[RFC 2/2] GenWQE: Make use of the generic CRC kernel infrastructure

From: Frank Haverkamp
Date: Wed Dec 11 2013 - 11:49:41 EST


Instead of reimplementing the CRC, make use of the generic CRC kernel
infrastructure. Note that GenWQE seems currently the only one using
this particular polynomial.

This change requires a previous patch which adds the GenWQE crc32 to
the generic kernel crc32 support.

Signed-off-by: Frank Haverkamp <haver@xxxxxxxxxxxxxxxxxx>
---
drivers/misc/genwqe/card_base.c | 2 0 + 2 - 0 !
drivers/misc/genwqe/card_base.h | 1 0 + 1 - 0 !
drivers/misc/genwqe/card_utils.c | 39 2 + 37 - 0 !
3 files changed, 2 insertions(+), 40 deletions(-)

--- a/drivers/misc/genwqe/card_base.c
+++ b/drivers/misc/genwqe/card_base.c
@@ -1016,8 +1016,6 @@ static int genwqe_probe(struct pci_dev *
int err;
struct genwqe_dev *cd;

- genwqe_init_crc32();
-
cd = genwqe_dev_alloc();
if (IS_ERR(cd)) {
dev_err(&pci_dev->dev, "err: could not alloc mem (err=%d)!\n",
--- a/drivers/misc/genwqe/card_base.h
+++ b/drivers/misc/genwqe/card_base.h
@@ -441,7 +441,6 @@ int genwqe_ffdc_dump_dma(struct genwqe_
int genwqe_init_debug_data(struct genwqe_dev *cd,
struct genwqe_debug_data *d);

-void genwqe_init_crc32(void);
int genwqe_read_app_id(struct genwqe_dev *cd, char *app_name, int len);

/* Memory allocation/deallocation; dma address handling */
--- a/drivers/misc/genwqe/card_utils.c
+++ b/drivers/misc/genwqe/card_utils.c
@@ -37,6 +37,7 @@
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
+#include <linux/crc32.h>
#include <asm/pgtable.h>

#include "genwqe_driver.h"
@@ -151,34 +152,6 @@ int genwqe_read_app_id(struct genwqe_dev
}

/**
- * genwqe_init_crc32() - Prepare a lookup table for fast crc32 calculations
- *
- * Existing kernel functions seem to use a different polynom,
- * therefore we could not use them here.
- *
- * Genwqe's Polynomial = 0x20044009
- */
-#define CRC32_POLYNOMIAL 0x20044009
-static u32 crc32_tab[256]; /* crc32 lookup table */
-
-void genwqe_init_crc32(void)
-{
- int i, j;
- u32 crc;
-
- for (i = 0; i < 256; i++) {
- crc = i << 24;
- for (j = 0; j < 8; j++) {
- if (crc & 0x80000000)
- crc = (crc << 1) ^ CRC32_POLYNOMIAL;
- else
- crc = (crc << 1);
- }
- crc32_tab[i] = crc;
- }
-}
-
-/**
* genwqe_crc32() - Generate 32-bit crc as required for DDCBs
* @buff: pointer to data buffer
* @len: length of data for calculation
@@ -195,15 +168,7 @@ void genwqe_init_crc32(void)
*/
u32 genwqe_crc32(u8 *buff, size_t len, u32 init)
{
- int i;
- u32 crc;
-
- crc = init;
- while (len--) {
- i = ((crc >> 24) ^ *buff++) & 0xFF;
- crc = (crc << 8) ^ crc32_tab[i];
- }
- return crc;
+ return __crc32g_be(init, buff, len);
}

void *__genwqe_alloc_consistent(struct genwqe_dev *cd, size_t size,

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