mhi/ep/ring.c

10 size_t mhi_ep_ring_addr2offset(struct mhi_ep_ring *ring, u64 ptr)
12 	return (ptr - ring->rbase) / sizeof(struct mhi_ring_element);
15 static u32 mhi_ep_ring_num_elems(struct mhi_ep_ring *ring)
19 	memcpy_fromio(&rlen, (void __iomem *) &ring->ring_ctx->generic.rlen, sizeof(u64));
24 void mhi_ep_ring_inc_index(struct mhi_ep_ring *ring)
26 	ring->rd_offset = (ring->rd_offset + 1) % ring->ring_size;
29 static int __mhi_ep_cache_ring(struct mhi_ep_ring *ring, size_t end)
31 	struct mhi_ep_cntrl *mhi_cntrl = ring->mhi_cntrl;
37 	/* Don't proceed in the case of event ring. This happens during mhi_ep_ring_start(). */
38 	if (ring->type == RING_TYPE_ER)
41 	/* No need to cache the ring if write pointer is unmodified */
42 	if (ring->wr_offset == end)
45 	start = ring->wr_offset;
48 		buf_info.host_addr = ring->rbase + (start * sizeof(struct mhi_ring_element));
49 		buf_info.dev_addr = &ring->ring_cache[start];
55 		buf_info.size = (ring->ring_size - start) * sizeof(struct mhi_ring_element);
56 		buf_info.host_addr = ring->rbase + (start * sizeof(struct mhi_ring_element));
57 		buf_info.dev_addr = &ring->ring_cache[start];
64 			buf_info.host_addr = ring->rbase;
65 			buf_info.dev_addr = &ring->ring_cache[0];
74 	dev_dbg(dev, "Cached ring: start %zu end %zu size %zu\n", start, end, buf_info.size);
79 static int mhi_ep_cache_ring(struct mhi_ep_ring *ring, u64 wr_ptr)
84 	wr_offset = mhi_ep_ring_addr2offset(ring, wr_ptr);
86 	/* Cache the host ring till write offset */
87 	ret = __mhi_ep_cache_ring(ring, wr_offset);
91 	ring->wr_offset = wr_offset;
96 int mhi_ep_update_wr_offset(struct mhi_ep_ring *ring)
100 	wr_ptr = mhi_ep_mmio_get_db(ring);
102 	return mhi_ep_cache_ring(ring, wr_ptr);
105 /* TODO: Support for adding multiple ring elements to the ring */
106 int mhi_ep_ring_add_element(struct mhi_ep_ring *ring, struct mhi_ring_element *el)
108 	struct mhi_ep_cntrl *mhi_cntrl = ring->mhi_cntrl;
116 	ret = mhi_ep_update_wr_offset(ring);
122 	if (ring->rd_offset < ring->wr_offset)
123 		num_free_elem = (ring->wr_offset - ring->rd_offset) - 1;
125 		num_free_elem = ((ring->ring_size - ring->rd_offset) + ring->wr_offset) - 1;
127 	/* Check if there is space in ring for adding at least an element */
129 		dev_err(dev, "No space left in the ring\n");
133 	old_offset = ring->rd_offset;
134 	mhi_ep_ring_inc_index(ring);
136 	dev_dbg(dev, "Adding an element to ring at offset (%zu)\n", ring->rd_offset);
138 	/* Update rp in ring context */
139 	rp = cpu_to_le64(ring->rd_offset * sizeof(*el) + ring->rbase);
140 	memcpy_toio((void __iomem *) &ring->ring_ctx->generic.rp, &rp, sizeof(u64));
142 	buf_info.host_addr = ring->rbase + (old_offset * sizeof(*el));
149 void mhi_ep_ring_init(struct mhi_ep_ring *ring, enum mhi_ep_ring_type type, u32 id)
151 	ring->type = type;
152 	if (ring->type == RING_TYPE_CMD) {
153 		ring->db_offset_h = EP_CRDB_HIGHER;
154 		ring->db_offset_l = EP_CRDB_LOWER;
155 	} else if (ring->type == RING_TYPE_CH) {
156 		ring->db_offset_h = CHDB_HIGHER_n(id);
157 		ring->db_offset_l = CHDB_LOWER_n(id);
158 		ring->ch_id = id;
160 		ring->db_offset_h = ERDB_HIGHER_n(id);
161 		ring->db_offset_l = ERDB_LOWER_n(id);
167 	struct mhi_ep_ring *ring = container_of(work, struct mhi_ep_ring, intmodt_work.work);
168 	struct mhi_ep_cntrl *mhi_cntrl = ring->mhi_cntrl;
170 	mhi_cntrl->raise_irq(mhi_cntrl, ring->irq_vector);
171 	WRITE_ONCE(ring->irq_pending, false);
174 int mhi_ep_ring_start(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_ring *ring,
181 	ring->mhi_cntrl = mhi_cntrl;
182 	ring->ring_ctx = ctx;
183 	ring->ring_size = mhi_ep_ring_num_elems(ring);
184 	memcpy_fromio(&val, (void __iomem *) &ring->ring_ctx->generic.rbase, sizeof(u64));
185 	ring->rbase = le64_to_cpu(val);
187 	if (ring->type == RING_TYPE_CH)
188 		ring->er_index = le32_to_cpu(ring->ring_ctx->ch.erindex);
190 	if (ring->type == RING_TYPE_ER) {
191 		ring->irq_vector = le32_to_cpu(ring->ring_ctx->ev.msivec);
192 		ring->intmodt = FIELD_GET(EV_CTX_INTMODT_MASK,
193 					  le32_to_cpu(ring->ring_ctx->ev.intmod));
195 		INIT_DELAYED_WORK(&ring->intmodt_work, mhi_ep_raise_irq);
198 	/* During ring init, both rp and wp are equal */
199 	memcpy_fromio(&val, (void __iomem *) &ring->ring_ctx->generic.rp, sizeof(u64));
200 	ring->rd_offset = mhi_ep_ring_addr2offset(ring, le64_to_cpu(val));
201 	ring->wr_offset = mhi_ep_ring_addr2offset(ring, le64_to_cpu(val));
203 	/* Allocate ring cache memory for holding the copy of host ring */
204 	ring->ring_cache = kcalloc(ring->ring_size, sizeof(struct mhi_ring_element), GFP_KERNEL);
205 	if (!ring->ring_cache)
208 	memcpy_fromio(&val, (void __iomem *) &ring->ring_ctx->generic.wp, sizeof(u64));
209 	ret = mhi_ep_cache_ring(ring, le64_to_cpu(val));
211 		dev_err(dev, "Failed to cache ring\n");
212 		kfree(ring->ring_cache);
216 	ring->started = true;
221 void mhi_ep_ring_reset(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_ring *ring)
223 	if (ring->type == RING_TYPE_ER)
224 		cancel_delayed_work_sync(&ring->intmodt_work);
226 	ring->started = false;
227 	kfree(ring->ring_cache);
228 	ring->ring_cache = NULL;