Re: [RFC][AGPGART]Allow multiple backends to be initialized

From: Mike Werner
Date: Fri Dec 10 2004 - 00:04:40 EST

Here is a modified patch which is much simpler.
Please comment for further improvements.
# This is a BitKeeper generated diff -Nru style patch.
#
# Allow multiple agpgart backends to be initialized and addressed.
#
diff -Nru a/drivers/char/agp/agp.h b/drivers/char/agp/agp.h
--- a/drivers/char/agp/agp.h 2004-12-09 20:46:37 -08:00
+++ b/drivers/char/agp/agp.h 2004-12-09 20:46:37 -08:00
@@ -1,5 +1,6 @@
/*
* AGPGART
+ * Copyright (C) 2004 Silicon Graphics, Inc.
* Copyright (C) 2002-2004 Dave Jones
* Copyright (C) 1999 Jeff Hartmann
* Copyright (C) 1999 Precision Insight, Inc.
@@ -139,6 +140,7 @@
int capndx;
char major_version;
char minor_version;
+ struct list_head list;
};

#define OUTREG64(mmap, addr, val) __raw_writeq((val), (mmap)+(addr))
@@ -271,6 +273,7 @@
void global_cache_flush(void);
void get_agp_version(struct agp_bridge_data *bridge);
unsigned long agp_generic_mask_memory(unsigned long addr, int type);
+struct agp_bridge_data *agp_generic_find_bridge(struct pci_dev *pdev);

/* generic routines for agp>=3 */
int agp3_generic_fetch_size(void);
diff -Nru a/drivers/char/agp/backend.c b/drivers/char/agp/backend.c
--- a/drivers/char/agp/backend.c 2004-12-09 20:46:37 -08:00
+++ b/drivers/char/agp/backend.c 2004-12-09 20:46:37 -08:00
@@ -1,5 +1,6 @@
/*
* AGPGART driver backend routines.
+ * Copyright (C) 2004 Silicon Graphics, Inc.
* Copyright (C) 2002-2003 Dave Jones.
* Copyright (C) 1999 Jeff Hartmann.
* Copyright (C) 1999 Precision Insight, Inc.
@@ -42,34 +43,36 @@
* fix some real stupidity. It's only by chance we can bump
* past 0.99 at all due to some boolean logic error. */
#define AGPGART_VERSION_MAJOR 0
-#define AGPGART_VERSION_MINOR 100
+#define AGPGART_VERSION_MINOR 101
static struct agp_version agp_current_version =
{
.major = AGPGART_VERSION_MAJOR,
.minor = AGPGART_VERSION_MINOR,
};

-static int agp_count=0;
-
-struct agp_bridge_data agp_bridge_dummy = { .type = NOT_SUPPORTED };
-struct agp_bridge_data *agp_bridge = &agp_bridge_dummy;
+struct agp_bridge_data *agp_bridge;
+LIST_HEAD(agp_bridges);
+struct agp_bridge_data *(*agp_find_bridge)(struct pci_dev *) = &agp_generic_find_bridge;
EXPORT_SYMBOL(agp_bridge);
-
+EXPORT_SYMBOL(agp_bridges);

/**
- * agp_backend_acquire - attempt to acquire the agp backend.
+ * agp_backend_acquire - attempt to acquire an agp backend.
*
- * returns -EBUSY if agp is in use,
- * returns 0 if the caller owns the agp backend
*/
-int agp_backend_acquire(void)
+struct agp_bridge_data *agp_backend_acquire(struct pci_dev *pdev)
{
- if (agp_bridge->type == NOT_SUPPORTED)
- return -EINVAL;
- if (atomic_read(&agp_bridge->agp_in_use))
- return -EBUSY;
- atomic_inc(&agp_bridge->agp_in_use);
- return 0;
+ struct agp_bridge_data *bridge;
+
+ bridge = agp_find_bridge(pdev);
+
+ if (!bridge)
+ return NULL;
+
+ if (atomic_read(&bridge->agp_in_use))
+ return NULL;
+ atomic_inc(&bridge->agp_in_use);
+ return bridge;
}
EXPORT_SYMBOL(agp_backend_acquire);

@@ -82,10 +85,11 @@
*
* (Ensure that all memory it bound is unbound.)
*/
-void agp_backend_release(void)
+void agp_backend_release(struct agp_bridge_data *bridge)
{
- if (agp_bridge->type != NOT_SUPPORTED)
- atomic_dec(&agp_bridge->agp_in_use);
+
+ if (bridge)
+ atomic_dec(&bridge->agp_in_use);
}
EXPORT_SYMBOL(agp_backend_release);

@@ -121,7 +125,6 @@
(maxes_table[index].agp - maxes_table[index - 1].agp)) /
(maxes_table[index].mem - maxes_table[index - 1].mem);

- printk(KERN_INFO PFX "Maximum main memory to use for agp memory: %ldM\n", result);
result = result << (20 - PAGE_SHIFT);
return result;
}
@@ -178,9 +181,6 @@
goto err_out;
}

- printk(KERN_INFO PFX "AGP aperture is %dM @ 0x%lx\n",
- size_value, bridge->gart_bus_addr);
-
return 0;

err_out:
@@ -225,16 +225,31 @@
&agp_copy_info
};

-/* XXX Kludge alert: agpgart isn't ready for multiple bridges yet */
+/* When we remove the global variable agp_bridge from all drivers
+ * then agp_alloc_bridge and agp_generic_find_bridge need to be updated
+ */
+
struct agp_bridge_data *agp_alloc_bridge(void)
{
- return agp_bridge;
+ struct agp_bridge_data *bridge = kmalloc(sizeof(*bridge), GFP_KERNEL);
+
+ if (!bridge)
+ return NULL;
+
+ if (list_empty(&agp_bridges))
+ agp_bridge = bridge;
+
+ return bridge;
}
EXPORT_SYMBOL(agp_alloc_bridge);


void agp_put_bridge(struct agp_bridge_data *bridge)
{
+ kfree(bridge);
+
+ if (list_empty(&agp_bridges))
+ agp_bridge = NULL;
}
EXPORT_SYMBOL(agp_put_bridge);

@@ -251,43 +266,41 @@
return -EINVAL;
}

- if (agp_count) {
- printk (KERN_INFO PFX
- "Only one agpgart device currently supported.\n");
- return -ENODEV;
- }
-
/* Grab reference on the chipset driver. */
if (!try_module_get(bridge->driver->owner)) {
printk (KERN_INFO PFX "Couldn't lock chipset driver.\n");
return -EINVAL;
}

- bridge->type = SUPPORTED;
-
- error = agp_backend_initialize(agp_bridge);
+ error = agp_backend_initialize(bridge);
if (error) {
printk (KERN_INFO PFX "agp_backend_initialize() failed.\n");
goto err_out;
}

- error = agp_frontend_initialize();
- if (error) {
- printk (KERN_INFO PFX "agp_frontend_initialize() failed.\n");
- goto frontend_err;
- }
+ if (list_empty(&agp_bridges)) {
+ error = agp_frontend_initialize();
+ if (error) {
+ printk (KERN_INFO PFX "agp_frontend_initialize() failed.\n");
+ goto frontend_err;
+ }
+
+ /* FIXME: What to do with this? */
+ inter_module_register("drm_agp", THIS_MODULE, &drm_agp);
+
+ printk(KERN_INFO PFX "AGP aperture is %dM @ 0x%lx\n",
+ bridge->driver->fetch_size(), bridge->gart_bus_addr);

- /* FIXME: What to do with this? */
- inter_module_register("drm_agp", THIS_MODULE, &drm_agp);
+ }

- agp_count++;
+ list_add(&bridge->list, &agp_bridges);
return 0;

frontend_err:
- agp_backend_cleanup(agp_bridge);
+ agp_backend_cleanup(bridge);
err_out:
- bridge->type = NOT_SUPPORTED;
module_put(bridge->driver->owner);
+ agp_put_bridge(bridge);
return error;
}
EXPORT_SYMBOL_GPL(agp_add_bridge);
@@ -295,11 +308,12 @@

void agp_remove_bridge(struct agp_bridge_data *bridge)
{
- bridge->type = NOT_SUPPORTED;
- agp_frontend_cleanup();
agp_backend_cleanup(bridge);
- inter_module_unregister("drm_agp");
- agp_count--;
+ list_del(&bridge->list);
+ if (list_empty(&agp_bridges)) {
+ agp_frontend_cleanup();
+ inter_module_unregister("drm_agp");
+ }
module_put(bridge->driver->owner);
}
EXPORT_SYMBOL_GPL(agp_remove_bridge);
diff -Nru a/drivers/char/agp/frontend.c b/drivers/char/agp/frontend.c
--- a/drivers/char/agp/frontend.c 2004-12-09 20:46:37 -08:00
+++ b/drivers/char/agp/frontend.c 2004-12-09 20:46:37 -08:00
@@ -1,5 +1,6 @@
/*
* AGPGART driver frontend
+ * Copyright (C) 2004 Silicon Graphics, Inc.
* Copyright (C) 2002-2003 Dave Jones
* Copyright (C) 1999 Jeff Hartmann
* Copyright (C) 1999 Precision Insight, Inc.
@@ -292,14 +293,14 @@
static void agp_free_memory_wrap(struct agp_memory *memory)
{
agp_remove_from_pool(memory);
- agp_free_memory(memory);
+ agp_free_memory(agp_bridge, memory);
}

static struct agp_memory *agp_allocate_memory_wrap(size_t pg_count, u32 type)
{
struct agp_memory *memory;

- memory = agp_allocate_memory(pg_count, type);
+ memory = agp_allocate_memory(agp_bridge, pg_count, type);
if (memory == NULL)
return NULL;

@@ -420,7 +421,7 @@
if (agp_fe.current_controller == controller) {
agp_fe.current_controller = NULL;
agp_fe.backend_acquired = FALSE;
- agp_backend_release();
+ agp_backend_release(agp_bridge);
}
kfree(controller);
return 0;
@@ -468,7 +469,7 @@

agp_fe.current_controller = NULL;
agp_fe.used_by_controller = FALSE;
- agp_backend_release();
+ agp_backend_release(agp_bridge);
}

/*
@@ -605,7 +606,7 @@
if (!(test_bit(AGP_FF_IS_VALID, &priv->access_flags)))
goto out_eperm;

- agp_copy_info(&kerninfo);
+ agp_copy_info(agp_bridge, &kerninfo);
size = vma->vm_end - vma->vm_start;
current_size = kerninfo.aper_size;
current_size = current_size * 0x100000;
@@ -757,7 +758,7 @@
struct agp_info userinfo;
struct agp_kern_info kerninfo;

- agp_copy_info(&kerninfo);
+ agp_copy_info(agp_bridge, &kerninfo);

userinfo.version.major = kerninfo.version.major;
userinfo.version.minor = kerninfo.version.minor;
@@ -777,7 +778,6 @@

static int agpioc_acquire_wrap(struct agp_file_private *priv)
{
- int ret;
struct agp_controller *controller;

DBG("");
@@ -788,11 +788,15 @@
if (agp_fe.current_controller != NULL)
return -EBUSY;

- ret = agp_backend_acquire();
- if (ret == 0)
- agp_fe.backend_acquired = TRUE;
- else
- return ret;
+ if(!agp_bridge)
+ return -ENODEV;
+
+ if (atomic_read(&agp_bridge->agp_in_use))
+ return -EBUSY;
+
+ atomic_inc(&agp_bridge->agp_in_use);
+
+ agp_fe.backend_acquired = TRUE;

controller = agp_find_controller_by_pid(priv->my_pid);

@@ -803,7 +807,7 @@

if (controller == NULL) {
agp_fe.backend_acquired = FALSE;
- agp_backend_release();
+ agp_backend_release(agp_bridge);
return -ENOMEM;
}
agp_insert_controller(controller);
@@ -830,7 +834,7 @@
if (copy_from_user(&mode, arg, sizeof(struct agp_setup)))
return -EFAULT;

- agp_enable(mode.agp_mode);
+ agp_enable(agp_bridge, mode.agp_mode);
return 0;
}

@@ -961,7 +965,7 @@
if (memory == NULL)
return -EINVAL;

- return agp_bind_memory(memory, bind_info.pg_start);
+ return agp_bind_memory(agp_bridge, memory, bind_info.pg_start);
}

static int agpioc_unbind_wrap(struct agp_file_private *priv, void __user *arg)
@@ -978,7 +982,7 @@
if (memory == NULL)
return -EINVAL;

- return agp_unbind_memory(memory);
+ return agp_unbind_memory(agp_bridge, memory);
}

static int agp_ioctl(struct inode *inode, struct file *file,
diff -Nru a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
--- a/drivers/char/agp/generic.c 2004-12-09 20:46:37 -08:00
+++ b/drivers/char/agp/generic.c 2004-12-09 20:46:37 -08:00
@@ -1,5 +1,6 @@
/*
* AGPGART driver.
+ * Copyright (C) 2004 Silicon Graphics, Inc.
* Copyright (C) 2002-2004 Dave Jones.
* Copyright (C) 1999 Jeff Hartmann.
* Copyright (C) 1999 Precision Insight, Inc.
@@ -112,23 +113,23 @@
* It is the only function that can be called when the backend is not owned
* by the caller. (So it can free memory on client death.)
*/
-void agp_free_memory(struct agp_memory *curr)
+void agp_free_memory(struct agp_bridge_data *bridge, struct agp_memory *curr)
{
size_t i;

- if ((agp_bridge->type == NOT_SUPPORTED) || (curr == NULL))
+ if ((bridge == NULL) || (curr == NULL))
return;

if (curr->is_bound == TRUE)
- agp_unbind_memory(curr);
+ agp_unbind_memory(bridge, curr);

if (curr->type != 0) {
- agp_bridge->driver->free_by_type(curr);
+ bridge->driver->free_by_type(curr);
return;
}
if (curr->page_count != 0) {
for (i = 0; i < curr->page_count; i++) {
- agp_bridge->driver->agp_destroy_page(phys_to_virt(curr->memory[i]));
+ bridge->driver->agp_destroy_page(phys_to_virt(curr->memory[i]));
}
}
agp_free_key(curr->key);
@@ -150,20 +151,20 @@
*
* It returns NULL whenever memory is unavailable.
*/
-struct agp_memory *agp_allocate_memory(size_t page_count, u32 type)
+struct agp_memory *agp_allocate_memory(struct agp_bridge_data *bridge, size_t page_count, u32 type)
{
int scratch_pages;
struct agp_memory *new;
size_t i;

- if (agp_bridge->type == NOT_SUPPORTED)
+ if (!bridge)
return NULL;

- if ((atomic_read(&agp_bridge->current_memory_agp) + page_count) > agp_bridge->max_memory_agp)
+ if ((atomic_read(&bridge->current_memory_agp) + page_count) > bridge->max_memory_agp)
return NULL;

if (type != 0) {
- new = agp_bridge->driver->alloc_by_type(page_count, type);
+ new = bridge->driver->alloc_by_type(page_count, type);
return new;
}

@@ -175,14 +176,14 @@
return NULL;

for (i = 0; i < page_count; i++) {
- void *addr = agp_bridge->driver->agp_alloc_page();
+ void *addr = bridge->driver->agp_alloc_page();

if (addr == NULL) {
- agp_free_memory(new);
+ agp_free_memory(bridge, new);
return NULL;
}
new->memory[i] =
- agp_bridge->driver->mask_memory(virt_to_phys(addr), type);
+ bridge->driver->mask_memory(virt_to_phys(addr), type);
new->page_count++;
}

@@ -196,14 +197,14 @@
/* End - Generic routines for handling agp_memory structures */


-static int agp_return_size(void)
+static int agp_return_size(struct agp_bridge_data *bridge)
{
int current_size;
void *temp;

- temp = agp_bridge->current_size;
+ temp = bridge->current_size;

- switch (agp_bridge->driver->size_type) {
+ switch (bridge->driver->size_type) {
case U8_APER_SIZE:
current_size = A_SIZE_8(temp)->size;
break;
@@ -275,26 +276,25 @@
* This function copies information about the agp bridge device and the state of
* the agp backend into an agp_kern_info pointer.
*/
-int agp_copy_info(struct agp_kern_info *info)
+int agp_copy_info(struct agp_bridge_data *bridge, struct agp_kern_info *info)
{
memset(info, 0, sizeof(struct agp_kern_info));
- if (!agp_bridge || agp_bridge->type == NOT_SUPPORTED ||
- !agp_bridge->version) {
+ if (!bridge) {
info->chipset = NOT_SUPPORTED;
return -EIO;
}

- info->version.major = agp_bridge->version->major;
- info->version.minor = agp_bridge->version->minor;
- info->chipset = agp_bridge->type;
- info->device = agp_bridge->dev;
- info->mode = agp_bridge->mode;
- info->aper_base = agp_bridge->gart_bus_addr;
- info->aper_size = agp_return_size();
- info->max_memory = agp_bridge->max_memory_agp;
- info->current_memory = atomic_read(&agp_bridge->current_memory_agp);
- info->cant_use_aperture = agp_bridge->driver->cant_use_aperture;
- info->vm_ops = agp_bridge->vm_ops;
+ info->version.major = bridge->version->major;
+ info->version.minor = bridge->version->minor;
+ info->chipset = SUPPORTED;
+ info->device = bridge->dev;
+ info->mode = bridge->mode;
+ info->aper_base = bridge->gart_bus_addr;
+ info->aper_size = agp_return_size(bridge);
+ info->max_memory = bridge->max_memory_agp;
+ info->current_memory = atomic_read(&bridge->current_memory_agp);
+ info->cant_use_aperture = bridge->driver->cant_use_aperture;
+ info->vm_ops = bridge->vm_ops;
info->page_mask = ~0UL;
return 0;
}
@@ -319,11 +319,11 @@
* It returns -EINVAL if the pointer == NULL.
* It returns -EBUSY if the area of the table requested is already in use.
*/
-int agp_bind_memory(struct agp_memory *curr, off_t pg_start)
+int agp_bind_memory(struct agp_bridge_data *bridge, struct agp_memory *curr, off_t pg_start)
{
int ret_val;

- if ((agp_bridge->type == NOT_SUPPORTED) || (curr == NULL))
+ if ((bridge == NULL) || (curr == NULL))
return -EINVAL;

if (curr->is_bound == TRUE) {
@@ -331,10 +331,10 @@
return -EINVAL;
}
if (curr->is_flushed == FALSE) {
- agp_bridge->driver->cache_flush();
+ bridge->driver->cache_flush();
curr->is_flushed = TRUE;
}
- ret_val = agp_bridge->driver->insert_memory(curr, pg_start, curr->type);
+ ret_val = bridge->driver->insert_memory(curr, pg_start, curr->type);

if (ret_val != 0)
return ret_val;
@@ -354,11 +354,11 @@
* It returns -EINVAL if this piece of agp_memory is not currently bound to
* the graphics aperture translation table or if the agp_memory pointer == NULL
*/
-int agp_unbind_memory(struct agp_memory *curr)
+int agp_unbind_memory(struct agp_bridge_data *bridge, struct agp_memory *curr)
{
int ret_val;

- if ((agp_bridge->type == NOT_SUPPORTED) || (curr == NULL))
+ if ((bridge == NULL) || (curr == NULL))
return -EINVAL;

if (curr->is_bound != TRUE) {
@@ -366,7 +366,7 @@
return -EINVAL;
}

- ret_val = agp_bridge->driver->remove_memory(curr, curr->pg_start, curr->type);
+ ret_val = bridge->driver->remove_memory(curr, curr->pg_start, curr->type);

if (ret_val != 0)
return ret_val;
@@ -949,14 +949,25 @@
*
* @mode: agp mode register value to configure with.
*/
-void agp_enable(u32 mode)
+void agp_enable(struct agp_bridge_data *bridge, u32 mode)
{
- if (agp_bridge->type == NOT_SUPPORTED)
+ if (!bridge)
return;
- agp_bridge->driver->agp_enable(mode);
+ bridge->driver->agp_enable(mode);
}
EXPORT_SYMBOL(agp_enable);

+/* When we remove the global variable agp_bridge from all drivers
+ * then agp_alloc_bridge and agp_generic_find_bridge need to be updated
+ */
+
+struct agp_bridge_data *agp_generic_find_bridge(struct pci_dev *pdev)
+{
+ if (list_empty(&agp_bridges))
+ return NULL;
+
+ return agp_bridge;
+}

#ifdef CONFIG_SMP
static void ipi_handler(void *null)
diff -Nru a/include/linux/agp_backend.h b/include/linux/agp_backend.h
--- a/include/linux/agp_backend.h 2004-12-09 20:46:37 -08:00
+++ b/include/linux/agp_backend.h 2004-12-09 20:46:37 -08:00
@@ -1,6 +1,7 @@
/*
* AGPGART backend specific includes. Not for userspace consumption.
*
+ * Copyright (C) 2004 Silicon Graphics, Inc.
* Copyright (C) 2002-2003 Dave Jones
* Copyright (C) 1999 Jeff Hartmann
* Copyright (C) 1999 Precision Insight, Inc.
@@ -87,14 +88,17 @@

#define AGP_NORMAL_MEMORY 0

-extern void agp_free_memory(struct agp_memory *);
-extern struct agp_memory *agp_allocate_memory(size_t, u32);
-extern int agp_copy_info(struct agp_kern_info *);
-extern int agp_bind_memory(struct agp_memory *, off_t);
-extern int agp_unbind_memory(struct agp_memory *);
-extern void agp_enable(u32);
-extern int agp_backend_acquire(void);
-extern void agp_backend_release(void);
+extern struct agp_bridge_data *agp_bridge;
+extern struct list_head agp_bridges;
+
+extern void agp_free_memory(struct agp_bridge_data *, struct agp_memory *);
+extern struct agp_memory *agp_allocate_memory(struct agp_bridge_data *, size_t, u32);
+extern int agp_copy_info(struct agp_bridge_data *, struct agp_kern_info *);
+extern int agp_bind_memory(struct agp_bridge_data *, struct agp_memory *, off_t);
+extern int agp_unbind_memory(struct agp_bridge_data *, struct agp_memory *);
+extern void agp_enable(struct agp_bridge_data *, u32);
+extern struct agp_bridge_data *agp_backend_acquire(struct pci_dev *);
+extern void agp_backend_release(struct agp_bridge_data *);

/*
* Interface between drm and agp code. When agp initializes, it makes
@@ -102,14 +106,14 @@
* use it. Keith Owens <kaos@xxxxxxxxxx> 28 Oct 2000.
*/
typedef struct {
- void (*free_memory)(struct agp_memory *);
- struct agp_memory * (*allocate_memory)(size_t, u32);
- int (*bind_memory)(struct agp_memory *, off_t);
- int (*unbind_memory)(struct agp_memory *);
- void (*enable)(u32);
- int (*acquire)(void);
- void (*release)(void);
- int (*copy_info)(struct agp_kern_info *);
+ void (*free_memory)(struct agp_bridge_data *, struct agp_memory *);
+ struct agp_memory * (*allocate_memory)(struct agp_bridge_data *, size_t, u32);
+ int (*bind_memory)(struct agp_bridge_data *, struct agp_memory *, off_t);
+ int (*unbind_memory)(struct agp_bridge_data *, struct agp_memory *);
+ void (*enable)(struct agp_bridge_data *, u32);
+ struct agp_bridge_data *(*acquire)(struct pci_dev *);
+ void (*release)(struct agp_bridge_data *);
+ int (*copy_info)(struct agp_bridge_data *, struct agp_kern_info *);
} drm_agp_t;

extern const drm_agp_t *drm_agp_p;
-
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