[kvm-unit-tests PATCH 11/14] pci: edu: introduce pci-edu helpers

[Peter Xu <peterx@redhat.com>]

QEMU edu device is a pci device that is originally written for
educational purpose, however it also suits for IOMMU unit test. Adding
helpers for this specific device to implement the device logic.

The device supports lots of functions, here only DMA operation is
supported.

The spec of the device can be found at:

  https://github.com/qemu/qemu/blob/master/docs/specs/edu.txt

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 lib/pci-edu.c | 128 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/pci-edu.h |  29 +++++++++++++
 2 files changed, 157 insertions(+)
 create mode 100644 lib/pci-edu.c
 create mode 100644 lib/pci-edu.h

diff --git a/lib/pci-edu.c b/lib/pci-edu.c
new file mode 100644
index 0000000..4d1a5ab
--- /dev/null
+++ b/lib/pci-edu.c
@@ -0,0 +1,128 @@
+/*
+ * Edu PCI device.
+ *
+ * Copyright (C) 2016 Red Hat, Inc.
+ *
+ * Authors:
+ *   Peter Xu <peterx@redhat.com>,
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or
+ * later.
+ */
+
+#include "pci-edu.h"
+
+#define  PCI_VENDOR_ID_QEMU              (0x1234)
+#define  PCI_DEVICE_ID_EDU               (0x11e8)
+
+/* The only bar used by EDU device */
+#define EDU_BAR_MEM                 (0)
+#define EDU_MAGIC                   (0xed)
+#define EDU_VERSION                 (0x100)
+#define EDU_DMA_BUF_SIZE            (1 << 20)
+#define EDU_INPUT_BUF_SIZE          (256)
+
+#define EDU_REG_ID                  (0x0)
+#define EDU_REG_ALIVE               (0x4)
+#define EDU_REG_FACTORIAL           (0x8)
+#define EDU_REG_STATUS              (0x20)
+#define EDU_REG_DMA_SRC             (0x80)
+#define EDU_REG_DMA_DST             (0x88)
+#define EDU_REG_DMA_COUNT           (0x90)
+#define EDU_REG_DMA_CMD             (0x98)
+
+#define EDU_CMD_DMA_START           (0x01)
+#define EDU_CMD_DMA_FROM            (0x02)
+#define EDU_CMD_DMA_TO              (0x00)
+
+#define EDU_STATUS_FACTORIAL        (0x1)
+#define EDU_STATUS_INT_ENABLE       (0x80)
+
+#define EDU_DMA_START               (0x40000)
+#define EDU_DMA_SIZE_MAX            (4096)
+
+uint64_t edu_reg_readq(pci_edu_dev_t *dev, int reg)
+{
+	return *(volatile uint64_t *)(dev->pci_dev.pci_bar[EDU_BAR_MEM] + reg);
+}
+
+uint32_t edu_reg_read(pci_edu_dev_t *dev, int reg)
+{
+	return *(volatile uint32_t *)(dev->pci_dev.pci_bar[EDU_BAR_MEM] + reg);
+}
+
+void edu_reg_writeq(pci_edu_dev_t *dev, int reg, uint64_t val)
+{
+	*(volatile uint64_t *)(dev->pci_dev.pci_bar[EDU_BAR_MEM] + reg) = val;
+}
+
+void edu_reg_write(pci_edu_dev_t *dev, int reg, uint32_t val)
+{
+	*(volatile uint32_t *)(dev->pci_dev.pci_bar[EDU_BAR_MEM] + reg) = val;
+}
+
+/* Return true if alive */
+bool edu_check_alive(pci_edu_dev_t *dev)
+{
+	static uint32_t live_count = 1;
+	uint32_t value;
+
+	edu_reg_write(dev, EDU_REG_ALIVE, live_count++);
+	value = edu_reg_read(dev, EDU_REG_ALIVE);
+	return (live_count - 1 == ~value);
+}
+
+int edu_init(pci_edu_dev_t *dev)
+{
+	int ret;
+
+	ret = pci_dev_init(&dev->pci_dev, PCI_VENDOR_ID_QEMU,
+			   PCI_DEVICE_ID_EDU);
+	if (ret)
+		return ret;
+
+	if (!edu_check_alive(dev)) {
+		printf("edu device not alive!\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+uint32_t edu_status(pci_edu_dev_t *dev)
+{
+	return edu_reg_read(dev, EDU_REG_STATUS);
+}
+
+void edu_dma(pci_edu_dev_t *dev, iova_t iova,
+	     size_t size, int dev_offset, pci_dma_dir_t dir)
+{
+	uint64_t from, to;
+	uint32_t cmd = EDU_CMD_DMA_START;
+
+	assert(size <= EDU_DMA_SIZE_MAX);
+	assert(dev_offset < EDU_DMA_SIZE_MAX &&
+	       dev_offset >= 0);
+
+	printf("edu device DMA start %s addr %p size 0x%lu off 0x%x\n",
+	       dir == PCI_DMA_FROM_DEVICE ? "FROM" : "TO",
+	       (void *)iova, size, dev_offset);
+
+	if (dir == PCI_DMA_FROM_DEVICE) {
+		from = dev_offset + EDU_DMA_START;
+		to = iova;
+		cmd |= EDU_CMD_DMA_FROM;
+	} else {
+		from = iova;
+		to = EDU_DMA_START + dev_offset;
+		cmd |= EDU_CMD_DMA_TO;
+	}
+
+	edu_reg_writeq(dev, EDU_REG_DMA_SRC, from);
+	edu_reg_writeq(dev, EDU_REG_DMA_DST, to);
+	edu_reg_writeq(dev, EDU_REG_DMA_COUNT, size);
+	edu_reg_write(dev, EDU_REG_DMA_CMD, cmd);
+
+	/* Wait until DMA finished */
+	while (edu_reg_read(dev, EDU_REG_DMA_CMD) & EDU_CMD_DMA_START);
+}
diff --git a/lib/pci-edu.h b/lib/pci-edu.h
new file mode 100644
index 0000000..6b7dbfd
--- /dev/null
+++ b/lib/pci-edu.h
@@ -0,0 +1,29 @@
+/*
+ * Edu PCI device header.
+ *
+ * Copyright (C) 2016 Red Hat, Inc.
+ *
+ * Authors:
+ *   Peter Xu <peterx@redhat.com>,
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or
+ * later.
+ *
+ * Edu device is a virtualized device in QEMU. Please refer to
+ * docs/specs/edu.txt in QEMU repository for EDU device manual.
+ */
+#ifndef __PCI_EDU_H__
+#define __PCI_EDU_H__
+
+#include "pci.h"
+
+struct pci_edu_dev {
+	pci_dev pci_dev;
+};
+typedef struct pci_edu_dev pci_edu_dev_t;
+
+int edu_init(pci_edu_dev_t *dev);
+void edu_dma(pci_edu_dev_t *dev, iova_t iova,
+	     size_t size, int dev_offset, pci_dma_dir_t dir);
+
+#endif
-- 
2.7.4