9843d7a625
one page at a time, and use safecopies to copy it to the requesting process. This lets /dev/mem access the entire physical address space, as the minix page tables only allow access by default to physical RAM, which breaks e.g. the VESA X driver in some cases.
487 lines
14 KiB
C
487 lines
14 KiB
C
/* This file contains the device dependent part of the drivers for the
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* following special files:
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* /dev/ram - RAM disk
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* /dev/mem - absolute memory
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* /dev/kmem - kernel virtual memory
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* /dev/null - null device (data sink)
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* /dev/boot - boot device loaded from boot image
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* /dev/zero - null byte stream generator
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*
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* Changes:
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* Apr 29, 2005 added null byte generator (Jorrit N. Herder)
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* Apr 09, 2005 added support for boot device (Jorrit N. Herder)
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* Jul 26, 2004 moved RAM driver to user-space (Jorrit N. Herder)
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* Apr 20, 1992 device dependent/independent split (Kees J. Bot)
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*/
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#include "../drivers.h"
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#include "../libdriver/driver.h"
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#include <sys/ioc_memory.h>
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#include <env.h>
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#include <minix/ds.h>
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#include "../../kernel/const.h"
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#include "../../kernel/config.h"
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#include "../../kernel/type.h"
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#define MY_DS_NAME_BASE "dev:memory:ramdisk_base"
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#define MY_DS_NAME_SIZE "dev:memory:ramdisk_size"
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#include <sys/vm.h>
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#include "assert.h"
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#include "local.h"
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#define NR_DEVS 7 /* number of minor devices */
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PRIVATE struct device m_geom[NR_DEVS]; /* base and size of each device */
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PRIVATE int m_seg[NR_DEVS]; /* segment index of each device */
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PRIVATE int m_device; /* current device */
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PRIVATE struct kinfo kinfo; /* kernel information */
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extern int errno; /* error number for PM calls */
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FORWARD _PROTOTYPE( char *m_name, (void) );
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FORWARD _PROTOTYPE( struct device *m_prepare, (int device) );
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FORWARD _PROTOTYPE( int m_transfer, (int proc_nr, int opcode, u64_t position,
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iovec_t *iov, unsigned nr_req, int safe));
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FORWARD _PROTOTYPE( int m_do_open, (struct driver *dp, message *m_ptr) );
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FORWARD _PROTOTYPE( void m_init, (void) );
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FORWARD _PROTOTYPE( int m_ioctl, (struct driver *dp, message *m_ptr, int safe));
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FORWARD _PROTOTYPE( void m_geometry, (struct partition *entry) );
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/* Entry points to this driver. */
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PRIVATE struct driver m_dtab = {
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m_name, /* current device's name */
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m_do_open, /* open or mount */
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do_nop, /* nothing on a close */
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m_ioctl, /* specify ram disk geometry */
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m_prepare, /* prepare for I/O on a given minor device */
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m_transfer, /* do the I/O */
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nop_cleanup, /* no need to clean up */
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m_geometry, /* memory device "geometry" */
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nop_signal, /* system signals */
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nop_alarm,
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nop_cancel,
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nop_select,
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NULL,
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NULL
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};
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/* One page of temporary mapping area - enough to be able to page-align
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* one page.
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*/
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static char pagedata_buf[2*PAGE_SIZE];
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vir_bytes pagedata_aligned;
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/* Buffer for the /dev/zero null byte feed. */
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#define ZERO_BUF_SIZE 1024
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PRIVATE char dev_zero[ZERO_BUF_SIZE];
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#define click_to_round_k(n) \
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((unsigned) ((((unsigned long) (n) << CLICK_SHIFT) + 512) / 1024))
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/*===========================================================================*
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* main *
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*===========================================================================*/
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PUBLIC int main(void)
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{
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/* Main program. Initialize the memory driver and start the main loop. */
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struct sigaction sa;
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sa.sa_handler = SIG_MESS;
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sigemptyset(&sa.sa_mask);
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sa.sa_flags = 0;
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if (sigaction(SIGTERM,&sa,NULL)<0) panic("MEM","sigaction failed", errno);
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m_init();
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driver_task(&m_dtab);
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return(OK);
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}
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/*===========================================================================*
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* m_name *
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*===========================================================================*/
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PRIVATE char *m_name()
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{
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/* Return a name for the current device. */
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static char name[] = "memory";
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return name;
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}
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/*===========================================================================*
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* m_prepare *
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*===========================================================================*/
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PRIVATE struct device *m_prepare(device)
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int device;
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{
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/* Prepare for I/O on a device: check if the minor device number is ok. */
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if (device < 0 || device >= NR_DEVS) return(NIL_DEV);
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m_device = device;
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return(&m_geom[device]);
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}
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/*===========================================================================*
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* m_transfer *
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*===========================================================================*/
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PRIVATE int m_transfer(proc_nr, opcode, pos64, iov, nr_req, safe)
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int proc_nr; /* process doing the request */
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int opcode; /* DEV_GATHER_S or DEV_SCATTER_S */
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u64_t pos64; /* offset on device to read or write */
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iovec_t *iov; /* pointer to read or write request vector */
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unsigned nr_req; /* length of request vector */
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int safe; /* safe copies */
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{
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/* Read or write one the driver's minor devices. */
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phys_bytes mem_phys;
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int seg;
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unsigned count, left, chunk;
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vir_bytes user_vir, vir_offset = 0;
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struct device *dv;
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unsigned long dv_size;
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int s, r;
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off_t position;
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if(!safe) {
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printf("m_transfer: unsafe?\n");
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return EPERM;
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}
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if (ex64hi(pos64) != 0)
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return OK; /* Beyond EOF */
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position= cv64ul(pos64);
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/* Get minor device number and check for /dev/null. */
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dv = &m_geom[m_device];
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dv_size = cv64ul(dv->dv_size);
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while (nr_req > 0) {
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/* How much to transfer and where to / from. */
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count = iov->iov_size;
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user_vir = iov->iov_addr;
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switch (m_device) {
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/* No copying; ignore request. */
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case NULL_DEV:
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if (opcode == DEV_GATHER_S) return(OK); /* always at EOF */
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break;
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/* Virtual copying. For RAM disk, kernel memory and boot device. */
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case RAM_DEV:
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case KMEM_DEV:
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case BOOT_DEV:
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if (position >= dv_size) return(OK); /* check for EOF */
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if (position + count > dv_size) count = dv_size - position;
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seg = m_seg[m_device];
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if (opcode == DEV_GATHER_S) { /* copy actual data */
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r=sys_safecopyto(proc_nr, user_vir, vir_offset,
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position, count, seg);
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} else {
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r=sys_safecopyfrom(proc_nr, user_vir, vir_offset,
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position, count, seg);
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}
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if(r != OK) {
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panic("MEM","I/O copy failed",r);
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}
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break;
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/* Physical copying. Only used to access entire memory.
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* Transfer one 'page window' at a time.
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*/
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case MEM_DEV:
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{
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u32_t pagestart, page_off;
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static u32_t pagestart_mapped;
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static int any_mapped = 0;
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int r;
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u32_t subcount;
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if (position >= dv_size)
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return(OK); /* check for EOF */
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if (position + count > dv_size)
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count = dv_size - position;
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mem_phys = cv64ul(dv->dv_base) + position;
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page_off = mem_phys % PAGE_SIZE;
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pagestart = mem_phys - page_off;
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/* All memory to the map call has to be page-aligned.
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* Don't have to map same page over and over.
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*/
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if(!any_mapped || pagestart_mapped != pagestart) {
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if((r=sys_vm_map(SELF, 1, pagedata_aligned,
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PAGE_SIZE, pagestart)) != OK) {
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printf("memory: sys_vm_map failed: %d\n", r);
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return r;
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}
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any_mapped = 1;
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pagestart_mapped = pagestart;
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}
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/* how much to be done within this page. */
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subcount = PAGE_SIZE-page_off;
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if(subcount > count)
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subcount = count;
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if (opcode == DEV_GATHER_S) { /* copy data */
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s=sys_safecopyto(proc_nr, user_vir,
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vir_offset, pagedata_aligned+page_off, subcount, D);
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} else {
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s=sys_safecopyfrom(proc_nr, user_vir,
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vir_offset, pagedata_aligned+page_off, subcount, D);
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}
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if(s != OK)
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return s;
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count = subcount;
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break;
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}
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/* Null byte stream generator. */
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case ZERO_DEV:
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if (opcode == DEV_GATHER_S) {
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size_t suboffset = 0;
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left = count;
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while (left > 0) {
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chunk = (left > ZERO_BUF_SIZE) ? ZERO_BUF_SIZE : left;
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s=sys_safecopyto(proc_nr, user_vir,
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vir_offset+suboffset, (vir_bytes) dev_zero, chunk, D);
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if(s != OK)
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report("MEM","sys_safecopyto failed", s);
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left -= chunk;
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suboffset += chunk;
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}
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}
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break;
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case IMGRD_DEV:
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if (position >= dv_size) return(OK); /* check for EOF */
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if (position + count > dv_size) count = dv_size - position;
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if (opcode == DEV_GATHER_S) { /* copy actual data */
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s=sys_safecopyto(proc_nr, user_vir, vir_offset,
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(vir_bytes)&imgrd[position], count, D);
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} else {
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s=sys_safecopyfrom(proc_nr, user_vir, vir_offset,
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(vir_bytes)&imgrd[position], count, D);
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}
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break;
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/* Unknown (illegal) minor device. */
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default:
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return(EINVAL);
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}
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/* Book the number of bytes transferred. */
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position += count;
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vir_offset += count;
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if ((iov->iov_size -= count) == 0) { iov++; nr_req--; vir_offset = 0; }
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}
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return(OK);
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}
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/*===========================================================================*
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* m_do_open *
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*===========================================================================*/
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PRIVATE int m_do_open(dp, m_ptr)
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struct driver *dp;
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message *m_ptr;
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{
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int r;
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/* Check device number on open. */
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if (m_prepare(m_ptr->DEVICE) == NIL_DEV) return(ENXIO);
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if (m_device == MEM_DEV)
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{
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r = sys_enable_iop(m_ptr->IO_ENDPT);
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if (r != OK)
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{
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printf("m_do_open: sys_enable_iop failed for %d: %d\n",
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m_ptr->IO_ENDPT, r);
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return r;
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}
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}
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return(OK);
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}
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/*===========================================================================*
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* m_init *
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*===========================================================================*/
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PRIVATE void m_init()
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{
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/* Initialize this task. All minor devices are initialized one by one. */
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u32_t ramdev_size;
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u32_t ramdev_base;
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int i, s;
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if (OK != (s=sys_getkinfo(&kinfo))) {
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panic("MEM","Couldn't get kernel information.",s);
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}
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/* Install remote segment for /dev/kmem memory. */
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m_geom[KMEM_DEV].dv_base = cvul64(kinfo.kmem_base);
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m_geom[KMEM_DEV].dv_size = cvul64(kinfo.kmem_size);
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if (OK != (s=sys_segctl(&m_seg[KMEM_DEV], (u16_t *) &s, (vir_bytes *) &s,
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kinfo.kmem_base, kinfo.kmem_size))) {
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panic("MEM","Couldn't install remote segment.",s);
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}
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/* Install remote segment for /dev/boot memory, if enabled. */
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m_geom[BOOT_DEV].dv_base = cvul64(kinfo.bootdev_base);
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m_geom[BOOT_DEV].dv_size = cvul64(kinfo.bootdev_size);
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if (kinfo.bootdev_base > 0) {
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if (OK != (s=sys_segctl(&m_seg[BOOT_DEV], (u16_t *) &s, (vir_bytes *) &s,
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kinfo.bootdev_base, kinfo.bootdev_size))) {
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panic("MEM","Couldn't install remote segment.",s);
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}
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}
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/* See if there are already RAM disk details at the Data Store server. */
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if(ds_retrieve_u32(MY_DS_NAME_BASE, &ramdev_base) == OK &&
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ds_retrieve_u32(MY_DS_NAME_SIZE, &ramdev_size) == OK) {
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printf("MEM retrieved size %u and base %u from DS, status %d\n",
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ramdev_size, ramdev_base, s);
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if (OK != (s=sys_segctl(&m_seg[RAM_DEV], (u16_t *) &s,
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(vir_bytes *) &s, ramdev_base, ramdev_size))) {
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panic("MEM","Couldn't install remote segment.",s);
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}
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m_geom[RAM_DEV].dv_base = cvul64(ramdev_base);
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m_geom[RAM_DEV].dv_size = cvul64(ramdev_size);
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printf("MEM stored retrieved details as new RAM disk\n");
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}
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/* Ramdisk image built into the memory driver */
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m_geom[IMGRD_DEV].dv_base= cvul64(0);
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m_geom[IMGRD_DEV].dv_size= cvul64(imgrd_size);
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/* Initialize /dev/zero. Simply write zeros into the buffer. */
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for (i=0; i<ZERO_BUF_SIZE; i++) {
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dev_zero[i] = '\0';
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}
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/* Page-align page pointer. */
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pagedata_aligned = (u32_t) pagedata_buf + PAGE_SIZE;
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pagedata_aligned -= pagedata_aligned % PAGE_SIZE;
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/* Set up memory range for /dev/mem. */
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m_geom[MEM_DEV].dv_size = cvul64(0xffffffff);
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}
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/*===========================================================================*
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* m_ioctl *
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*===========================================================================*/
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PRIVATE int m_ioctl(dp, m_ptr, safe)
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struct driver *dp; /* pointer to driver structure */
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message *m_ptr; /* pointer to control message */
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int safe;
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{
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/* I/O controls for the memory driver. Currently there is one I/O control:
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* - MIOCRAMSIZE: to set the size of the RAM disk.
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*/
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struct device *dv;
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if(!safe) {
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printf("m_transfer: unsafe?\n");
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return EPERM;
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}
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switch (m_ptr->REQUEST) {
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case MIOCRAMSIZE: {
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/* Someone wants to create a new RAM disk with the given size. */
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static int first_time= 1;
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u32_t ramdev_size;
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phys_bytes ramdev_base;
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int s;
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/* A ramdisk can be created only once, and only on RAM disk device. */
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if (!first_time) return(EPERM);
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if (m_ptr->DEVICE != RAM_DEV) return(EINVAL);
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if ((dv = m_prepare(m_ptr->DEVICE)) == NIL_DEV) return(ENXIO);
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#if 0
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ramdev_size= m_ptr->POSITION;
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#else
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/* Get request structure */
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s= sys_safecopyfrom(m_ptr->IO_ENDPT, (vir_bytes)m_ptr->IO_GRANT,
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0, (vir_bytes)&ramdev_size, sizeof(ramdev_size), D);
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if (s != OK)
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return s;
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#endif
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#if DEBUG
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printf("allocating ramdisk of size 0x%x\n", ramdev_size);
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#endif
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/* Try to allocate a piece of memory for the RAM disk. */
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if (allocmem(ramdev_size, &ramdev_base) < 0) {
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report("MEM", "warning, allocmem failed", errno);
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return(ENOMEM);
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}
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/* Store the values we got in the data store so we can retrieve
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* them later on, in the unfortunate event of a crash.
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*/
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if(ds_publish_u32(MY_DS_NAME_BASE, ramdev_base) != OK ||
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ds_publish_u32(MY_DS_NAME_SIZE, ramdev_size) != OK) {
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panic("MEM","Couldn't store RAM disk details at DS.",s);
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}
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#if DEBUG
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printf("MEM stored size %u and base %u at DS, names %s and %s\n",
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ramdev_size, ramdev_base, MY_DS_NAME_BASE, MY_DS_NAME_SIZE);
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#endif
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if (OK != (s=sys_segctl(&m_seg[RAM_DEV], (u16_t *) &s,
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(vir_bytes *) &s, ramdev_base, ramdev_size))) {
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panic("MEM","Couldn't install remote segment.",s);
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}
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dv->dv_base = cvul64(ramdev_base);
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dv->dv_size = cvul64(ramdev_size);
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first_time= 0;
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break;
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}
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case MIOCMAP:
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case MIOCUNMAP: {
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int r, do_map;
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struct mapreq mapreq;
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if ((*dp->dr_prepare)(m_ptr->DEVICE) == NIL_DEV) return(ENXIO);
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if (m_device != MEM_DEV)
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return ENOTTY;
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do_map= (m_ptr->REQUEST == MIOCMAP); /* else unmap */
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/* Get request structure */
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r= sys_safecopyfrom(m_ptr->IO_ENDPT, (vir_bytes)m_ptr->IO_GRANT,
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0, (vir_bytes)&mapreq, sizeof(mapreq), D);
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if (r != OK)
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return r;
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r= sys_vm_map(m_ptr->IO_ENDPT, do_map,
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(phys_bytes)mapreq.base, mapreq.size, mapreq.offset);
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return r;
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}
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default:
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return(do_diocntl(&m_dtab, m_ptr, safe));
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}
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return(OK);
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}
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/*===========================================================================*
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* m_geometry *
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*===========================================================================*/
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PRIVATE void m_geometry(entry)
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struct partition *entry;
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{
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/* Memory devices don't have a geometry, but the outside world insists. */
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entry->cylinders = div64u(m_geom[m_device].dv_size, SECTOR_SIZE) / (64 * 32);
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entry->heads = 64;
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entry->sectors = 32;
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}
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