drm/amdgpu: Move fault hash table to amdgpu vm

In stead of share one fault hash table per device, make it
per vm. This can avoid inter-process lock issue when fault
hash table is full.

Change-Id: I5d1281b7c41eddc8e26113e010516557588d3708
Signed-off-by: Oak Zeng <Oak.Zeng@amd.com>
Suggested-by: Christian Konig <Christian.Koenig@amd.com>
Suggested-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian Konig <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c

@@ -197,78 +197,3 @@ restart_ih:
 	return IRQ_HANDLED;
 }
 
-/**
- * amdgpu_ih_add_fault - Add a page fault record
- *
- * @adev: amdgpu device pointer
- * @key: 64-bit encoding of PASID and address
- *
- * This should be called when a retry page fault interrupt is
- * received. If this is a new page fault, it will be added to a hash
- * table. The return value indicates whether this is a new fault, or
- * a fault that was already known and is already being handled.
- *
- * If there are too many pending page faults, this will fail. Retry
- * interrupts should be ignored in this case until there is enough
- * free space.
- *
- * Returns 0 if the fault was added, 1 if the fault was already known,
- * -ENOSPC if there are too many pending faults.
- */
-int amdgpu_ih_add_fault(struct amdgpu_device *adev, u64 key)
-{
-	unsigned long flags;
-	int r = -ENOSPC;
-
-	if (WARN_ON_ONCE(!adev->irq.ih.faults))
-		/* Should be allocated in <IP>_ih_sw_init on GPUs that
-		 * support retry faults and require retry filtering.
-		 */
-		return r;
-
-	spin_lock_irqsave(&adev->irq.ih.faults->lock, flags);
-
-	/* Only let the hash table fill up to 50% for best performance */
-	if (adev->irq.ih.faults->count >= (1 << (AMDGPU_PAGEFAULT_HASH_BITS-1)))
-		goto unlock_out;
-
-	r = chash_table_copy_in(&adev->irq.ih.faults->hash, key, NULL);
-	if (!r)
-		adev->irq.ih.faults->count++;
-
-	/* chash_table_copy_in should never fail unless we're losing count */
-	WARN_ON_ONCE(r < 0);
-
-unlock_out:
-	spin_unlock_irqrestore(&adev->irq.ih.faults->lock, flags);
-	return r;
-}
-
-/**
- * amdgpu_ih_clear_fault - Remove a page fault record
- *
- * @adev: amdgpu device pointer
- * @key: 64-bit encoding of PASID and address
- *
- * This should be called when a page fault has been handled. Any
- * future interrupt with this key will be processed as a new
- * page fault.
- */
-void amdgpu_ih_clear_fault(struct amdgpu_device *adev, u64 key)
-{
-	unsigned long flags;
-	int r;
-
-	if (!adev->irq.ih.faults)
-		return;
-
-	spin_lock_irqsave(&adev->irq.ih.faults->lock, flags);
-
-	r = chash_table_remove(&adev->irq.ih.faults->hash, key, NULL);
-	if (!WARN_ON_ONCE(r < 0)) {
-		adev->irq.ih.faults->count--;
-		WARN_ON_ONCE(adev->irq.ih.faults->count < 0);
-	}
-
-	spin_unlock_irqrestore(&adev->irq.ih.faults->lock, flags);
-}

drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h

@@ -24,7 +24,6 @@
 #ifndef __AMDGPU_IH_H__
 #define __AMDGPU_IH_H__
 
-#include <linux/chash.h>
 #include "soc15_ih_clientid.h"
 
 struct amdgpu_device;
@@ -32,13 +31,6 @@ struct amdgpu_device;
 #define AMDGPU_IH_CLIENTID_LEGACY 0
 #define AMDGPU_IH_CLIENTID_MAX SOC15_IH_CLIENTID_MAX
 
-#define AMDGPU_PAGEFAULT_HASH_BITS 8
-struct amdgpu_retryfault_hashtable {
-	DECLARE_CHASH_TABLE(hash, AMDGPU_PAGEFAULT_HASH_BITS, 8, 0);
-	spinlock_t	lock;
-	int		count;
-};
-
 /*
  * R6xx+ IH ring
  */
@@ -57,7 +49,6 @@ struct amdgpu_ih_ring {
 	bool			use_doorbell;
 	bool			use_bus_addr;
 	dma_addr_t		rb_dma_addr; /* only used when use_bus_addr = true */
-	struct amdgpu_retryfault_hashtable *faults;
 };
 
 #define AMDGPU_IH_SRC_DATA_MAX_SIZE_DW 4
@@ -95,7 +86,5 @@ int amdgpu_ih_ring_init(struct amdgpu_device *adev, unsigned ring_size,
 			bool use_bus_addr);
 void amdgpu_ih_ring_fini(struct amdgpu_device *adev);
 int amdgpu_ih_process(struct amdgpu_device *adev);
-int amdgpu_ih_add_fault(struct amdgpu_device *adev, u64 key);
-void amdgpu_ih_clear_fault(struct amdgpu_device *adev, u64 key);
 
 #endif

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c

@@ -2717,6 +2717,22 @@ void amdgpu_vm_adjust_size(struct amdgpu_device *adev, uint32_t min_vm_size,
 		 adev->vm_manager.fragment_size);
 }
 
+static struct amdgpu_retryfault_hashtable *init_fault_hash(void)
+{
+	struct amdgpu_retryfault_hashtable *fault_hash;
+
+	fault_hash = kmalloc(sizeof(*fault_hash), GFP_KERNEL);
+	if (!fault_hash)
+		return fault_hash;
+
+	INIT_CHASH_TABLE(fault_hash->hash,
+			AMDGPU_PAGEFAULT_HASH_BITS, 8, 0);
+	spin_lock_init(&fault_hash->lock);
+	fault_hash->count = 0;
+
+	return fault_hash;
+}
+
 /**
  * amdgpu_vm_init - initialize a vm instance
  *
@@ -2805,6 +2821,12 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 		vm->pasid = pasid;
 	}
 
+	vm->fault_hash = init_fault_hash();
+	if (!vm->fault_hash) {
+		r = -ENOMEM;
+		goto error_free_root;
+	}
+
 	INIT_KFIFO(vm->faults);
 	vm->fault_credit = 16;
 
@@ -2998,7 +3020,7 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 
 	/* Clear pending page faults from IH when the VM is destroyed */
 	while (kfifo_get(&vm->faults, &fault))
-		amdgpu_ih_clear_fault(adev, fault);
+		amdgpu_vm_clear_fault(vm->fault_hash, fault);
 
 	if (vm->pasid) {
 		unsigned long flags;
@@ -3008,6 +3030,9 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 		spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
 	}
 
+	kfree(vm->fault_hash);
+	vm->fault_hash = NULL;
+
 	drm_sched_entity_destroy(&vm->entity);
 
 	if (!RB_EMPTY_ROOT(&vm->va.rb_root)) {
@@ -3208,3 +3233,78 @@ void amdgpu_vm_set_task_info(struct amdgpu_vm *vm)
 		}
 	}
 }
+
+/**
+ * amdgpu_vm_add_fault - Add a page fault record to fault hash table
+ *
+ * @fault_hash: fault hash table
+ * @key: 64-bit encoding of PASID and address
+ *
+ * This should be called when a retry page fault interrupt is
+ * received. If this is a new page fault, it will be added to a hash
+ * table. The return value indicates whether this is a new fault, or
+ * a fault that was already known and is already being handled.
+ *
+ * If there are too many pending page faults, this will fail. Retry
+ * interrupts should be ignored in this case until there is enough
+ * free space.
+ *
+ * Returns 0 if the fault was added, 1 if the fault was already known,
+ * -ENOSPC if there are too many pending faults.
+ */
+int amdgpu_vm_add_fault(struct amdgpu_retryfault_hashtable *fault_hash, u64 key)
+{
+	unsigned long flags;
+	int r = -ENOSPC;
+
+	if (WARN_ON_ONCE(!fault_hash))
+		/* Should be allocated in amdgpu_vm_init
+		 */
+		return r;
+
+	spin_lock_irqsave(&fault_hash->lock, flags);
+
+	/* Only let the hash table fill up to 50% for best performance */
+	if (fault_hash->count >= (1 << (AMDGPU_PAGEFAULT_HASH_BITS-1)))
+		goto unlock_out;
+
+	r = chash_table_copy_in(&fault_hash->hash, key, NULL);
+	if (!r)
+		fault_hash->count++;
+
+	/* chash_table_copy_in should never fail unless we're losing count */
+	WARN_ON_ONCE(r < 0);
+
+unlock_out:
+	spin_unlock_irqrestore(&fault_hash->lock, flags);
+	return r;
+}
+
+/**
+ * amdgpu_vm_clear_fault - Remove a page fault record
+ *
+ * @fault_hash: fault hash table
+ * @key: 64-bit encoding of PASID and address
+ *
+ * This should be called when a page fault has been handled. Any
+ * future interrupt with this key will be processed as a new
+ * page fault.
+ */
+void amdgpu_vm_clear_fault(struct amdgpu_retryfault_hashtable *fault_hash, u64 key)
+{
+	unsigned long flags;
+	int r;
+
+	if (!fault_hash)
+		return;
+
+	spin_lock_irqsave(&fault_hash->lock, flags);
+
+	r = chash_table_remove(&fault_hash->hash, key, NULL);
+	if (!WARN_ON_ONCE(r < 0)) {
+		fault_hash->count--;
+		WARN_ON_ONCE(fault_hash->count < 0);
+	}
+
+	spin_unlock_irqrestore(&fault_hash->lock, flags);
+}

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h

@@ -30,6 +30,7 @@
 #include <drm/gpu_scheduler.h>
 #include <drm/drm_file.h>
 #include <drm/ttm/ttm_bo_driver.h>
+#include <linux/chash.h>
 
 #include "amdgpu_sync.h"
 #include "amdgpu_ring.h"
@@ -178,6 +179,13 @@ struct amdgpu_task_info {
 	pid_t	tgid;
 };
 
+#define AMDGPU_PAGEFAULT_HASH_BITS 8
+struct amdgpu_retryfault_hashtable {
+	DECLARE_CHASH_TABLE(hash, AMDGPU_PAGEFAULT_HASH_BITS, 8, 0);
+	spinlock_t	lock;
+	int		count;
+};
+
 struct amdgpu_vm {
 	/* tree of virtual addresses mapped */
 	struct rb_root_cached	va;
@@ -240,6 +248,7 @@ struct amdgpu_vm {
 	struct ttm_lru_bulk_move lru_bulk_move;
 	/* mark whether can do the bulk move */
 	bool			bulk_moveable;
+	struct amdgpu_retryfault_hashtable *fault_hash;
 };
 
 struct amdgpu_vm_manager {
@@ -355,4 +364,8 @@ void amdgpu_vm_set_task_info(struct amdgpu_vm *vm);
 void amdgpu_vm_move_to_lru_tail(struct amdgpu_device *adev,
 				struct amdgpu_vm *vm);
 
+int amdgpu_vm_add_fault(struct amdgpu_retryfault_hashtable *fault_hash, u64 key);
+
+void amdgpu_vm_clear_fault(struct amdgpu_retryfault_hashtable *fault_hash, u64 key);
+
 #endif

drivers/gpu/drm/amd/amdgpu/vega10_ih.c

@@ -265,35 +265,36 @@ static bool vega10_ih_prescreen_iv(struct amdgpu_device *adev)
 		return true;
 	}
 
-	addr = ((u64)(dw5 & 0xf) << 44) | ((u64)dw4 << 12);
-	key = AMDGPU_VM_FAULT(pasid, addr);
-	r = amdgpu_ih_add_fault(adev, key);
-
-	/* Hash table is full or the fault is already being processed,
-	 * ignore further page faults
-	 */
-	if (r != 0)
-		goto ignore_iv;
-
 	/* Track retry faults in per-VM fault FIFO. */
 	spin_lock(&adev->vm_manager.pasid_lock);
 	vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
+	addr = ((u64)(dw5 & 0xf) << 44) | ((u64)dw4 << 12);
+	key = AMDGPU_VM_FAULT(pasid, addr);
 	if (!vm) {
 		/* VM not found, process it normally */
 		spin_unlock(&adev->vm_manager.pasid_lock);
-		amdgpu_ih_clear_fault(adev, key);
 		return true;
+	} else {
+		r = amdgpu_vm_add_fault(vm->fault_hash, key);
+
+		/* Hash table is full or the fault is already being processed,
+		 * ignore further page faults
+		 */
+		if (r != 0) {
+			spin_unlock(&adev->vm_manager.pasid_lock);
+			goto ignore_iv;
+		}
 	}
 	/* No locking required with single writer and single reader */
 	r = kfifo_put(&vm->faults, key);
 	if (!r) {
 		/* FIFO is full. Ignore it until there is space */
+		amdgpu_vm_clear_fault(vm->fault_hash, key);
 		spin_unlock(&adev->vm_manager.pasid_lock);
-		amdgpu_ih_clear_fault(adev, key);
 		goto ignore_iv;
 	}
-	spin_unlock(&adev->vm_manager.pasid_lock);
 
+	spin_unlock(&adev->vm_manager.pasid_lock);
 	/* It's the first fault for this address, process it normally */
 	return true;
 
@@ -386,14 +387,6 @@ static int vega10_ih_sw_init(void *handle)
 	adev->irq.ih.use_doorbell = true;
 	adev->irq.ih.doorbell_index = AMDGPU_DOORBELL64_IH << 1;
 
-	adev->irq.ih.faults = kmalloc(sizeof(*adev->irq.ih.faults), GFP_KERNEL);
-	if (!adev->irq.ih.faults)
-		return -ENOMEM;
-	INIT_CHASH_TABLE(adev->irq.ih.faults->hash,
-			 AMDGPU_PAGEFAULT_HASH_BITS, 8, 0);
-	spin_lock_init(&adev->irq.ih.faults->lock);
-	adev->irq.ih.faults->count = 0;
-
 	r = amdgpu_irq_init(adev);
 
 	return r;
@@ -406,9 +399,6 @@ static int vega10_ih_sw_fini(void *handle)
 	amdgpu_irq_fini(adev);
 	amdgpu_ih_ring_fini(adev);
 
-	kfree(adev->irq.ih.faults);
-	adev->irq.ih.faults = NULL;
-
 	return 0;
 }