blob: b009da4f89e46c41169084b137210ad0cf582f55 [file] [log] [blame]
/*
* 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 "qemu/osdep.h"
#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;
}
pci_dma_read(dev, le64_to_cpu(info->desc.buf_addr), info->buf, size);
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++) {
g_free(ring->info[i].buf);
}
ring->size = size;
ring->head = ring->tail = 0;
ring->info = g_renew(DescInfo, ring->info, size);
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_new0(DescRing, 1);
ring->r = r;
ring->index = index;
return ring;
}
void desc_ring_free(DescRing *ring)
{
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;
}