Commit 8c61b7a7 authored by Segher Boessenkool's avatar Segher Boessenkool Committed by David Woodhouse

[MTD] [NAND] Use rslib for CAFÉ ECC

Signed-off-by: default avatarSegher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
parent d7e5a546
......@@ -232,11 +232,13 @@ config MTD_NAND_BASLER_EXCITE
will be named "excite_nandflash.ko".
config MTD_NAND_CAFE
tristate "NAND support for OLPC CAFÉ chip"
depends on PCI
help
Use NAND flash attached to the CAFÉ chip designed for the $100
laptop.
tristate "NAND support for OLPC CAFÉ chip"
depends on PCI
select REED_SOLOMON
select REED_SOLOMON_DEC16
help
Use NAND flash attached to the CAFÉ chip designed for the $100
laptop.
config MTD_NAND_CS553X
tristate "NAND support for CS5535/CS5536 (AMD Geode companion chip)"
......
......@@ -28,4 +28,4 @@ obj-$(CONFIG_MTD_NAND_CM_X270) += cmx270_nand.o
obj-$(CONFIG_MTD_NAND_BASLER_EXCITE) += excite_nandflash.o
nand-objs := nand_base.o nand_bbt.o
cafe_nand-objs := cafe.o cafe_ecc.o
cafe_nand-objs := cafe.o
......@@ -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 @@ static int cafe_nand_read_page(struct mtd_info *mtd, struct nand_chip *chip,
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];
}
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 ((i = cafe_correct_ecc(buf, syn)) < 0) {
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 @@ static int cafe_nand_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
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 @@ static int __devinit cafe_nand_probe(struct pci_dev *pdev,
}
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 @@ static void __devexit cafe_nand_remove(struct pci_dev *pdev)
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);
......
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