/* * 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/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; }