[U-Boot-Users] [PATCH 3/5] OneNAND support

[PATCH] OneNAND support
Signed-off-by: Kyungmin Park kyungmin.park@samsung.com --- diff --git a/drivers/onenand/onenand_base.c b/drivers/onenand/onenand_base.c new file mode 100644 index 0000000..997bd00 --- /dev/null +++ b/drivers/onenand/onenand_base.c @@ -0,0 +1,1312 @@ +/* + * linux/drivers/mtd/onenand/onenand_base.c + * + * Copyright (C) 2005-2007 Samsung Electronics + * Kyungmin Park kyungmin.park@samsung.com + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <common.h> + +#ifdef CONFIG_CMD_ONENAND + +#include <linux/mtd/onenand.h> + +#undef __mem_pci +#include <asm/io.h> + +#ifdef __ARM__ +extern void memcpy32(void *, void *, size_t); + +static void *memcpy(void *dest, const void *src, size_t count) +{ + if (count < 32) { + unsigned short *_s = (unsigned short *)(src); + unsigned short *_d = (unsigned short *)(dest); + count >>= 1; + while (count--) + *_d++ = *_s++; + return _d; + } + + memcpy32(dest, (void *)src, count); + + return (void *)count; +} +#endif + +static const unsigned char ffchars[] = { + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 16 */ + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 32 */ + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 48 */ + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 64 */ +}; + +/** + * onenand_readw - [OneNAND Interface] Read OneNAND register + * @param addr address to read + * + * Read OneNAND register + */ +static unsigned short onenand_readw(void __iomem * addr) +{ + return readw(addr); +} + +/** + * onenand_writew - [OneNAND Interface] Write OneNAND register with value + * @param value value to write + * @param addr address to write + * + * Write OneNAND register with value + */ +static void onenand_writew(unsigned short value, void __iomem * addr) +{ + writew(value, addr); +} + +/** + * onenand_block_address - [DEFAULT] Get block address + * @param device the device id + * @param block the block + * @return translated block address if DDP, otherwise same + * + * Setup Start Address 1 Register (F100h) + */ +static int onenand_block_address(int device, int block) +{ + if (device & ONENAND_DEVICE_IS_DDP) { + /* Device Flash Core select, NAND Flash Block Address */ + int dfs = 0, density, mask; + + density = device >> ONENAND_DEVICE_DENSITY_SHIFT; + mask = (1 << (density + 6)); + + if (block & mask) + dfs = 1; + + return (dfs << ONENAND_DDP_SHIFT) | (block & (mask - 1)); + } + + return block; +} + +/** + * onenand_bufferram_address - [DEFAULT] Get bufferram address + * @param device the device id + * @param block the block + * @return set DBS value if DDP, otherwise 0 + * + * Setup Start Address 2 Register (F101h) for DDP + */ +static int onenand_bufferram_address(int device, int block) +{ + if (device & ONENAND_DEVICE_IS_DDP) { + /* Device BufferRAM Select */ + int dbs = 0, density, mask; + + density = device >> ONENAND_DEVICE_DENSITY_SHIFT; + mask = (1 << (density + 6)); + + if (block & mask) + dbs = 1; + + return (dbs << ONENAND_DDP_SHIFT); + } + + return 0; +} + +/** + * onenand_page_address - [DEFAULT] Get page address + * @param page the page address + * @param sector the sector address + * @return combined page and sector address + * + * Setup Start Address 8 Register (F107h) + */ +static int onenand_page_address(int page, int sector) +{ + /* Flash Page Address, Flash Sector Address */ + int fpa, fsa; + + fpa = page & ONENAND_FPA_MASK; + fsa = sector & ONENAND_FSA_MASK; + + return ((fpa << ONENAND_FPA_SHIFT) | fsa); +} + +/** + * onenand_buffer_address - [DEFAULT] Get buffer address + * @param dataram1 DataRAM index + * @param sectors the sector address + * @param count the number of sectors + * @return the start buffer value + * + * Setup Start Buffer Register (F200h) + */ +static int onenand_buffer_address(int dataram1, int sectors, int count) +{ + int bsa, bsc; + + /* BufferRAM Sector Address */ + bsa = sectors & ONENAND_BSA_MASK; + + if (dataram1) + bsa |= ONENAND_BSA_DATARAM1; /* DataRAM1 */ + else + bsa |= ONENAND_BSA_DATARAM0; /* DataRAM0 */ + + /* BufferRAM Sector Count */ + bsc = count & ONENAND_BSC_MASK; + + return ((bsa << ONENAND_BSA_SHIFT) | bsc); +} + +/** + * onenand_command - [DEFAULT] Send command to OneNAND device + * @param mtd MTD device structure + * @param cmd the command to be sent + * @param addr offset to read from or write to + * @param len number of bytes to read or write + * + * Send command to OneNAND device. This function is used for middle/large page + * devices (1KB/2KB Bytes per page) + */ +static int onenand_command(struct mtd_info *mtd, int cmd, loff_t addr, + size_t len) +{ + struct onenand_chip *this = mtd->priv; + int value, readcmd = 0; + int block, page; + /* Now we use page size operation */ + int sectors = 4, count = 4; + + /* Address translation */ + switch (cmd) { + case ONENAND_CMD_UNLOCK: + case ONENAND_CMD_LOCK: + case ONENAND_CMD_LOCK_TIGHT: + block = -1; + page = -1; + break; + + case ONENAND_CMD_ERASE: + case ONENAND_CMD_BUFFERRAM: + block = (int)(addr >> this->erase_shift); + page = -1; + break; + + default: + block = (int)(addr >> this->erase_shift); + page = (int)(addr >> this->page_shift); + page &= this->page_mask; + break; + } + + /* NOTE: The setting order of the registers is very important! */ + if (cmd == ONENAND_CMD_BUFFERRAM) { + /* Select DataRAM for DDP */ + value = onenand_bufferram_address(this->device_id, block); + this->write_word(value, + this->base + ONENAND_REG_START_ADDRESS2); + + /* Switch to the next data buffer */ + ONENAND_SET_NEXT_BUFFERRAM(this); + + return 0; + } + + if (block != -1) { + /* Write 'DFS, FBA' of Flash */ + value = onenand_block_address(this->device_id, block); + this->write_word(value, + this->base + ONENAND_REG_START_ADDRESS1); + } + + if (page != -1) { + int dataram; + + switch (cmd) { + case ONENAND_CMD_READ: + case ONENAND_CMD_READOOB: + dataram = ONENAND_SET_NEXT_BUFFERRAM(this); + readcmd = 1; + break; + + default: + dataram = ONENAND_CURRENT_BUFFERRAM(this); + break; + } + + /* Write 'FPA, FSA' of Flash */ + value = onenand_page_address(page, sectors); + this->write_word(value, + this->base + ONENAND_REG_START_ADDRESS8); + + /* Write 'BSA, BSC' of DataRAM */ + value = onenand_buffer_address(dataram, sectors, count); + this->write_word(value, this->base + ONENAND_REG_START_BUFFER); + + if (readcmd) { + /* Select DataRAM for DDP */ + value = + onenand_bufferram_address(this->device_id, block); + this->write_word(value, + this->base + + ONENAND_REG_START_ADDRESS2); + } + } + + /* Interrupt clear */ + this->write_word(ONENAND_INT_CLEAR, this->base + ONENAND_REG_INTERRUPT); + /* Write command */ + this->write_word(cmd, this->base + ONENAND_REG_COMMAND); + + return 0; +} + +/** + * onenand_wait - [DEFAULT] wait until the command is done + * @param mtd MTD device structure + * @param state state to select the max. timeout value + * + * Wait for command done. This applies to all OneNAND command + * Read can take up to 30us, erase up to 2ms and program up to 350us + * according to general OneNAND specs + */ +static int onenand_wait(struct mtd_info *mtd, int state) +{ + struct onenand_chip *this = mtd->priv; + unsigned int flags = ONENAND_INT_MASTER; + unsigned int interrupt = 0; + unsigned int ctrl, ecc; + + while (1) { + interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT); + if (interrupt & flags) + break; + } + + ctrl = this->read_word(this->base + ONENAND_REG_CTRL_STATUS); + + if (ctrl & ONENAND_CTRL_ERROR) { + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_wait: controller error = 0x%04x\n", ctrl); + return -EAGAIN; + } + + if (ctrl & ONENAND_CTRL_LOCK) { + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_wait: it's locked error = 0x%04x\n", ctrl); + return -EIO; + } + + if (interrupt & ONENAND_INT_READ) { + ecc = this->read_word(this->base + ONENAND_REG_ECC_STATUS); + if (ecc & ONENAND_ECC_2BIT_ALL) { + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_wait: ECC error = 0x%04x\n", ecc); + return -EBADMSG; + } + } + + return 0; +} + +/** + * onenand_bufferram_offset - [DEFAULT] BufferRAM offset + * @param mtd MTD data structure + * @param area BufferRAM area + * @return offset given area + * + * Return BufferRAM offset given area + */ +static inline int onenand_bufferram_offset(struct mtd_info *mtd, int area) +{ + struct onenand_chip *this = mtd->priv; + + if (ONENAND_CURRENT_BUFFERRAM(this)) { + if (area == ONENAND_DATARAM) + return mtd->oobblock; + if (area == ONENAND_SPARERAM) + return mtd->oobsize; + } + + return 0; +} + +/** + * onenand_read_bufferram - [OneNAND Interface] Read the bufferram area + * @param mtd MTD data structure + * @param area BufferRAM area + * @param buffer the databuffer to put/get data + * @param offset offset to read from or write to + * @param count number of bytes to read/write + * + * Read the BufferRAM area + */ +static int onenand_read_bufferram(struct mtd_info *mtd, int area, + unsigned char *buffer, int offset, + size_t count) +{ + struct onenand_chip *this = mtd->priv; + void __iomem *bufferram; + + bufferram = this->base + area; + bufferram += onenand_bufferram_offset(mtd, area); + + memcpy(buffer, bufferram + offset, count); + + return 0; +} + +/** + * onenand_sync_read_bufferram - [OneNAND Interface] Read the bufferram area with Sync. Burst mode + * @param mtd MTD data structure + * @param area BufferRAM area + * @param buffer the databuffer to put/get data + * @param offset offset to read from or write to + * @param count number of bytes to read/write + * + * Read the BufferRAM area with Sync. Burst Mode + */ +static int onenand_sync_read_bufferram(struct mtd_info *mtd, int area, + unsigned char *buffer, int offset, + size_t count) +{ + struct onenand_chip *this = mtd->priv; + void __iomem *bufferram; + + bufferram = this->base + area; + bufferram += onenand_bufferram_offset(mtd, area); + + this->mmcontrol(mtd, ONENAND_SYS_CFG1_SYNC_READ); + + memcpy(buffer, bufferram + offset, count); + + this->mmcontrol(mtd, 0); + + return 0; +} + +/** + * onenand_write_bufferram - [OneNAND Interface] Write the bufferram area + * @param mtd MTD data structure + * @param area BufferRAM area + * @param buffer the databuffer to put/get data + * @param offset offset to read from or write to + * @param count number of bytes to read/write + * + * Write the BufferRAM area + */ +static int onenand_write_bufferram(struct mtd_info *mtd, int area, + const unsigned char *buffer, int offset, + size_t count) +{ + struct onenand_chip *this = mtd->priv; + void __iomem *bufferram; + + bufferram = this->base + area; + bufferram += onenand_bufferram_offset(mtd, area); + + memcpy(bufferram + offset, buffer, count); + + return 0; +} + +/** + * onenand_check_bufferram - [GENERIC] Check BufferRAM information + * @param mtd MTD data structure + * @param addr address to check + * @return 1 if there are valid data, otherwise 0 + * + * Check bufferram if there is data we required + */ +static int onenand_check_bufferram(struct mtd_info *mtd, loff_t addr) +{ + struct onenand_chip *this = mtd->priv; + int block, page; + int i; + + block = (int)(addr >> this->erase_shift); + page = (int)(addr >> this->page_shift); + page &= this->page_mask; + + i = ONENAND_CURRENT_BUFFERRAM(this); + + /* Is there valid data? */ + if (this->bufferram[i].block == block && + this->bufferram[i].page == page && this->bufferram[i].valid) + return 1; + + return 0; +} + +/** + * onenand_update_bufferram - [GENERIC] Update BufferRAM information + * @param mtd MTD data structure + * @param addr address to update + * @param valid valid flag + * + * Update BufferRAM information + */ +static int onenand_update_bufferram(struct mtd_info *mtd, loff_t addr, + int valid) +{ + struct onenand_chip *this = mtd->priv; + int block, page; + int i; + + block = (int)(addr >> this->erase_shift); + page = (int)(addr >> this->page_shift); + page &= this->page_mask; + + /* Invalidate BufferRAM */ + for (i = 0; i < MAX_BUFFERRAM; i++) { + if (this->bufferram[i].block == block && + this->bufferram[i].page == page) + this->bufferram[i].valid = 0; + } + + /* Update BufferRAM */ + i = ONENAND_CURRENT_BUFFERRAM(this); + this->bufferram[i].block = block; + this->bufferram[i].page = page; + this->bufferram[i].valid = valid; + + return 0; +} + +/** + * onenand_get_device - [GENERIC] Get chip for selected access + * @param mtd MTD device structure + * @param new_state the state which is requested + * + * Get the device and lock it for exclusive access + */ +static void onenand_get_device(struct mtd_info *mtd, int new_state) +{ + /* Do nothing */ +} + +/** + * onenand_release_device - [GENERIC] release chip + * @param mtd MTD device structure + * + * Deselect, release chip lock and wake up anyone waiting on the device + */ +static void onenand_release_device(struct mtd_info *mtd) +{ + /* Do nothing */ +} + +/** + * onenand_read_ecc - [MTD Interface] Read data with ECC + * @param mtd MTD device structure + * @param from offset to read from + * @param len number of bytes to read + * @param retlen pointer to variable to store the number of read bytes + * @param buf the databuffer to put data + * @param oob_buf filesystem supplied oob data buffer + * @param oobsel oob selection structure + * + * OneNAND read with ECC + */ +static int onenand_read_ecc(struct mtd_info *mtd, loff_t from, size_t len, + size_t * retlen, u_char * buf, + u_char * oob_buf, struct nand_oobinfo *oobsel) +{ + struct onenand_chip *this = mtd->priv; + int read = 0, column; + int thislen; + int ret = 0; + + DEBUG(MTD_DEBUG_LEVEL3, "onenand_read_ecc: from = 0x%08x, len = %i\n", + (unsigned int)from, (int)len); + + /* Do not allow reads past end of device */ + if ((from + len) > mtd->size) { + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_read_ecc: Attempt read beyond end of device\n"); + *retlen = 0; + return -EINVAL; + } + + /* Grab the lock and see if the device is available */ + onenand_get_device(mtd, FL_READING); + + while (read < len) { + thislen = min_t(int, mtd->oobblock, len - read); + + column = from & (mtd->oobblock - 1); + if (column + thislen > mtd->oobblock) + thislen = mtd->oobblock - column; + + if (!onenand_check_bufferram(mtd, from)) { + this->command(mtd, ONENAND_CMD_READ, from, + mtd->oobblock); + ret = this->wait(mtd, FL_READING); + /* First copy data and check return value for ECC handling */ + onenand_update_bufferram(mtd, from, 1); + } + + this->read_bufferram(mtd, ONENAND_DATARAM, buf, column, + thislen); + + read += thislen; + if (read == len) + break; + + if (ret) { + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_read_ecc: read failed = %d\n", ret); + break; + } + + from += thislen; + buf += thislen; + } + + /* Deselect and wake up anyone waiting on the device */ + onenand_release_device(mtd); + + /* + * Return success, if no ECC failures, else -EBADMSG + * fs driver will take care of that, because + * retlen == desired len and result == -EBADMSG + */ + *retlen = read; + return ret; +} + +/** + * onenand_read - [MTD Interface] MTD compability function for onenand_read_ecc + * @param mtd MTD device structure + * @param from offset to read from + * @param len number of bytes to read + * @param retlen pointer to variable to store the number of read bytes + * @param buf the databuffer to put data + * + * This function simply calls onenand_read_ecc with oob buffer and oobsel = NULL +*/ +int onenand_read(struct mtd_info *mtd, loff_t from, size_t len, + size_t * retlen, u_char * buf) +{ + return onenand_read_ecc(mtd, from, len, retlen, buf, NULL, NULL); +} + +/** + * onenand_read_oob - [MTD Interface] OneNAND read out-of-band + * @param mtd MTD device structure + * @param from offset to read from + * @param len number of bytes to read + * @param retlen pointer to variable to store the number of read bytes + * @param buf the databuffer to put data + * + * OneNAND read out-of-band data from the spare area + */ +int onenand_read_oob(struct mtd_info *mtd, loff_t from, size_t len, + size_t * retlen, u_char * buf) +{ + struct onenand_chip *this = mtd->priv; + int read = 0, thislen, column; + int ret = 0; + + DEBUG(MTD_DEBUG_LEVEL3, "onenand_read_oob: from = 0x%08x, len = %i\n", + (unsigned int)from, (int)len); + + /* Initialize return length value */ + *retlen = 0; + + /* Do not allow reads past end of device */ + if (unlikely((from + len) > mtd->size)) { + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_read_oob: Attempt read beyond end of device\n"); + return -EINVAL; + } + + /* Grab the lock and see if the device is available */ + onenand_get_device(mtd, FL_READING); + + column = from & (mtd->oobsize - 1); + + while (read < len) { + thislen = mtd->oobsize - column; + thislen = min_t(int, thislen, len); + + this->command(mtd, ONENAND_CMD_READOOB, from, mtd->oobsize); + + onenand_update_bufferram(mtd, from, 0); + + ret = this->wait(mtd, FL_READING); + /* First copy data and check return value for ECC handling */ + + this->read_bufferram(mtd, ONENAND_SPARERAM, buf, column, + thislen); + + read += thislen; + if (read == len) + break; + + if (ret) { + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_read_oob: read failed = %d\n", ret); + break; + } + + buf += thislen; + /* Read more? */ + if (read < len) { + /* Page size */ + from += mtd->oobblock; + column = 0; + } + } + + /* Deselect and wake up anyone waiting on the device */ + onenand_release_device(mtd); + + *retlen = read; + return ret; +} + +#ifdef CONFIG_MTD_ONENAND_VERIFY_WRITE +/** + * onenand_verify_page - [GENERIC] verify the chip contents after a write + * @param mtd MTD device structure + * @param buf the databuffer to verify + * @param block block address + * @param page page address + * + * Check DataRAM area directly + */ +static int onenand_verify_page(struct mtd_info *mtd, u_char * buf, + loff_t addr, int block, int page) +{ + struct onenand_chip *this = mtd->priv; + void __iomem *dataram0, *dataram1; + int ret = 0; + + this->command(mtd, ONENAND_CMD_READ, addr, mtd->oobblock); + + ret = this->wait(mtd, FL_READING); + if (ret) + return ret; + + onenand_update_bufferram(mtd, addr, 1); + + /* Check, if the two dataram areas are same */ + dataram0 = this->base + ONENAND_DATARAM; + dataram1 = dataram0 + mtd->oobblock; + + if (memcmp(dataram0, dataram1, mtd->oobblock)) + return -EBADMSG; + + return 0; +} +#else +#define onenand_verify_page(...) (0) +#endif + +#define NOTALIGNED(x) ((x & (mtd->oobblock - 1)) != 0) + +/** + * onenand_write_ecc - [MTD Interface] OneNAND write with ECC + * @param mtd MTD device structure + * @param to offset to write to + * @param len number of bytes to write + * @param retlen pointer to variable to store the number of written bytes + * @param buf the data to write + * @param eccbuf filesystem supplied oob data buffer + * @param oobsel oob selection structure + * + * OneNAND write with ECC + */ +static int onenand_write_ecc(struct mtd_info *mtd, loff_t to, size_t len, + size_t * retlen, const u_char * buf, + u_char * eccbuf, struct nand_oobinfo *oobsel) +{ + struct onenand_chip *this = mtd->priv; + int written = 0; + int ret = 0; + + DEBUG(MTD_DEBUG_LEVEL3, "onenand_write_ecc: to = 0x%08x, len = %i\n", + (unsigned int)to, (int)len); + + /* Initialize retlen, in case of early exit */ + *retlen = 0; + + /* Do not allow writes past end of device */ + if (unlikely((to + len) > mtd->size)) { + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_write_ecc: Attempt write to past end of device\n"); + return -EINVAL; + } + + /* Reject writes, which are not page aligned */ + if (unlikely(NOTALIGNED(to)) || unlikely(NOTALIGNED(len))) { + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_write_ecc: Attempt to write not page aligned data\n"); + return -EINVAL; + } + + /* Grab the lock and see if the device is available */ + onenand_get_device(mtd, FL_WRITING); + + /* Loop until all data write */ + while (written < len) { + int thislen = min_t(int, mtd->oobblock, len - written); + + this->command(mtd, ONENAND_CMD_BUFFERRAM, to, mtd->oobblock); + + this->write_bufferram(mtd, ONENAND_DATARAM, buf, 0, thislen); + this->write_bufferram(mtd, ONENAND_SPARERAM, ffchars, 0, + mtd->oobsize); + + this->command(mtd, ONENAND_CMD_PROG, to, mtd->oobblock); + + onenand_update_bufferram(mtd, to, 1); + + ret = this->wait(mtd, FL_WRITING); + if (ret) { + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_write_ecc: write filaed %d\n", ret); + break; + } + + written += thislen; + + /* Only check verify write turn on */ + ret = onenand_verify_page(mtd, (u_char *) buf, to, block, page); + if (ret) { + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_write_ecc: verify failed %d\n", ret); + break; + } + + if (written == len) + break; + + to += thislen; + buf += thislen; + } + + /* Deselect and wake up anyone waiting on the device */ + onenand_release_device(mtd); + + *retlen = written; + + return ret; +} + +/** + * onenand_write - [MTD Interface] compability function for onenand_write_ecc + * @param mtd MTD device structure + * @param to offset to write to + * @param len number of bytes to write + * @param retlen pointer to variable to store the number of written bytes + * @param buf the data to write + * + * This function simply calls onenand_write_ecc + * with oob buffer and oobsel = NULL + */ +int onenand_write(struct mtd_info *mtd, loff_t to, size_t len, + size_t * retlen, const u_char * buf) +{ + return onenand_write_ecc(mtd, to, len, retlen, buf, NULL, NULL); +} + +/** + * onenand_write_oob - [MTD Interface] OneNAND write out-of-band + * @param mtd MTD device structure + * @param to offset to write to + * @param len number of bytes to write + * @param retlen pointer to variable to store the number of written bytes + * @param buf the data to write + * + * OneNAND write out-of-band + */ +int onenand_write_oob(struct mtd_info *mtd, loff_t to, size_t len, + size_t * retlen, const u_char * buf) +{ + struct onenand_chip *this = mtd->priv; + int column, status; + int written = 0; + + DEBUG(MTD_DEBUG_LEVEL3, "onenand_write_oob: to = 0x%08x, len = %i\n", + (unsigned int)to, (int)len); + + /* Initialize retlen, in case of early exit */ + *retlen = 0; + + /* Do not allow writes past end of device */ + if (unlikely((to + len) > mtd->size)) { + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_write_oob: Attempt write to past end of device\n"); + return -EINVAL; + } + + /* Grab the lock and see if the device is available */ + onenand_get_device(mtd, FL_WRITING); + + /* Loop until all data write */ + while (written < len) { + int thislen = min_t(int, mtd->oobsize, len - written); + + column = to & (mtd->oobsize - 1); + + this->command(mtd, ONENAND_CMD_BUFFERRAM, to, mtd->oobsize); + + this->write_bufferram(mtd, ONENAND_SPARERAM, ffchars, 0, + mtd->oobsize); + this->write_bufferram(mtd, ONENAND_SPARERAM, buf, column, + thislen); + + this->command(mtd, ONENAND_CMD_PROGOOB, to, mtd->oobsize); + + onenand_update_bufferram(mtd, to, 0); + + status = this->wait(mtd, FL_WRITING); + if (status) + break; + + written += thislen; + if (written == len) + break; + + to += thislen; + buf += thislen; + } + + /* Deselect and wake up anyone waiting on the device */ + onenand_release_device(mtd); + + *retlen = written; + + return 0; +} + +/** + * onenand_erase - [MTD Interface] erase block(s) + * @param mtd MTD device structure + * @param instr erase instruction + * + * Erase one ore more blocks + */ +int onenand_erase(struct mtd_info *mtd, struct erase_info *instr) +{ + struct onenand_chip *this = mtd->priv; + unsigned int block_size; + loff_t addr; + int len; + int ret = 0; + + DEBUG(MTD_DEBUG_LEVEL3, "onenand_erase: start = 0x%08x, len = %i\n", + (unsigned int)instr->addr, (unsigned int)instr->len); + + block_size = (1 << this->erase_shift); + + /* Start address must align on block boundary */ + if (unlikely(instr->addr & (block_size - 1))) { + DEBUG(MTD_DEBUG_LEVEL0, "onenand_erase: Unaligned address\n"); + return -EINVAL; + } + + /* Length must align on block boundary */ + if (unlikely(instr->len & (block_size - 1))) { + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_erase: Length not block aligned\n"); + return -EINVAL; + } + + /* Do not allow erase past end of device */ + if (unlikely((instr->len + instr->addr) > mtd->size)) { + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_erase: Erase past end of device\n"); + return -EINVAL; + } + + instr->fail_addr = 0xffffffff; + + /* Grab the lock and see if the device is available */ + onenand_get_device(mtd, FL_ERASING); + + /* Loop throught the pages */ + len = instr->len; + addr = instr->addr; + + instr->state = MTD_ERASING; + + while (len) { + + /* TODO Check badblock */ + + this->command(mtd, ONENAND_CMD_ERASE, addr, block_size); + + ret = this->wait(mtd, FL_ERASING); + /* Check, if it is write protected */ + if (ret) { + if (ret == -EPERM) + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_erase: Device is write protected!!!\n"); + else + DEBUG(MTD_DEBUG_LEVEL0, + "onenand_erase: Failed erase, block %d\n", + (unsigned)(addr >> this->erase_shift)); + instr->state = MTD_ERASE_FAILED; + instr->fail_addr = addr; + goto erase_exit; + } + + len -= block_size; + addr += block_size; + } + + instr->state = MTD_ERASE_DONE; + + erase_exit: + + ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO; + /* Do call back function */ + if (!ret) + mtd_erase_callback(instr); + + /* Deselect and wake up anyone waiting on the device */ + onenand_release_device(mtd); + + return ret; +} + +/** + * onenand_sync - [MTD Interface] sync + * @param mtd MTD device structure + * + * Sync is actually a wait for chip ready function + */ +void onenand_sync(struct mtd_info *mtd) +{ + DEBUG(MTD_DEBUG_LEVEL3, "onenand_sync: called\n"); + + /* Grab the lock and see if the device is available */ + onenand_get_device(mtd, FL_SYNCING); + + /* Release it and go back */ + onenand_release_device(mtd); +} + +/** + * onenand_block_isbad - [MTD Interface] Check whether the block at the given offset is bad + * @param mtd MTD device structure + * @param ofs offset relative to mtd start + */ +int onenand_block_isbad(struct mtd_info *mtd, loff_t ofs) +{ + /* + * TODO + * 1. Bad block table (BBT) + * -> using NAND BBT to support JFFS2 + * 2. Bad block management (BBM) + * -> bad block replace scheme + * + * Currently we do nothing + */ + return 0; +} + +/** + * onenand_block_markbad - [MTD Interface] Mark the block at the given offset as bad + * @param mtd MTD device structure + * @param ofs offset relative to mtd start + */ +int onenand_block_markbad(struct mtd_info *mtd, loff_t ofs) +{ + /* see above */ + return 0; +} + +/** + * onenand_unlock - [MTD Interface] Unlock block(s) + * @param mtd MTD device structure + * @param ofs offset relative to mtd start + * @param len number of bytes to unlock + * + * Unlock one or more blocks + */ +int onenand_unlock(struct mtd_info *mtd, loff_t ofs, size_t len) +{ + struct onenand_chip *this = mtd->priv; + int start, end, block, value, status; + + start = ofs >> this->erase_shift; + end = len >> this->erase_shift; + + /* Continuous lock scheme */ + if (this->options & ONENAND_CONT_LOCK) { + /* Set start block address */ + this->write_word(start, + this->base + ONENAND_REG_START_BLOCK_ADDRESS); + /* Set end block address */ + this->write_word(end - 1, + this->base + ONENAND_REG_END_BLOCK_ADDRESS); + /* Write unlock command */ + this->command(mtd, ONENAND_CMD_UNLOCK, 0, 0); + + /* There's no return value */ + this->wait(mtd, FL_UNLOCKING); + + /* Sanity check */ + while (this->read_word(this->base + ONENAND_REG_CTRL_STATUS) + & ONENAND_CTRL_ONGO) + continue; + + /* Check lock status */ + status = this->read_word(this->base + ONENAND_REG_WP_STATUS); + if (!(status & ONENAND_WP_US)) + printk(KERN_ERR "wp status = 0x%x\n", status); + + return 0; + } + + /* Block lock scheme */ + for (block = start; block < end; block++) { + /* Set start block address */ + this->write_word(block, + this->base + ONENAND_REG_START_BLOCK_ADDRESS); + /* Write unlock command */ + this->command(mtd, ONENAND_CMD_UNLOCK, 0, 0); + + /* There's no return value */ + this->wait(mtd, FL_UNLOCKING); + + /* Sanity check */ + while (this->read_word(this->base + ONENAND_REG_CTRL_STATUS) + & ONENAND_CTRL_ONGO) + continue; + + /* Set block address for read block status */ + value = onenand_block_address(this->device_id, block); + this->write_word(value, + this->base + ONENAND_REG_START_ADDRESS1); + + /* Check lock status */ + status = this->read_word(this->base + ONENAND_REG_WP_STATUS); + if (!(status & ONENAND_WP_US)) + printk(KERN_ERR "block = %d, wp status = 0x%x\n", + block, status); + } + + return 0; +} + +/** + * onenand_print_device_info - Print device ID + * @param device device ID + * + * Print device ID + */ +void onenand_print_device_info(int device, int verbose) +{ + int vcc, demuxed, ddp, density; + + if (!verbose) + return; + + vcc = device & ONENAND_DEVICE_VCC_MASK; + demuxed = device & ONENAND_DEVICE_IS_DEMUX; + ddp = device & ONENAND_DEVICE_IS_DDP; + density = device >> ONENAND_DEVICE_DENSITY_SHIFT; + printk(KERN_INFO "%sOneNAND%s %dMB %sV 16-bit (0x%02x)\n", + demuxed ? "" : "Muxed ", + ddp ? "(DDP)" : "", + (16 << density), vcc ? "2.65/3.3" : "1.8", device); +} + +static const struct onenand_manufacturers onenand_manuf_ids[] = { + {ONENAND_MFR_SAMSUNG, "Samsung"}, + {ONENAND_MFR_UNKNOWN, "Unknown"} +}; + +/** + * onenand_check_maf - Check manufacturer ID + * @param manuf manufacturer ID + * + * Check manufacturer ID + */ +static int onenand_check_maf(int manuf) +{ + int i; + + for (i = 0; onenand_manuf_ids[i].id; i++) { + if (manuf == onenand_manuf_ids[i].id) + break; + } + +#ifdef ONENAND_DEBUG + printk(KERN_DEBUG "OneNAND Manufacturer: %s (0x%0x)\n", + onenand_manuf_ids[i].name, manuf); +#endif + + return (i != ONENAND_MFR_UNKNOWN); +} + +/** + * onenand_probe - [OneNAND Interface] Probe the OneNAND device + * @param mtd MTD device structure + * + * OneNAND detection method: + * Compare the the values from command with ones from register + */ +static int onenand_probe(struct mtd_info *mtd) +{ + struct onenand_chip *this = mtd->priv; + int bram_maf_id, bram_dev_id, maf_id, dev_id; + int version_id; + int density; + + /* Send the command for reading device ID from BootRAM */ + this->write_word(ONENAND_CMD_READID, this->base + ONENAND_BOOTRAM); + + /* Read manufacturer and device IDs from BootRAM */ + bram_maf_id = this->read_word(this->base + ONENAND_BOOTRAM + 0x0); + bram_dev_id = this->read_word(this->base + ONENAND_BOOTRAM + 0x2); + + /* Check manufacturer ID */ + if (onenand_check_maf(bram_maf_id)) + return -ENXIO; + + /* Reset OneNAND to read default register values */ + this->write_word(ONENAND_CMD_RESET, this->base + ONENAND_BOOTRAM); + + { + int i; + for (i = 0; i < 10000; i++) ; + } + + /* Read manufacturer and device IDs from Register */ + maf_id = this->read_word(this->base + ONENAND_REG_MANUFACTURER_ID); + dev_id = this->read_word(this->base + ONENAND_REG_DEVICE_ID); + + /* Check OneNAND device */ + if (maf_id != bram_maf_id || dev_id != bram_dev_id) + return -ENXIO; + + /* Flash device information */ + onenand_print_device_info(dev_id, 0); + this->device_id = dev_id; + + density = dev_id >> ONENAND_DEVICE_DENSITY_SHIFT; + this->chipsize = (16 << density) << 20; + + /* OneNAND page size & block size */ + /* The data buffer size is equal to page size */ + mtd->oobblock = + this->read_word(this->base + ONENAND_REG_DATA_BUFFER_SIZE); + mtd->oobsize = mtd->oobblock >> 5; + /* Pagers per block is always 64 in OneNAND */ + mtd->erasesize = mtd->oobblock << 6; + + this->erase_shift = ffs(mtd->erasesize) - 1; + this->page_shift = ffs(mtd->oobblock) - 1; + this->ppb_shift = (this->erase_shift - this->page_shift); + this->page_mask = (mtd->erasesize / mtd->oobblock) - 1; + + /* REVIST: Multichip handling */ + + mtd->size = this->chipsize; + + /* Version ID */ + version_id = this->read_word(this->base + ONENAND_REG_VERSION_ID); +#ifdef ONENAND_DEBUG + printk(KERN_DEBUG "OneNAND version = 0x%04x\n", version_id); +#endif + + /* Lock scheme */ + if (density <= ONENAND_DEVICE_DENSITY_512Mb && + !(version_id >> ONENAND_VERSION_PROCESS_SHIFT)) { + printk(KERN_INFO "Lock scheme is Continues Lock\n"); + this->options |= ONENAND_CONT_LOCK; + } + + return 0; +} + +/** + * onenand_scan - [OneNAND Interface] Scan for the OneNAND device + * @param mtd MTD device structure + * @param maxchips Number of chips to scan for + * + * This fills out all the not initialized function pointers + * with the defaults. + * The flash ID is read and the mtd/chip structures are + * filled with the appropriate values. + */ +int onenand_scan(struct mtd_info *mtd, int maxchips) +{ + struct onenand_chip *this = mtd->priv; + + if (!this->read_word) + this->read_word = onenand_readw; + if (!this->write_word) + this->write_word = onenand_writew; + + if (!this->command) + this->command = onenand_command; + if (!this->wait) + this->wait = onenand_wait; + + if (!this->read_bufferram) + this->read_bufferram = onenand_read_bufferram; + if (!this->write_bufferram) + this->write_bufferram = onenand_write_bufferram; + + if (onenand_probe(mtd)) + return -ENXIO; + + /* Set Sync. Burst Read after probing */ + if (this->mmcontrol) { + printk(KERN_INFO "OneNAND Sync. Burst Read support\n"); + this->read_bufferram = onenand_sync_read_bufferram; + } + + onenand_unlock(mtd, 0, mtd->size); + + return onenand_default_bbt(mtd); +} + +/** + * onenand_release - [OneNAND Interface] Free resources held by the OneNAND device + * @param mtd MTD device structure + */ +void onenand_release(struct mtd_info *mtd) +{ +} + +/* + * OneNAND initialization at U-Boot + */ +struct mtd_info onenand_mtd; +struct onenand_chip onenand_chip; + +void onenand_init(void) +{ + memset(&onenand_mtd, 0, sizeof(struct mtd_info)); + memset(&onenand_chip, 0, sizeof(struct onenand_chip)); + + onenand_chip.base = (void *)CFG_ONENAND_BASE; + onenand_mtd.priv = &onenand_chip; + + onenand_scan(&onenand_mtd, 1); + + puts("OneNAND: "); + print_size(onenand_mtd.size, "\n"); +} + +#endif /* CFG_CMD_ONENAND */

In message 20070907005923.GA19912@party you wrote:
[PATCH] OneNAND support
Signed-off-by: Kyungmin Park kyungmin.park@samsung.com
diff --git a/drivers/onenand/onenand_base.c b/drivers/onenand/onenand_base.c new file mode 100644 index 0000000..997bd00 --- /dev/null +++ b/drivers/onenand/onenand_base.c
...
+#ifdef __ARM__ +extern void memcpy32(void *, void *, size_t);
+static void *memcpy(void *dest, const void *src, size_t count) +{
- if (count < 32) {
unsigned short *_s = (unsigned short *)(src);
unsigned short *_d = (unsigned short *)(dest);
count >>= 1;
while (count--)
*_d++ = *_s++;
return _d;
- }
- memcpy32(dest, (void *)src, count);
- return (void *)count;
+} +#endif
Why exactly do we need this? And why do we need an additonal special function memcpy32?
+static const unsigned char ffchars[] = {
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 16 */
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 32 */
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 48 */
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 64 */
+};
Using a dynamic buffer and a memset() call in the init code may helpt to reduce the memory footprint. What do you think?
+static unsigned short onenand_readw(void __iomem * addr) +{
- return readw(addr);
+}
...
+static void onenand_writew(unsigned short value, void __iomem * addr) +{
- writew(value, addr);
+}
If this is all you do, you should probably use an inline or a macro.
- Get the device and lock it for exclusive access
- */
+static void onenand_get_device(struct mtd_info *mtd, int new_state) +{
- /* Do nothing */
+}
...
- Deselect, release chip lock and wake up anyone waiting on the device
- */
+static void onenand_release_device(struct mtd_info *mtd) +{
- /* Do nothing */
+}
Inline? Macro?
+int onenand_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t * retlen, u_char * buf)
+{
- return onenand_read_ecc(mtd, from, len, retlen, buf, NULL, NULL);
+}
Inline? Macro?
+int onenand_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t * retlen, const u_char * buf)
+{
- return onenand_write_ecc(mtd, to, len, retlen, buf, NULL, NULL);
+}
Inline? Macro?
+int onenand_block_isbad(struct mtd_info *mtd, loff_t ofs) +{
- /*
* TODO
* 1. Bad block table (BBT)
* -> using NAND BBT to support JFFS2
* 2. Bad block management (BBM)
* -> bad block replace scheme
*
* Currently we do nothing
*/
- return 0;
+}
+/**
- onenand_block_markbad - [MTD Interface] Mark the block at the given offset as bad
- @param mtd MTD device structure
- @param ofs offset relative to mtd start
- */
+int onenand_block_markbad(struct mtd_info *mtd, loff_t ofs) +{
- /* see above */
- return 0;
+}
Do we need these, then?
+/**
- onenand_release - [OneNAND Interface] Free resources held by the OneNAND device
- @param mtd MTD device structure
- */
+void onenand_release(struct mtd_info *mtd) +{ +}
Do we need this, then?
Best regards,
Wolfgang Denk

...
+#ifdef __ARM__ +extern void memcpy32(void *, void *, size_t);
+static void *memcpy(void *dest, const void *src, size_t count) +{
- if (count < 32) {
unsigned short *_s = (unsigned short *)(src);
unsigned short *_d = (unsigned short *)(dest);
count >>= 1;
while (count--)
*_d++ = *_s++;
return _d;
- }
- memcpy32(dest, (void *)src, count);
- return (void *)count;
+} +#endif
Why exactly do we need this? And why do we need an additonal special function memcpy32?
It's for performance. Now ARM used the char-based memcpy. Even though it's working with current char-based memcpy, I want to use the optimized memcpy. And basically OneNAND uses the 16-bit buswidth so we don't sure the correct behavior in OneNAND BufferRAM if we use the char-based memcpy.
Memcpy32 is 32-bytes aligned optimized. Since we know the memcpy usages in OneNAND driver, we guarantee the usage of memcpy32.
+static const unsigned char ffchars[] = {
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 16 */
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 32 */
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 48 */
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 64 */
+};
Using a dynamic buffer and a memset() call in the init code may helpt to reduce the memory footprint. What do you think?
At first I want to sync between the linux OneNAND code and u-boot one. The current code of u-boot patch is the first implementation of linux OneNAND. There are a lot of works to sync. So after committing of patches, I will modify it.
+static unsigned short onenand_readw(void __iomem * addr) +{
- return readw(addr);
+}
...
+static void onenand_writew(unsigned short value, void __iomem * addr) +{
- writew(value, addr);
+}
If this is all you do, you should probably use an inline or a macro.
It's same reason as above. In linux OneNAND, we can overwrite the readw and writew. But I'm now sure it's needed at u-boot. if (!this->read_word) this->read_word = onenand_readw; if (!this->write_word) this->write_word = onenand_writew;
- Get the device and lock it for exclusive access
- */
+static void onenand_get_device(struct mtd_info *mtd, int new_state) +{
- /* Do nothing */
+}
...
- Deselect, release chip lock and wake up anyone waiting on the device
- */
+static void onenand_release_device(struct mtd_info *mtd) +{
- /* Do nothing */
+}
Inline? Macro?
Also others are same. Some functions are don't needed at u-boot. But it was remained for easy adaptation from linux to u-boot.
Thank you, Kyungmin Park

In message 002501c7f347$e1d579c0$e1ac580a@swcenter.sec.samsung.co.kr you wrote:
...
+#ifdef __ARM__ +extern void memcpy32(void *, void *, size_t);
+static void *memcpy(void *dest, const void *src, size_t count) +{
- if (count < 32) {
unsigned short *_s = (unsigned short *)(src);
unsigned short *_d = (unsigned short *)(dest);
count >>= 1;
while (count--)
*_d++ = *_s++;
return _d;
- }
- memcpy32(dest, (void *)src, count);
- return (void *)count;
+} +#endif
Why exactly do we need this? And why do we need an additonal special function memcpy32?
It's for performance. Now ARM used the char-based memcpy. Even though it's working with current char-based memcpy, I want to use the optimized memcpy.
How much difference does this optimization make in real life? Do you have any time measurements at hand?
I'm concerned about correctness. What happens in your coide when I write
memcpy (dst, src, 5);
How many bytes will be copied?
What happens when src or dst or both are pointing to odd addresses, i. e. in case of unaligned accesses?
And basically OneNAND uses the 16-bit buswidth so we don't sure the correct behavior in OneNAND BufferRAM if we use the char-based memcpy.
I remember that ARM is terribly broken there... :-(
Memcpy32 is 32-bytes aligned optimized. Since we know the memcpy usages in OneNAND driver, we guarantee the usage of memcpy32.
But the memcpy() you provide will also be used in all other partrs of U-Boot, won't it?
Using a dynamic buffer and a memset() call in the init code may helpt to reduce the memory footprint. What do you think?
At first I want to sync between the linux OneNAND code and u-boot one. The current code of u-boot patch is the first implementation of linux OneNAND. There are a lot of works to sync. So after committing of patches, I will modify it.
Agreed.
Also others are same. Some functions are don't needed at u-boot. But it was remained for easy adaptation from linux to u-boot.
Understood and agreed.
Thank you,
Thank *you*.
Best regards,
Wolfgang Denk

-----Original Message----- From: wd@denx.de [mailto:wd@denx.de] Sent: Monday, September 10, 2007 4:07 PM To: kmpark@infradead.org Cc: u-boot-users@lists.sourceforge.net Subject: Re: [U-Boot-Users] [PATCH 3/5] OneNAND support
In message 002501c7f347$e1d579c0$e1ac580a@swcenter.sec.samsung.co.kr you wrote:
...
+#ifdef __ARM__ +extern void memcpy32(void *, void *, size_t);
+static void *memcpy(void *dest, const void *src, size_t count) +{
- if (count < 32) {
unsigned short *_s = (unsigned short *)(src);
unsigned short *_d = (unsigned short *)(dest);
count >>= 1;
while (count--)
*_d++ = *_s++;
return _d;
- }
- memcpy32(dest, (void *)src, count);
- return (void *)count;
+} +#endif
Why exactly do we need this? And why do we need an additonal special function memcpy32?
It's for performance. Now ARM used the char-based memcpy. Even though it's working with current
char-based memcpy, I want to use the
optimized memcpy.
How much difference does this optimization make in real life? Do you have any time measurements at hand?
It's also discuss the at previous time http://sourceforge.net/mailarchive/message.php?msg_id=f3f1b91a0703141856n180...
I'm concerned about correctness. What happens in your coide when I write
memcpy (dst, src, 5);
How many bytes will be copied?
What happens when src or dst or both are pointing to odd addresses, i. e. in case of unaligned accesses?
Agreed
And basically OneNAND uses the 16-bit buswidth so we don't sure the correct behavior in OneNAND
BufferRAM if we use the char-based
memcpy.
I remember that ARM is terribly broken there... :-(
Memcpy32 is 32-bytes aligned optimized. Since we know the memcpy usages in OneNAND driver, we
guarantee the usage of memcpy32.
But the memcpy() you provide will also be used in all other partrs of U-Boot, won't it?
If you concern the portability issues, I can omit it at this time. How do you think about it?
Thank you, Kyungmin Park

In message 003101c7f37f$1fcb6cd0$e1ac580a@swcenter.sec.samsung.co.kr you wrote:
+static void *memcpy(void *dest, const void *src, size_t count) +{
- if (count < 32) {
unsigned short *_s = (unsigned short *)(src);
unsigned short *_d = (unsigned short *)(dest);
count >>= 1;
while (count--)
*_d++ = *_s++;
return _d;
- }
...
How much difference does this optimization make in real life? Do you have any time measurements at hand?
It's also discuss the at previous time http://sourceforge.net/mailarchive/message.php?msg_id=f3f1b91a0703141856n180...
Now I remember, thanks for the link.
I'm concerned about correctness. What happens in your coide when I write
memcpy (dst, src, 5);
How many bytes will be copied?
What happens when src or dst or both are pointing to odd addresses, i. e. in case of unaligned accesses?
Agreed
If my interpretation is right, that above implementation will copy only 4 bytes when I ask for 5 to be copied, then the answer is simple: fix it, or dump it.
I remember that ARM is terribly broken there... :-(
Memcpy32 is 32-bytes aligned optimized. Since we know the memcpy usages in OneNAND driver, we
guarantee the usage of memcpy32.
But the memcpy() you provide will also be used in all other partrs of U-Boot, won't it?
If you concern the portability issues, I can omit it at this time. How do you think about it?
Portability is one thing, but it seems to be not correct, which is a strict No, No to me.
Best regards,
Wolfgang Denk
participants (2)
-
Kyungmin Park
-
Wolfgang Denk