2 * QEMU rocker switch emulation - Descriptor ring support
4 * Copyright (c) 2014 Scott Feldman <sfeldma@gmail.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
19 #include "hw/pci/pci.h"
22 #include "rocker_hw.h"
23 #include "rocker_desc.h"
35 desc_ring_consume *consume;
46 uint16_t desc_buf_size(DescInfo *info)
48 return le16_to_cpu(info->desc.buf_size);
51 uint16_t desc_tlv_size(DescInfo *info)
53 return le16_to_cpu(info->desc.tlv_size);
56 char *desc_get_buf(DescInfo *info, bool read_only)
58 PCIDevice *dev = PCI_DEVICE(info->ring->r);
59 size_t size = read_only ? le16_to_cpu(info->desc.tlv_size) :
60 le16_to_cpu(info->desc.buf_size);
62 if (size > info->buf_size) {
63 info->buf = g_realloc(info->buf, size);
64 info->buf_size = size;
71 if (pci_dma_read(dev, le64_to_cpu(info->desc.buf_addr), info->buf, size)) {
78 int desc_set_buf(DescInfo *info, size_t tlv_size)
80 PCIDevice *dev = PCI_DEVICE(info->ring->r);
82 if (tlv_size > info->buf_size) {
83 DPRINTF("ERROR: trying to write more to desc buf than it "
84 "can hold buf_size %zu tlv_size %zu\n",
85 info->buf_size, tlv_size);
86 return -ROCKER_EMSGSIZE;
89 info->desc.tlv_size = cpu_to_le16(tlv_size);
90 pci_dma_write(dev, le64_to_cpu(info->desc.buf_addr), info->buf, tlv_size);
95 DescRing *desc_get_ring(DescInfo *info)
100 int desc_ring_index(DescRing *ring)
105 static bool desc_ring_empty(DescRing *ring)
107 return ring->head == ring->tail;
110 bool desc_ring_set_base_addr(DescRing *ring, uint64_t base_addr)
112 if (base_addr & 0x7) {
113 DPRINTF("ERROR: ring[%d] desc base addr (0x" TARGET_FMT_plx
114 ") not 8-byte aligned\n", ring->index, base_addr);
118 ring->base_addr = base_addr;
123 uint64_t desc_ring_get_base_addr(DescRing *ring)
125 return ring->base_addr;
128 bool desc_ring_set_size(DescRing *ring, uint32_t size)
132 if (size < 2 || size > 0x10000 || (size & (size - 1))) {
133 DPRINTF("ERROR: ring[%d] size (%d) not a power of 2 "
134 "or in range [2, 64K]\n", ring->index, size);
138 for (i = 0; i < ring->size; i++) {
139 if (ring->info[i].buf) {
140 g_free(ring->info[i].buf);
145 ring->head = ring->tail = 0;
147 ring->info = g_realloc(ring->info, size * sizeof(DescInfo));
152 memset(ring->info, 0, size * sizeof(DescInfo));
154 for (i = 0; i < size; i++) {
155 ring->info[i].ring = ring;
161 uint32_t desc_ring_get_size(DescRing *ring)
166 static DescInfo *desc_read(DescRing *ring, uint32_t index)
168 PCIDevice *dev = PCI_DEVICE(ring->r);
169 DescInfo *info = &ring->info[index];
170 hwaddr addr = ring->base_addr + (sizeof(RockerDesc) * index);
172 pci_dma_read(dev, addr, &info->desc, sizeof(info->desc));
177 static void desc_write(DescRing *ring, uint32_t index)
179 PCIDevice *dev = PCI_DEVICE(ring->r);
180 DescInfo *info = &ring->info[index];
181 hwaddr addr = ring->base_addr + (sizeof(RockerDesc) * index);
183 pci_dma_write(dev, addr, &info->desc, sizeof(info->desc));
186 static bool desc_ring_base_addr_check(DescRing *ring)
188 if (!ring->base_addr) {
189 DPRINTF("ERROR: ring[%d] not-initialized desc base address!\n",
196 static DescInfo *__desc_ring_fetch_desc(DescRing *ring)
198 return desc_read(ring, ring->tail);
201 DescInfo *desc_ring_fetch_desc(DescRing *ring)
203 if (desc_ring_empty(ring) || !desc_ring_base_addr_check(ring)) {
207 return desc_read(ring, ring->tail);
210 static bool __desc_ring_post_desc(DescRing *ring, int err)
212 uint16_t comp_err = 0x8000 | (uint16_t)-err;
213 DescInfo *info = &ring->info[ring->tail];
215 info->desc.comp_err = cpu_to_le16(comp_err);
216 desc_write(ring, ring->tail);
217 ring->tail = (ring->tail + 1) % ring->size;
219 /* return true if starting credit count */
221 return ring->credits++ == 0;
224 bool desc_ring_post_desc(DescRing *ring, int err)
226 if (desc_ring_empty(ring)) {
227 DPRINTF("ERROR: ring[%d] trying to post desc to empty ring\n",
232 if (!desc_ring_base_addr_check(ring)) {
236 return __desc_ring_post_desc(ring, err);
239 static bool ring_pump(DescRing *ring)
245 /* If the ring has a consumer, call consumer for each
246 * desc starting at tail and stopping when tail reaches
247 * head (the empty ring condition).
251 while (ring->head != ring->tail) {
252 info = __desc_ring_fetch_desc(ring);
253 err = ring->consume(ring->r, info);
254 if (__desc_ring_post_desc(ring, err)) {
263 bool desc_ring_set_head(DescRing *ring, uint32_t new)
265 uint32_t tail = ring->tail;
266 uint32_t head = ring->head;
268 if (!desc_ring_base_addr_check(ring)) {
272 if (new >= ring->size) {
273 DPRINTF("ERROR: trying to set head (%d) past ring[%d] size (%d)\n",
274 new, ring->index, ring->size);
278 if (((head < tail) && ((new >= tail) || (new < head))) ||
279 ((head > tail) && ((new >= tail) && (new < head)))) {
280 DPRINTF("ERROR: trying to wrap ring[%d] "
281 "(head %d, tail %d, new head %d)\n",
282 ring->index, head, tail, new);
286 if (new == ring->head) {
287 DPRINTF("WARNING: setting head (%d) to current head position\n", new);
292 return ring_pump(ring);
295 uint32_t desc_ring_get_head(DescRing *ring)
300 uint32_t desc_ring_get_tail(DescRing *ring)
305 void desc_ring_set_ctrl(DescRing *ring, uint32_t val)
307 if (val & ROCKER_DMA_DESC_CTRL_RESET) {
308 DPRINTF("ring[%d] resetting\n", ring->index);
309 desc_ring_reset(ring);
313 bool desc_ring_ret_credits(DescRing *ring, uint32_t credits)
315 if (credits > ring->credits) {
316 DPRINTF("ERROR: trying to return more credits (%d) "
317 "than are outstanding (%d)\n", credits, ring->credits);
322 ring->credits -= credits;
324 /* return true if credits are still outstanding */
326 return ring->credits > 0;
329 uint32_t desc_ring_get_credits(DescRing *ring)
331 return ring->credits;
334 void desc_ring_set_consume(DescRing *ring, desc_ring_consume *consume,
337 ring->consume = consume;
338 ring->msix_vector = vector;
341 unsigned desc_ring_get_msix_vector(DescRing *ring)
343 return ring->msix_vector;
346 DescRing *desc_ring_alloc(Rocker *r, int index)
350 ring = g_malloc0(sizeof(DescRing));
361 void desc_ring_free(DescRing *ring)
369 void desc_ring_reset(DescRing *ring)