/*
* Copyright 2014 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.
*
*/
#include <linux/dma-mapping.h>
#include "amdgpu.h"
#include "amdgpu_ih.h"
/**
* amdgpu_ih_ring_init - initialize the IH state
*
* @adev: amdgpu_device pointer
* @ih: ih ring to initialize
* @ring_size: ring size to allocate
* @use_bus_addr: true when we can use dma_alloc_coherent
*
* Initializes the IH state and allocates a buffer
* for the IH ring buffer.
* Returns 0 for success, errors for failure.
*/
int amdgpu_ih_ring_init(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih,
unsigned ring_size, bool use_bus_addr)
{
u32 rb_bufsz;
int r;
/* Align ring size */
rb_bufsz = order_base_2(ring_size / 4);
ring_size = (1 << rb_bufsz) * 4;
ih->ring_size = ring_size;
ih->ptr_mask = ih->ring_size - 1;
ih->rptr = 0;
ih->use_bus_addr = use_bus_addr;
if (use_bus_addr) {
dma_addr_t dma_addr;
if (ih->ring)
return 0;
/* add 8 bytes for the rptr/wptr shadows and
* add them to the end of the ring allocation.
*/
ih->ring = dma_alloc_coherent(adev->dev, ih->ring_size + 8,
&dma_addr, GFP_KERNEL);
if (ih->ring == NULL)
return -ENOMEM;
memset((void *)ih->ring, 0, ih->ring_size + 8);
ih->gpu_addr = dma_addr;
ih->wptr_addr = dma_addr + ih->ring_size;
ih->wptr_cpu = &ih->ring[ih->ring_size / 4];
ih->rptr_addr = dma_addr + ih->ring_size + 4;
ih->rptr_cpu = &ih->ring[(ih->ring_size / 4) + 1];
} else {
unsigned wptr_offs, rptr_offs;
r = amdgpu_device_wb_get(adev, &wptr_offs);
if (r)
return r;
r = amdgpu_device_wb_get(adev, &rptr_offs);
if (r) {
amdgpu_device_wb_free(adev, wptr_offs);
return r;
}
r = amdgpu_bo_create_kernel(adev, ih->ring_size, PAGE_SIZE,
AMDGPU_GEM_DOMAIN_GTT,
&ih->ring_obj, &ih->gpu_addr,
(void **)&ih->ring);
if (r) {
amdgpu_device_wb_free(adev, rptr_offs);
amdgpu_device_wb_free(adev, wptr_offs);
return r;
}
ih->wptr_addr = adev->wb.gpu_addr + wptr_offs * 4;
ih->wptr_cpu = &adev->wb.wb[wptr_offs];
ih->rptr_addr = adev->wb.gpu_addr + rptr_offs * 4;
ih->rptr_cpu = &adev->wb.wb[rptr_offs];
}
return 0;
}
/**
* amdgpu_ih_ring_fini - tear down the IH state
*
* @adev: amdgpu_device pointer
* @ih: ih ring to tear down
*
* Tears down the IH state and frees buffer
* used for the IH ring buffer.
*/
void amdgpu_ih_ring_fini(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih)
{
if (ih->use_bus_addr) {
if (!ih->ring)
return;
/* add 8 bytes for the rptr/wptr shadows and
* add them to the end of the ring allocation.
*/
dma_free_coherent(adev->dev, ih->ring_size + 8,
(void *)ih->ring, ih->gpu_addr);
ih->ring = NULL;
} else {
amdgpu_bo_free_kernel(&ih->ring_obj, &ih->gpu_addr,
(void **)&ih->ring);
amdgpu_device_wb_free(adev, (ih->wptr_addr - ih->gpu_addr) / 4);
amdgpu_device_wb_free(adev, (ih->rptr_addr - ih->gpu_addr) / 4);
}
}
/**
* amdgpu_ih_process - interrupt handler
*
* @adev: amdgpu_device pointer
* @ih: ih ring to process
*
* Interrupt hander (VI), walk the IH ring.
* Returns irq process return code.
*/
int amdgpu_ih_process(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih)
{
unsigned int count = AMDGPU_IH_MAX_NUM_IVS;
u32 wptr;
if (!ih->enabled || adev->shutdown)
return IRQ_NONE;
wptr = amdgpu_ih_get_wptr(adev, ih);
restart_ih:
/* is somebody else already processing irqs? */
if (atomic_xchg(&ih->lock, 1))
return IRQ_NONE;
DRM_DEBUG("%s: rptr %d, wptr %d\n", __func__, ih->rptr, wptr);
/* Order reading of wptr vs. reading of IH ring data */
rmb();
while (ih->rptr != wptr && --count) {
amdgpu_irq_dispatch(adev, ih);
ih->rptr &= ih->ptr_mask;
}
amdgpu_ih_set_rptr(adev, ih);
atomic_set(&ih->lock, 0);
/* make sure wptr hasn't changed while processing */
wptr = amdgpu_ih_get_wptr(adev, ih);
if (wptr != ih->rptr)
goto restart_ih;
return IRQ_HANDLED;
}
