| /* |
| * linux/kernel/chr_drv/mem.c |
| * |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/errno.h> |
| #include <linux/sched.h> |
| #include <linux/kernel.h> |
| #include <linux/tty.h> |
| #include <linux/mouse.h> |
| |
| #include <linux/user.h> |
| #include <linux/a.out.h> |
| #include <linux/string.h> |
| |
| #include <asm/segment.h> |
| #include <asm/io.h> |
| |
| extern long soundcard_init(long mem_start); |
| |
| static int read_ram(struct inode * inode, struct file * file,char * buf, int count) |
| { |
| return -EIO; |
| } |
| |
| static int write_ram(struct inode * inode, struct file * file,char * buf, int count) |
| { |
| return -EIO; |
| } |
| |
| static int read_core(struct inode * inode, struct file * file,char * buf, int count) |
| { |
| unsigned long p = file->f_pos; |
| int read; |
| int count1; |
| char * pnt; |
| struct user dump; |
| |
| memset(&dump, 0, sizeof(struct user)); |
| dump.magic = CMAGIC; |
| dump.u_dsize = high_memory >> 12; |
| |
| if (count < 0) |
| return -EINVAL; |
| if (p >= high_memory) |
| return 0; |
| if (count > high_memory - p) |
| count = high_memory - p; |
| read = 0; |
| |
| if (p < sizeof(struct user) && count > 0) { |
| count1 = count; |
| if (p + count1 > sizeof(struct user)) |
| count1 = sizeof(struct user)-p; |
| pnt = (char *) &dump + p; |
| memcpy_tofs(buf,(void *) pnt, count1); |
| buf += count1; |
| p += count1; |
| count -= count1; |
| read += count1; |
| } |
| |
| while (p < (4096 + 4096) && count > 0) { |
| put_fs_byte(0,buf); |
| buf++; |
| p++; |
| count--; |
| read++; |
| } |
| memcpy_tofs(buf,(void *) (p - 4096),count); |
| read += count; |
| file->f_pos += read; |
| return read; |
| } |
| |
| static int read_mem(struct inode * inode, struct file * file,char * buf, int count) |
| { |
| unsigned long p = file->f_pos; |
| int read; |
| |
| if (count < 0) |
| return -EINVAL; |
| if (p >= high_memory) |
| return 0; |
| if (count > high_memory - p) |
| count = high_memory - p; |
| read = 0; |
| while (p < 4096 && count > 0) { |
| put_fs_byte(0,buf); |
| buf++; |
| p++; |
| count--; |
| read++; |
| } |
| memcpy_tofs(buf,(void *) p,count); |
| read += count; |
| file->f_pos += read; |
| return read; |
| } |
| |
| static int write_mem(struct inode * inode, struct file * file,char * buf, int count) |
| { |
| unsigned long p = file->f_pos; |
| int written; |
| |
| if (count < 0) |
| return -EINVAL; |
| if (p >= high_memory) |
| return 0; |
| if (count > high_memory - p) |
| count = high_memory - p; |
| written = 0; |
| while (p < 4096 && count > 0) { |
| /* Hmm. Do something? */ |
| buf++; |
| p++; |
| count--; |
| written++; |
| } |
| memcpy_fromfs((void *) p,buf,count); |
| written += count; |
| file->f_pos += written; |
| return count; |
| } |
| |
| static int mmap_mem(struct inode * inode, struct file * file, |
| unsigned long addr, size_t len, int prot, unsigned long off) |
| { |
| if (len > high_memory || off > high_memory - len) /* avoid overflow */ |
| return -ENXIO; |
| |
| if (remap_page_range(addr, off, len, prot)) |
| return -EAGAIN; |
| |
| return 0; |
| } |
| |
| static int read_port(struct inode * inode,struct file * file,char * buf, int count) |
| { |
| unsigned int i = file->f_pos; |
| char * tmp = buf; |
| |
| while (count-- > 0 && i < 65536) { |
| put_fs_byte(inb(i),tmp); |
| i++; |
| tmp++; |
| } |
| file->f_pos = i; |
| return tmp-buf; |
| } |
| |
| static int write_port(struct inode * inode,struct file * file,char * buf, int count) |
| { |
| unsigned int i = file->f_pos; |
| char * tmp = buf; |
| |
| while (count-- > 0 && i < 65536) { |
| outb(get_fs_byte(tmp),i); |
| i++; |
| tmp++; |
| } |
| file->f_pos = i; |
| return tmp-buf; |
| } |
| |
| static int read_null(struct inode * node,struct file * file,char * buf,int count) |
| { |
| return 0; |
| } |
| |
| static int write_null(struct inode * inode,struct file * file,char * buf, int count) |
| { |
| return count; |
| } |
| |
| static int read_zero(struct inode * node,struct file * file,char * buf,int count) |
| { |
| int left; |
| |
| for (left = count; left > 0; left--) { |
| put_fs_byte(0,buf); |
| buf++; |
| } |
| return count; |
| } |
| |
| static int write_zero(struct inode * inode,struct file * file,char * buf, int count) |
| { |
| return count; |
| } |
| |
| static int mmap_zero(struct inode * inode, struct file * file, |
| unsigned long addr, size_t len, int prot, unsigned long off) |
| { |
| if (prot & PAGE_RW) |
| return -EINVAL; |
| if (zeromap_page_range(addr, len, prot)) |
| return -EAGAIN; |
| return 0; |
| } |
| |
| /* |
| * The memory devices use the full 32 bits of the offset, and so we cannot |
| * check against negative addresses: they are ok. The return value is weird, |
| * though, in that case (0). |
| * |
| * also note that seeking relative to the "end of file" isn't supported: |
| * it has no meaning, so it returns -EINVAL. |
| */ |
| static int memory_lseek(struct inode * inode, struct file * file, off_t offset, int orig) |
| { |
| switch (orig) { |
| case 0: |
| file->f_pos = offset; |
| return file->f_pos; |
| case 1: |
| file->f_pos += offset; |
| return file->f_pos; |
| default: |
| return -EINVAL; |
| } |
| if (file->f_pos < 0) |
| return 0; |
| return file->f_pos; |
| } |
| |
| #define read_kmem read_mem |
| #define write_kmem write_mem |
| #define mmap_kmem mmap_mem |
| |
| static struct file_operations ram_fops = { |
| memory_lseek, |
| read_ram, |
| write_ram, |
| NULL, /* ram_readdir */ |
| NULL, /* ram_select */ |
| NULL, /* ram_ioctl */ |
| NULL, /* ram_mmap */ |
| NULL, /* no special open code */ |
| NULL /* no special release code */ |
| }; |
| |
| static struct file_operations mem_fops = { |
| memory_lseek, |
| read_mem, |
| write_mem, |
| NULL, /* mem_readdir */ |
| NULL, /* mem_select */ |
| NULL, /* mem_ioctl */ |
| mmap_mem, |
| NULL, /* no special open code */ |
| NULL /* no special release code */ |
| }; |
| |
| static struct file_operations kmem_fops = { |
| memory_lseek, |
| read_kmem, |
| write_kmem, |
| NULL, /* kmem_readdir */ |
| NULL, /* kmem_select */ |
| NULL, /* kmem_ioctl */ |
| mmap_kmem, |
| NULL, /* no special open code */ |
| NULL /* no special release code */ |
| }; |
| |
| static struct file_operations null_fops = { |
| memory_lseek, |
| read_null, |
| write_null, |
| NULL, /* null_readdir */ |
| NULL, /* null_select */ |
| NULL, /* null_ioctl */ |
| NULL, /* null_mmap */ |
| NULL, /* no special open code */ |
| NULL /* no special release code */ |
| }; |
| |
| static struct file_operations port_fops = { |
| memory_lseek, |
| read_port, |
| write_port, |
| NULL, /* port_readdir */ |
| NULL, /* port_select */ |
| NULL, /* port_ioctl */ |
| NULL, /* port_mmap */ |
| NULL, /* no special open code */ |
| NULL /* no special release code */ |
| }; |
| |
| static struct file_operations zero_fops = { |
| memory_lseek, |
| read_zero, |
| write_zero, |
| NULL, /* zero_readdir */ |
| NULL, /* zero_select */ |
| NULL, /* zero_ioctl */ |
| mmap_zero, |
| NULL, /* no special open code */ |
| NULL /* no special release code */ |
| }; |
| |
| static struct file_operations core_fops = { |
| memory_lseek, |
| read_core, |
| NULL, |
| NULL, /* zero_readdir */ |
| NULL, /* zero_select */ |
| NULL, /* zero_ioctl */ |
| NULL, /* zero_mmap */ |
| NULL, /* no special open code */ |
| NULL /* no special release code */ |
| }; |
| |
| static int memory_open(struct inode * inode, struct file * filp) |
| { |
| switch (MINOR(inode->i_rdev)) { |
| case 0: |
| filp->f_op = &ram_fops; |
| break; |
| case 1: |
| filp->f_op = &mem_fops; |
| break; |
| case 2: |
| filp->f_op = &kmem_fops; |
| break; |
| case 3: |
| filp->f_op = &null_fops; |
| break; |
| case 4: |
| filp->f_op = &port_fops; |
| break; |
| case 5: |
| filp->f_op = &zero_fops; |
| break; |
| case 6: |
| filp->f_op = &core_fops; |
| break; |
| default: |
| return -ENODEV; |
| } |
| if (filp->f_op && filp->f_op->open) |
| return filp->f_op->open(inode,filp); |
| return 0; |
| } |
| |
| static struct file_operations memory_fops = { |
| NULL, /* lseek */ |
| NULL, /* read */ |
| NULL, /* write */ |
| NULL, /* readdir */ |
| NULL, /* select */ |
| NULL, /* ioctl */ |
| NULL, /* mmap */ |
| memory_open, /* just a selector for the real open */ |
| NULL /* release */ |
| }; |
| |
| long chr_dev_init(long mem_start, long mem_end) |
| { |
| if (register_chrdev(1,"mem",&memory_fops)) |
| printk("unable to get major 1 for memory devs\n"); |
| mem_start = tty_init(mem_start); |
| mem_start = lp_init(mem_start); |
| mem_start = mouse_init(mem_start); |
| mem_start = soundcard_init(mem_start); |
| return mem_start; |
| } |