Initial add of mmfs module.

main
Eric Anholt 2008-04-22 16:08:23 -07:00
parent c82894034f
commit 47a2b7dc03
7 changed files with 551 additions and 3 deletions

1
.gitignore vendored
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@ -58,6 +58,7 @@ tests/getclient
tests/getstats
tests/getversion
tests/lock
tests/mmfs_basic
tests/openclose
tests/setversion
tests/updatedraw

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@ -58,7 +58,7 @@ endif
# Modules for all architectures
MODULE_LIST := drm.o tdfx.o r128.o radeon.o mga.o sis.o savage.o via.o \
mach64.o nv.o nouveau.o xgi.o
mach64.o nv.o nouveau.o xgi.o mmfs.o
# Modules only for ix86 architectures
ifneq (,$(findstring 86,$(MACHINE)))
@ -92,6 +92,7 @@ NVHEADERS = nv_drv.h $(DRMHEADERS)
FFBHEADERS = ffb_drv.h $(DRMHEADERS)
NOUVEAUHEADERS = nouveau_drv.h nouveau_drm.h nouveau_reg.h $(DRMHEADERS)
XGIHEADERS = xgi_cmdlist.h xgi_drv.h xgi_misc.h xgi_regs.h $(DRMHEADERS)
MMFSHEADERS = mmfs.h mmfs_priv.h
PROGS = dristat drmstat

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@ -41,6 +41,7 @@ mach64-objs := mach64_drv.o mach64_dma.o mach64_irq.o mach64_state.o
nv-objs := nv_drv.o
xgi-objs := xgi_cmdlist.o xgi_drv.o xgi_fb.o xgi_misc.o xgi_pcie.o \
xgi_fence.o
mmfs-objs := mmfs_drv.o
ifeq ($(CONFIG_COMPAT),y)
drm-objs += drm_ioc32.o
@ -52,7 +53,7 @@ nouveau-objs += nouveau_ioc32.o
xgi-objs += xgi_ioc32.o
endif
obj-m += drm.o
obj-m += drm.o mmfs.o
obj-$(CONFIG_DRM_TDFX) += tdfx.o
obj-$(CONFIG_DRM_R128) += r128.o
obj-$(CONFIG_DRM_RADEON)+= radeon.o

176
linux-core/mmfs.h Normal file
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@ -0,0 +1,176 @@
/*
* Copyright © 2008 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* Authors:
* Eric Anholt <eric@anholt.net>
*
*/
/** @file mmfs.h
* This file provides ioctl and ioctl argument definitions for using the
* mmfs device.
*/
#ifdef __KERNEL__
#include <linux/spinlock.h>
#include <linux/idr.h>
/** @file mmfs_priv.h
* This file provides internal structure definitions for mmfs..
*/
/**
* This structure defines the mmfs memory object, which will be used by the
* DRM for its buffer objects.
*/
struct mmfs_object {
/** File representing the shmem storage */
struct file *filp;
spinlock_t lock;
size_t size;
/** Reference count of this object, protected by object_lock */
int refcount;
};
/**
* This structure defines the process (actually per-fd) mapping of object
* handles to mmfs objects.
*/
struct mmfs_file {
/** Mapping of object handles to object pointers. */
struct idr object_idr;
/**
* Lock for synchronization of access to object->refcount and
* object_idr. See note in mmfs_unreference_ioctl.
*/
spinlock_t delete_lock;
};
void mmfs_object_reference(struct mmfs_object *obj);
void mmfs_object_unreference(struct mmfs_object *obj);
#endif /* __KERNEL__ */
#define MMFS_DEVICE_PATH "/dev/mmfs"
/* XXX: Choose non-experimental major */
#define MMFS_DEVICE_MAJOR 246
struct mmfs_alloc_args {
/**
* Requested size for the object.
*
* The (page-aligned) allocated size for the object will be returned.
*/
uint32_t size;
/** Returned handle for the object. */
uint32_t handle;
};
struct mmfs_unreference_args {
/** Handle of the object to be unreferenced. */
uint32_t handle;
};
struct mmfs_link_args {
/** Handle for the object being given a name. */
uint32_t handle;
/** Requested file name to export the object under. */
char *name;
/** Requested file mode to export the object under. */
mode_t mode;
};
struct mmfs_pread_args {
/** Handle for the object being read. */
uint32_t handle;
/** Offset into the object to read from */
off_t offset;
/** Length of data to read */
size_t size;
/** Pointer to write the data into. */
void *data;
};
struct mmfs_pwrite_args {
/** Handle for the object being written to. */
uint32_t handle;
/** Offset into the object to write to */
off_t offset;
/** Length of data to write */
size_t size;
/** Pointer to read the data from. */
void *data;
};
struct mmfs_mmap_args {
/** Handle for the object being mapped. */
uint32_t handle;
/** Offset in the object to map. */
off_t offset;
/**
* Length of data to map.
*
* The value will be page-aligned.
*/
size_t size;
/** Returned pointer the data was mapped at */
void *addr;
};
/**
* \name Ioctls Definitions
*/
/* @{ */
#define MMFS_IOCTL_BASE 'm'
#define MMFS_IO(nr) _IO(MMFS_IOCTL_BASE, nr)
#define MMFS_IOR(nr,type) _IOR(MMFS_IOCTL_BASE, nr, type)
#define MMFS_IOW(nr,type) _IOW(MMFS_IOCTL_BASE, nr, type)
#define MMFS_IOWR(nr,type) _IOWR(MMFS_IOCTL_BASE, nr, type)
/** This ioctl allocates an object and returns a handle referencing it. */
#define MMFS_IOCTL_ALLOC MMFS_IOWR(0x00, struct mmfs_alloc_args)
/**
* This ioctl releases the reference on the handle returned from
* MMFS_IOCTL_ALLOC.
*/
#define MMFS_IOCTL_UNREFERENCE MMFS_IOR(0x01, struct mmfs_unreference_args)
/**
* This ioctl creates a file in the mmfs filesystem representing an object.
*
* XXX: Need a way to get handle from fd or name.
*/
#define MMFS_IOCTL_LINK MMFS_IOWR(0x02, struct mmfs_link_args)
/** This ioctl copies data from an object into a user address. */
#define MMFS_IOCTL_PREAD MMFS_IOWR(0x03, struct mmfs_pread_args)
/** This ioctl copies data from a user address into an object. */
#define MMFS_IOCTL_PWRITE MMFS_IOWR(0x04, struct mmfs_pwrite_args)
/** This ioctl maps data from the object into the user address space. */
#define MMFS_IOCTL_MMAP MMFS_IOWR(0x05, struct mmfs_mmap_args)
/* }@ */

299
linux-core/mmfs_drv.c Normal file
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@ -0,0 +1,299 @@
/*
* Copyright © 2008 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* Authors:
* Eric Anholt <eric@anholt.net>
*
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/uaccess.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/module.h>
#include "mmfs.h"
/** @file mmfs.c
*
* This file provides the filesystem for memory manager objects used by the
* DRM.
*
* The goal is to have swap-backed object allocation managed through
* struct file. However, file descriptors as handles to a struct file have
* two major failings:
* - Process limits prevent more than 1024 or so being used at a time by
* default.
* - Inability to allocate high fds will aggravate the X Server's select()
* handling, and likely that of many GL client applications as well.
*
* This led to a plan of using our own integer IDs (called handles, following
* DRM terminology) to mimic fds, and implement the fd syscalls we need as
* ioctls. The objects themselves will still include the struct file so
* that we can transition to fds if the required kernel infrastructure shows
* up at a later data, and as our interface with shmfs for memory allocation.
*/
static struct mmfs_object *
mmfs_object_alloc(size_t size)
{
struct mmfs_object *obj;
BUG_ON((size & (PAGE_SIZE - 1)) != 0);
obj = kcalloc(1, sizeof(*obj), GFP_KERNEL);
obj->filp = shmem_file_setup("mmfs object", size, 0);
if (IS_ERR(obj->filp)) {
kfree(obj);
return NULL;
}
obj->refcount = 1;
return obj;
}
/**
* Removes the mapping from handle to filp for this object.
*/
static int
mmfs_handle_delete(struct mmfs_file *mmfs_filp, int handle)
{
struct mmfs_object *obj;
/* This is gross. The idr system doesn't let us try a delete and
* return an error code. It just spews if you fail at deleting.
* So, we have to grab a lock around finding the object and then
* doing the delete on it and dropping the refcount, or the user
* could race us to double-decrement the refcount and cause a
* use-after-free later. Given the frequency of our handle lookups,
* we may want to use ida for number allocation and a hash table
* for the pointers, anyway.
*/
spin_lock(&mmfs_filp->delete_lock);
/* Check if we currently have a reference on the object */
obj = idr_find(&mmfs_filp->object_idr, handle);
if (obj == NULL) {
spin_unlock(&mmfs_filp->delete_lock);
return -EINVAL;
}
/* Release reference and decrement refcount. */
idr_remove(&mmfs_filp->object_idr, handle);
mmfs_object_unreference(obj);
spin_unlock(&mmfs_filp->delete_lock);
return 0;
}
/**
* Allocates a new mmfs object and returns a handle to it.
*/
static int
mmfs_alloc_ioctl(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
struct mmfs_file *mmfs_filp = filp->private_data;
struct mmfs_alloc_args args;
struct mmfs_object *obj;
int handle, ret;
if (copy_from_user(&args, (void __user *)arg, sizeof(args)))
return -EFAULT;
/* Round requested size up to page size */
args.size = (args.size + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
/* Allocate the new object */
obj = mmfs_object_alloc(args.size);
if (obj == NULL)
return -ENOMEM;
/* Get the user-visible handle using idr.
*
* I'm not really sure why the idr api needs us to do this in two
* repeating steps. It handles internal locking of its data
* structure, yet insists that we keep its memory allocation step
* separate from its slot-finding step for locking purposes.
*/
do {
if (idr_pre_get(&mmfs_filp->object_idr, GFP_KERNEL) == 0) {
kfree(obj);
return -EFAULT;
}
ret = idr_get_new(&mmfs_filp->object_idr, obj, &handle);
} while (ret == -EAGAIN);
if (ret != 0) {
mmfs_object_unreference(obj);
return -EFAULT;
}
args.handle = handle;
if (copy_to_user((void __user *)arg, &args, sizeof(args))) {
mmfs_handle_delete(mmfs_filp, args.handle);
return -EFAULT;
}
return 0;
}
/**
* Allocates a new mmfs object and returns a handle to it.
*/
static int
mmfs_unreference_ioctl(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
struct mmfs_file *mmfs_filp = filp->private_data;
struct mmfs_unreference_args args;
int ret;
if (copy_from_user(&args, (void __user *)arg, sizeof(args)))
return -EFAULT;
ret = mmfs_handle_delete(mmfs_filp, args.handle);
return ret;
}
static int
mmfs_ioctl(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case MMFS_IOCTL_ALLOC:
return mmfs_alloc_ioctl(inode, filp, cmd, arg);
case MMFS_IOCTL_UNREFERENCE:
return mmfs_unreference_ioctl(inode, filp, cmd, arg);
default:
return -EINVAL;
}
}
/**
* Sets up the file private for keeping track of our mappings of handles to
* mmfs objects.
*/
int
mmfs_open(struct inode *inode, struct file *filp)
{
struct mmfs_file *mmfs_filp;
if (filp->f_flags & O_EXCL)
return -EBUSY; /* No exclusive opens */
mmfs_filp = kcalloc(1, sizeof(*mmfs_filp), GFP_KERNEL);
if (mmfs_filp == NULL)
return -ENOMEM;
filp->private_data = mmfs_filp;
idr_init(&mmfs_filp->object_idr);
return 0;
}
/** Called at device close to release the file's references on objects. */
static int
mmfs_object_release(int id, void *ptr, void *data)
{
struct mmfs_object *obj = ptr;
mmfs_object_unreference(obj);
return 0;
}
/**
* Called at close time when the filp is going away.
*
* Releases any remaining references on objects by this filp.
*/
int
mmfs_close(struct inode *inode, struct file *filp)
{
struct mmfs_file *mmfs_filp = filp->private_data;
idr_for_each(&mmfs_filp->object_idr, &mmfs_object_release, NULL);
idr_destroy(&mmfs_filp->object_idr);
kfree(mmfs_filp);
filp->private_data = NULL;
return 0;
}
void
mmfs_object_reference(struct mmfs_object *obj)
{
spin_lock(&obj->lock);
obj->refcount++;
spin_unlock(&obj->lock);
}
void
mmfs_object_unreference(struct mmfs_object *obj)
{
spin_lock(&obj->lock);
obj->refcount--;
spin_unlock(&obj->lock);
if (obj->refcount == 0) {
fput(obj->filp);
kfree(obj);
}
}
/** File operations structure */
static const struct file_operations mmfs_dev_fops = {
.owner = THIS_MODULE,
.open = mmfs_open,
.release = mmfs_close,
.ioctl = mmfs_ioctl,
};
static int __init mmfs_init(void)
{
int ret;
ret = register_chrdev(MMFS_DEVICE_MAJOR, "mmfs", &mmfs_dev_fops);
if (ret != 0)
return ret;
return 0;
}
static void __exit mmfs_exit(void)
{
unregister_chrdev(MMFS_DEVICE_MAJOR, "mmfs");
}
module_init(mmfs_init);
module_exit(mmfs_exit);
MODULE_LICENSE("GPL and additional rights");

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@ -1,4 +1,5 @@
AM_CFLAGS = \
-I $(top_srcdir)/linux-core \
-I $(top_srcdir)/shared-core \
-I $(top_srcdir)/libdrm
@ -22,7 +23,8 @@ TESTS = auth \
getstats \
lock \
setversion \
updatedraw
updatedraw \
mmfs_basic
EXTRA_PROGRAMS = $(TESTS)
CLEANFILES = $(EXTRA_PROGRAMS) $(EXTRA_LTLIBRARIES)

68
tests/mmfs_basic.c Normal file
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@ -0,0 +1,68 @@
/*
* Copyright © 2008 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* Authors:
* Eric Anholt <eric@anholt.net>
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <fcntl.h>
#include <inttypes.h>
#include <sys/stat.h>
#include "mmfs.h"
static void
create_mmfs_device()
{
struct stat sb;
int ret;
ret = stat(MMFS_DEVICE_PATH, &sb);
if (ret == 0)
return;
ret = mknod(MMFS_DEVICE_PATH, S_IFCHR | S_IRUSR | S_IWUSR,
makedev(MMFS_DEVICE_MAJOR, 0));
if (ret != 0)
errx(1, "mknod()");
}
int main(int argc, char **argv)
{
int fd;
create_mmfs_device();
fd = open(MMFS_DEVICE_PATH, O_RDWR);
if (fd == -1)
errx(1, "open()");
close(fd);
return 0;
}