[UNIKRAFT PATCH RFCv2 13/27] plat/virtio_mmio: Implement platform probe for virtio_mmio

[Jia He <justin.he@xxxxxxx>]

This implements the probe interface for virtio_mmio device upon platform
bus.

Signed-off-by: Jia He <justin.he@xxxxxxx>
---
 plat/drivers/virtio/virtio_mmio.c | 101 +++++++++++++++++++++++++-----
 1 file changed, 86 insertions(+), 15 deletions(-)

diff --git a/plat/drivers/virtio/virtio_mmio.c 
b/plat/drivers/virtio/virtio_mmio.c
index 6716153..9be07c1 100644
--- a/plat/drivers/virtio/virtio_mmio.c
+++ b/plat/drivers/virtio/virtio_mmio.c
@@ -42,12 +42,16 @@
 #include <uk/plat/irq.h>
 #include <uk/bus.h>
 #include <uk/bitops.h>
+#include <libfdt.h>
+#include <ofw/fdt.h>
+#include <kvm/config.h>
 
 #include <platform_bus.h>
 #include <virtio/virtio_config.h>
 #include <virtio/virtio_bus.h>
 #include <virtio/virtqueue.h>
 #include <virtio/virtio_mmio.h>
+#include <gic/gic-v2.h>
 
 /* The alignment to use between consumer and producer parts of vring.
  * Currently hardcoded to the page size. */
@@ -389,6 +393,48 @@ static struct virtio_config_ops virtio_mmio_config_ops = {
        .vq_setup       = vm_setup_vq,
 };
 
+static int virtio_mmio_probe(struct pf_device *pfdev)
+{
+       const fdt32_t *prop;
+       int type, hwirq, prop_len;
+       int fdt_vm = pfdev->fdt_offset;
+       __u64 reg_base;
+       __u64 reg_size;
+
+       if (fdt_vm == -FDT_ERR_NOTFOUND) {
+               uk_pr_info("device not found in fdt\n");
+               goto error_exit;
+       } else {
+               prop = fdt_getprop(_libkvmplat_cfg.dtb, fdt_vm, "interrupts", 
&prop_len);
+               if (!prop) {
+                       uk_pr_err("irq of device not found in fdt\n");
+                       goto error_exit;
+               }
+
+               type = fdt32_to_cpu(prop[0]);
+               hwirq = fdt32_to_cpu(prop[1]);
+
+               prop = fdt_getprop(_libkvmplat_cfg.dtb, fdt_vm, "reg", 
&prop_len);
+               if (!prop) {
+                       uk_pr_err("reg of device not found in fdt\n");
+                       goto error_exit;
+               }
+
+               /* only care about base addr, ignore the size */
+               fdt_get_address(_libkvmplat_cfg.dtb, fdt_vm, 0,
+                                       &reg_base, &reg_size);
+       }
+
+       pfdev->base = reg_base;
+       pfdev->irq = gic_irq_translate(type, hwirq);
+       uk_pr_info("virtio mmio probe base(0x%lx) irq(%ld)\n",
+                               pfdev->base, pfdev->irq);
+       return 0;
+
+error_exit:
+       return -EFAULT;
+}
+
 static int virtio_mmio_add_dev(struct pf_device *pfdev)
 {
        struct virtio_mmio_device *vm_dev;
@@ -401,7 +447,8 @@ static int virtio_mmio_add_dev(struct pf_device *pfdev)
        vm_dev = uk_malloc(a, sizeof(*vm_dev));
        if (!vm_dev) {
                uk_pr_err("Failed to allocate virtio-pci device\n");
-               return -ENOMEM;
+               rc = -ENOMEM;
+               goto free_vmdev;
        }
 
        /* Fetch Pf Device information */
@@ -410,20 +457,24 @@ static int virtio_mmio_add_dev(struct pf_device *pfdev)
        vm_dev->vdev.cops = &virtio_mmio_config_ops;
        vm_dev->name = "virtio_mmio";
 
-       if (vm_dev->base == NULL)
-               return -EFAULT;
+       if (vm_dev->base == NULL) {
+               rc = -EFAULT;
+               goto free_vmdev;
+       }
 
        magic = virtio_cread32(vm_dev->base, VIRTIO_MMIO_MAGIC_VALUE);
        if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) {
                uk_pr_err("Wrong magic value 0x%x!\n", magic);
-               return -ENODEV;
+               rc = -ENODEV;
+               goto free_vmdev;
        }
 
        /* Check device version */
        vm_dev->version = virtio_cread32(vm_dev->base, VIRTIO_MMIO_VERSION);
        if (vm_dev->version < 1 || vm_dev->version > 2) {
                uk_pr_err("Version %ld not supported!\n", vm_dev->version);
-               return -ENXIO;
+               rc = -ENXIO;
+               goto free_vmdev;
        }
 
        vm_dev->vdev.id.virtio_device_id = virtio_cread32(vm_dev->base, 
VIRTIO_MMIO_DEVICE_ID);
@@ -434,7 +485,8 @@ static int virtio_mmio_add_dev(struct pf_device *pfdev)
                 */
                uk_pr_err("virtio_device_id is 0\n");
 
-               return -ENODEV;
+               rc = -ENODEV;
+               goto free_vmdev;
        }
        vm_dev->id.vendor = virtio_cread32(vm_dev->base, VIRTIO_MMIO_VENDOR_ID);
 
@@ -443,17 +495,15 @@ static int virtio_mmio_add_dev(struct pf_device *pfdev)
        rc = virtio_bus_register_device(&vm_dev->vdev);
        if (rc != 0) {
                uk_pr_err("Failed to register the virtio device: %d\n", rc);
-               goto free_pf_dev;
+               goto free_vmdev;
        }
 
-       uk_pr_info("finish add a virtio mmio dev\n");
-
-       return rc;
-
-free_pf_dev:
-       uk_free(a, vm_dev);
+       uk_pr_info("finish probing a virtio mmio dev\n");
 
        return 0;
+
+free_vmdev:
+       return rc;
 }
 
 static int virtio_mmio_drv_init(struct uk_alloc *drv_allocator)
@@ -467,14 +517,35 @@ static int virtio_mmio_drv_init(struct uk_alloc 
*drv_allocator)
        return 0;
 }
 
-static const struct pf_device_id virtio_mmio_ids = {
+static const struct device_match_table virtio_mmio_match_table[];
+
+static int virtio_mmio_id_match_compatible(const char *compatible)
+{
+       int i;
+
+       for (i = 0; virtio_mmio_match_table[i].compatible != NULL; i++)
+               if (strcmp(virtio_mmio_match_table[i].compatible, compatible) 
== 0)
+                       return virtio_mmio_match_table[i].id->device_id;
+
+       return -1;
+}
+
+static struct pf_device_id virtio_mmio_ids = {
                .device_id = VIRTIO_MMIO_ID
 };
 
 static struct pf_driver virtio_mmio_drv = {
        .device_ids = &virtio_mmio_ids,
        .init = virtio_mmio_drv_init,
-       .add_dev = virtio_mmio_add_dev
+       .probe = virtio_mmio_probe,
+       .add_dev = virtio_mmio_add_dev,
+       .match = virtio_mmio_id_match_compatible
+};
+
+static const struct device_match_table virtio_mmio_match_table[] = {
+       { .compatible = "virtio,mmio",
+         .id = &virtio_mmio_ids },
+       {NULL}
 };
 
 PF_REGISTER_DRIVER(&virtio_mmio_drv);
-- 
2.17.1