drm/amdkfd: Centralize IOMMUv2 code and make it conditional

dGPUs work without IOMMUv2. Make IOMMUv2 initialization dependent on
ASIC information. Also allow building KFD without IOMMUv2 support.
This is still useful for dGPUs and prepares for enabling KFD on
architectures that don't support AMD IOMMUv2.

v2:
* Centralize IOMMUv2 code to avoid #ifdefs in too many places

v3:
* Imply AMD_IOMMU_V2 in Kconfig

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Christian Konig <christian.koenig@amd.com>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

drivers/gpu/drm/amd/amdkfd/Kconfig

@@ -4,6 +4,7 @@
 
 config HSA_AMD
 	tristate "HSA kernel driver for AMD GPU devices"
-	depends on DRM_AMDGPU && AMD_IOMMU_V2 && X86_64
+	depends on DRM_AMDGPU && X86_64
+	imply AMD_IOMMU_V2
 	help
 	  Enable this if you want to use HSA features on AMD GPU devices.

drivers/gpu/drm/amd/amdkfd/Makefile

@@ -37,6 +37,10 @@ amdkfd-y	:= kfd_module.o kfd_device.o kfd_chardev.o kfd_topology.o \
 		kfd_interrupt.o kfd_events.o cik_event_interrupt.o \
 		kfd_dbgdev.o kfd_dbgmgr.o kfd_crat.o
 
+ifneq ($(CONFIG_AMD_IOMMU_V2),)
+amdkfd-y += kfd_iommu.o
+endif
+
 amdkfd-$(CONFIG_DEBUG_FS) += kfd_debugfs.o
 
 obj-$(CONFIG_HSA_AMD)	+= amdkfd.o

drivers/gpu/drm/amd/amdkfd/kfd_crat.c

@@ -22,10 +22,10 @@
 
 #include <linux/pci.h>
 #include <linux/acpi.h>
-#include <linux/amd-iommu.h>
 #include "kfd_crat.h"
 #include "kfd_priv.h"
 #include "kfd_topology.h"
+#include "kfd_iommu.h"
 
 /* GPU Processor ID base for dGPUs for which VCRAT needs to be created.
  * GPU processor ID are expressed with Bit[31]=1.
@@ -1037,15 +1037,11 @@ static int kfd_create_vcrat_image_gpu(void *pcrat_image,
 	struct crat_subtype_generic *sub_type_hdr;
 	struct crat_subtype_computeunit *cu;
 	struct kfd_cu_info cu_info;
-	struct amd_iommu_device_info iommu_info;
 	int avail_size = *size;
 	uint32_t total_num_of_cu;
 	int num_of_cache_entries = 0;
 	int cache_mem_filled = 0;
 	int ret = 0;
-	const u32 required_iommu_flags = AMD_IOMMU_DEVICE_FLAG_ATS_SUP |
-					 AMD_IOMMU_DEVICE_FLAG_PRI_SUP |
-					 AMD_IOMMU_DEVICE_FLAG_PASID_SUP;
 	struct kfd_local_mem_info local_mem_info;
 
 	if (!pcrat_image || avail_size < VCRAT_SIZE_FOR_GPU)
@@ -1106,12 +1102,8 @@ static int kfd_create_vcrat_image_gpu(void *pcrat_image,
 	/* Check if this node supports IOMMU. During parsing this flag will
 	 * translate to HSA_CAP_ATS_PRESENT
 	 */
-	iommu_info.flags = 0;
-	if (amd_iommu_device_info(kdev->pdev, &iommu_info) == 0) {
-		if ((iommu_info.flags & required_iommu_flags) ==
-				required_iommu_flags)
-			cu->hsa_capability |= CRAT_CU_FLAGS_IOMMU_PRESENT;
-	}
+	if (!kfd_iommu_check_device(kdev))
+		cu->hsa_capability |= CRAT_CU_FLAGS_IOMMU_PRESENT;
 
 	crat_table->length += sub_type_hdr->length;
 	crat_table->total_entries++;

drivers/gpu/drm/amd/amdkfd/kfd_device.c

@@ -20,17 +20,21 @@
  * OTHER DEALINGS IN THE SOFTWARE.
  */
 
+#if defined(CONFIG_AMD_IOMMU_V2_MODULE) || defined(CONFIG_AMD_IOMMU_V2)
 #include <linux/amd-iommu.h>
+#endif
 #include <linux/bsearch.h>
 #include <linux/pci.h>
 #include <linux/slab.h>
 #include "kfd_priv.h"
 #include "kfd_device_queue_manager.h"
 #include "kfd_pm4_headers_vi.h"
 #include "cwsr_trap_handler_gfx8.asm"
+#include "kfd_iommu.h"
 
 #define MQD_SIZE_ALIGNED 768
 
+#ifdef KFD_SUPPORT_IOMMU_V2
 static const struct kfd_device_info kaveri_device_info = {
 	.asic_family = CHIP_KAVERI,
 	.max_pasid_bits = 16,
@@ -41,6 +45,7 @@ static const struct kfd_device_info kaveri_device_info = {
 	.num_of_watch_points = 4,
 	.mqd_size_aligned = MQD_SIZE_ALIGNED,
 	.supports_cwsr = false,
+	.needs_iommu_device = true,
 	.needs_pci_atomics = false,
 };
 
@@ -54,8 +59,10 @@ static const struct kfd_device_info carrizo_device_info = {
 	.num_of_watch_points = 4,
 	.mqd_size_aligned = MQD_SIZE_ALIGNED,
 	.supports_cwsr = true,
+	.needs_iommu_device = true,
 	.needs_pci_atomics = false,
 };
+#endif
 
 static const struct kfd_device_info hawaii_device_info = {
 	.asic_family = CHIP_HAWAII,
@@ -67,6 +74,7 @@ static const struct kfd_device_info hawaii_device_info = {
 	.num_of_watch_points = 4,
 	.mqd_size_aligned = MQD_SIZE_ALIGNED,
 	.supports_cwsr = false,
+	.needs_iommu_device = false,
 	.needs_pci_atomics = false,
 };
 
@@ -79,6 +87,7 @@ static const struct kfd_device_info tonga_device_info = {
 	.num_of_watch_points = 4,
 	.mqd_size_aligned = MQD_SIZE_ALIGNED,
 	.supports_cwsr = false,
+	.needs_iommu_device = false,
 	.needs_pci_atomics = true,
 };
 
@@ -91,6 +100,7 @@ static const struct kfd_device_info tonga_vf_device_info = {
 	.num_of_watch_points = 4,
 	.mqd_size_aligned = MQD_SIZE_ALIGNED,
 	.supports_cwsr = false,
+	.needs_iommu_device = false,
 	.needs_pci_atomics = false,
 };
 
@@ -103,6 +113,7 @@ static const struct kfd_device_info fiji_device_info = {
 	.num_of_watch_points = 4,
 	.mqd_size_aligned = MQD_SIZE_ALIGNED,
 	.supports_cwsr = true,
+	.needs_iommu_device = false,
 	.needs_pci_atomics = true,
 };
 
@@ -115,6 +126,7 @@ static const struct kfd_device_info fiji_vf_device_info = {
 	.num_of_watch_points = 4,
 	.mqd_size_aligned = MQD_SIZE_ALIGNED,
 	.supports_cwsr = true,
+	.needs_iommu_device = false,
 	.needs_pci_atomics = false,
 };
 
@@ -128,6 +140,7 @@ static const struct kfd_device_info polaris10_device_info = {
 	.num_of_watch_points = 4,
 	.mqd_size_aligned = MQD_SIZE_ALIGNED,
 	.supports_cwsr = true,
+	.needs_iommu_device = false,
 	.needs_pci_atomics = true,
 };
 
@@ -140,6 +153,7 @@ static const struct kfd_device_info polaris10_vf_device_info = {
 	.num_of_watch_points = 4,
 	.mqd_size_aligned = MQD_SIZE_ALIGNED,
 	.supports_cwsr = true,
+	.needs_iommu_device = false,
 	.needs_pci_atomics = false,
 };
 
@@ -152,6 +166,7 @@ static const struct kfd_device_info polaris11_device_info = {
 	.num_of_watch_points = 4,
 	.mqd_size_aligned = MQD_SIZE_ALIGNED,
 	.supports_cwsr = true,
+	.needs_iommu_device = false,
 	.needs_pci_atomics = true,
 };
 
@@ -162,6 +177,7 @@ struct kfd_deviceid {
 };
 
 static const struct kfd_deviceid supported_devices[] = {
+#ifdef KFD_SUPPORT_IOMMU_V2
 	{ 0x1304, &kaveri_device_info },	/* Kaveri */
 	{ 0x1305, &kaveri_device_info },	/* Kaveri */
 	{ 0x1306, &kaveri_device_info },	/* Kaveri */
@@ -189,6 +205,7 @@ static const struct kfd_deviceid supported_devices[] = {
 	{ 0x9875, &carrizo_device_info },	/* Carrizo */
 	{ 0x9876, &carrizo_device_info },	/* Carrizo */
 	{ 0x9877, &carrizo_device_info },	/* Carrizo */
+#endif
 	{ 0x67A0, &hawaii_device_info },	/* Hawaii */
 	{ 0x67A1, &hawaii_device_info },	/* Hawaii */
 	{ 0x67A2, &hawaii_device_info },	/* Hawaii */
@@ -302,77 +319,6 @@ struct kfd_dev *kgd2kfd_probe(struct kgd_dev *kgd,
 	return kfd;
 }
 
-static bool device_iommu_pasid_init(struct kfd_dev *kfd)
-{
-	const u32 required_iommu_flags = AMD_IOMMU_DEVICE_FLAG_ATS_SUP |
-					AMD_IOMMU_DEVICE_FLAG_PRI_SUP |
-					AMD_IOMMU_DEVICE_FLAG_PASID_SUP;
-
-	struct amd_iommu_device_info iommu_info;
-	unsigned int pasid_limit;
-	int err;
-
-	err = amd_iommu_device_info(kfd->pdev, &iommu_info);
-	if (err < 0) {
-		dev_err(kfd_device,
-			"error getting iommu info. is the iommu enabled?\n");
-		return false;
-	}
-
-	if ((iommu_info.flags & required_iommu_flags) != required_iommu_flags) {
-		dev_err(kfd_device, "error required iommu flags ats %i, pri %i, pasid %i\n",
-		       (iommu_info.flags & AMD_IOMMU_DEVICE_FLAG_ATS_SUP) != 0,
-		       (iommu_info.flags & AMD_IOMMU_DEVICE_FLAG_PRI_SUP) != 0,
-		       (iommu_info.flags & AMD_IOMMU_DEVICE_FLAG_PASID_SUP)
-									!= 0);
-		return false;
-	}
-
-	pasid_limit = min_t(unsigned int,
-			(unsigned int)(1 << kfd->device_info->max_pasid_bits),
-			iommu_info.max_pasids);
-
-	if (!kfd_set_pasid_limit(pasid_limit)) {
-		dev_err(kfd_device, "error setting pasid limit\n");
-		return false;
-	}
-
-	return true;
-}
-
-static void iommu_pasid_shutdown_callback(struct pci_dev *pdev, int pasid)
-{
-	struct kfd_dev *dev = kfd_device_by_pci_dev(pdev);
-
-	if (dev)
-		kfd_process_iommu_unbind_callback(dev, pasid);
-}
-
-/*
- * This function called by IOMMU driver on PPR failure
- */
-static int iommu_invalid_ppr_cb(struct pci_dev *pdev, int pasid,
-		unsigned long address, u16 flags)
-{
-	struct kfd_dev *dev;
-
-	dev_warn(kfd_device,
-			"Invalid PPR device %x:%x.%x pasid %d address 0x%lX flags 0x%X",
-			PCI_BUS_NUM(pdev->devfn),
-			PCI_SLOT(pdev->devfn),
-			PCI_FUNC(pdev->devfn),
-			pasid,
-			address,
-			flags);
-
-	dev = kfd_device_by_pci_dev(pdev);
-	if (!WARN_ON(!dev))
-		kfd_signal_iommu_event(dev, pasid, address,
-			flags & PPR_FAULT_WRITE, flags & PPR_FAULT_EXEC);
-
-	return AMD_IOMMU_INV_PRI_RSP_INVALID;
-}
-
 static void kfd_cwsr_init(struct kfd_dev *kfd)
 {
 	if (cwsr_enable && kfd->device_info->supports_cwsr) {
@@ -462,11 +408,9 @@ bool kgd2kfd_device_init(struct kfd_dev *kfd,
 		goto device_queue_manager_error;
 	}
 
-	if (!device_iommu_pasid_init(kfd)) {
-		dev_err(kfd_device,
-			"Error initializing iommuv2 for device %x:%x\n",
-			kfd->pdev->vendor, kfd->pdev->device);
-		goto device_iommu_pasid_error;
+	if (kfd_iommu_device_init(kfd)) {
+		dev_err(kfd_device, "Error initializing iommuv2\n");
+		goto device_iommu_error;
 	}
 
 	kfd_cwsr_init(kfd);
@@ -486,7 +430,7 @@ bool kgd2kfd_device_init(struct kfd_dev *kfd,
 	goto out;
 
 kfd_resume_error:
-device_iommu_pasid_error:
+device_iommu_error:
 	device_queue_manager_uninit(kfd->dqm);
 device_queue_manager_error:
 	kfd_interrupt_exit(kfd);
@@ -527,11 +471,7 @@ void kgd2kfd_suspend(struct kfd_dev *kfd)
 
 	kfd->dqm->ops.stop(kfd->dqm);
 
-	kfd_unbind_processes_from_device(kfd);
-
-	amd_iommu_set_invalidate_ctx_cb(kfd->pdev, NULL);
-	amd_iommu_set_invalid_ppr_cb(kfd->pdev, NULL);
-	amd_iommu_free_device(kfd->pdev);
+	kfd_iommu_suspend(kfd);
 }
 
 int kgd2kfd_resume(struct kfd_dev *kfd)
@@ -546,19 +486,14 @@ int kgd2kfd_resume(struct kfd_dev *kfd)
 static int kfd_resume(struct kfd_dev *kfd)
 {
 	int err = 0;
-	unsigned int pasid_limit = kfd_get_pasid_limit();
-
-	err = amd_iommu_init_device(kfd->pdev, pasid_limit);
-	if (err)
-		return -ENXIO;
-	amd_iommu_set_invalidate_ctx_cb(kfd->pdev,
-					iommu_pasid_shutdown_callback);
-	amd_iommu_set_invalid_ppr_cb(kfd->pdev,
-				     iommu_invalid_ppr_cb);
 
-	err = kfd_bind_processes_to_device(kfd);
-	if (err)
-		goto processes_bind_error;
+	err = kfd_iommu_resume(kfd);
+	if (err) {
+		dev_err(kfd_device,
+			"Failed to resume IOMMU for device %x:%x\n",
+			kfd->pdev->vendor, kfd->pdev->device);
+		return err;
+	}
 
 	err = kfd->dqm->ops.start(kfd->dqm);
 	if (err) {
@@ -571,9 +506,7 @@ static int kfd_resume(struct kfd_dev *kfd)
 	return err;
 
 dqm_start_error:
-processes_bind_error:
-	amd_iommu_free_device(kfd->pdev);
-
+	kfd_iommu_suspend(kfd);
 	return err;
 }
 

drivers/gpu/drm/amd/amdkfd/kfd_events.c

@@ -30,6 +30,7 @@
 #include <linux/memory.h>
 #include "kfd_priv.h"
 #include "kfd_events.h"
+#include "kfd_iommu.h"
 #include <linux/device.h>
 
 /*
@@ -837,6 +838,7 @@ static void lookup_events_by_type_and_signal(struct kfd_process *p,
 	}
 }
 
+#ifdef KFD_SUPPORT_IOMMU_V2
 void kfd_signal_iommu_event(struct kfd_dev *dev, unsigned int pasid,
 		unsigned long address, bool is_write_requested,
 		bool is_execute_requested)
@@ -905,6 +907,7 @@ void kfd_signal_iommu_event(struct kfd_dev *dev, unsigned int pasid,
 	mutex_unlock(&p->event_mutex);
 	kfd_unref_process(p);
 }
+#endif /* KFD_SUPPORT_IOMMU_V2 */
 
 void kfd_signal_hw_exception_event(unsigned int pasid)
 {