[PATCH 5/9] drm/amdkfd: Use PASID manager from KGD

[Felix Kuehling]

Also fixed PASID limit setting for dGPUs.

Change-Id: If3bb8c0742019745bedf09077a271b1ed14deea1
Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_device.c | 11 ++---
 drivers/gpu/drm/amd/amdkfd/kfd_module.c |  6 ---
 drivers/gpu/drm/amd/amdkfd/kfd_pasid.c  | 84 +++++++++++++--------------------
 3 files changed, 39 insertions(+), 62 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device.c b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
index 378a9cf..1915e93 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
@@ -391,7 +391,6 @@ static bool device_iommu_pasid_init(struct kfd_dev *kfd)
 					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);
@@ -410,11 +409,7 @@ static bool device_iommu_pasid_init(struct kfd_dev *kfd)
 		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)) {
+	if (!kfd_set_pasid_limit(iommu_info.max_pasids)) {
 		dev_err(kfd_device, "error setting pasid limit\n");
 		return false;
 	}
@@ -605,6 +600,10 @@ bool kgd2kfd_device_init(struct kfd_dev *kfd,
 		goto device_queue_manager_error;
 	}
 
+	if (!kfd_set_pasid_limit(1U << kfd->device_info->max_pasid_bits)) {
+		dev_err(kfd_device, "Error setting pasid limit\n");
+		goto device_iommu_pasid_error;
+	}
 #if defined(CONFIG_AMD_IOMMU_V2_MODULE) || defined(CONFIG_AMD_IOMMU_V2)
 	if (kfd->device_info->is_need_iommu_device) {
 		if (!device_iommu_pasid_init(kfd)) {
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_module.c b/drivers/gpu/drm/amd/amdkfd/kfd_module.c
index aba3e9d..9846d58 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_module.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_module.c
@@ -131,10 +131,6 @@ static int __init kfd_module_init(void)
 		return -1;
 	}
 
-	err = kfd_pasid_init();
-	if (err < 0)
-		return err;
-
 	err = kfd_chardev_init();
 	if (err < 0)
 		goto err_ioctl;
@@ -162,7 +158,6 @@ static int __init kfd_module_init(void)
 err_topology:
 	kfd_chardev_exit();
 err_ioctl:
-	kfd_pasid_exit();
 	return err;
 }
 
@@ -175,7 +170,6 @@ static void __exit kfd_module_exit(void)
 	kfd_process_destroy_wq();
 	kfd_topology_shutdown();
 	kfd_chardev_exit();
-	kfd_pasid_exit();
 	dev_info(kfd_device, "Removed module\n");
 }
 
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_pasid.c b/drivers/gpu/drm/amd/amdkfd/kfd_pasid.c
index 1e06de0..ed78937 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_pasid.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_pasid.c
@@ -20,78 +20,62 @@
  * OTHER DEALINGS IN THE SOFTWARE.
  */
 
-#include <linux/slab.h>
 #include <linux/types.h>
 #include "kfd_priv.h"
 
-static unsigned long *pasid_bitmap;
-static unsigned int pasid_limit;
-static DEFINE_MUTEX(pasid_mutex);
-
-int kfd_pasid_init(void)
-{
-	pasid_limit = KFD_MAX_NUM_OF_PROCESSES;
-
-	pasid_bitmap = kcalloc(BITS_TO_LONGS(pasid_limit), sizeof(long),
-				GFP_KERNEL);
-	if (!pasid_bitmap)
-		return -ENOMEM;
-
-	set_bit(0, pasid_bitmap); /* PASID 0 is reserved. */
-
-	return 0;
-}
-
-void kfd_pasid_exit(void)
-{
-	kfree(pasid_bitmap);
-}
+static unsigned int pasid_bits = 16;
+static const struct kfd2kgd_calls *kfd2kgd;
 
 bool kfd_set_pasid_limit(unsigned int new_limit)
 {
-	if (new_limit < pasid_limit) {
-		bool ok;
-
-		mutex_lock(&pasid_mutex);
-
-		/* ensure that no pasids >= new_limit are in-use */
-		ok = (find_next_bit(pasid_bitmap, pasid_limit, new_limit) ==
-								pasid_limit);
-		if (ok)
-			pasid_limit = new_limit;
-
-		mutex_unlock(&pasid_mutex);
-
-		return ok;
+	if (new_limit < 2)
+		return false;
+
+	if (new_limit < (1U << pasid_bits)) {
+		if (kfd2kgd)
+			/* We've already allocated user PASIDs, too late to
+			 * change the limit
+			 */
+			return false;
+
+		while (new_limit < (1U << pasid_bits))
+			pasid_bits--;
 	}
 
 	return true;
 }
 
-inline unsigned int kfd_get_pasid_limit(void)
+unsigned int kfd_get_pasid_limit(void)
 {
-	return pasid_limit;
+	return 1U << pasid_bits;
 }
 
 unsigned int kfd_pasid_alloc(void)
 {
-	unsigned int found;
+	int r;
+
+	/* Find the first best KFD device for calling KGD */
+	if (!kfd2kgd) {
+		struct kfd_dev *dev = NULL;
+		unsigned int i;
 
-	mutex_lock(&pasid_mutex);
+		for (i = 0; kfd_topology_enum_kfd_devices(i, &dev) == 0; i++)
+			if (dev && dev->kfd2kgd) {
+				kfd2kgd = dev->kfd2kgd;
+				break;
+			}
 
-	found = find_first_zero_bit(pasid_bitmap, pasid_limit);
-	if (found == pasid_limit)
-		found = 0;
-	else
-		set_bit(found, pasid_bitmap);
+		if (!kfd2kgd)
+			return false;
+	}
 
-	mutex_unlock(&pasid_mutex);
+	r = kfd2kgd->alloc_pasid(pasid_bits);
 
-	return found;
+	return r > 0 ? r : 0;
 }
 
 void kfd_pasid_free(unsigned int pasid)
 {
-	if (!WARN_ON(pasid == 0 || pasid >= pasid_limit))
-		clear_bit(pasid, pasid_bitmap);
+	if (kfd2kgd)
+		kfd2kgd->free_pasid(pasid);
 }
-- 
2.7.4