summaryrefslogtreecommitdiff
path: root/sys/vm
diff options
context:
space:
mode:
Diffstat (limited to 'sys/vm')
-rw-r--r--sys/vm/vm_device.c78
-rw-r--r--sys/vm/vm_map.c124
-rw-r--r--sys/vm/vm_vnode.c1
3 files changed, 175 insertions, 28 deletions
diff --git a/sys/vm/vm_device.c b/sys/vm/vm_device.c
new file mode 100644
index 0000000..e990b47
--- /dev/null
+++ b/sys/vm/vm_device.c
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <sys/device.h>
+#include <sys/syslog.h>
+#include <vm/vm_device.h>
+
+#define pr_trace(fmt, ...) kprintf("vm_device: " fmt, ##__VA_ARGS__)
+#define pr_error(...) pr_trace(__VA_ARGS__)
+
+const struct vm_pagerops dv_vnops;
+
+/*
+ * Attach a cdev to a vm_object
+ *
+ * @major: Char device major
+ * @minor: Char device minor.
+ */
+struct vm_object *
+dv_attach(devmajor_t major, dev_t dev, vm_prot_t prot)
+{
+ int error;
+ struct cdevsw *cdevp;
+ struct vm_object *vmobj;
+
+ if ((cdevp = dev_get(major, dev)) == NULL) {
+ pr_error("bad attach (major=%d, dev=%d)\n", major, dev);
+ return NULL;
+ }
+
+ if (cdevp->mmap == NULL) {
+ pr_error("cdev lacks mmap() (major=%d, dev=%d)\n", major, dev);
+ return NULL;
+ }
+
+ error = vm_obj_init(&cdevp->vmobj, &dv_vnops, 1);
+ if (error != 0) {
+ return NULL;
+ }
+
+ vmobj = &cdevp->vmobj;
+ vmobj->prot = prot;
+ vmobj->data = cdevp;
+ vmobj->pgops = &dv_vnops;
+ return vmobj;
+}
+
+/* TODO */
+const struct vm_pagerops dv_vnops = {
+ .get = NULL,
+};
diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index b56e896..26effdb 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -35,8 +35,10 @@
#include <sys/syscall.h>
#include <sys/syslog.h>
#include <sys/mman.h>
+#include <sys/filedesc.h>
#include <vm/dynalloc.h>
#include <vm/vm_pager.h>
+#include <vm/vm_device.h>
#include <vm/pmap.h>
#include <vm/map.h>
#include <vm/vm.h>
@@ -157,51 +159,113 @@ vm_map_modify(struct vas vas, vaddr_t va, paddr_t pa, vm_prot_t prot, bool unmap
* crashes.
*/
void *
-mmap_at(void *addr, size_t len, int prot, int flags, int fildes, off_t off)
+mmap(void *addr, size_t len, int prot, int flags, int fildes, off_t off)
{
- struct vm_object *map_obj;
+ struct vm_object *map_obj = NULL;
+ struct cdevsw *cdevp;
struct vm_page *pg;
struct mmap_entry *ep;
+ struct vnode *vp;
+ struct filedesc *fdp;
struct proc *td;
struct vas vas;
int error, npgs;
paddr_t pa;
vaddr_t va;
size_t misalign;
+ off_t page_off;
misalign = len & (DEFAULT_PAGESIZE - 1);
len = ALIGN_UP(len + misalign, DEFAULT_PAGESIZE);
npgs = len / DEFAULT_PAGESIZE;
-
- if (addr == NULL) {
- pr_error("mmap: NULL addr not supported\n");
- return NULL;
- }
+ vas = pmap_read_vas();
/* Validate flags */
- if (ISSET(flags, MAP_FIXED | MAP_SHARED)) {
- pr_error("mmap: fixed/shared mappings not yet supported\n");
+ if (ISSET(flags, MAP_FIXED)) {
+ pr_error("mmap: fixed mappings not yet supported\n");
mmap_dbg(addr, len, prot, flags, fildes, off);
return NULL;
}
- map_obj = dynalloc(sizeof(*map_obj));
- if (map_obj == NULL) {
- kprintf("mmap: failed to allocate map object\n");
- return NULL;
+
+ /*
+ * Attempt to open the file if mapping
+ * is shared.
+ */
+ if (ISSET(flags, MAP_SHARED)) {
+ fdp = fd_get(fildes);
+ if (fdp == NULL) {
+ pr_error("mmap: no such fd (fd=%d)\n", fildes);
+ return NULL;
+ }
+
+ vp = fdp->vp;
+ if (vp->type != VCHR) {
+ /* TODO */
+ pr_error("mmap: only device files supported\n");
+ return NULL;
+ }
+
+ map_obj = dv_attach(vp->major, vp->dev, prot);
+ if (map_obj == NULL) {
+ kprintf("mmap: dv_attach() failure\n");
+ return NULL;
+ }
+
+ cdevp = map_obj->data;
+ if ((pa = cdevp->mmap(vp->dev, len, off, 0)) == 0) {
+ kprintf("mmap: dev mmap() gave 0\n");
+ return NULL;
+ }
+
+ /*
+ * If the address passed is NULL, just identity
+ * map everything.
+ *
+ * XXX: This is why the bounds check done in the
+ * cdev mmap() *must* be correct.
+ *
+ * TODO: Use copy-on-write for this instead. Since mapping
+ * certain devices may required a lot of memory to
+ * be referenced anyways, we could use a buffered
+ * copy-on-write technique where only a window of
+ * pages can be mapped on-demand and other pages
+ * freed when that window is exceeded.
+ */
+ if (addr == NULL) {
+ addr = (void *)pa;
+ }
+
+ va = ALIGN_DOWN((vaddr_t)addr, DEFAULT_PAGESIZE);
+ error = vm_map(vas, va, pa, prot, len);
+ if (error != 0) {
+ kprintf("mmap: map failed (error=%d)\n", error);
+ return NULL;
+ }
+
+ goto done;
}
- error = vm_obj_init(map_obj, &vm_anonops, 1);
- if (error < 0) {
- kprintf("mmap: vm_obj_init() returned %d\n", error);
- kprintf("mmap: failed to init object\n");
- return NULL;
+
+ /* Only allocate new obj if needed */
+ if (map_obj == NULL) {
+ map_obj = dynalloc(sizeof(*map_obj));
+ if (map_obj == NULL) {
+ kprintf("mmap: failed to allocate map object\n");
+ return NULL;
+ }
+ error = vm_obj_init(map_obj, &vm_anonops, 1);
+ if (error < 0) {
+ kprintf("mmap: vm_obj_init() returned %d\n", error);
+ kprintf("mmap: failed to init object\n");
+ return NULL;
+ }
}
/* XXX: Assuming private */
- vas = pmap_read_vas();
va = ALIGN_DOWN((vaddr_t)addr, DEFAULT_PAGESIZE);
for (int i = 0; i < npgs; ++i) {
pg = vm_pagealloc(map_obj, PALLOC_ZERO);
+ page_off = i * DEFAULT_PAGESIZE;
if (pg == NULL) {
/* TODO */
@@ -209,15 +273,21 @@ mmap_at(void *addr, size_t len, int prot, int flags, int fildes, off_t off)
return NULL;
}
+ /* TODO: copy-on-write */
+ if (addr == NULL) {
+ va = pg->phys_addr;
+ addr = (void *)va;
+ }
+
pa = pg->phys_addr;
- error = vm_map(vas, va, pa, prot, len);
- pr_trace("va=%p, len=%d\n", va, len);
+ error = vm_map(vas, va + page_off, pa, prot, len);
if (error < 0) {
pr_error("mmap: failed to map page (retval=%x)\n", error);
return NULL;
}
}
+done:
/* Add entry to ledger */
td = this_td();
ep = dynalloc(sizeof(*ep));
@@ -243,7 +313,7 @@ mmap_at(void *addr, size_t len, int prot, int flags, int fildes, off_t off)
* multiple of the machine page size.
*/
int
-munmap_at(void *addr, size_t len)
+munmap(void *addr, size_t len)
{
int pgno;
vaddr_t va;
@@ -299,7 +369,7 @@ munmap_at(void *addr, size_t len)
* arg5 -> off
*/
scret_t
-mmap(struct syscall_args *scargs)
+sys_mmap(struct syscall_args *scargs)
{
void *addr;
size_t len;
@@ -308,11 +378,11 @@ mmap(struct syscall_args *scargs)
addr = (void *)scargs->arg0;
len = scargs->arg1;
- prot = scargs->arg2;
+ prot = scargs->arg2 | PROT_USER;
flags = scargs->arg3;
fildes = scargs->arg4;
off = scargs->arg5;
- return (scret_t)mmap_at(addr, len, prot, flags, fildes, off);
+ return (scret_t)mmap(addr, len, prot, flags, fildes, off);
}
/*
@@ -322,14 +392,14 @@ mmap(struct syscall_args *scargs)
* arg1 -> len
*/
scret_t
-munmap(struct syscall_args *scargs)
+sys_munmap(struct syscall_args *scargs)
{
void *addr;
size_t len;
addr = (void *)scargs->arg0;
len = scargs->arg1;
- return (scret_t)munmap_at(addr, len);
+ return (scret_t)munmap(addr, len);
}
/*
diff --git a/sys/vm/vm_vnode.c b/sys/vm/vm_vnode.c
index 2457c97..27defc9 100644
--- a/sys/vm/vm_vnode.c
+++ b/sys/vm/vm_vnode.c
@@ -162,7 +162,6 @@ vn_attach(struct vnode *vp, vm_prot_t prot)
if (vp->type != VREG) {
pr_error("vn_attach: vp=%p, prot=%x\n", vp, prot);
- pr_error("vn_attach: Special files not supported yet!\n");
return NULL;
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-06-06 12:49:23 +0000