--- /dev/null
+/*
+ * QEMU rocker switch emulation - Descriptor ring support
+ *
+ * Copyright (c) 2014 Scott Feldman <sfeldma@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include "net/net.h"
+#include "hw/hw.h"
+#include "hw/pci/pci.h"
+
+#include "rocker.h"
+#include "rocker_hw.h"
+#include "rocker_desc.h"
+
+struct desc_ring {
+ hwaddr base_addr;
+ uint32_t size;
+ uint32_t head;
+ uint32_t tail;
+ uint32_t ctrl;
+ uint32_t credits;
+ Rocker *r;
+ DescInfo *info;
+ int index;
+ desc_ring_consume *consume;
+ unsigned msix_vector;
+};
+
+struct desc_info {
+ DescRing *ring;
+ RockerDesc desc;
+ char *buf;
+ size_t buf_size;
+};
+
+uint16_t desc_buf_size(DescInfo *info)
+{
+ return le16_to_cpu(info->desc.buf_size);
+}
+
+uint16_t desc_tlv_size(DescInfo *info)
+{
+ return le16_to_cpu(info->desc.tlv_size);
+}
+
+char *desc_get_buf(DescInfo *info, bool read_only)
+{
+ PCIDevice *dev = PCI_DEVICE(info->ring->r);
+ size_t size = read_only ? le16_to_cpu(info->desc.tlv_size) :
+ le16_to_cpu(info->desc.buf_size);
+
+ if (size > info->buf_size) {
+ info->buf = g_realloc(info->buf, size);
+ info->buf_size = size;
+ }
+
+ if (!info->buf) {
+ return NULL;
+ }
+
+ if (pci_dma_read(dev, le64_to_cpu(info->desc.buf_addr), info->buf, size)) {
+ return NULL;
+ }
+
+ return info->buf;
+}
+
+int desc_set_buf(DescInfo *info, size_t tlv_size)
+{
+ PCIDevice *dev = PCI_DEVICE(info->ring->r);
+
+ if (tlv_size > info->buf_size) {
+ DPRINTF("ERROR: trying to write more to desc buf than it "
+ "can hold buf_size %zu tlv_size %zu\n",
+ info->buf_size, tlv_size);
+ return -ROCKER_EMSGSIZE;
+ }
+
+ info->desc.tlv_size = cpu_to_le16(tlv_size);
+ pci_dma_write(dev, le64_to_cpu(info->desc.buf_addr), info->buf, tlv_size);
+
+ return ROCKER_OK;
+}
+
+DescRing *desc_get_ring(DescInfo *info)
+{
+ return info->ring;
+}
+
+int desc_ring_index(DescRing *ring)
+{
+ return ring->index;
+}
+
+static bool desc_ring_empty(DescRing *ring)
+{
+ return ring->head == ring->tail;
+}
+
+bool desc_ring_set_base_addr(DescRing *ring, uint64_t base_addr)
+{
+ if (base_addr & 0x7) {
+ DPRINTF("ERROR: ring[%d] desc base addr (0x" TARGET_FMT_plx
+ ") not 8-byte aligned\n", ring->index, base_addr);
+ return false;
+ }
+
+ ring->base_addr = base_addr;
+
+ return true;
+}
+
+uint64_t desc_ring_get_base_addr(DescRing *ring)
+{
+ return ring->base_addr;
+}
+
+bool desc_ring_set_size(DescRing *ring, uint32_t size)
+{
+ int i;
+
+ if (size < 2 || size > 0x10000 || (size & (size - 1))) {
+ DPRINTF("ERROR: ring[%d] size (%d) not a power of 2 "
+ "or in range [2, 64K]\n", ring->index, size);
+ return false;
+ }
+
+ for (i = 0; i < ring->size; i++) {
+ if (ring->info[i].buf) {
+ g_free(ring->info[i].buf);
+ }
+ }
+
+ ring->size = size;
+ ring->head = ring->tail = 0;
+
+ ring->info = g_realloc(ring->info, size * sizeof(DescInfo));
+ if (!ring->info) {
+ return false;
+ }
+
+ memset(ring->info, 0, size * sizeof(DescInfo));
+
+ for (i = 0; i < size; i++) {
+ ring->info[i].ring = ring;
+ }
+
+ return true;
+}
+
+uint32_t desc_ring_get_size(DescRing *ring)
+{
+ return ring->size;
+}
+
+static DescInfo *desc_read(DescRing *ring, uint32_t index)
+{
+ PCIDevice *dev = PCI_DEVICE(ring->r);
+ DescInfo *info = &ring->info[index];
+ hwaddr addr = ring->base_addr + (sizeof(RockerDesc) * index);
+
+ pci_dma_read(dev, addr, &info->desc, sizeof(info->desc));
+
+ return info;
+}
+
+static void desc_write(DescRing *ring, uint32_t index)
+{
+ PCIDevice *dev = PCI_DEVICE(ring->r);
+ DescInfo *info = &ring->info[index];
+ hwaddr addr = ring->base_addr + (sizeof(RockerDesc) * index);
+
+ pci_dma_write(dev, addr, &info->desc, sizeof(info->desc));
+}
+
+static bool desc_ring_base_addr_check(DescRing *ring)
+{
+ if (!ring->base_addr) {
+ DPRINTF("ERROR: ring[%d] not-initialized desc base address!\n",
+ ring->index);
+ return false;
+ }
+ return true;
+}
+
+static DescInfo *__desc_ring_fetch_desc(DescRing *ring)
+{
+ return desc_read(ring, ring->tail);
+}
+
+DescInfo *desc_ring_fetch_desc(DescRing *ring)
+{
+ if (desc_ring_empty(ring) || !desc_ring_base_addr_check(ring)) {
+ return NULL;
+ }
+
+ return desc_read(ring, ring->tail);
+}
+
+static bool __desc_ring_post_desc(DescRing *ring, int err)
+{
+ uint16_t comp_err = 0x8000 | (uint16_t)-err;
+ DescInfo *info = &ring->info[ring->tail];
+
+ info->desc.comp_err = cpu_to_le16(comp_err);
+ desc_write(ring, ring->tail);
+ ring->tail = (ring->tail + 1) % ring->size;
+
+ /* return true if starting credit count */
+
+ return ring->credits++ == 0;
+}
+
+bool desc_ring_post_desc(DescRing *ring, int err)
+{
+ if (desc_ring_empty(ring)) {
+ DPRINTF("ERROR: ring[%d] trying to post desc to empty ring\n",
+ ring->index);
+ return false;
+ }
+
+ if (!desc_ring_base_addr_check(ring)) {
+ return false;
+ }
+
+ return __desc_ring_post_desc(ring, err);
+}
+
+static bool ring_pump(DescRing *ring)
+{
+ DescInfo *info;
+ bool primed = false;
+ int err;
+
+ /* If the ring has a consumer, call consumer for each
+ * desc starting at tail and stopping when tail reaches
+ * head (the empty ring condition).
+ */
+
+ if (ring->consume) {
+ while (ring->head != ring->tail) {
+ info = __desc_ring_fetch_desc(ring);
+ err = ring->consume(ring->r, info);
+ if (__desc_ring_post_desc(ring, err)) {
+ primed = true;
+ }
+ }
+ }
+
+ return primed;
+}
+
+bool desc_ring_set_head(DescRing *ring, uint32_t new)
+{
+ uint32_t tail = ring->tail;
+ uint32_t head = ring->head;
+
+ if (!desc_ring_base_addr_check(ring)) {
+ return false;
+ }
+
+ if (new >= ring->size) {
+ DPRINTF("ERROR: trying to set head (%d) past ring[%d] size (%d)\n",
+ new, ring->index, ring->size);
+ return false;
+ }
+
+ if (((head < tail) && ((new >= tail) || (new < head))) ||
+ ((head > tail) && ((new >= tail) && (new < head)))) {
+ DPRINTF("ERROR: trying to wrap ring[%d] "
+ "(head %d, tail %d, new head %d)\n",
+ ring->index, head, tail, new);
+ return false;
+ }
+
+ if (new == ring->head) {
+ DPRINTF("WARNING: setting head (%d) to current head position\n", new);
+ }
+
+ ring->head = new;
+
+ return ring_pump(ring);
+}
+
+uint32_t desc_ring_get_head(DescRing *ring)
+{
+ return ring->head;
+}
+
+uint32_t desc_ring_get_tail(DescRing *ring)
+{
+ return ring->tail;
+}
+
+void desc_ring_set_ctrl(DescRing *ring, uint32_t val)
+{
+ if (val & ROCKER_DMA_DESC_CTRL_RESET) {
+ DPRINTF("ring[%d] resetting\n", ring->index);
+ desc_ring_reset(ring);
+ }
+}
+
+bool desc_ring_ret_credits(DescRing *ring, uint32_t credits)
+{
+ if (credits > ring->credits) {
+ DPRINTF("ERROR: trying to return more credits (%d) "
+ "than are outstanding (%d)\n", credits, ring->credits);
+ ring->credits = 0;
+ return false;
+ }
+
+ ring->credits -= credits;
+
+ /* return true if credits are still outstanding */
+
+ return ring->credits > 0;
+}
+
+uint32_t desc_ring_get_credits(DescRing *ring)
+{
+ return ring->credits;
+}
+
+void desc_ring_set_consume(DescRing *ring, desc_ring_consume *consume,
+ unsigned vector)
+{
+ ring->consume = consume;
+ ring->msix_vector = vector;
+}
+
+unsigned desc_ring_get_msix_vector(DescRing *ring)
+{
+ return ring->msix_vector;
+}
+
+DescRing *desc_ring_alloc(Rocker *r, int index)
+{
+ DescRing *ring;
+
+ ring = g_malloc0(sizeof(DescRing));
+ if (!ring) {
+ return NULL;
+ }
+
+ ring->r = r;
+ ring->index = index;
+
+ return ring;
+}
+
+void desc_ring_free(DescRing *ring)
+{
+ if (ring->info) {
+ g_free(ring->info);
+ }
+ g_free(ring);
+}
+
+void desc_ring_reset(DescRing *ring)
+{
+ ring->base_addr = 0;
+ ring->size = 0;
+ ring->head = 0;
+ ring->tail = 0;
+ ring->ctrl = 0;
+ ring->credits = 0;
+}
Code Review / kvmfornfv.git / blobdiff