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Subject[PATCH 2/3] libcrc32c: Expose big-endian version of crc32c
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Provide a big-endian version of crc32c for modules that want it.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---
include/linux/crc32c.h | 5 +++--
lib/libcrc32c.c | 43 ++++++++++++++++++++++++++++++++++---------
2 files changed, 37 insertions(+), 11 deletions(-)


diff --git a/include/linux/crc32c.h b/include/linux/crc32c.h
index bd8b44d..33320e1 100644
--- a/include/linux/crc32c.h
+++ b/include/linux/crc32c.h
@@ -3,9 +3,10 @@

#include <linux/types.h>

-extern u32 crc32c(u32 crc, const void *address, unsigned int length);
+extern u32 crc32c_le(u32 crc, const void *address, unsigned int length);
+extern u32 crc32c_be(u32 crc, const void *address, unsigned int length);

/* This macro exists for backwards-compatibility. */
-#define crc32c_le crc32c
+#define crc32c crc32c_le

#endif /* _LINUX_CRC32C_H */
diff --git a/lib/libcrc32c.c b/lib/libcrc32c.c
index 244f548..e421ff5 100644
--- a/lib/libcrc32c.c
+++ b/lib/libcrc32c.c
@@ -37,17 +37,17 @@
#include <linux/kernel.h>
#include <linux/module.h>

-static struct crypto_shash *tfm;
+static struct crypto_shash *tfm_le, *tfm_be;

-u32 crc32c(u32 crc, const void *address, unsigned int length)
+u32 crc32c_le(u32 crc, const void *address, unsigned int length)
{
struct {
struct shash_desc shash;
- char ctx[crypto_shash_descsize(tfm)];
+ char ctx[crypto_shash_descsize(tfm_le)];
} desc;
int err;

- desc.shash.tfm = tfm;
+ desc.shash.tfm = tfm_le;
desc.shash.flags = 0;
*(u32 *)desc.ctx = crc;

@@ -56,21 +56,46 @@ u32 crc32c(u32 crc, const void *address, unsigned int length)

return *(u32 *)desc.ctx;
}
+EXPORT_SYMBOL(crc32c_le);

-EXPORT_SYMBOL(crc32c);
+u32 crc32c_be(u32 crc, const void *address, unsigned int length)
+{
+ struct {
+ struct shash_desc shash;
+ char ctx[crypto_shash_descsize(tfm_be)];
+ } desc;
+ int err;
+
+ desc.shash.tfm = tfm_be;
+ desc.shash.flags = 0;
+ *(u32 *)desc.ctx = crc;
+
+ err = crypto_shash_update(&desc.shash, address, length);
+ BUG_ON(err);
+
+ return *(u32 *)desc.ctx;
+}
+EXPORT_SYMBOL(crc32c_be);

static int __init libcrc32c_mod_init(void)
{
- tfm = crypto_alloc_shash("crc32c", 0, 0);
- if (IS_ERR(tfm))
- return PTR_ERR(tfm);
+ tfm_le = crypto_alloc_shash("crc32c", 0, 0);
+ if (IS_ERR(tfm_le))
+ return PTR_ERR(tfm_le);
+
+ tfm_be = crypto_alloc_shash("crc32c-be", 0, 0);
+ if (IS_ERR(tfm_be)) {
+ crypto_free_shash(tfm_le);
+ return PTR_ERR(tfm_be);
+ }

return 0;
}

static void __exit libcrc32c_mod_fini(void)
{
- crypto_free_shash(tfm);
+ crypto_free_shash(tfm_be);
+ crypto_free_shash(tfm_le);
}

module_init(libcrc32c_mod_init);


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