nuttx/drivers/misc/ramdisk.c
chao an 664927c86e mm/alloc: remove all unnecessary cast for alloc
Fix the minor style issue and remove unnecessary cast

Signed-off-by: chao an <anchao@xiaomi.com>
2023-08-30 14:34:20 +08:00

464 lines
13 KiB
C

/****************************************************************************
* drivers/misc/ramdisk.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <debug.h>
#include <errno.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>
#include <nuttx/drivers/ramdisk.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Helpers for rdflags */
/* User input flags */
#define RDFLAG_USER (RDFLAG_WRENABLED | RDFLAG_FUNLINK)
#define RDFLAG_IS_WRENABLED(f) (((f) & RDFLAG_WRENABLED) != 0)
#define RDFLAG_IS_FUNLINK(f) (((f) & RDFLAG_FUNLINK) != 0)
/* Flag set when the RAM disk block driver is unlink */
#define RDFLAG_UNLINK(f) do { (f) |= RDFLAG_UNLINKED; } while (0)
#define RDFLAG_IS_UNLINKED(f) (((f) & RDFLAG_UNLINKED) != 0)
/****************************************************************************
* Private Types
****************************************************************************/
struct rd_struct_s
{
uint32_t rd_nsectors; /* Number of sectors on device */
uint16_t rd_sectsize; /* The size of one sector */
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
uint8_t rd_crefs; /* Open reference count */
#endif
uint8_t rd_flags; /* See RDFLAG_* definitions */
FAR uint8_t *rd_buffer; /* RAM disk backup memory */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
static void rd_destroy(FAR struct rd_struct_s *dev);
static int rd_open(FAR struct inode *inode);
static int rd_close(FAR struct inode *inode);
#endif
static ssize_t rd_read(FAR struct inode *inode, FAR unsigned char *buffer,
blkcnt_t start_sector, unsigned int nsectors);
static ssize_t rd_write(FAR struct inode *inode,
FAR const unsigned char *buffer, blkcnt_t start_sector,
unsigned int nsectors);
static int rd_geometry(FAR struct inode *inode,
FAR struct geometry *geometry);
static int rd_ioctl(FAR struct inode *inode, int cmd,
unsigned long arg);
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
static int rd_unlink(FAR struct inode *inode);
#endif
/****************************************************************************
* Private Data
****************************************************************************/
static const struct block_operations g_bops =
{
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
rd_open, /* open */
rd_close, /* close */
#else
0, /* open */
0, /* close */
#endif
rd_read, /* read */
rd_write, /* write */
rd_geometry, /* geometry */
rd_ioctl, /* ioctl */
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
rd_unlink /* unlink */
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: rd_destroy
*
* Description:
* Free all resources used by the RAM disk
*
****************************************************************************/
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
static void rd_destroy(FAR struct rd_struct_s *dev)
{
finfo("Destroying RAM disk\n");
/* We we configured to free the RAM disk memory when unlinked? */
if (RDFLAG_IS_UNLINKED(dev->rd_flags))
{
/* Yes.. do it */
if (dev->rd_flags & RDFLAG_USER)
{
kmm_free(dev->rd_buffer);
}
}
/* And free the block driver itself */
kmm_free(dev);
}
#endif
/****************************************************************************
* Name: rd_open
*
* Description: Open the block device
*
****************************************************************************/
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
static int rd_open(FAR struct inode *inode)
{
FAR struct rd_struct_s *dev;
DEBUGASSERT(inode->i_private);
dev = inode->i_private;
/* Increment the open reference count */
dev->rd_crefs++;
DEBUGASSERT(dev->rd_crefs > 0);
finfo("rd_crefs: %d\n", dev->rd_crefs);
return OK;
}
#endif
/****************************************************************************
* Name: rd_close
*
* Description: close the block device
*
****************************************************************************/
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
static int rd_close(FAR struct inode *inode)
{
FAR struct rd_struct_s *dev;
DEBUGASSERT(inode->i_private);
dev = inode->i_private;
/* Increment the open reference count */
DEBUGASSERT(dev->rd_crefs > 0);
dev->rd_crefs--;
finfo("rd_crefs: %d\n", dev->rd_crefs);
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
/* Was that the last open reference to the RAM disk? */
if (dev->rd_crefs == 0)
{
/* Yes.. Have we been unlinked? */
if (RDFLAG_IS_UNLINKED(dev->rd_flags))
{
/* Yes.. Release all of the RAM disk resources */
rd_destroy(dev);
}
}
#endif
return OK;
}
#endif
/****************************************************************************
* Name: rd_read
*
* Description: Read the specified number of sectors
*
****************************************************************************/
static ssize_t rd_read(FAR struct inode *inode, unsigned char *buffer,
blkcnt_t start_sector, unsigned int nsectors)
{
FAR struct rd_struct_s *dev;
DEBUGASSERT(inode->i_private);
dev = inode->i_private;
finfo("sector: %" PRIuOFF " nsectors: %u sectorsize: %d\n",
start_sector, nsectors, dev->rd_sectsize);
if (start_sector < dev->rd_nsectors &&
start_sector + nsectors <= dev->rd_nsectors)
{
finfo("Transfer %d bytes from %p\n",
nsectors * dev->rd_sectsize,
&dev->rd_buffer[start_sector * dev->rd_sectsize]);
memcpy(buffer,
&dev->rd_buffer[start_sector * dev->rd_sectsize],
nsectors * dev->rd_sectsize);
return nsectors;
}
return -EINVAL;
}
/****************************************************************************
* Name: rd_write
*
* Description: Write the specified number of sectors
*
****************************************************************************/
static ssize_t rd_write(FAR struct inode *inode, const unsigned char *buffer,
blkcnt_t start_sector, unsigned int nsectors)
{
struct rd_struct_s *dev;
DEBUGASSERT(inode->i_private);
dev = inode->i_private;
finfo("sector: %" PRIuOFF " nsectors: %u sectorsize: %d\n",
start_sector, nsectors, dev->rd_sectsize);
if (!RDFLAG_IS_WRENABLED(dev->rd_flags))
{
return -EACCES;
}
else if (start_sector < dev->rd_nsectors &&
start_sector + nsectors <= dev->rd_nsectors)
{
finfo("Transfer %d bytes to %p\n",
nsectors * dev->rd_sectsize,
&dev->rd_buffer[start_sector * dev->rd_sectsize]);
memcpy(&dev->rd_buffer[start_sector * dev->rd_sectsize],
buffer,
nsectors * dev->rd_sectsize);
return nsectors;
}
return -EFBIG;
}
/****************************************************************************
* Name: rd_geometry
*
* Description: Return device geometry
*
****************************************************************************/
static int rd_geometry(FAR struct inode *inode, struct geometry *geometry)
{
struct rd_struct_s *dev;
finfo("Entry\n");
if (geometry)
{
dev = inode->i_private;
memset(geometry, 0, sizeof(*geometry));
geometry->geo_available = true;
geometry->geo_mediachanged = false;
geometry->geo_writeenabled = RDFLAG_IS_WRENABLED(dev->rd_flags);
geometry->geo_nsectors = dev->rd_nsectors;
geometry->geo_sectorsize = dev->rd_sectsize;
finfo("available: true mediachanged: false writeenabled: %s\n",
geometry->geo_writeenabled ? "true" : "false");
finfo("nsectors: %" PRIuOFF " sectorsize: %" PRIi16 "\n",
geometry->geo_nsectors, geometry->geo_sectorsize);
return OK;
}
return -EINVAL;
}
/****************************************************************************
* Name: rd_ioctl
*
* Description:
* Return device geometry
*
****************************************************************************/
static int rd_ioctl(FAR struct inode *inode, int cmd, unsigned long arg)
{
FAR struct rd_struct_s *dev;
FAR void **ppv = (void**)((uintptr_t)arg);
finfo("Entry\n");
/* Only one ioctl command is supported */
DEBUGASSERT(inode->i_private);
if (cmd == BIOC_XIPBASE && ppv)
{
dev = inode->i_private;
*ppv = (FAR void *)dev->rd_buffer;
finfo("ppv: %p\n", *ppv);
return OK;
}
return -ENOTTY;
}
/****************************************************************************
* Name: rd_unlink
*
* Description:
* The block driver has been unlinked.
*
****************************************************************************/
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
static int rd_unlink(FAR struct inode *inode)
{
FAR struct rd_struct_s *dev;
DEBUGASSERT(inode->i_private);
dev = inode->i_private;
/* Mark the pipe unlinked */
RDFLAG_UNLINK(dev->rd_flags);
/* Are the any open references to the driver? */
if (dev->rd_crefs == 0)
{
/* No... release all resources held by the block driver */
rd_destroy(dev);
}
return OK;
}
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: ramdisk_register or romdisk_register
*
* Description:
* Non-standard function to register a ramdisk or a romdisk
*
* Input Parameters:
* minor: Selects suffix of device named /dev/ramN, N={1,2,3...}
* nsectors: Number of sectors on device
* sectize: The size of one sector
* rdflags: See RDFLAG_* definitions
* buffer: RAM disk backup memory
*
* Returned Value:
* Zero on success; a negated errno value on failure.
*
****************************************************************************/
int ramdisk_register(int minor, FAR uint8_t *buffer, uint32_t nsectors,
uint16_t sectsize, uint8_t rdflags)
{
struct rd_struct_s *dev;
char devname[16];
int ret = -ENOMEM;
finfo("buffer: %p nsectors: %" PRIu32 " sectsize: %" PRIu16 "\n",
buffer, nsectors, sectsize);
/* Sanity check */
#ifdef CONFIG_DEBUG_FEATURES
if (minor < 0 || minor > 255 || !buffer || !nsectors || !sectsize)
{
return -EINVAL;
}
#endif
/* Allocate a ramdisk device structure */
dev = kmm_zalloc(sizeof(struct rd_struct_s));
if (dev)
{
/* Initialize the ramdisk device structure */
dev->rd_nsectors = nsectors; /* Number of sectors on device */
dev->rd_sectsize = sectsize; /* The size of one sector */
dev->rd_buffer = buffer; /* RAM disk backup memory */
dev->rd_flags = rdflags & RDFLAG_USER;
/* Create a ramdisk device name */
snprintf(devname, 16, "/dev/ram%d", minor);
/* Inode private data is a reference to the ramdisk device structure */
ret = register_blockdriver(devname, &g_bops, 0, dev);
if (ret < 0)
{
ferr("register_blockdriver failed: %d\n", -ret);
kmm_free(dev);
}
}
return ret;
}