svn commit: r336655 - in head/stand/efi: include libefi

[Warner Losh]

Author: imp
Date: Mon Jul 23 20:36:54 2018
New Revision: 336655
URL: https://svnweb.freebsd.org/changeset/base/336655

Log:
  Implement efiblk_get_pdinfo_by_device_path
  
  Lookup a block device by it's device path. We use a 'loose' lookup
  whereby we scan forward to the first Media Path portion of the device
  path, then look at all our handles for one whose first Media Path
  matches. This will also work if the device path pointed to has a
  following file path (or paths) as that's ignored. It assumes that
  there's only one media path node that describes the entire device,
  which is true as of the latest UEFI spec (2.7 Errata A) as far as I've
  been able to determine.
  
  Sponsored by: Netflix

Modified:
  head/stand/efi/include/efilib.h
  head/stand/efi/libefi/efipart.c

Modified: head/stand/efi/include/efilib.h
==============================================================================
--- head/stand/efi/include/efilib.h	Mon Jul 23 20:36:50 2018	(r336654)
+++ head/stand/efi/include/efilib.h	Mon Jul 23 20:36:54 2018	(r336655)
@@ -66,6 +66,7 @@ typedef struct pdinfo
 pdinfo_list_t *efiblk_get_pdinfo_list(struct devsw *dev);
 pdinfo_t *efiblk_get_pdinfo(struct devdesc *dev);
 pdinfo_t *efiblk_get_pdinfo_by_handle(EFI_HANDLE h);
+pdinfo_t *efiblk_get_pdinfo_by_device_path(EFI_DEVICE_PATH *path);
 
 void *efi_get_table(EFI_GUID *tbl);
 

Modified: head/stand/efi/libefi/efipart.c
==============================================================================
--- head/stand/efi/libefi/efipart.c	Mon Jul 23 20:36:50 2018	(r336654)
+++ head/stand/efi/libefi/efipart.c	Mon Jul 23 20:36:54 2018	(r336655)
@@ -137,6 +137,28 @@ efiblk_get_pdinfo(struct devdesc *dev)
 	return (pd);
 }
 
+pdinfo_t *
+efiblk_get_pdinfo_by_device_path(EFI_DEVICE_PATH *path)
+{
+	unsigned i;
+	EFI_DEVICE_PATH *media, *devpath;
+	EFI_HANDLE h;
+
+	media = efi_devpath_to_media_path(path);
+	if (media == NULL)
+		return (NULL);
+	for (i = 0; i < efipart_nhandles; i++) {
+		h = efipart_handles[i];
+		devpath = efi_lookup_devpath(h);
+		if (devpath == NULL)
+			continue;
+		if (!efi_devpath_match_node(media, efi_devpath_to_media_path(devpath)))
+			continue;
+		return (efiblk_get_pdinfo_by_handle(h));
+	}
+	return (NULL);
+}
+
 static bool
 same_handle(pdinfo_t *pd, EFI_HANDLE h)
 {