drm/amdgpu: remove chash

Remove the chash implementation for now since it isn't used any more.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/Kconfig

@@ -225,8 +225,6 @@ config DRM_AMDGPU
 
 source "drivers/gpu/drm/amd/amdgpu/Kconfig"
 
-source "drivers/gpu/drm/amd/lib/Kconfig"
-
 source "drivers/gpu/drm/nouveau/Kconfig"
 
 source "drivers/gpu/drm/i915/Kconfig"

drivers/gpu/drm/Makefile

@@ -56,7 +56,6 @@ obj-$(CONFIG_DRM_TTM)	+= ttm/
 obj-$(CONFIG_DRM_SCHED)	+= scheduler/
 obj-$(CONFIG_DRM_TDFX)	+= tdfx/
 obj-$(CONFIG_DRM_R128)	+= r128/
-obj-y			+= amd/lib/
 obj-$(CONFIG_HSA_AMD) += amd/amdkfd/
 obj-$(CONFIG_DRM_RADEON)+= radeon/
 obj-$(CONFIG_DRM_AMDGPU)+= amd/amdgpu/

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

@@ -2977,22 +2977,6 @@ 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
  *
@@ -3084,12 +3068,6 @@ 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);
 
 	return 0;
@@ -3243,15 +3221,10 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 	struct amdgpu_bo_va_mapping *mapping, *tmp;
 	bool prt_fini_needed = !!adev->gmc.gmc_funcs->set_prt;
 	struct amdgpu_bo *root;
-	u64 fault;
 	int i, r;
 
 	amdgpu_amdkfd_gpuvm_destroy_cb(adev, vm);
 
-	/* Clear pending page faults from IH when the VM is destroyed */
-	while (kfifo_get(&vm->faults, &fault))
-		amdgpu_vm_clear_fault(vm->fault_hash, fault);
-
 	if (vm->pasid) {
 		unsigned long flags;
 
@@ -3260,9 +3233,6 @@ 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)) {
@@ -3430,78 +3400,3 @@ 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

@@ -30,7 +30,6 @@
 #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"
@@ -178,13 +177,6 @@ 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;
@@ -244,7 +236,6 @@ 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 {
@@ -354,11 +345,6 @@ 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);
-
 void amdgpu_vm_del_from_lru_notify(struct ttm_buffer_object *bo);
 
 #endif

drivers/gpu/drm/amd/lib/Kconfig

-menu "AMD Library routines"
-
-#
-# Closed hash table
-#
-config CHASH
-	tristate
-	default DRM_AMDGPU
-	help
-	 Statically sized closed hash table implementation with low
-	 memory and CPU overhead.
-
-config CHASH_STATS
-	bool "Closed hash table performance statistics"
-	depends on CHASH
-	default n
-	help
-	 Enable collection of performance statistics for closed hash tables.
-
-config CHASH_SELFTEST
-	bool "Closed hash table self test"
-	depends on CHASH
-	default n
-	help
-	 Runs a selftest during module load. Several module parameters
-	 are available to modify the behaviour of the test.
-
-endmenu

drivers/gpu/drm/amd/lib/Makefile

-#
-# Copyright 2017 Advanced Micro Devices, Inc.
-#
-# Permission is hereby granted, free of charge, to any person obtaining a
-# copy of this software and associated documentation files (the "Software"),
-# to deal in the Software without restriction, including without limitation
-# the rights to use, copy, modify, merge, publish, distribute, sublicense,
-# and/or sell copies of the Software, and to permit persons to whom the
-# Software is furnished to do so, subject to the following conditions:
-#
-# The above copyright notice and this permission notice shall be included in
-# all copies or substantial portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
-# THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
-# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
-# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
-# OTHER DEALINGS IN THE SOFTWARE.
-#
-#
-# Makefile for AMD library routines, which are used by AMD driver
-# components.
-#
-# This is for common library routines that can be shared between AMD
-# driver components or later moved to kernel/lib for sharing with
-# other drivers.
-
-ccflags-y := -I$(src)/../include
-
-obj-$(CONFIG_CHASH) += chash.o