[PATCH v2 2/2] efi_loader: support all uclasses in device path

[Heinrich Schuchardt]

On devices with multiple USB mass storage devices errors like

    Path /../USB(0x0,0x0)/USB(0x1,0x0)/Ctrl(0x0)
    already installed.

are seen. This is due to creating non-unique device paths. To uniquely
identify devices we must provide path nodes for all devices on the path
from the root device.

Add support for generating device path nodes for all uclasses.

Reported-by: Suniel Mahesh <sunil at amarulasolutions.com>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
---
v2:
	no change
---
 include/efi_api.h                |  7 ++++
 lib/efi_loader/efi_device_path.c | 56 ++++++++++++++------------------
 2 files changed, 32 insertions(+), 31 deletions(-)

diff --git a/include/efi_api.h b/include/efi_api.h
index 55a4c989fc..8f5ef5f680 100644
--- a/include/efi_api.h
+++ b/include/efi_api.h
@@ -579,6 +579,13 @@ struct efi_device_path_vendor {
 	u8 vendor_data[];
 } __packed;
 
+struct efi_device_path_udevice {
+	struct efi_device_path dp;
+	efi_guid_t guid;
+	int uclass_id;
+	int dev_number;
+} __packed;
+
 struct efi_device_path_controller {
 	struct efi_device_path dp;
 	u32 controller_number;
diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
index c135e2883d..19e8861ef4 100644
--- a/lib/efi_loader/efi_device_path.c
+++ b/lib/efi_loader/efi_device_path.c
@@ -10,6 +10,7 @@
 #include <common.h>
 #include <blk.h>
 #include <dm.h>
+#include <dm/root.h>
 #include <log.h>
 #include <net.h>
 #include <usb.h>
@@ -38,16 +39,6 @@ const struct efi_device_path END = {
 	.length   = sizeof(END),
 };
 
-/* template ROOT node: */
-static const struct efi_device_path_vendor ROOT = {
-	.dp = {
-		.type     = DEVICE_PATH_TYPE_HARDWARE_DEVICE,
-		.sub_type = DEVICE_PATH_SUB_TYPE_VENDOR,
-		.length   = sizeof(ROOT),
-	},
-	.guid = U_BOOT_GUID,
-};
-
 #if defined(CONFIG_MMC)
 /*
  * Determine if an MMC device is an SD card.
@@ -497,13 +488,12 @@ bool efi_dp_is_multi_instance(const struct efi_device_path *dp)
 __maybe_unused static unsigned int dp_size(struct udevice *dev)
 {
 	if (!dev || !dev->driver)
-		return sizeof(ROOT);
+		return sizeof(struct efi_device_path_udevice);
 
 	switch (device_get_uclass_id(dev)) {
 	case UCLASS_ROOT:
-	case UCLASS_SIMPLE_BUS:
 		/* stop traversing parents at this point: */
-		return sizeof(ROOT);
+		return sizeof(struct efi_device_path_udevice);
 	case UCLASS_ETH:
 		return dp_size(dev->parent) +
 			sizeof(struct efi_device_path_mac_addr);
@@ -582,8 +572,8 @@ __maybe_unused static unsigned int dp_size(struct udevice *dev)
 		return dp_size(dev->parent) +
 			sizeof(struct efi_device_path_usb);
 	default:
-		/* just skip over unknown classes: */
-		return dp_size(dev->parent);
+		return dp_size(dev->parent) +
+			sizeof(struct efi_device_path_udevice);
 	}
 }
 
@@ -600,13 +590,6 @@ __maybe_unused static void *dp_fill(void *buf, struct udevice *dev)
 		return buf;
 
 	switch (device_get_uclass_id(dev)) {
-	case UCLASS_ROOT:
-	case UCLASS_SIMPLE_BUS: {
-		/* stop traversing parents at this point: */
-		struct efi_device_path_vendor *vdp = buf;
-		*vdp = ROOT;
-		return &vdp[1];
-	}
 #ifdef CONFIG_NETDEVICES
 	case UCLASS_ETH: {
 		struct efi_device_path_mac_addr *dp =
@@ -805,11 +788,24 @@ __maybe_unused static void *dp_fill(void *buf, struct udevice *dev)
 
 		return &udp[1];
 	}
-	default:
-		/* If the uclass driver is missing, this will show NULL */
-		log_debug("unhandled device class: %s (%s)\n", dev->name,
-			  dev_get_uclass_name(dev));
-		return dp_fill(buf, dev->parent);
+	default: {
+		struct efi_device_path_udevice *vdp;
+		enum uclass_id uclass_id = device_get_uclass_id(dev);
+
+		if (uclass_id == UCLASS_ROOT)
+			vdp = buf;
+		else
+			vdp = dp_fill(buf, dev->parent);
+
+		vdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
+		vdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_VENDOR;
+		vdp->dp.length = sizeof(*vdp);
+		memcpy(&vdp->guid, &efi_u_boot_guid, sizeof(efi_guid_t));
+		vdp->uclass_id = uclass_id;
+		vdp->dev_number = dev->seq_;
+
+		return &vdp[1];
+	    }
 	}
 }
 
@@ -1046,14 +1042,12 @@ struct efi_device_path *efi_dp_from_uart(void)
 {
 	void *buf, *pos;
 	struct efi_device_path_uart *uart;
-	size_t dpsize = sizeof(ROOT) + sizeof(*uart) + sizeof(END);
+	size_t dpsize = dp_size(dm_root()) + sizeof(*uart) + sizeof(END);
 
 	buf = efi_alloc(dpsize);
 	if (!buf)
 		return NULL;
-	pos = buf;
-	memcpy(pos, &ROOT, sizeof(ROOT));
-	pos += sizeof(ROOT);
+	pos = dp_fill(buf, dm_root());
 	uart = pos;
 	uart->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
 	uart->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_UART;
-- 
2.40.1