1 files changed, 348 insertions, 0 deletions

diff --git a/drivers/char/agp/backend.c b/drivers/char/agp/backend.c
new file mode 100644
index 000000000000..c3442f3c6480
--- /dev/null
+++ b/drivers/char/agp/backend.c
@@ -0,0 +1,348 @@
+/*
+ * 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.
+ * Copyright (C) 1999 Xi Graphics, Inc.
+ *
+ * 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 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
+ * JEFF HARTMANN, DAVE JONES, OR ANY OTHER CONTRIBUTORS 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.
+ *
+ * TODO:
+ * - Allocate more than order 0 pages to avoid too much linear map splitting.
+ */
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/miscdevice.h>
+#include <linux/pm.h>
+#include <linux/agp_backend.h>
+#include <linux/agpgart.h>
+#include <linux/vmalloc.h>
+#include <asm/io.h>
+#include "agp.h"
+
+/* Due to XFree86 brain-damage, we can't go to 1.0 until they
+ * 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 101
+static struct agp_version agp_current_version =
+{
+        .major = AGPGART_VERSION_MAJOR,
+        .minor = AGPGART_VERSION_MINOR,
+};
+
+struct agp_bridge_data *(*agp_find_bridge)(struct pci_dev *) =
+        &agp_generic_find_bridge;
+
+struct agp_bridge_data *agp_bridge;
+LIST_HEAD(agp_bridges);
+EXPORT_SYMBOL(agp_bridge);
+EXPORT_SYMBOL(agp_bridges);
+EXPORT_SYMBOL(agp_find_bridge);
+
+/**
+ *      agp_backend_acquire  -  attempt to acquire an agp backend.
+ *
+ */
+struct agp_bridge_data *agp_backend_acquire(struct pci_dev *pdev)
+{
+        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);
+
+
+/**
+ *      agp_backend_release  -  release the lock on the agp backend.
+ *
+ *      The caller must insure that the graphics aperture translation table
+ *      is read for use by another entity.
+ *
+ *      (Ensure that all memory it bound is unbound.)
+ */
+void agp_backend_release(struct agp_bridge_data *bridge)
+{
+
+        if (bridge)
+                atomic_dec(&bridge->agp_in_use);
+}
+EXPORT_SYMBOL(agp_backend_release);
+
+
+struct { int mem, agp; } maxes_table[] = {
+        {0, 0},
+        {32, 4},
+        {64, 28},
+        {128, 96},
+        {256, 204},
+        {512, 440},
+        {1024, 942},
+        {2048, 1920},
+        {4096, 3932}
+};
+
+static int agp_find_max(void)
+{
+        long memory, index, result;
+
+#if PAGE_SHIFT < 20
+        memory = num_physpages >> (20 - PAGE_SHIFT);
+#else
+        memory = num_physpages << (PAGE_SHIFT - 20);
+#endif
+        index = 1;
+
+        while ((memory > maxes_table[index].mem) && (index < 8))
+                index++;
+
+        result = maxes_table[index - 1].agp +
+           ( (memory - maxes_table[index - 1].mem)  *
+             (maxes_table[index].agp - maxes_table[index - 1].agp)) /
+           (maxes_table[index].mem - maxes_table[index - 1].mem);
+
+        result = result << (20 - PAGE_SHIFT);
+        return result;
+}
+
+
+static int agp_backend_initialize(struct agp_bridge_data *bridge)
+{
+        int size_value, rc, got_gatt=0, got_keylist=0;
+
+        bridge->max_memory_agp = agp_find_max();
+        bridge->version = &agp_current_version;
+
+        if (bridge->driver->needs_scratch_page) {
+                void *addr = bridge->driver->agp_alloc_page(bridge);
+
+                if (!addr) {
+                        printk(KERN_ERR PFX "unable to get memory for scratch page.\n");
+                        return -ENOMEM;
+                }
+
+                bridge->scratch_page_real = virt_to_phys(addr);
+                bridge->scratch_page =
+                    bridge->driver->mask_memory(bridge, bridge->scratch_page_real, 0);
+        }
+
+        size_value = bridge->driver->fetch_size();
+        if (size_value == 0) {
+                printk(KERN_ERR PFX "unable to determine aperture size.\n");
+                rc = -EINVAL;
+                goto err_out;
+        }
+        if (bridge->driver->create_gatt_table(bridge)) {
+                printk(KERN_ERR PFX
+                    "unable to get memory for graphics translation table.\n");
+                rc = -ENOMEM;
+                goto err_out;
+        }
+        got_gatt = 1;
+
+        bridge->key_list = vmalloc(PAGE_SIZE * 4);
+        if (bridge->key_list == NULL) {
+                printk(KERN_ERR PFX "error allocating memory for key lists.\n");
+                rc = -ENOMEM;
+                goto err_out;
+        }
+        got_keylist = 1;
+
+        /* FIXME vmalloc'd memory not guaranteed contiguous */
+        memset(bridge->key_list, 0, PAGE_SIZE * 4);
+
+        if (bridge->driver->configure()) {
+                printk(KERN_ERR PFX "error configuring host chipset.\n");
+                rc = -EINVAL;
+                goto err_out;
+        }
+
+        return 0;
+
+err_out:
+        if (bridge->driver->needs_scratch_page)
+                bridge->driver->agp_destroy_page(
+                                phys_to_virt(bridge->scratch_page_real));
+        if (got_gatt)
+                bridge->driver->free_gatt_table(bridge);
+        if (got_keylist) {
+                vfree(bridge->key_list);
+                bridge->key_list = NULL;
+        }
+        return rc;
+}
+
+/* cannot be __exit b/c as it could be called from __init code */
+static void agp_backend_cleanup(struct agp_bridge_data *bridge)
+{
+        if (bridge->driver->cleanup)
+                bridge->driver->cleanup();
+        if (bridge->driver->free_gatt_table)
+                bridge->driver->free_gatt_table(bridge);
+        if (bridge->key_list) {
+                vfree(bridge->key_list);
+                bridge->key_list = NULL;
+        }
+
+        if (bridge->driver->agp_destroy_page &&
+            bridge->driver->needs_scratch_page)
+                bridge->driver->agp_destroy_page(
+                                phys_to_virt(bridge->scratch_page_real));
+}
+
+/* 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)
+{
+        struct agp_bridge_data *bridge = kmalloc(sizeof(*bridge), GFP_KERNEL);
+
+        if (!bridge)
+                return NULL;
+
+        memset(bridge, 0, sizeof(*bridge));
+        atomic_set(&bridge->agp_in_use, 0);
+        atomic_set(&bridge->current_memory_agp, 0);
+
+        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);
+
+
+int agp_add_bridge(struct agp_bridge_data *bridge)
+{
+        int error;
+
+        if (agp_off)
+                return -ENODEV;
+
+        if (!bridge->dev) {
+                printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
+                return -EINVAL;
+        }
+
+        /* 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;
+        }
+
+        error = agp_backend_initialize(bridge);
+        if (error) {
+                printk (KERN_INFO PFX "agp_backend_initialize() failed.\n");
+                goto err_out;
+        }
+
+        if (list_empty(&agp_bridges)) {
+                error = agp_frontend_initialize();
+                if (error) {
+                        printk (KERN_INFO PFX "agp_frontend_initialize() failed.\n");
+                        goto frontend_err;
+                }
+
+                printk(KERN_INFO PFX "AGP aperture is %dM @ 0x%lx\n",
+                        bridge->driver->fetch_size(), bridge->gart_bus_addr);
+
+        }
+
+        list_add(&bridge->list, &agp_bridges);
+        return 0;
+
+frontend_err:
+        agp_backend_cleanup(bridge);
+err_out:
+        module_put(bridge->driver->owner);
+        agp_put_bridge(bridge);
+        return error;
+}
+EXPORT_SYMBOL_GPL(agp_add_bridge);
+
+
+void agp_remove_bridge(struct agp_bridge_data *bridge)
+{
+        agp_backend_cleanup(bridge);
+        list_del(&bridge->list);
+        if (list_empty(&agp_bridges))
+                agp_frontend_cleanup();
+        module_put(bridge->driver->owner);
+}
+EXPORT_SYMBOL_GPL(agp_remove_bridge);
+
+int agp_off;
+int agp_try_unsupported_boot;
+EXPORT_SYMBOL(agp_off);
+EXPORT_SYMBOL(agp_try_unsupported_boot);
+
+static int __init agp_init(void)
+{
+        if (!agp_off)
+                printk(KERN_INFO "Linux agpgart interface v%d.%d (c) Dave Jones\n",
+                        AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
+        return 0;
+}
+
+void __exit agp_exit(void)
+{
+}
+
+#ifndef MODULE
+static __init int agp_setup(char *s)
+{
+        if (!strcmp(s,"off"))
+                agp_off = 1;
+        if (!strcmp(s,"try_unsupported"))
+                agp_try_unsupported_boot = 1;
+        return 1;
+}
+__setup("agp=", agp_setup);
+#endif
+
+MODULE_AUTHOR("Dave Jones <davej@codemonkey.org.uk>");
+MODULE_DESCRIPTION("AGP GART driver");
+MODULE_LICENSE("GPL and additional rights");
+MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
+
+module_init(agp_init);
+module_exit(agp_exit);
+