[SLOF] [PATCH v1 07/27] virtio: add virtio 1.0 capability parsing

[Nikunj A Dadhania]

Signed-off-by: Nikunj A Dadhania <nikunj at linux.vnet.ibm.com>
---
 lib/libvirtio/virtio.c | 135 +++++++++++++++++++++++++++++++++++++++++++++++++
 lib/libvirtio/virtio.h |   3 +-
 2 files changed, 137 insertions(+), 1 deletion(-)

diff --git a/lib/libvirtio/virtio.c b/lib/libvirtio/virtio.c
index 7e0d6a3..bcf050b 100644
--- a/lib/libvirtio/virtio.c
+++ b/lib/libvirtio/virtio.c
@@ -14,6 +14,7 @@
 #include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stddef.h>
 #include <cpu.h>
 #include <cache.h>
 #include <byteorder.h>
@@ -31,6 +32,140 @@
 #define VIRTIOHDR_ISR_STATUS		19
 #define VIRTIOHDR_DEVICE_CONFIG 	20
 
+/* PCI defines */
+#define PCI_BASE_ADDR_SPACE_IO	0x01
+#define PCI_BASE_ADDR_SPACE_MEM	0x00
+#define PCI_BASE_ADDR_MEM_MASK	(~0x0fUL)
+#define PCI_BASE_ADDR_IO_MASK	(~0x03UL)
+
+#define PCI_BASE_ADDR_REG_0	0x10
+#define PCI_CONFIG_CAP_REG	0x34
+
+#define PCI_CAP_ID_VNDR		0x9
+
+#define VIRTIO_PCI_CAP_COMMON 1
+#define VIRTIO_PCI_CAP_NOTIFY 2
+#define VIRTIO_PCI_CAP_ISR    3
+#define VIRTIO_PCI_CAP_DEVICE 4
+#define VIRTIO_PCI_CAP_PCI    5
+
+#define VIRTIO_CAP_VNDR     0
+#define VIRTIO_CAP_NEXT     1
+#define VIRTIO_CAP_LEN      2
+#define VIRTIO_CAP_CFG_TYPE 3
+#define VIRTIO_CAP_BAR      4
+#define VIRTIO_CAP_OFFSET   8
+#define VIRTIO_CAP_LENGTH  12
+
+#define le64 uint64_t
+#define le32 uint32_t
+#define le16 uint16_t
+
+struct virtio_dev_common {
+	le32 dev_features_sel;
+	le32 dev_features;
+	le32 drv_features_sel;
+	le32 drv_features;
+	le16 msix_config;
+	le16 num_queues;
+	uint8_t dev_status;
+	uint8_t cfg_generation;
+
+	le16 q_select;
+	le16 q_size;
+	le16 q_msix_vec;
+	le16 q_enable;
+	le16 q_notify_off;
+	le64 q_desc;
+	le64 q_avail;
+	le64 q_used;
+} __attribute__ ((packed));
+
+static void virtio_process_cap(struct virtio_device *dev, uint8_t cap_ptr)
+{
+	struct virtio_cap *cap;
+	uint8_t cfg_type, bar;
+	uint32_t offset;
+	uint64_t addr = 0;
+
+	cfg_type = SLOF_pci_config_read8(cap_ptr + VIRTIO_CAP_CFG_TYPE);
+	bar = SLOF_pci_config_read8(cap_ptr + VIRTIO_CAP_BAR);
+	offset = SLOF_pci_config_read32(cap_ptr + VIRTIO_CAP_OFFSET);
+
+	switch(cfg_type) {
+	case VIRTIO_PCI_CAP_COMMON:
+		cap = &dev->common;
+		break;
+	case VIRTIO_PCI_CAP_NOTIFY:
+		cap = &dev->notify;
+		dev->notify_off_mul = SLOF_pci_config_read32(cap_ptr + sizeof(struct virtio_cap));
+		break;
+	case VIRTIO_PCI_CAP_ISR:
+		cap = &dev->isr;
+		break;
+	case VIRTIO_PCI_CAP_DEVICE:
+		cap = &dev->device;
+		break;
+	default:
+		cap = NULL;
+	}
+
+	if (cap && cfg_type) {
+		cap->bar = bar;
+		addr = SLOF_pci_config_read32(PCI_BASE_ADDR_REG_0 + 4 * cap->bar);
+		if (addr & PCI_BASE_ADDR_SPACE_IO) {
+			cap->is_io = 1;
+			addr = addr & PCI_BASE_ADDR_IO_MASK;
+		} else if (addr & 4) {
+			addr = SLOF_pci_config_read32(PCI_BASE_ADDR_REG_0 + 4 * cap->bar) |
+				(SLOF_pci_config_read32(PCI_BASE_ADDR_REG_0 + 4 * (cap->bar + 1)) << 32);
+			addr = (uint64_t)SLOF_translate_my_address((void *)addr);
+			addr = addr & PCI_BASE_ADDR_MEM_MASK;
+		}
+		else {
+			cap->is_io = 0;
+			addr = addr & PCI_BASE_ADDR_MEM_MASK;
+		}
+		cap->addr = (void *)addr + offset;
+		cap->cap_id = cfg_type;
+	}
+	return;
+}
+/**
+ * Setup virtio device details, gets called from SLOF routines
+ * Determines legacy or modern device.
+ */
+void virtio_setup_device(struct virtio_device *dev)
+{
+	uint8_t cap_ptr, cap_vndr;
+	uint64_t addr = 0;
+
+	cap_ptr = SLOF_pci_config_read8(PCI_CONFIG_CAP_REG);
+	while (cap_ptr != 0)
+	{
+		cap_vndr = SLOF_pci_config_read8(cap_ptr + VIRTIO_CAP_VNDR);
+		if (cap_vndr == PCI_CAP_ID_VNDR)
+			virtio_process_cap(dev, cap_ptr);
+		cap_ptr = SLOF_pci_config_read8(cap_ptr+VIRTIO_CAP_NEXT);
+	}
+	if (dev->common.cap_id && dev->notify.cap_id && dev->isr.cap_id && dev->device.cap_id)
+		dev->is_modern = 1;
+	else {
+		dev->is_modern = 0;
+		dev->legacy.cap_id = 0;
+		dev->legacy.bar = 0;
+		addr = SLOF_pci_config_read32(PCI_BASE_ADDR_REG_0);
+		if (addr & PCI_BASE_ADDR_SPACE_IO) {
+			dev->legacy.is_io = 1;
+			addr = addr & PCI_BASE_ADDR_IO_MASK;
+		} else {
+			dev->legacy.is_io = 0;
+			addr = addr & PCI_BASE_ADDR_MEM_MASK;
+		}
+		dev->legacy.addr = (void *)addr;
+	}
+	return;
+}
 
 /**
  * Calculate ring size according to queue size number
diff --git a/lib/libvirtio/virtio.h b/lib/libvirtio/virtio.h
index 56e044b..eee3144 100644
--- a/lib/libvirtio/virtio.h
+++ b/lib/libvirtio/virtio.h
@@ -74,7 +74,7 @@ struct vring_used {
 
 /* Structure shared with SLOF and is 16bytes */
 struct virtio_cap {
-	uint64_t addr;
+	void *addr;
 	uint8_t bar;
 	uint8_t is_io;
 	uint8_t cap_id;
@@ -116,6 +116,7 @@ extern void virtio_fill_desc(struct vring_desc *desc,
                              uint16_t flags, uint16_t next);
 extern int virtio_queue_init_vq(struct virtio_device *dev, struct vqs *vq, unsigned int id);
 
+extern void virtio_setup_device(struct virtio_device *dev);
 extern void virtio_reset_device(struct virtio_device *dev);
 extern void virtio_queue_notify(struct virtio_device *dev, int queue);
 extern void virtio_set_status(struct virtio_device *dev, int status);
-- 
2.5.0