gma500: GEM and GEM glue

The driver uses GEM along with a couple of small bits of wrapping of its
own. The only real oddity here is the support for using the 'stolen' memory
rather than wasting several MB.

We use a simple resource manager as we don't need to manage our space
intensively at all as we only do 2D work. We also have a GTT which is
entirely GPU facing so in the Cedarview case are not even allocating from
host address space.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

3 files changed, 386 insertions, 0 deletions

diff --git a/drivers/gpu/drm/gma500/gem.c b/drivers/gpu/drm/gma500/gem.c
new file mode 100644
index 000000000000..65fdd6b8ab16
--- /dev/null
+++ b/drivers/gpu/drm/gma500/gem.c
@@ -0,0 +1,295 @@
+/*
+ *  psb GEM interface
+ *
+ * Copyright (c) 2011, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Authors: Alan Cox
+ *
+ * TODO:
+ *      -       we need to work out if the MMU is relevant (eg for
+ *              accelerated operations on a GEM object)
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm.h>
+#include "psb_drm.h"
+#include "psb_drv.h"
+
+int psb_gem_init_object(struct drm_gem_object *obj)
+{
+        return -EINVAL;
+}
+
+void psb_gem_free_object(struct drm_gem_object *obj)
+{
+        struct gtt_range *gtt = container_of(obj, struct gtt_range, gem);
+        drm_gem_object_release_wrap(obj);
+        /* This must occur last as it frees up the memory of the GEM object */
+        psb_gtt_free_range(obj->dev, gtt);
+}
+
+int psb_gem_get_aperture(struct drm_device *dev, void *data,
+                                struct drm_file *file)
+{
+        return -EINVAL;
+}
+
+/**
+ *      psb_gem_dumb_map_gtt    -       buffer mapping for dumb interface
+ *      @file: our drm client file
+ *      @dev: drm device
+ *      @handle: GEM handle to the object (from dumb_create)
+ *
+ *      Do the necessary setup to allow the mapping of the frame buffer
+ *      into user memory. We don't have to do much here at the moment.
+ */
+int psb_gem_dumb_map_gtt(struct drm_file *file, struct drm_device *dev,
+                         uint32_t handle, uint64_t *offset)
+{
+        int ret = 0;
+        struct drm_gem_object *obj;
+
+        if (!(dev->driver->driver_features & DRIVER_GEM))
+                return -ENODEV;
+
+        mutex_lock(&dev->struct_mutex);
+
+        /* GEM does all our handle to object mapping */
+        obj = drm_gem_object_lookup(dev, file, handle);
+        if (obj == NULL) {
+                ret = -ENOENT;
+                goto unlock;
+        }
+        /* What validation is needed here ? */
+
+        /* Make it mmapable */
+        if (!obj->map_list.map) {
+                ret = gem_create_mmap_offset(obj);
+                if (ret)
+                        goto out;
+        }
+        /* GEM should really work out the hash offsets for us */
+        *offset = (u64)obj->map_list.hash.key << PAGE_SHIFT;
+out:
+        drm_gem_object_unreference(obj);
+unlock:
+        mutex_unlock(&dev->struct_mutex);
+        return ret;
+}
+
+/**
+ *      psb_gem_create          -       create a mappable object
+ *      @file: the DRM file of the client
+ *      @dev: our device
+ *      @size: the size requested
+ *      @handlep: returned handle (opaque number)
+ *
+ *      Create a GEM object, fill in the boilerplate and attach a handle to
+ *      it so that userspace can speak about it. This does the core work
+ *      for the various methods that do/will create GEM objects for things
+ */
+static int psb_gem_create(struct drm_file *file,
+        struct drm_device *dev, uint64_t size, uint32_t *handlep)
+{
+        struct gtt_range *r;
+        int ret;
+        u32 handle;
+
+        size = roundup(size, PAGE_SIZE);
+
+        /* Allocate our object - for now a direct gtt range which is not
+           stolen memory backed */
+        r = psb_gtt_alloc_range(dev, size, "gem", 0);
+        if (r == NULL) {
+                dev_err(dev->dev, "no memory for %lld byte GEM object\n", size);
+                return -ENOSPC;
+        }
+        /* Initialize the extra goodies GEM needs to do all the hard work */
+        if (drm_gem_object_init(dev, &r->gem, size) != 0) {
+                psb_gtt_free_range(dev, r);
+                /* GEM doesn't give an error code and we don't have an
+                   EGEMSUCKS so make something up for now - FIXME */
+                dev_err(dev->dev, "GEM init failed for %lld\n", size);
+                return -ENOMEM;
+        }
+        /* Give the object a handle so we can carry it more easily */
+        ret = drm_gem_handle_create(file, &r->gem, &handle);
+        if (ret) {
+                dev_err(dev->dev, "GEM handle failed for %p, %lld\n",
+                                                        &r->gem, size);
+                drm_gem_object_release(&r->gem);
+                psb_gtt_free_range(dev, r);
+                return ret;
+        }
+        /* We have the initial and handle reference but need only one now */
+        drm_gem_object_unreference(&r->gem);
+        *handlep = handle;
+        return 0;
+}
+
+/**
+ *      psb_gem_dumb_create     -       create a dumb buffer
+ *      @drm_file: our client file
+ *      @dev: our device
+ *      @args: the requested arguments copied from userspace
+ *
+ *      Allocate a buffer suitable for use for a frame buffer of the
+ *      form described by user space. Give userspace a handle by which
+ *      to reference it.
+ */
+int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
+                        struct drm_mode_create_dumb *args)
+{
+        args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64);
+        args->size = args->pitch * args->height;
+        return psb_gem_create(file, dev, args->size, &args->handle);
+}
+
+/**
+ *      psb_gem_dumb_destroy    -       destroy a dumb buffer
+ *      @file: client file
+ *      @dev: our DRM device
+ *      @handle: the object handle
+ *
+ *      Destroy a handle that was created via psb_gem_dumb_create, at least
+ *      we hope it was created that way. i915 seems to assume the caller
+ *      does the checking but that might be worth review ! FIXME
+ */
+int psb_gem_dumb_destroy(struct drm_file *file, struct drm_device *dev,
+                        uint32_t handle)
+{
+        /* No special work needed, drop the reference and see what falls out */
+        return drm_gem_handle_delete(file, handle);
+}
+
+/**
+ *      psb_gem_fault           -       pagefault handler for GEM objects
+ *      @vma: the VMA of the GEM object
+ *      @vmf: fault detail
+ *
+ *      Invoked when a fault occurs on an mmap of a GEM managed area. GEM
+ *      does most of the work for us including the actual map/unmap calls
+ *      but we need to do the actual page work.
+ *
+ *      This code eventually needs to handle faulting objects in and out
+ *      of the GTT and repacking it when we run out of space. We can put
+ *      that off for now and for our simple uses
+ *
+ *      The VMA was set up by GEM. In doing so it also ensured that the
+ *      vma->vm_private_data points to the GEM object that is backing this
+ *      mapping.
+ *
+ *      FIXME
+ */
+int psb_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+        struct drm_gem_object *obj;
+        struct gtt_range *r;
+        int ret;
+        unsigned long pfn;
+        pgoff_t page_offset;
+        struct drm_device *dev;
+        struct drm_psb_private *dev_priv;
+
+        obj = vma->vm_private_data;     /* GEM object */
+        dev = obj->dev;
+        dev_priv = dev->dev_private;
+
+        r = container_of(obj, struct gtt_range, gem);   /* Get the gtt range */
+
+        /* Make sure we don't parallel update on a fault, nor move or remove
+           something from beneath our feet */
+        mutex_lock(&dev->struct_mutex);
+
+        /* For now the mmap pins the object and it stays pinned. As things
+           stand that will do us no harm */
+        if (r->mmapping == 0) {
+                ret = psb_gtt_pin(r);
+                if (ret < 0) {
+                        dev_err(dev->dev, "gma500: pin failed: %d\n", ret);
+                        goto fail;
+                }
+                r->mmapping = 1;
+        }
+
+        /* Page relative to the VMA start - we must calculate this ourselves
+           because vmf->pgoff is the fake GEM offset */
+        page_offset = ((unsigned long) vmf->virtual_address - vma->vm_start)
+                                >> PAGE_SHIFT;
+
+        /* CPU view of the page, don't go via the GART for CPU writes */
+        if (r->stolen)
+                pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT;
+        else
+                pfn = page_to_pfn(r->pages[page_offset]);
+        ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
+
+fail:
+        mutex_unlock(&dev->struct_mutex);
+        switch (ret) {
+        case 0:
+        case -ERESTARTSYS:
+        case -EINTR:
+                return VM_FAULT_NOPAGE;
+        case -ENOMEM:
+                return VM_FAULT_OOM;
+        default:
+                return VM_FAULT_SIGBUS;
+        }
+}
+
+static int psb_gem_create_stolen(struct drm_file *file, struct drm_device *dev,
+                                                int size, u32 *handle)
+{
+        struct gtt_range *gtt = psb_gtt_alloc_range(dev, size, "gem", 1);
+        if (gtt == NULL)
+                return -ENOMEM;
+        if (drm_gem_private_object_init(dev, &gtt->gem, size) != 0)
+                goto free_gtt;
+        if (drm_gem_handle_create(file, &gtt->gem, handle) == 0)
+                return 0;
+free_gtt:
+        psb_gtt_free_range(dev, gtt);
+        return -ENOMEM;
+}
+
+/*
+ *      GEM interfaces for our specific client
+ */
+int psb_gem_create_ioctl(struct drm_device *dev, void *data,
+                                        struct drm_file *file)
+{
+        struct drm_psb_gem_create *args = data;
+        int ret;
+        if (args->flags & PSB_GEM_CREATE_STOLEN) {
+                ret = psb_gem_create_stolen(file, dev, args->size,
+                                                        &args->handle);
+                if (ret == 0)
+                        return 0;
+                /* Fall throguh */
+                args->flags &= ~PSB_GEM_CREATE_STOLEN;
+        }
+        return psb_gem_create(file, dev, args->size, &args->handle);
+}
+
+int psb_gem_mmap_ioctl(struct drm_device *dev, void *data,
+                                        struct drm_file *file)
+{
+        struct drm_psb_gem_mmap *args = data;
+        return dev->driver->dumb_map_offset(file, dev,
+                                                args->handle, &args->offset);
+}
+
diff --git a/drivers/gpu/drm/gma500/gem_glue.c b/drivers/gpu/drm/gma500/gem_glue.c
new file mode 100644
index 000000000000..daac12120653
--- /dev/null
+++ b/drivers/gpu/drm/gma500/gem_glue.c
@@ -0,0 +1,89 @@
+/**************************************************************************
+ * Copyright (c) 2011, Intel Corporation.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ **************************************************************************/
+
+#include <drm/drmP.h>
+#include <drm/drm.h>
+
+void drm_gem_object_release_wrap(struct drm_gem_object *obj)
+{
+        /* Remove the list map if one is present */
+        if (obj->map_list.map) {
+                struct drm_gem_mm *mm = obj->dev->mm_private;
+                struct drm_map_list *list = &obj->map_list;
+                drm_ht_remove_item(&mm->offset_hash, &list->hash);
+                drm_mm_put_block(list->file_offset_node);
+                kfree(list->map);
+                list->map = NULL;
+        }
+        drm_gem_object_release(obj);
+}
+
+/**
+ *      gem_create_mmap_offset          -       invent an mmap offset
+ *      @obj: our object
+ *
+ *      Standard implementation of offset generation for mmap as is
+ *      duplicated in several drivers. This belongs in GEM.
+ */
+int gem_create_mmap_offset(struct drm_gem_object *obj)
+{
+        struct drm_device *dev = obj->dev;
+        struct drm_gem_mm *mm = dev->mm_private;
+        struct drm_map_list *list;
+        struct drm_local_map *map;
+        int ret;
+
+        list = &obj->map_list;
+        list->map = kzalloc(sizeof(struct drm_map_list), GFP_KERNEL);
+        if (list->map == NULL)
+                return -ENOMEM;
+        map = list->map;
+        map->type = _DRM_GEM;
+        map->size = obj->size;
+        map->handle = obj;
+
+        list->file_offset_node = drm_mm_search_free(&mm->offset_manager,
+                                        obj->size / PAGE_SIZE, 0, 0);
+        if (!list->file_offset_node) {
+                dev_err(dev->dev, "failed to allocate offset for bo %d\n",
+                                                                obj->name);
+                ret = -ENOSPC;
+                goto free_it;
+        }
+        list->file_offset_node = drm_mm_get_block(list->file_offset_node,
+                                        obj->size / PAGE_SIZE, 0);
+        if (!list->file_offset_node) {
+                ret = -ENOMEM;
+                goto free_it;
+        }
+        list->hash.key = list->file_offset_node->start;
+        ret = drm_ht_insert_item(&mm->offset_hash, &list->hash);
+        if (ret) {
+                dev_err(dev->dev, "failed to add to map hash\n");
+                goto free_mm;
+        }
+        return 0;
+
+free_mm:
+        drm_mm_put_block(list->file_offset_node);
+free_it:
+        kfree(list->map);
+        list->map = NULL;
+        return ret;
+}
diff --git a/drivers/gpu/drm/gma500/gem_glue.h b/drivers/gpu/drm/gma500/gem_glue.h
new file mode 100644
index 000000000000..ce5ce30f74db
--- /dev/null
+++ b/drivers/gpu/drm/gma500/gem_glue.h
@@ -0,0 +1,2 @@
+extern void drm_gem_object_release_wrap(struct drm_gem_object *obj);
+extern int gem_create_mmap_offset(struct drm_gem_object *obj);