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.
17 #include "qemu/osdep.h"
20 #include "hw/pci/pci.h"
23 #include "rocker_hw.h"
24 #include "rocker_desc.h"
36 desc_ring_consume *consume;
47 uint16_t desc_buf_size(DescInfo *info)
49 return le16_to_cpu(info->desc.buf_size);
52 uint16_t desc_tlv_size(DescInfo *info)
54 return le16_to_cpu(info->desc.tlv_size);
57 char *desc_get_buf(DescInfo *info, bool read_only)
59 PCIDevice *dev = PCI_DEVICE(info->ring->r);
60 size_t size = read_only ? le16_to_cpu(info->desc.tlv_size) :
61 le16_to_cpu(info->desc.buf_size);
63 if (size > info->buf_size) {
64 info->buf = g_realloc(info->buf, size);
65 info->buf_size = size;
72 if (pci_dma_read(dev, le64_to_cpu(info->desc.buf_addr), info->buf, size)) {
79 int desc_set_buf(DescInfo *info, size_t tlv_size)
81 PCIDevice *dev = PCI_DEVICE(info->ring->r);
83 if (tlv_size > info->buf_size) {
84 DPRINTF("ERROR: trying to write more to desc buf than it "
85 "can hold buf_size %zu tlv_size %zu\n",
86 info->buf_size, tlv_size);
87 return -ROCKER_EMSGSIZE;
90 info->desc.tlv_size = cpu_to_le16(tlv_size);
91 pci_dma_write(dev, le64_to_cpu(info->desc.buf_addr), info->buf, tlv_size);
96 DescRing *desc_get_ring(DescInfo *info)
101 int desc_ring_index(DescRing *ring)
106 static bool desc_ring_empty(DescRing *ring)
108 return ring->head == ring->tail;
111 bool desc_ring_set_base_addr(DescRing *ring, uint64_t base_addr)
113 if (base_addr & 0x7) {
114 DPRINTF("ERROR: ring[%d] desc base addr (0x" TARGET_FMT_plx
115 ") not 8-byte aligned\n", ring->index, base_addr);
119 ring->base_addr = base_addr;
124 uint64_t desc_ring_get_base_addr(DescRing *ring)
126 return ring->base_addr;
129 bool desc_ring_set_size(DescRing *ring, uint32_t size)
133 if (size < 2 || size > 0x10000 || (size & (size - 1))) {
134 DPRINTF("ERROR: ring[%d] size (%d) not a power of 2 "
135 "or in range [2, 64K]\n", ring->index, size);
139 for (i = 0; i < ring->size; i++) {
140 g_free(ring->info[i].buf);
144 ring->head = ring->tail = 0;
146 ring->info = g_renew(DescInfo, ring->info, size);
151 memset(ring->info, 0, size * sizeof(DescInfo));
153 for (i = 0; i < size; i++) {
154 ring->info[i].ring = ring;
160 uint32_t desc_ring_get_size(DescRing *ring)
165 static DescInfo *desc_read(DescRing *ring, uint32_t index)
167 PCIDevice *dev = PCI_DEVICE(ring->r);
168 DescInfo *info = &ring->info[index];
169 hwaddr addr = ring->base_addr + (sizeof(RockerDesc) * index);
171 pci_dma_read(dev, addr, &info->desc, sizeof(info->desc));
176 static void desc_write(DescRing *ring, uint32_t index)
178 PCIDevice *dev = PCI_DEVICE(ring->r);
179 DescInfo *info = &ring->info[index];
180 hwaddr addr = ring->base_addr + (sizeof(RockerDesc) * index);
182 pci_dma_write(dev, addr, &info->desc, sizeof(info->desc));
185 static bool desc_ring_base_addr_check(DescRing *ring)
187 if (!ring->base_addr) {
188 DPRINTF("ERROR: ring[%d] not-initialized desc base address!\n",
195 static DescInfo *__desc_ring_fetch_desc(DescRing *ring)
197 return desc_read(ring, ring->tail);
200 DescInfo *desc_ring_fetch_desc(DescRing *ring)
202 if (desc_ring_empty(ring) || !desc_ring_base_addr_check(ring)) {
206 return desc_read(ring, ring->tail);
209 static bool __desc_ring_post_desc(DescRing *ring, int err)
211 uint16_t comp_err = 0x8000 | (uint16_t)-err;
212 DescInfo *info = &ring->info[ring->tail];
214 info->desc.comp_err = cpu_to_le16(comp_err);
215 desc_write(ring, ring->tail);
216 ring->tail = (ring->tail + 1) % ring->size;
218 /* return true if starting credit count */
220 return ring->credits++ == 0;
223 bool desc_ring_post_desc(DescRing *ring, int err)
225 if (desc_ring_empty(ring)) {
226 DPRINTF("ERROR: ring[%d] trying to post desc to empty ring\n",
231 if (!desc_ring_base_addr_check(ring)) {
235 return __desc_ring_post_desc(ring, err);
238 static bool ring_pump(DescRing *ring)
244 /* If the ring has a consumer, call consumer for each
245 * desc starting at tail and stopping when tail reaches
246 * head (the empty ring condition).
250 while (ring->head != ring->tail) {
251 info = __desc_ring_fetch_desc(ring);
252 err = ring->consume(ring->r, info);
253 if (__desc_ring_post_desc(ring, err)) {
262 bool desc_ring_set_head(DescRing *ring, uint32_t new)
264 uint32_t tail = ring->tail;
265 uint32_t head = ring->head;
267 if (!desc_ring_base_addr_check(ring)) {
271 if (new >= ring->size) {
272 DPRINTF("ERROR: trying to set head (%d) past ring[%d] size (%d)\n",
273 new, ring->index, ring->size);
277 if (((head < tail) && ((new >= tail) || (new < head))) ||
278 ((head > tail) && ((new >= tail) && (new < head)))) {
279 DPRINTF("ERROR: trying to wrap ring[%d] "
280 "(head %d, tail %d, new head %d)\n",
281 ring->index, head, tail, new);
285 if (new == ring->head) {
286 DPRINTF("WARNING: setting head (%d) to current head position\n", new);
291 return ring_pump(ring);
294 uint32_t desc_ring_get_head(DescRing *ring)
299 uint32_t desc_ring_get_tail(DescRing *ring)
304 void desc_ring_set_ctrl(DescRing *ring, uint32_t val)
306 if (val & ROCKER_DMA_DESC_CTRL_RESET) {
307 DPRINTF("ring[%d] resetting\n", ring->index);
308 desc_ring_reset(ring);
312 bool desc_ring_ret_credits(DescRing *ring, uint32_t credits)
314 if (credits > ring->credits) {
315 DPRINTF("ERROR: trying to return more credits (%d) "
316 "than are outstanding (%d)\n", credits, ring->credits);
321 ring->credits -= credits;
323 /* return true if credits are still outstanding */
325 return ring->credits > 0;
328 uint32_t desc_ring_get_credits(DescRing *ring)
330 return ring->credits;
333 void desc_ring_set_consume(DescRing *ring, desc_ring_consume *consume,
336 ring->consume = consume;
337 ring->msix_vector = vector;
340 unsigned desc_ring_get_msix_vector(DescRing *ring)
342 return ring->msix_vector;
345 DescRing *desc_ring_alloc(Rocker *r, int index)
349 ring = g_new0(DescRing, 1);
360 void desc_ring_free(DescRing *ring)
366 void desc_ring_reset(DescRing *ring)