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

/*
 * Copyright 2014 Advanced Micro Devices, Inc.
 * Copyright 2008 Red Hat Inc.
 * Copyright 2009 Jerome Glisse.
 *
 * 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 <drm/drmP.h>
#include "amdgpu.h"
#include "amdgpu_gfx.h"

/*
 * GPU scratch registers helpers function.
 */
/**
 * amdgpu_gfx_scratch_get - Allocate a scratch register
 *
 * @adev: amdgpu_device pointer
 * @reg: scratch register mmio offset
 *
 * Allocate a CP scratch register for use by the driver (all asics).
 * Returns 0 on success or -EINVAL on failure.
 */
int amdgpu_gfx_scratch_get(struct amdgpu_device *adev, uint32_t *reg)
{
	int i;

	i = ffs(adev->gfx.scratch.free_mask);
	if (i != 0 && i <= adev->gfx.scratch.num_reg) {
		i--;
		adev->gfx.scratch.free_mask &= ~(1u << i);
		*reg = adev->gfx.scratch.reg_base + i;
		return 0;
	}
	return -EINVAL;
}

/**
 * amdgpu_gfx_scratch_free - Free a scratch register
 *
 * @adev: amdgpu_device pointer
 * @reg: scratch register mmio offset
 *
 * Free a CP scratch register allocated for use by the driver (all asics)
 */
void amdgpu_gfx_scratch_free(struct amdgpu_device *adev, uint32_t reg)
{
	adev->gfx.scratch.free_mask |= 1u << (reg - adev->gfx.scratch.reg_base);
}

/**
 * amdgpu_gfx_parse_disable_cu - Parse the disable_cu module parameter
 *
 * @mask: array in which the per-shader array disable masks will be stored
 * @max_se: number of SEs
 * @max_sh: number of SHs
 *
 * The bitmask of CUs to be disabled in the shader array determined by se and
 * sh is stored in mask[se * max_sh + sh].
 */
void amdgpu_gfx_parse_disable_cu(unsigned *mask, unsigned max_se, unsigned max_sh)
{
	unsigned se, sh, cu;
	const char *p;

	memset(mask, 0, sizeof(*mask) * max_se * max_sh);

	if (!amdgpu_disable_cu || !*amdgpu_disable_cu)
		return;

	p = amdgpu_disable_cu;
	for (;;) {
		char *next;
		int ret = sscanf(p, "%u.%u.%u", &se, &sh, &cu);
		if (ret < 3) {
			DRM_ERROR("amdgpu: could not parse disable_cu\n");
			return;
		}

		if (se < max_se && sh < max_sh && cu < 16) {
			DRM_INFO("amdgpu: disabling CU %u.%u.%u\n", se, sh, cu);
			mask[se * max_sh + sh] |= 1u << cu;
		} else {
			DRM_ERROR("amdgpu: disable_cu %u.%u.%u is out of range\n",
				  se, sh, cu);
		}

		next = strchr(p, ',');
		if (!next)
			break;
		p = next + 1;
	}
}

void amdgpu_gfx_compute_queue_acquire(struct amdgpu_device *adev)
{
	int i, queue, pipe, mec;

	/* policy for amdgpu compute queue ownership */
	for (i = 0; i < AMDGPU_MAX_COMPUTE_QUEUES; ++i) {
		queue = i % adev->gfx.mec.num_queue_per_pipe;
		pipe = (i / adev->gfx.mec.num_queue_per_pipe)
			% adev->gfx.mec.num_pipe_per_mec;
		mec = (i / adev->gfx.mec.num_queue_per_pipe)
			/ adev->gfx.mec.num_pipe_per_mec;

		/* we've run out of HW */
		if (mec >= adev->gfx.mec.num_mec)
			break;

		if (adev->gfx.mec.num_mec > 1) {
			/* policy: amdgpu owns the first two queues of the first MEC */
			if (mec == 0 && queue < 2)
				set_bit(i, adev->gfx.mec.queue_bitmap);
		} else {
			/* policy: amdgpu owns all queues in the first pipe */
			if (mec == 0 && pipe == 0)
				set_bit(i, adev->gfx.mec.queue_bitmap);
		}
	}

	/* update the number of active compute rings */
	adev->gfx.num_compute_rings =
		bitmap_weight(adev->gfx.mec.queue_bitmap, AMDGPU_MAX_COMPUTE_QUEUES);

	/* If you hit this case and edited the policy, you probably just
	 * need to increase AMDGPU_MAX_COMPUTE_RINGS */
	if (WARN_ON(adev->gfx.num_compute_rings > AMDGPU_MAX_COMPUTE_RINGS))
		adev->gfx.num_compute_rings = AMDGPU_MAX_COMPUTE_RINGS;
}