[PATCH 14/35] efi: Locate all block devices in the app

[Simon Glass <sjg@chromium.org>]

When starting the app, locate all block devices and make them available
to U-Boot. This allows listing partitions and accessing files in
filesystems.

EFI also has the concept of 'disks', meaning boot media. For now, this
is not obviously useful in U-Boot, but add code to at least locate these.
This can be expanded later as needed.

Signed-off-by: Simon Glass <sjg@chromium.org>
---

 include/efi.h     |  15 ++++++
 include/efi_api.h |  15 ++++++
 lib/efi/efi_app.c | 119 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 149 insertions(+)

diff --git a/include/efi.h b/include/efi.h
index 0ec5913ddd1..c0fddf7f6cd 100644
--- a/include/efi.h
+++ b/include/efi.h
@@ -529,4 +529,19 @@ void efi_putc(struct efi_priv *priv, const char ch);
  */
 int efi_info_get(enum efi_entry_t type, void **datap, int *sizep);
 
+/**
+ * efi_bind_block() - bind a new block device to an EFI device
+ *
+ * Binds a new top-level EFI_MEDIA device as well as a child block device so
+ * that the block device can be accessed in U-Boot.
+ *
+ * The device can then be accessed using 'part list efi 0', 'fat ls efi 0:1',
+ * for example, just like any other interface type.
+ *
+ * @handle: handle of the controller on which this driver is installed
+ * @blkio: block io protocol proxied by this driver
+ * @return 0 if OK, -ve on error
+ */
+int efi_bind_block(efi_handle_t handle, struct efi_block_io *blkio);
+
 #endif /* _LINUX_EFI_H */
diff --git a/include/efi_api.h b/include/efi_api.h
index c8f959bb720..0e88b3e5dbe 100644
--- a/include/efi_api.h
+++ b/include/efi_api.h
@@ -1994,4 +1994,19 @@ struct efi_firmware_management_protocol {
 			const u16 *package_version_name);
 };
 
+#define EFI_DISK_IO_PROTOCOL_GUID	\
+	EFI_GUID(0xce345171, 0xba0b, 0x11d2, 0x8e, 0x4f, \
+		 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b)
+
+struct efi_disk {
+	u64 revision;
+	efi_status_t (EFIAPI *read_disk)(struct efi_disk *this, u32 media_id,
+					 u64 offset, efi_uintn_t buffer_size,
+					 void *buffer);
+
+	efi_status_t (EFIAPI *write_disk)(struct efi_disk *this, u32 media_id,
+					  u64 offset, efi_uintn_t buffer_size,
+					  void *buffer);
+};
+
 #endif
diff --git a/lib/efi/efi_app.c b/lib/efi/efi_app.c
index f61665686c5..9ba48517422 100644
--- a/lib/efi/efi_app.c
+++ b/lib/efi/efi_app.c
@@ -21,6 +21,9 @@
 #include <efi.h>
 #include <efi_api.h>
 #include <sysreset.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <dm/root.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -46,6 +49,33 @@ int efi_info_get(enum efi_entry_t type, void **datap, int *sizep)
 	return -ENOSYS;
 }
 
+/**
+ * Create a block device so U-Boot can access an EFI device
+ *
+ * @handle:	EFI handle to bind
+ * @blkio:	block io protocol
+ * Return:	0 = success
+ */
+int efi_bind_block(efi_handle_t handle, struct efi_block_io *blkio)
+{
+	struct efi_media_plat plat;
+	struct udevice *dev;
+	char name[18];
+	int ret;
+
+	plat.handle = handle;
+	plat.blkio = blkio;
+	ret = device_bind(dm_root(), DM_DRIVER_GET(efi_media), "efi_media",
+			  &plat, ofnode_null(), &dev);
+	if (ret)
+		return log_msg_ret("bind", ret);
+
+	snprintf(name, sizeof(name), "efi_media_%x", dev_seq(dev));
+	device_set_name(dev, name);
+
+	return 0;
+}
+
 static efi_status_t setup_memory(struct efi_priv *priv)
 {
 	struct efi_boot_services *boot = priv->boot;
@@ -105,6 +135,95 @@ static void free_memory(struct efi_priv *priv)
 	global_data_ptr = NULL;
 }
 
+static int setup_disks(void)
+{
+	/* This is not fully implemented yet */
+	return 0;
+
+	efi_guid_t efi_disk_guid = EFI_DISK_IO_PROTOCOL_GUID;
+	struct efi_boot_services *boot = efi_get_boot();
+	struct efi_disk *disk;
+	int ret;
+
+	if (!boot)
+		return log_msg_ret("sys", -ENOSYS);
+	ret = boot->locate_protocol(&efi_disk_guid, NULL, (void **)&disk);
+	if (ret)
+		return log_msg_ret("prot", -ENOTSUPP);
+
+	return 0;
+}
+
+static int setup_block(void)
+{
+	efi_guid_t efi_blkio_guid = EFI_BLOCK_IO_PROTOCOL_GUID;
+	efi_guid_t efi_devpath_guid = EFI_DEVICE_PATH_PROTOCOL_GUID;
+	struct efi_boot_services *boot = efi_get_boot();
+	struct efi_block_io *blkio;
+	struct efi_device_path device_path;
+	efi_handle_t handle[100];
+	efi_uintn_t buf_size;
+	int num_handles;
+	int ret, i;
+
+	if (!boot)
+		return log_msg_ret("sys", -ENOSYS);
+
+	buf_size = sizeof(handle);
+	ret = boot->locate_handle(BY_PROTOCOL, &efi_blkio_guid, NULL,
+				  &buf_size, handle);
+	if (ret)
+		return log_msg_ret("loc", -ENOTSUPP);
+
+	num_handles = buf_size / sizeof(efi_handle_t);
+	log_info("Found %d EFI handles\n", num_handles);
+
+	for (i = 0; i < num_handles; i++) {
+		ret = boot->handle_protocol(handle[i], &efi_devpath_guid,
+					    (void **)&device_path);
+		if (ret) {
+			log_warning("- devpath %d failed (ret=%d)\n", i, ret);
+			continue;
+		}
+
+		ret = boot->handle_protocol(handle[i], &efi_blkio_guid,
+					    (void **)&blkio);
+		if (ret) {
+			log_warning("- blkio %d failed (ret=%d)\n", i, ret);
+			continue;
+		}
+
+		ret = efi_bind_block(handle[i], blkio);
+		if (ret) {
+			log_warning("- blkio bind %d failed (ret=%d)\n", i, ret);
+			continue;
+		}
+	}
+	if (ret)
+		return log_msg_ret("prot", -ENOTSUPP);
+
+	return 0;
+}
+
+int dm_scan_other(bool pre_reloc_only)
+{
+	if (gd->flags & GD_FLG_RELOC) {
+		int ret;
+
+		/* Find all block devices and setup EFI devices for them */
+		ret = setup_block();
+		if (ret)
+			return ret;
+
+		/* Not needed at present, but could be useful one day? */
+		ret = setup_disks();
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 /**
  * efi_main() - Start an EFI image
  *
-- 
2.33.0.153.gba50c8fa24-goog