
-static struct arm_smmu_cmdq *arm_smmu_get_cmdq(struct arm_smmu_device *smmu)
+static struct arm_smmu_cmdq *arm_smmu_get_cmdq(struct arm_smmu_device *smmu,
+					       u8 opcode)
 {
 	struct arm_smmu_cmdq *cmdq = NULL;
 
 	if (smmu->impl_ops && smmu->impl_ops->get_secondary_cmdq)
-		cmdq = smmu->impl_ops->get_secondary_cmdq(smmu);
+		cmdq = smmu->impl_ops->get_secondary_cmdq(smmu, opcode);
 
 	return cmdq ?: &smmu->cmdq;
 }
@@ -889,7 +890,7 @@ static int __arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu,
 	}
 
 	return arm_smmu_cmdq_issue_cmdlist(
-		smmu, arm_smmu_get_cmdq(smmu), cmd, 1, sync);
+		smmu, arm_smmu_get_cmdq(smmu, ent->opcode), cmd, 1, sync);
 }
 
 static int arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu,
@@ -905,10 +906,13 @@ static int arm_smmu_cmdq_issue_cmd_with_sync(struct arm_smmu_device *smmu,
 }
 
 static void arm_smmu_cmdq_batch_init(struct arm_smmu_device *smmu,
-				     struct arm_smmu_cmdq_batch *cmds)
+				     struct arm_smmu_cmdq_batch *cmds,
+				     u8 opcode)
 {
+	WARN_ON_ONCE(!opcode);
+
 	cmds->num = 0;
-	cmds->cmdq = arm_smmu_get_cmdq(smmu);
+	cmds->cmdq = arm_smmu_get_cmdq(smmu, opcode);
 }
 
 static void arm_smmu_cmdq_batch_add(struct arm_smmu_device *smmu,
@@ -1195,7 +1199,7 @@ static void arm_smmu_sync_cd(struct arm_smmu_master *master,
 		},
 	};
 
-	arm_smmu_cmdq_batch_init(smmu, &cmds);
+	arm_smmu_cmdq_batch_init(smmu, &cmds, CMDQ_OP_CFGI_CD);
 	for (i = 0; i < master->num_streams; i++) {
 		cmd.cfgi.sid = master->streams[i].id;
 		arm_smmu_cmdq_batch_add(smmu, &cmds, &cmd);
@@ -2046,7 +2050,7 @@ static int arm_smmu_atc_inv_master(struct arm_smmu_master *master,
 
 	arm_smmu_atc_inv_to_cmd(ssid, 0, 0, &cmd);
 
-	arm_smmu_cmdq_batch_init(master->smmu, &cmds);
+	arm_smmu_cmdq_batch_init(master->smmu, &cmds, CMDQ_OP_ATC_INV);
 	for (i = 0; i < master->num_streams; i++) {
 		cmd.atc.sid = master->streams[i].id;
 		arm_smmu_cmdq_batch_add(master->smmu, &cmds, &cmd);
@@ -2084,7 +2088,7 @@ int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain,
 	if (!atomic_read(&smmu_domain->nr_ats_masters))
 		return 0;
 
-	arm_smmu_cmdq_batch_init(smmu_domain->smmu, &cmds);
+	arm_smmu_cmdq_batch_init(smmu_domain->smmu, &cmds, CMDQ_OP_ATC_INV);
 
 	spin_lock_irqsave(&smmu_domain->devices_lock, flags);
 	list_for_each_entry(master_domain, &smmu_domain->devices,
@@ -2166,7 +2170,7 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd,
 			num_pages++;
 	}
 
-	arm_smmu_cmdq_batch_init(smmu, &cmds);
+	arm_smmu_cmdq_batch_init(smmu, &cmds, cmd->opcode);
 
 	while (iova < end) {
 		if (smmu->features & ARM_SMMU_FEAT_RANGE_INV) {
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +2 -1
index 7f1bd95f3f25..30534839348b 100644
@@ -633,7 +633,8 @@ struct arm_smmu_strtab_cfg {
 struct arm_smmu_impl_ops {
 	int (*device_reset)(struct arm_smmu_device *smmu);
 	void (*device_remove)(struct arm_smmu_device *smmu);
-	struct arm_smmu_cmdq *(*get_secondary_cmdq)(struct arm_smmu_device *smmu);
+	struct arm_smmu_cmdq *(*get_secondary_cmdq)(struct arm_smmu_device *smmu,
+			       u8 opcode);
 };
 
 /* An SMMUv3 instance */
drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c +34 -1
index 844c27cdc946..cfb9f2784f6a 100644
@@ -144,6 +144,7 @@ struct tegra241_vcmdq {
  * struct tegra241_vintf - Virtual Interface
  * @idx: Global index in the CMDQV
  * @enabled: Enable status
+ * @hyp_own: Owned by hypervisor (in-kernel)
  * @cmdqv: Parent CMDQV pointer
  * @lvcmdqs: List of logical VCMDQ pointers
  * @base: MMIO base address
@@ -152,6 +153,7 @@ struct tegra241_vintf {
 	u16 idx;
 
 	bool enabled;
+	bool hyp_own;
 
 	struct tegra241_cmdqv *cmdqv;
 	struct tegra241_vcmdq **lvcmdqs;
@@ -301,8 +303,25 @@ static irqreturn_t tegra241_cmdqv_isr(int irq, void *devid)
 
 /* Command Queue Function */
 
+static bool tegra241_vintf_support_cmd(struct tegra241_vintf *vintf, u8 opcode)
+{
+       /* Hypervisor-owned VINTF can execute any command in its VCMDQs */
+	if (READ_ONCE(vintf->hyp_own))
+		return true;
+
+	/* Guest-owned VINTF must check against the list of supported CMDs */
+	switch (opcode) {
+	case CMDQ_OP_TLBI_NH_ASID:
+	case CMDQ_OP_TLBI_NH_VA:
+	case CMDQ_OP_ATC_INV:
+		return true;
+	default:
+		return false;
+	}
+}
+
 static struct arm_smmu_cmdq *
-tegra241_cmdqv_get_cmdq(struct arm_smmu_device *smmu)
+tegra241_cmdqv_get_cmdq(struct arm_smmu_device *smmu, u8 opcode)
 {
 	struct tegra241_cmdqv *cmdqv =
 		container_of(smmu, struct tegra241_cmdqv, smmu);
@@ -317,6 +336,10 @@ tegra241_cmdqv_get_cmdq(struct arm_smmu_device *smmu)
 	if (!READ_ONCE(vintf->enabled))
 		return NULL;
 
+	/* Unsupported CMD go for smmu->cmdq pathway */
+	if (!tegra241_vintf_support_cmd(vintf, opcode))
+		return NULL;
+
 	/*
 	 * Select a LVCMDQ to use. Here we use a temporal solution to
 	 * balance out traffic on cmdq issuing: each cmdq has its own
@@ -406,12 +429,22 @@ static int tegra241_vintf_hw_init(struct tegra241_vintf *vintf, bool hyp_own)
 	tegra241_vintf_hw_deinit(vintf);
 
 	/* Configure and enable VINTF */
+	/*
+	 * Note that HYP_OWN bit is wired to zero when running in guest kernel,
+	 * whether enabling it here or not, as !HYP_OWN cmdq HWs only support a
+	 * restricted set of supported commands.
+	 */
 	regval = FIELD_PREP(VINTF_HYP_OWN, hyp_own);
 	writel(regval, REG_VINTF(vintf, CONFIG));
 
 	ret = vintf_write_config(vintf, regval | VINTF_EN);
 	if (ret)
 		return ret;
+	/*
+	 * As being mentioned above, HYP_OWN bit is wired to zero for a guest
+	 * kernel, so read it back from HW to ensure that reflects in hyp_own
+	 */
+	vintf->hyp_own = !!(VINTF_HYP_OWN & readl(REG_VINTF(vintf, CONFIG)));
 
 	for (lidx = 0; lidx < vintf->cmdqv->num_lvcmdqs_per_vintf; lidx++) {
 		if (vintf->lvcmdqs && vintf->lvcmdqs[lidx]) {
Signature · 1 line
2.43.0