1 files changed, 87 insertions, 0 deletions
diff --git a/block/partitions/sgi.c b/block/partitions/sgi.c
new file mode 100644
index 000000000..9cc6b8c1e
--- /dev/null
+++ b/block/partitions/sgi.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  fs/partitions/sgi.c
+ *
+ *  Code extracted from drivers/block/genhd.c
+ */
+
+#include "check.h"
+
+#define SGI_LABEL_MAGIC 0x0be5a941
+
+enum {
+	LINUX_RAID_PARTITION = 0xfd,	/* autodetect RAID partition */
+};
+
+struct sgi_disklabel {
+	__be32 magic_mushroom;		/* Big fat spliff... */
+	__be16 root_part_num;		/* Root partition number */
+	__be16 swap_part_num;		/* Swap partition number */
+	s8 boot_file[16];		/* Name of boot file for ARCS */
+	u8 _unused0[48];		/* Device parameter useless crapola.. */
+	struct sgi_volume {
+		s8 name[8];		/* Name of volume */
+		__be32 block_num;		/* Logical block number */
+		__be32 num_bytes;		/* How big, in bytes */
+	} volume[15];
+	struct sgi_partition {
+		__be32 num_blocks;		/* Size in logical blocks */
+		__be32 first_block;	/* First logical block */
+		__be32 type;		/* Type of this partition */
+	} partitions[16];
+	__be32 csum;			/* Disk label checksum */
+	__be32 _unused1;			/* Padding */
+};
+
+int sgi_partition(struct parsed_partitions *state)
+{
+	int i, csum;
+	__be32 magic;
+	int slot = 1;
+	unsigned int start, blocks;
+	__be32 *ui, cs;
+	Sector sect;
+	struct sgi_disklabel *label;
+	struct sgi_partition *p;
+
+	label = read_part_sector(state, 0, &sect);
+	if (!label)
+		return -1;
+	p = &label->partitions[0];
+	magic = label->magic_mushroom;
+	if(be32_to_cpu(magic) != SGI_LABEL_MAGIC) {
+		/*printk("Dev %s SGI disklabel: bad magic %08x\n",
+		       state->disk->disk_name, be32_to_cpu(magic));*/
+		put_dev_sector(sect);
+		return 0;
+	}
+	ui = ((__be32 *) (label + 1)) - 1;
+	for(csum = 0; ui >= ((__be32 *) label);) {
+		cs = *ui--;
+		csum += be32_to_cpu(cs);
+	}
+	if(csum) {
+		printk(KERN_WARNING "Dev %s SGI disklabel: csum bad, label corrupted\n",
+		       state->disk->disk_name);
+		put_dev_sector(sect);
+		return 0;
+	}
+	/* All SGI disk labels have 16 partitions, disks under Linux only
+	 * have 15 minor's.  Luckily there are always a few zero length
+	 * partitions which we don't care about so we never overflow the
+	 * current_minor.
+	 */
+	for(i = 0; i < 16; i++, p++) {
+		blocks = be32_to_cpu(p->num_blocks);
+		start  = be32_to_cpu(p->first_block);
+		if (blocks) {
+			put_partition(state, slot, start, blocks);
+			if (be32_to_cpu(p->type) == LINUX_RAID_PARTITION)
+				state->parts[slot].flags = ADDPART_FLAG_RAID;
+		}
+		slot++;
+	}
+	strlcat(state->pp_buf, "\n", PAGE_SIZE);
+	put_dev_sector(sect);
+	return 1;
+}