1 /*
2 * Edu PCI device.
3 *
4 * Copyright (C) 2016 Red Hat, Inc.
5 *
6 * Authors:
7 * Peter Xu <peterx@redhat.com>,
8 *
9 * This work is licensed under the terms of the GNU LGPL, version 2 or
10 * later.
11 */
12
13 #include "pci-edu.h"
14 #include "asm/barrier.h"
15
16 /* Return true if alive */
edu_check_alive(struct pci_edu_dev * dev)17 static inline bool edu_check_alive(struct pci_edu_dev *dev)
18 {
19 static uint32_t live_count = 1;
20 uint32_t value;
21
22 edu_reg_writel(dev, EDU_REG_ALIVE, live_count++);
23 value = edu_reg_readl(dev, EDU_REG_ALIVE);
24 return (live_count - 1 == ~value);
25 }
26
edu_init(struct pci_edu_dev * dev)27 bool edu_init(struct pci_edu_dev *dev)
28 {
29 pcidevaddr_t dev_addr;
30
31 dev_addr = pci_find_dev(PCI_VENDOR_ID_QEMU, PCI_DEVICE_ID_EDU);
32 if (dev_addr == PCIDEVADDR_INVALID)
33 return false;
34
35 pci_dev_init(&dev->pci_dev, dev_addr);
36 pci_enable_defaults(&dev->pci_dev);
37 dev->reg_base = ioremap(dev->pci_dev.resource[EDU_BAR], PAGE_SIZE);
38 assert(edu_check_alive(dev));
39 return true;
40 }
41
edu_dma(struct pci_edu_dev * dev,iova_t iova,size_t size,unsigned int dev_offset,bool from_device)42 void edu_dma(struct pci_edu_dev *dev, iova_t iova,
43 size_t size, unsigned int dev_offset, bool from_device)
44 {
45 uint64_t from, to;
46 uint32_t cmd = EDU_CMD_DMA_START;
47
48 assert(size <= EDU_DMA_SIZE_MAX);
49 assert(dev_offset < EDU_DMA_SIZE_MAX);
50
51 printf("edu device DMA start %s addr %#" PRIx64 " size %lu off %#x\n",
52 from_device ? "FROM" : "TO",
53 iova, (ulong)size, dev_offset);
54
55 if (from_device) {
56 from = dev_offset + EDU_DMA_START;
57 to = iova;
58 cmd |= EDU_CMD_DMA_FROM;
59 } else {
60 from = iova;
61 to = EDU_DMA_START + dev_offset;
62 cmd |= EDU_CMD_DMA_TO;
63 }
64
65 edu_reg_writeq(dev, EDU_REG_DMA_SRC, from);
66 edu_reg_writeq(dev, EDU_REG_DMA_DST, to);
67 edu_reg_writeq(dev, EDU_REG_DMA_COUNT, size);
68 edu_reg_writel(dev, EDU_REG_DMA_CMD, cmd);
69
70 /* Wait until DMA finished */
71 while (edu_reg_readl(dev, EDU_REG_DMA_CMD) & EDU_CMD_DMA_START)
72 cpu_relax();
73 }
74