drm/amdgpu: use doorbell mgr for MES kernel doorbells

This patch:
- Removes the existing doorbell management code, and its variables
  from the doorbell_init function, it will be done in doorbell
  manager now.
- uses the doorbell page created for MES kernel level needs (doorbells
  for MES self tests)
- current MES code was allocating MES doorbells in MES process context,
  but those were getting written using kernel doorbell calls. This patch
  instead allocates a MES kernel doorbell for this (in add_hw_queue).

V2: Create an extra page of doorbells for MES during kernel doorbell
    creation (Alex)
V4: Move MES doorbell size and page offset objects in this patch from
    patch 6.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian Koenig <christian.koenig@amd.com>
Reviewed-by: Christian Koenig <christian.koenig@amd.com>
Signed-off-by: Shashank Sharma <shashank.sharma@amd.com>
Signed-off-by: Arvind Yadav <arvind.yadav@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -145,6 +145,10 @@ int amdgpu_doorbell_create_kernel_doorbells(struct amdgpu_device *adev)
 	/* Reserve first num_kernel_doorbells (page-aligned) for kernel ops */
 	size = ALIGN(adev->doorbell.num_kernel_doorbells * sizeof(u32), PAGE_SIZE);
 
+	/* Allocate an extra page for MES kernel usages (ring test) */
+	adev->mes.db_start_dw_offset = size / sizeof(u32);
+	size += PAGE_SIZE;
+
 	r = amdgpu_bo_create_kernel(adev,
 				    size,
 				    PAGE_SIZE,

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

@@ -68,91 +68,70 @@ unsigned int amdgpu_mes_get_doorbell_dw_offset_in_bar(
 		doorbell_id * 2);
 }
 
-static int amdgpu_mes_queue_doorbell_get(struct amdgpu_device *adev,
+static int amdgpu_mes_kernel_doorbell_get(struct amdgpu_device *adev,
 					 struct amdgpu_mes_process *process,
 					 int ip_type, uint64_t *doorbell_index)
 {
 	unsigned int offset, found;
+	struct amdgpu_mes *mes = &adev->mes;
 
-	if (ip_type == AMDGPU_RING_TYPE_SDMA) {
+	if (ip_type == AMDGPU_RING_TYPE_SDMA)
 		offset = adev->doorbell_index.sdma_engine[0];
-		found = find_next_zero_bit(process->doorbell_bitmap,
-					   AMDGPU_MES_MAX_NUM_OF_QUEUES_PER_PROCESS,
-					   offset);
-	} else {
-		found = find_first_zero_bit(process->doorbell_bitmap,
-					    AMDGPU_MES_MAX_NUM_OF_QUEUES_PER_PROCESS);
-	}
+	else
+		offset = 0;
 
-	if (found >= AMDGPU_MES_MAX_NUM_OF_QUEUES_PER_PROCESS) {
+	found = find_next_zero_bit(mes->doorbell_bitmap, mes->num_mes_dbs, offset);
+	if (found >= mes->num_mes_dbs) {
 		DRM_WARN("No doorbell available\n");
 		return -ENOSPC;
 	}
 
-	set_bit(found, process->doorbell_bitmap);
-
-	*doorbell_index = amdgpu_mes_get_doorbell_dw_offset_in_bar(adev,
-				process->doorbell_index, found);
+	set_bit(found, mes->doorbell_bitmap);
 
+	/* Get the absolute doorbell index on BAR */
+	*doorbell_index = mes->db_start_dw_offset + found * 2;
 	return 0;
 }
 
-static void amdgpu_mes_queue_doorbell_free(struct amdgpu_device *adev,
+static void amdgpu_mes_kernel_doorbell_free(struct amdgpu_device *adev,
 					   struct amdgpu_mes_process *process,
 					   uint32_t doorbell_index)
 {
-	unsigned int old, doorbell_id;
-
-	doorbell_id = doorbell_index -
-		(process->doorbell_index *
-		 amdgpu_mes_doorbell_process_slice(adev)) / sizeof(u32);
-	doorbell_id /= 2;
+	unsigned int old, rel_index;
+	struct amdgpu_mes *mes = &adev->mes;
 
-	old = test_and_clear_bit(doorbell_id, process->doorbell_bitmap);
+	/* Find the relative index of the doorbell in this object */
+	rel_index = (doorbell_index - mes->db_start_dw_offset) / 2;
+	old = test_and_clear_bit(rel_index, mes->doorbell_bitmap);
 	WARN_ON(!old);
 }
 
 static int amdgpu_mes_doorbell_init(struct amdgpu_device *adev)
 {
-	size_t doorbell_start_offset;
-	size_t doorbell_aperture_size;
-	size_t doorbell_process_limit;
-	size_t aggregated_doorbell_start;
 	int i;
+	struct amdgpu_mes *mes = &adev->mes;
 
-	aggregated_doorbell_start = (adev->doorbell_index.max_assignment + 1) * sizeof(u32);
-	aggregated_doorbell_start =
-		roundup(aggregated_doorbell_start, PAGE_SIZE);
-
-	doorbell_start_offset = aggregated_doorbell_start + PAGE_SIZE;
-	doorbell_start_offset =
-		roundup(doorbell_start_offset,
-			amdgpu_mes_doorbell_process_slice(adev));
-
-	doorbell_aperture_size = adev->doorbell.size;
-	doorbell_aperture_size =
-			rounddown(doorbell_aperture_size,
-				  amdgpu_mes_doorbell_process_slice(adev));
-
-	if (doorbell_aperture_size > doorbell_start_offset)
-		doorbell_process_limit =
-			(doorbell_aperture_size - doorbell_start_offset) /
-			amdgpu_mes_doorbell_process_slice(adev);
-	else
-		return -ENOSPC;
-
-	adev->mes.doorbell_id_offset = doorbell_start_offset / sizeof(u32);
-	adev->mes.max_doorbell_slices = doorbell_process_limit;
+	/* Bitmap for dynamic allocation of kernel doorbells */
+	mes->doorbell_bitmap = bitmap_zalloc(PAGE_SIZE / sizeof(u32), GFP_KERNEL);
+	if (!mes->doorbell_bitmap) {
+		DRM_ERROR("Failed to allocate MES doorbell bitmap\n");
+		return -ENOMEM;
+	}
 
-	/* allocate Qword range for aggregated doorbell */
-	for (i = 0; i < AMDGPU_MES_PRIORITY_NUM_LEVELS; i++)
-		adev->mes.aggregated_doorbells[i] =
-			aggregated_doorbell_start / sizeof(u32) + i * 2;
+	mes->num_mes_dbs = PAGE_SIZE / AMDGPU_ONE_DOORBELL_SIZE;
+	for (i = 0; i < AMDGPU_MES_PRIORITY_NUM_LEVELS; i++) {
+		adev->mes.aggregated_doorbells[i] = mes->db_start_dw_offset + i * 2;
+		set_bit(i, mes->doorbell_bitmap);
+	}
 
-	DRM_INFO("max_doorbell_slices=%zu\n", doorbell_process_limit);
 	return 0;
 }
 
+static void amdgpu_mes_doorbell_free(struct amdgpu_device *adev)
+{
+	bitmap_free(adev->mes.doorbell_bitmap);
+}
+
 int amdgpu_mes_init(struct amdgpu_device *adev)
 {
 	int i, r;
@@ -251,6 +230,7 @@ void amdgpu_mes_fini(struct amdgpu_device *adev)
 	amdgpu_device_wb_free(adev, adev->mes.sch_ctx_offs);
 	amdgpu_device_wb_free(adev, adev->mes.query_status_fence_offs);
 	amdgpu_device_wb_free(adev, adev->mes.read_val_offs);
+	amdgpu_mes_doorbell_free(adev);
 
 	idr_destroy(&adev->mes.pasid_idr);
 	idr_destroy(&adev->mes.gang_id_idr);
@@ -682,7 +662,7 @@ int amdgpu_mes_add_hw_queue(struct amdgpu_device *adev, int gang_id,
 	*queue_id = queue->queue_id = r;
 
 	/* allocate a doorbell index for the queue */
-	r = amdgpu_mes_queue_doorbell_get(adev, gang->process,
+	r = amdgpu_mes_kernel_doorbell_get(adev, gang->process,
 					  qprops->queue_type,
 					  &qprops->doorbell_off);
 	if (r)
@@ -740,7 +720,7 @@ int amdgpu_mes_add_hw_queue(struct amdgpu_device *adev, int gang_id,
 	return 0;
 
 clean_up_doorbell:
-	amdgpu_mes_queue_doorbell_free(adev, gang->process,
+	amdgpu_mes_kernel_doorbell_free(adev, gang->process,
 				       qprops->doorbell_off);
 clean_up_queue_id:
 	spin_lock_irqsave(&adev->mes.queue_id_lock, flags);
@@ -795,7 +775,7 @@ int amdgpu_mes_remove_hw_queue(struct amdgpu_device *adev, int queue_id)
 			  queue_id);
 
 	list_del(&queue->list);
-	amdgpu_mes_queue_doorbell_free(adev, gang->process,
+	amdgpu_mes_kernel_doorbell_free(adev, gang->process,
 				       queue->doorbell_off);
 	amdgpu_mes_unlock(&adev->mes);
 

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

@@ -27,6 +27,7 @@
 #include "amdgpu_irq.h"
 #include "kgd_kfd_interface.h"
 #include "amdgpu_gfx.h"
+#include "amdgpu_doorbell.h"
 #include <linux/sched/mm.h>
 
 #define AMDGPU_MES_MAX_COMPUTE_PIPES        8
@@ -128,6 +129,11 @@ struct amdgpu_mes {
 	int                             (*kiq_hw_init)(struct amdgpu_device *adev);
 	int                             (*kiq_hw_fini)(struct amdgpu_device *adev);
 
+	/* MES doorbells */
+	uint32_t			db_start_dw_offset;
+	uint32_t			num_mes_dbs;
+	unsigned long			*doorbell_bitmap;
+
 	/* ip specific functions */
 	const struct amdgpu_mes_funcs   *funcs;
 };