minix/lib/libc/sys-minix/mmap.c
Ben Gras b80e3ac26b vm: new secondary cache
Primary purpose of change: to support the mmap implementation, VM must
know both (a) about some block metadata for FS cache blocks, i.e. inode
numbers and inode offsets where applicable; and (b) know about *all*
cache blocks, i.e.  also of the FS primary caches and not just the
blocks that spill into the secondary one. This changes the interface and
VM data structures.

This change is only for the interface (libminixfs) and VM data
structures; the filesystem code is unmodified, so although the secondary
cache will be used as normal, blocks will not be annotated with inode
information until the FS is modified to provide this information. Until
it is modified, mmap of files will fail gracefully on such filesystems.

This is indicated to VFS/VM by returning ENOSYS for REQ_PEEK.

Change-Id: I5ddf51a27e3b85b87a10556be87fc33bb92b1090
2013-03-16 04:14:47 +00:00

151 lines
2.5 KiB
C

#define _SYSTEM 1
#include <sys/cdefs.h>
#include "namespace.h"
#include <lib.h>
#include <minix/u64.h>
#include <minix/vm.h>
/* INCLUDES HERE */
#ifdef __weak_alias
__weak_alias(vm_remap, _vm_remap)
__weak_alias(vm_unmap, _vm_unmap)
__weak_alias(vm_getphys, _vm_getphys)
__weak_alias(vm_getrefcount, _vm_getrefcount)
__weak_alias(minix_mmap, _minix_mmap)
__weak_alias(minix_munmap, _minix_munmap)
#endif
#include <sys/mman.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
void *minix_mmap_for(endpoint_t forwhom,
void *addr, size_t len, int prot, int flags, int fd, u64_t offset)
{
message m;
int r;
m.VMM_ADDR = (vir_bytes) addr;
m.VMM_LEN = len;
m.VMM_PROT = prot;
m.VMM_FLAGS = flags;
m.VMM_FD = fd;
m.VMM_OFFSET_LO = ex64lo(offset);
if(forwhom != SELF) {
m.VMM_FLAGS |= MAP_THIRDPARTY;
m.VMM_FORWHOM = forwhom;
} else {
m.VMM_OFFSET_HI = ex64hi(offset);
}
r = _syscall(VM_PROC_NR, VM_MMAP, &m);
if(r != OK) {
return MAP_FAILED;
}
return (void *) m.VMM_RETADDR;
}
void *minix_mmap(void *addr, size_t len, int prot, int flags,
int fd, off_t offset)
{
return minix_mmap_for(SELF, addr, len, prot, flags, fd, offset);
}
int minix_munmap(void *addr, size_t len)
{
message m;
m.VMUM_ADDR = addr;
m.VMUM_LEN = len;
return _syscall(VM_PROC_NR, VM_MUNMAP, &m);
}
void *vm_remap(endpoint_t d,
endpoint_t s,
void *da,
void *sa,
size_t size)
{
message m;
int r;
m.VMRE_D = d;
m.VMRE_S = s;
m.VMRE_DA = (char *) da;
m.VMRE_SA = (char *) sa;
m.VMRE_SIZE = size;
r = _syscall(VM_PROC_NR, VM_REMAP, &m);
if (r != OK)
return MAP_FAILED;
return (void *) m.VMRE_RETA;
}
void *vm_remap_ro(endpoint_t d,
endpoint_t s,
void *da,
void *sa,
size_t size)
{
message m;
int r;
m.VMRE_D = d;
m.VMRE_S = s;
m.VMRE_DA = (char *) da;
m.VMRE_SA = (char *) sa;
m.VMRE_SIZE = size;
r = _syscall(VM_PROC_NR, VM_REMAP_RO, &m);
if (r != OK)
return MAP_FAILED;
return (void *) m.VMRE_RETA;
}
int vm_unmap(endpoint_t endpt, void *addr)
{
message m;
m.VMUN_ENDPT = endpt;
m.VMUN_ADDR = (long) addr;
return _syscall(VM_PROC_NR, VM_SHM_UNMAP, &m);
}
unsigned long vm_getphys(int endpt, void *addr)
{
message m;
int r;
m.VMPHYS_ENDPT = endpt;
m.VMPHYS_ADDR = (long) addr;
r = _syscall(VM_PROC_NR, VM_GETPHYS, &m);
if (r != OK)
return 0;
return m.VMPHYS_RETA;
}
u8_t vm_getrefcount(endpoint_t endpt, void *addr)
{
message m;
int r;
m.VMREFCNT_ENDPT = endpt;
m.VMREFCNT_ADDR = (long) addr;
r = _syscall(VM_PROC_NR, VM_GETREF, &m);
if (r != OK)
return (u8_t) -1;
return (u8_t) m.VMREFCNT_RETC;
}