1 // SPDX-License-Identifier: GPL-2.0
3  * Copyright(c) 2016-2018 Intel Corporation. All rights reserved.
5 #include <linux/dma-mapping.h>
11  * mei_dmam_dscr_alloc() - allocate a managed coherent buffer
17  * * 0       - on success or zero allocation request
18  * * -EINVAL - if size is not power of 2
19  * * -ENOMEM - of allocation has failed
24 	if (!dscr->size)  in mei_dmam_dscr_alloc()
27 	if (WARN_ON(!is_power_of_2(dscr->size)))  in mei_dmam_dscr_alloc()
28 		return -EINVAL;  in mei_dmam_dscr_alloc()
30 	if (dscr->vaddr)  in mei_dmam_dscr_alloc()
33 	dscr->vaddr = dmam_alloc_coherent(dev->dev, dscr->size, &dscr->daddr,  in mei_dmam_dscr_alloc()
35 	if (!dscr->vaddr)  in mei_dmam_dscr_alloc()
36 		return -ENOMEM;  in mei_dmam_dscr_alloc()
42  * mei_dmam_dscr_free() - free a managed coherent buffer
50 	if (!dscr->vaddr)  in mei_dmam_dscr_free()
53 	dmam_free_coherent(dev->dev, dscr->size, dscr->vaddr, dscr->daddr);  in mei_dmam_dscr_free()
54 	dscr->vaddr = NULL;  in mei_dmam_dscr_free()
58  * mei_dmam_ring_free() - free dma ring buffers
66 		mei_dmam_dscr_free(dev, &dev->dr_dscr[i]);  in mei_dmam_ring_free()
70  * mei_dmam_ring_alloc() - allocate dma ring buffers
73  * Return: -ENOMEM on allocation failure 0 otherwise
80 		if (mei_dmam_dscr_alloc(dev, &dev->dr_dscr[i]))  in mei_dmam_ring_alloc()
87 	return -ENOMEM;  in mei_dmam_ring_alloc()
91  * mei_dma_ring_is_allocated() - check if dma ring is allocated
98 	return !!dev->dr_dscr[DMA_DSCR_HOST].vaddr;  in mei_dma_ring_is_allocated()
104 	return (struct hbm_dma_ring_ctrl *)dev->dr_dscr[DMA_DSCR_CTRL].vaddr;  in mei_dma_ring_ctrl()
108  * mei_dma_ring_reset() - reset the dma control block
113 	struct hbm_dma_ring_ctrl *ctrl = mei_dma_ring_ctrl(dev);  in mei_dma_ring_reset()  local
115 	if (!ctrl)  in mei_dma_ring_reset()
118 	memset(ctrl, 0, sizeof(*ctrl));  in mei_dma_ring_reset()
122  * mei_dma_copy_from() - copy from dma ring into buffer
133 	unsigned char *dbuf = dev->dr_dscr[DMA_DSCR_DEVICE].vaddr;  in mei_dma_copy_from()
144  * mei_dma_copy_to() - copy to a buffer to the dma ring
155 	unsigned char *hbuf = dev->dr_dscr[DMA_DSCR_HOST].vaddr;  in mei_dma_copy_to()
166  * mei_dma_ring_read() - read data from the ring
169  * @len: length to read.
171 void mei_dma_ring_read(struct mei_device *dev, unsigned char *buf, u32 len)  in mei_dma_ring_read()  argument
173 	struct hbm_dma_ring_ctrl *ctrl = mei_dma_ring_ctrl(dev);  in mei_dma_ring_read()  local
177 	if (WARN_ON(!ctrl))  in mei_dma_ring_read()
180 	dev_dbg(dev->dev, "reading from dma %u bytes\n", len);  in mei_dma_ring_read()
182 	if (!len)  in mei_dma_ring_read()
185 	dbuf_depth = dev->dr_dscr[DMA_DSCR_DEVICE].size >> 2;  in mei_dma_ring_read()
186 	rd_idx = READ_ONCE(ctrl->dbuf_rd_idx) & (dbuf_depth - 1);  in mei_dma_ring_read()
187 	slots = mei_data2slots(len);  in mei_dma_ring_read()
194 		buf += mei_dma_copy_from(dev, buf, rd_idx, dbuf_depth - rd_idx);  in mei_dma_ring_read()
195 		rem = slots - (dbuf_depth - rd_idx);  in mei_dma_ring_read()
203 	WRITE_ONCE(ctrl->dbuf_rd_idx, ctrl->dbuf_rd_idx + slots);  in mei_dma_ring_read()
208 	return dev->dr_dscr[DMA_DSCR_HOST].size >> 2;  in mei_dma_ring_hbuf_depth()
212  * mei_dma_ring_empty_slots() - calaculate number of empty slots in dma ring
219 	struct hbm_dma_ring_ctrl *ctrl = mei_dma_ring_ctrl(dev);  in mei_dma_ring_empty_slots()  local
225 	if (WARN_ON(!ctrl))  in mei_dma_ring_empty_slots()
230 	rd_idx = READ_ONCE(ctrl->hbuf_rd_idx);  in mei_dma_ring_empty_slots()
231 	wr_idx = READ_ONCE(ctrl->hbuf_wr_idx);  in mei_dma_ring_empty_slots()
234 		empty = rd_idx - wr_idx;  in mei_dma_ring_empty_slots()
236 		empty = hbuf_depth - (wr_idx - rd_idx);  in mei_dma_ring_empty_slots()
242  * mei_dma_ring_write - write data to dma ring host buffer
246  * @len: data length
248 void mei_dma_ring_write(struct mei_device *dev, unsigned char *buf, u32 len)  in mei_dma_ring_write()  argument
250 	struct hbm_dma_ring_ctrl *ctrl = mei_dma_ring_ctrl(dev);  in mei_dma_ring_write()  local
254 	if (WARN_ON(!ctrl))  in mei_dma_ring_write()
257 	dev_dbg(dev->dev, "writing to dma %u bytes\n", len);  in mei_dma_ring_write()
259 	wr_idx = READ_ONCE(ctrl->hbuf_wr_idx) & (hbuf_depth - 1);  in mei_dma_ring_write()
260 	slots = mei_data2slots(len);  in mei_dma_ring_write()
263 		buf += mei_dma_copy_to(dev, buf, wr_idx, hbuf_depth - wr_idx);  in mei_dma_ring_write()
264 		rem = slots - (hbuf_depth - wr_idx);  in mei_dma_ring_write()
272 	WRITE_ONCE(ctrl->hbuf_wr_idx, ctrl->hbuf_wr_idx + slots);  in mei_dma_ring_write()