[MTD] [NAND] Use rslib for CAFÉ ECC
Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/drivers/mtd/nand/cafe.c b/drivers/mtd/nand/cafe.c
index c328a75..05f6ec9 100644
--- a/drivers/mtd/nand/cafe.c
+++ b/drivers/mtd/nand/cafe.c
@@ -11,6 +11,7 @@
#undef DEBUG
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
+#include <linux/rslib.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
@@ -46,13 +47,11 @@
#define CAFE_GLOBAL_IRQ_MASK 0x300c
#define CAFE_NAND_RESET 0x3034
-int cafe_correct_ecc(unsigned char *buf,
- unsigned short *chk_syndrome_list);
-
struct cafe_priv {
struct nand_chip nand;
struct pci_dev *pdev;
void __iomem *mmio;
+ struct rs_control *rs;
uint32_t ctl1;
uint32_t ctl2;
int datalen;
@@ -374,28 +373,66 @@
chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
if (checkecc && cafe_readl(cafe, NAND_ECC_RESULT) & (1<<18)) {
- unsigned short syn[8];
- int i;
+ unsigned short syn[8], pat[4];
+ int pos[4];
+ u8 *oob = chip->oob_poi;
+ int i, n;
for (i=0; i<8; i+=2) {
uint32_t tmp = cafe_readl(cafe, NAND_ECC_SYN01 + (i*2));
- syn[i] = tmp & 0xfff;
- syn[i+1] = (tmp >> 16) & 0xfff;
+ syn[i] = cafe->rs->index_of[tmp & 0xfff];
+ syn[i+1] = cafe->rs->index_of[(tmp >> 16) & 0xfff];
}
- if ((i = cafe_correct_ecc(buf, syn)) < 0) {
+ n = decode_rs16(cafe->rs, NULL, NULL, 1367, syn, 0, pos, 0,
+ pat);
+
+ for (i = 0; i < n; i++) {
+ int p = pos[i];
+
+ /* The 12-bit symbols are mapped to bytes here */
+
+ if (p > 1374) {
+ /* out of range */
+ n = -1374;
+ } else if (p == 0) {
+ /* high four bits do not correspond to data */
+ if (pat[i] > 0xff)
+ n = -2048;
+ else
+ buf[0] ^= pat[i];
+ } else if (p == 1365) {
+ buf[2047] ^= pat[i] >> 4;
+ oob[0] ^= pat[i] << 4;
+ } else if (p > 1365) {
+ if ((p & 1) == 1) {
+ oob[3*p/2 - 2048] ^= pat[i] >> 4;
+ oob[3*p/2 - 2047] ^= pat[i] << 4;
+ } else {
+ oob[3*p/2 - 2049] ^= pat[i] >> 8;
+ oob[3*p/2 - 2048] ^= pat[i];
+ }
+ } else if ((p & 1) == 1) {
+ buf[3*p/2] ^= pat[i] >> 4;
+ buf[3*p/2 + 1] ^= pat[i] << 4;
+ } else {
+ buf[3*p/2 - 1] ^= pat[i] >> 8;
+ buf[3*p/2] ^= pat[i];
+ }
+ }
+
+ if (n < 0) {
dev_dbg(&cafe->pdev->dev, "Failed to correct ECC at %08x\n",
cafe_readl(cafe, NAND_ADDR2) * 2048);
- for (i=0; i< 0x5c; i+=4)
+ for (i = 0; i < 0x5c; i += 4)
printk("Register %x: %08x\n", i, readl(cafe->mmio + i));
mtd->ecc_stats.failed++;
} else {
- dev_dbg(&cafe->pdev->dev, "Corrected %d symbol errors\n", i);
- mtd->ecc_stats.corrected += i;
+ dev_dbg(&cafe->pdev->dev, "Corrected %d symbol errors\n", n);
+ mtd->ecc_stats.corrected += n;
}
}
-
return 0;
}
@@ -525,6 +562,48 @@
return 0;
}
+/* F_2[X]/(X**6+X+1) */
+static unsigned short __devinit gf64_mul(u8 a, u8 b)
+{
+ u8 c;
+ unsigned int i;
+
+ c = 0;
+ for (i = 0; i < 6; i++) {
+ if (a & 1)
+ c ^= b;
+ a >>= 1;
+ b <<= 1;
+ if ((b & 0x40) != 0)
+ b ^= 0x43;
+ }
+
+ return c;
+}
+
+/* F_64[X]/(X**2+X+A**-1) with A the generator of F_64[X] */
+static u16 __devinit gf4096_mul(u16 a, u16 b)
+{
+ u8 ah, al, bh, bl, ch, cl;
+
+ ah = a >> 6;
+ al = a & 0x3f;
+ bh = b >> 6;
+ bl = b & 0x3f;
+
+ ch = gf64_mul(ah ^ al, bh ^ bl) ^ gf64_mul(al, bl);
+ cl = gf64_mul(gf64_mul(ah, bh), 0x21) ^ gf64_mul(al, bl);
+
+ return (ch << 6) ^ cl;
+}
+
+static int __devinit cafe_mul(int x)
+{
+ if (x == 0)
+ return 1;
+ return gf4096_mul(x, 0xe01);
+}
+
static int __devinit cafe_nand_probe(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
@@ -564,6 +643,12 @@
}
cafe->nand.buffers = (void *)cafe->dmabuf + 2112;
+ cafe->rs = init_rs_non_canonical(12, &cafe_mul, 0, 1, 8);
+ if (!cafe->rs) {
+ err = -ENOMEM;
+ goto out_ior;
+ }
+
cafe->nand.cmdfunc = cafe_nand_cmdfunc;
cafe->nand.dev_ready = cafe_device_ready;
cafe->nand.read_byte = cafe_read_byte;
@@ -713,6 +798,7 @@
cafe_writel(cafe, ~1 & cafe_readl(cafe, GLOBAL_IRQ_MASK), GLOBAL_IRQ_MASK);
free_irq(pdev->irq, mtd);
nand_release(mtd);
+ free_rs(cafe->rs);
pci_iounmap(pdev, cafe->mmio);
dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);
kfree(mtd);