fs: ext4l: Add CRC32C implementation

Add ext4l_crc32c() which uses the Castagnoli polynomial (0x82F63B78)
required for ext4 checksums. The table is initialised on first mount.

Signed-off-by: Simon Glass <simon.glass@canonical.com>

fs/ext4l/ext4_uboot.h

@@ -35,6 +35,7 @@
 #include <linux/iomap.h>
 #include <linux/seq_file.h>
 #include <linux/rbtree.h>	/* Real rbtree implementation */
+#include <u-boot/crc.h>		/* For crc32() used by crc32_be */
 
 /*
  * Override no_printk to avoid format warnings in disabled debug prints.
@@ -2818,6 +2819,7 @@ struct wait_bit_entry {
 void free_buffer_head(struct buffer_head *bh);
 
 /* ext4l support functions (support.c) */
+void ext4l_crc32c_init(void);
 void bh_cache_clear(void);
 int ext4l_read_block(sector_t block, size_t size, void *buffer);
 

fs/ext4l/interface.c

@@ -92,6 +92,8 @@ int ext4l_probe(struct blk_desc *fs_dev_desc,
 	/* Set up block device for buffer I/O */
 	ext4l_set_blk_dev(fs_dev_desc, fs_partition);
 
+	ext4l_crc32c_init();
+
 	/* Initialise journal subsystem if enabled */
 	if (IS_ENABLED(CONFIG_EXT4_JOURNAL)) {
 		ret = jbd2_journal_init_global();

fs/ext4l/support.c

@@ -12,12 +12,33 @@
 #include <blk.h>
 #include <part.h>
 #include <malloc.h>
+#include <u-boot/crc.h>
 #include <linux/errno.h>
 #include <linux/types.h>
 
 #include "ext4_uboot.h"
 #include "ext4.h"
 
+/*
+ * CRC32C support - uses Castagnoli polynomial 0x82F63B78
+ * Table is initialised on first mount
+ */
+static u32 ext4l_crc32c_table[256];
+static bool ext4l_crc32c_inited;
+
+void ext4l_crc32c_init(void)
+{
+	if (!ext4l_crc32c_inited) {
+		crc32c_init(ext4l_crc32c_table, 0x82F63B78);
+		ext4l_crc32c_inited = true;
+	}
+}
+
+u32 ext4l_crc32c(u32 crc, const void *address, unsigned int length)
+{
+	return crc32c_cal(crc, address, length, ext4l_crc32c_table);
+}
+
 /*
  * Buffer cache implementation
  *