From a4742d515071b8b7889a6b608da48d36c1dfcc71 Mon Sep 17 00:00:00 2001 From: Vipin Kumar Date: Tue, 9 Oct 2012 16:14:50 +0530 Subject: [PATCH] mtd: fsmc_nand: use relaxed variants of io accessors Use relaxed variants of readl/writel accessors. readl/writel io accessors use explicit dsb instruction which causes stalls in the processor core resulting several cycles of delay for each access Use relaxed variants where ever possible. This also results in an improved read/write performance. Signed-off-by: Vipin Kumar Reviewed-by: Linus Walleij Reviewed-by: Viresh Kumar Signed-off-by: Artem Bityutskiy --- drivers/mtd/nand/fsmc_nand.c | 54 ++++++++++++++++++++++++-------------------- 1 file changed, 29 insertions(+), 25 deletions(-) diff --git a/drivers/mtd/nand/fsmc_nand.c b/drivers/mtd/nand/fsmc_nand.c index 82c0371..6b59223 100644 --- a/drivers/mtd/nand/fsmc_nand.c +++ b/drivers/mtd/nand/fsmc_nand.c @@ -383,13 +383,13 @@ static void fsmc_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl) pc |= FSMC_ENABLE; else pc &= ~FSMC_ENABLE; - writel(pc, FSMC_NAND_REG(regs, bank, PC)); + writel_relaxed(pc, FSMC_NAND_REG(regs, bank, PC)); } mb(); if (cmd != NAND_CMD_NONE) - writeb(cmd, this->IO_ADDR_W); + writeb_relaxed(cmd, this->IO_ADDR_W); } /* @@ -426,14 +426,18 @@ static void fsmc_nand_setup(void __iomem *regs, uint32_t bank, tset = (tims->tset & FSMC_TSET_MASK) << FSMC_TSET_SHIFT; if (busw) - writel(value | FSMC_DEVWID_16, FSMC_NAND_REG(regs, bank, PC)); + writel_relaxed(value | FSMC_DEVWID_16, + FSMC_NAND_REG(regs, bank, PC)); else - writel(value | FSMC_DEVWID_8, FSMC_NAND_REG(regs, bank, PC)); + writel_relaxed(value | FSMC_DEVWID_8, + FSMC_NAND_REG(regs, bank, PC)); - writel(readl(FSMC_NAND_REG(regs, bank, PC)) | tclr | tar, + writel_relaxed(readl(FSMC_NAND_REG(regs, bank, PC)) | tclr | tar, FSMC_NAND_REG(regs, bank, PC)); - writel(thiz | thold | twait | tset, FSMC_NAND_REG(regs, bank, COMM)); - writel(thiz | thold | twait | tset, FSMC_NAND_REG(regs, bank, ATTRIB)); + writel_relaxed(thiz | thold | twait | tset, + FSMC_NAND_REG(regs, bank, COMM)); + writel_relaxed(thiz | thold | twait | tset, + FSMC_NAND_REG(regs, bank, ATTRIB)); } /* @@ -446,11 +450,11 @@ static void fsmc_enable_hwecc(struct mtd_info *mtd, int mode) void __iomem *regs = host->regs_va; uint32_t bank = host->bank; - writel(readl(FSMC_NAND_REG(regs, bank, PC)) & ~FSMC_ECCPLEN_256, + writel_relaxed(readl(FSMC_NAND_REG(regs, bank, PC)) & ~FSMC_ECCPLEN_256, FSMC_NAND_REG(regs, bank, PC)); - writel(readl(FSMC_NAND_REG(regs, bank, PC)) & ~FSMC_ECCEN, + writel_relaxed(readl(FSMC_NAND_REG(regs, bank, PC)) & ~FSMC_ECCEN, FSMC_NAND_REG(regs, bank, PC)); - writel(readl(FSMC_NAND_REG(regs, bank, PC)) | FSMC_ECCEN, + writel_relaxed(readl(FSMC_NAND_REG(regs, bank, PC)) | FSMC_ECCEN, FSMC_NAND_REG(regs, bank, PC)); } @@ -470,7 +474,7 @@ static int fsmc_read_hwecc_ecc4(struct mtd_info *mtd, const uint8_t *data, unsigned long deadline = jiffies + FSMC_BUSY_WAIT_TIMEOUT; do { - if (readl(FSMC_NAND_REG(regs, bank, STS)) & FSMC_CODE_RDY) + if (readl_relaxed(FSMC_NAND_REG(regs, bank, STS)) & FSMC_CODE_RDY) break; else cond_resched(); @@ -481,25 +485,25 @@ static int fsmc_read_hwecc_ecc4(struct mtd_info *mtd, const uint8_t *data, return -ETIMEDOUT; } - ecc_tmp = readl(FSMC_NAND_REG(regs, bank, ECC1)); + ecc_tmp = readl_relaxed(FSMC_NAND_REG(regs, bank, ECC1)); ecc[0] = (uint8_t) (ecc_tmp >> 0); ecc[1] = (uint8_t) (ecc_tmp >> 8); ecc[2] = (uint8_t) (ecc_tmp >> 16); ecc[3] = (uint8_t) (ecc_tmp >> 24); - ecc_tmp = readl(FSMC_NAND_REG(regs, bank, ECC2)); + ecc_tmp = readl_relaxed(FSMC_NAND_REG(regs, bank, ECC2)); ecc[4] = (uint8_t) (ecc_tmp >> 0); ecc[5] = (uint8_t) (ecc_tmp >> 8); ecc[6] = (uint8_t) (ecc_tmp >> 16); ecc[7] = (uint8_t) (ecc_tmp >> 24); - ecc_tmp = readl(FSMC_NAND_REG(regs, bank, ECC3)); + ecc_tmp = readl_relaxed(FSMC_NAND_REG(regs, bank, ECC3)); ecc[8] = (uint8_t) (ecc_tmp >> 0); ecc[9] = (uint8_t) (ecc_tmp >> 8); ecc[10] = (uint8_t) (ecc_tmp >> 16); ecc[11] = (uint8_t) (ecc_tmp >> 24); - ecc_tmp = readl(FSMC_NAND_REG(regs, bank, STS)); + ecc_tmp = readl_relaxed(FSMC_NAND_REG(regs, bank, STS)); ecc[12] = (uint8_t) (ecc_tmp >> 16); return 0; @@ -519,7 +523,7 @@ static int fsmc_read_hwecc_ecc1(struct mtd_info *mtd, const uint8_t *data, uint32_t bank = host->bank; uint32_t ecc_tmp; - ecc_tmp = readl(FSMC_NAND_REG(regs, bank, ECC1)); + ecc_tmp = readl_relaxed(FSMC_NAND_REG(regs, bank, ECC1)); ecc[0] = (uint8_t) (ecc_tmp >> 0); ecc[1] = (uint8_t) (ecc_tmp >> 8); ecc[2] = (uint8_t) (ecc_tmp >> 16); @@ -628,10 +632,10 @@ static void fsmc_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len) uint32_t *p = (uint32_t *)buf; len = len >> 2; for (i = 0; i < len; i++) - writel(p[i], chip->IO_ADDR_W); + writel_relaxed(p[i], chip->IO_ADDR_W); } else { for (i = 0; i < len; i++) - writeb(buf[i], chip->IO_ADDR_W); + writeb_relaxed(buf[i], chip->IO_ADDR_W); } } @@ -651,10 +655,10 @@ static void fsmc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len) uint32_t *p = (uint32_t *)buf; len = len >> 2; for (i = 0; i < len; i++) - p[i] = readl(chip->IO_ADDR_R); + p[i] = readl_relaxed(chip->IO_ADDR_R); } else { for (i = 0; i < len; i++) - buf[i] = readb(chip->IO_ADDR_R); + buf[i] = readb_relaxed(chip->IO_ADDR_R); } } @@ -783,7 +787,7 @@ static int fsmc_bch8_correct_data(struct mtd_info *mtd, uint8_t *dat, uint32_t num_err, i; uint32_t ecc1, ecc2, ecc3, ecc4; - num_err = (readl(FSMC_NAND_REG(regs, bank, STS)) >> 10) & 0xF; + num_err = (readl_relaxed(FSMC_NAND_REG(regs, bank, STS)) >> 10) & 0xF; /* no bit flipping */ if (likely(num_err == 0)) @@ -826,10 +830,10 @@ static int fsmc_bch8_correct_data(struct mtd_info *mtd, uint8_t *dat, * uint64_t array and error offset indexes are populated in err_idx * array */ - ecc1 = readl(FSMC_NAND_REG(regs, bank, ECC1)); - ecc2 = readl(FSMC_NAND_REG(regs, bank, ECC2)); - ecc3 = readl(FSMC_NAND_REG(regs, bank, ECC3)); - ecc4 = readl(FSMC_NAND_REG(regs, bank, STS)); + ecc1 = readl_relaxed(FSMC_NAND_REG(regs, bank, ECC1)); + ecc2 = readl_relaxed(FSMC_NAND_REG(regs, bank, ECC2)); + ecc3 = readl_relaxed(FSMC_NAND_REG(regs, bank, ECC3)); + ecc4 = readl_relaxed(FSMC_NAND_REG(regs, bank, STS)); err_idx[0] = (ecc1 >> 0) & 0x1FFF; err_idx[1] = (ecc1 >> 13) & 0x1FFF; -- 2.7.4