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0dd5235f51
Some MTD drivers return -EINVAL if the 'phys' parameter is not NULL, trying to
convey that they cannot return the physical address. However, this is not very
logical because they still can return the virtual address ('virt'). But some
drivers (lpddr) just ignore the 'phys' parameter instead, which is a more
logical thing to do.
Let's harmonize this and:
1. Always initialize 'virt' and 'phys' to 'NULL' in 'mtd_point()'.
2. Do not return an error if the physical address cannot be found.
So as a result, all drivers will set 'phys' to 'NULL' if it is not supported.
None of the 'mtd_point()' users use 'phys' anyway, so this should not break
anything. I guess we could also just delete this parameter later.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
159 lines
3.6 KiB
C
159 lines
3.6 KiB
C
/*
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* mtdram - a test mtd device
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* Author: Alexander Larsson <alex@cendio.se>
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*
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* Copyright (c) 1999 Alexander Larsson <alex@cendio.se>
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* Copyright (c) 2005 Joern Engel <joern@wh.fh-wedel.de>
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*
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* This code is GPL
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*
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*/
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/ioport.h>
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#include <linux/vmalloc.h>
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#include <linux/init.h>
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/mtdram.h>
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static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE;
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static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE;
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#define MTDRAM_TOTAL_SIZE (total_size * 1024)
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#define MTDRAM_ERASE_SIZE (erase_size * 1024)
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#ifdef MODULE
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module_param(total_size, ulong, 0);
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MODULE_PARM_DESC(total_size, "Total device size in KiB");
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module_param(erase_size, ulong, 0);
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MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");
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#endif
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// We could store these in the mtd structure, but we only support 1 device..
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static struct mtd_info *mtd_info;
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static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
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{
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memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
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instr->state = MTD_ERASE_DONE;
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mtd_erase_callback(instr);
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return 0;
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}
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static int ram_point(struct mtd_info *mtd, loff_t from, size_t len,
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size_t *retlen, void **virt, resource_size_t *phys)
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{
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*virt = mtd->priv + from;
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*retlen = len;
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return 0;
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}
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static int ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
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{
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return 0;
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}
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/*
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* Allow NOMMU mmap() to directly map the device (if not NULL)
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* - return the address to which the offset maps
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* - return -ENOSYS to indicate refusal to do the mapping
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*/
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static unsigned long ram_get_unmapped_area(struct mtd_info *mtd,
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unsigned long len,
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unsigned long offset,
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unsigned long flags)
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{
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return (unsigned long) mtd->priv + offset;
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}
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static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
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size_t *retlen, u_char *buf)
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{
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memcpy(buf, mtd->priv + from, len);
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*retlen = len;
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return 0;
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}
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static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
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size_t *retlen, const u_char *buf)
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{
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memcpy((char *)mtd->priv + to, buf, len);
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*retlen = len;
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return 0;
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}
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static void __exit cleanup_mtdram(void)
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{
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if (mtd_info) {
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mtd_device_unregister(mtd_info);
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vfree(mtd_info->priv);
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kfree(mtd_info);
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}
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}
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int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
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unsigned long size, char *name)
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{
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memset(mtd, 0, sizeof(*mtd));
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/* Setup the MTD structure */
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mtd->name = name;
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mtd->type = MTD_RAM;
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mtd->flags = MTD_CAP_RAM;
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mtd->size = size;
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mtd->writesize = 1;
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mtd->writebufsize = 64; /* Mimic CFI NOR flashes */
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mtd->erasesize = MTDRAM_ERASE_SIZE;
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mtd->priv = mapped_address;
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mtd->owner = THIS_MODULE;
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mtd->_erase = ram_erase;
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mtd->_point = ram_point;
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mtd->_unpoint = ram_unpoint;
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mtd->_get_unmapped_area = ram_get_unmapped_area;
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mtd->_read = ram_read;
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mtd->_write = ram_write;
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if (mtd_device_register(mtd, NULL, 0))
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return -EIO;
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return 0;
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}
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static int __init init_mtdram(void)
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{
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void *addr;
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int err;
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if (!total_size)
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return -EINVAL;
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/* Allocate some memory */
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mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
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if (!mtd_info)
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return -ENOMEM;
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addr = vmalloc(MTDRAM_TOTAL_SIZE);
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if (!addr) {
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kfree(mtd_info);
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mtd_info = NULL;
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return -ENOMEM;
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}
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err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device");
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if (err) {
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vfree(addr);
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kfree(mtd_info);
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mtd_info = NULL;
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return err;
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}
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memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
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return err;
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}
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module_init(init_mtdram);
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module_exit(cleanup_mtdram);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
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MODULE_DESCRIPTION("Simulated MTD driver for testing");
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