[PATCH 03/29] gma500: Ensure the frame buffer has a linear virtualmapping

From: Alan Cox
Date: Thu Jun 16 2011 - 12:18:51 EST


From: Alan Cox <alan@xxxxxxxxxxxxxxx>

We need this for the framebuffer in order to ensure that the kernel
framebuffer layer can handle it when using KMS. Except for the base
framebuffer this isn't a concern.

Add an npage field to the gtt as too many copies of the page calculation
are getting spread around the code.

Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
---

drivers/staging/gma500/psb_fb.c | 47 ++++++++++++++++++++++++--------------
drivers/staging/gma500/psb_fb.h | 1 +
drivers/staging/gma500/psb_gtt.c | 18 ++++++---------
drivers/staging/gma500/psb_gtt.h | 5 ++--
4 files changed, 42 insertions(+), 29 deletions(-)

diff --git a/drivers/staging/gma500/psb_fb.c b/drivers/staging/gma500/psb_fb.c
index b276fe9..4b05cdc 100644
--- a/drivers/staging/gma500/psb_fb.c
+++ b/drivers/staging/gma500/psb_fb.c
@@ -254,17 +254,13 @@ static int psbfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
vma->vm_pgoff, fb_screen_base,
dev_priv->vram_addr);

- /* FIXME: ultimately this needs to become 'if entirely stolen memory' */
- if (1 || fb_screen_base == dev_priv->vram_addr) {
- vma->vm_ops = &psbfb_vm_ops;
- vma->vm_private_data = (void *)psbfb;
- vma->vm_flags |= VM_RESERVED | VM_IO |
- VM_MIXEDMAP | VM_DONTEXPAND;
- } else {
- /* GTT memory backed by kernel/user pages, needs a different
- approach ? - GEM ? */
- }
-
+ /* If this is a GEM object then info->screen_base is the virtual
+ kernel remapping of the object. FIXME: Review if this is
+ suitable for our mmap work */
+ vma->vm_ops = &psbfb_vm_ops;
+ vma->vm_private_data = (void *)psbfb;
+ vma->vm_flags |= VM_RESERVED | VM_IO |
+ VM_MIXEDMAP | VM_DONTEXPAND;
return 0;
}

@@ -349,8 +345,6 @@ err:
*
* FIXME: console speed up - allocate twice the space if room and use
* hardware scrolling for acceleration.
- * FIXME: we need to vm_map_ram a linear mapping if the object has to
- * be GEM host mapped, otherwise the cfb layer's brain will fall out.
*/
static struct gtt_range *psbfb_alloc(struct drm_device *dev, int aligned_size)
{
@@ -439,10 +433,22 @@ static int psbfb_create(struct psb_fbdev *fbdev,
info->fix.smem_start = dev->mode_config.fb_base;
info->fix.smem_len = size;

- /* Accessed via stolen memory directly, This only works for stolem
- memory however. Need to address this once we start using gtt
- pages we allocate. FIXME: vm_map_ram for that case */
- info->screen_base = (char *)dev_priv->vram_addr + backing->offset;
+ if (backing->stolen) {
+ /* Accessed stolen memory directly */
+ info->screen_base = (char *)dev_priv->vram_addr +
+ backing->offset;
+ } else {
+ /* Pin the pages into the GTT and create a mapping to them */
+ psb_gtt_pin(backing);
+ info->screen_base = vm_map_ram(backing->pages, backing->npage,
+ -1, PAGE_KERNEL);
+ if (info->screen_base == NULL) {
+ psb_gtt_unpin(backing);
+ ret = -ENOMEM;
+ goto out_err0;
+ }
+ psbfb->vm_map = 1;
+ }
info->screen_size = size;
memset(info->screen_base, 0, size);

@@ -570,6 +576,13 @@ int psb_fbdev_destroy(struct drm_device *dev, struct psb_fbdev *fbdev)

if (fbdev->psb_fb_helper.fbdev) {
info = fbdev->psb_fb_helper.fbdev;
+
+ /* If this is our base framebuffer then kill any virtual map
+ for the framebuffer layer and unpin it */
+ if (psbfb->vm_map) {
+ vm_unmap_ram(info->screen_base, psbfb->gtt->npage);
+ psb_gtt_unpin(psbfb->gtt);
+ }
/* FIXME: this is a bit more inside knowledge than I'd like
but I don't see how to make a fake GEM object of the
stolen space nicely */
diff --git a/drivers/staging/gma500/psb_fb.h b/drivers/staging/gma500/psb_fb.h
index c8ec0d6..2153c74 100644
--- a/drivers/staging/gma500/psb_fb.h
+++ b/drivers/staging/gma500/psb_fb.h
@@ -33,6 +33,7 @@ struct psb_framebuffer {
struct address_space *addr_space;
struct fb_info *fbdev;
struct gtt_range *gtt;
+ bool vm_map; /* True if we must undo a vm_map_ram */
};

struct psb_fbdev {
diff --git a/drivers/staging/gma500/psb_gtt.c b/drivers/staging/gma500/psb_gtt.c
index 2ddab50..6a24246 100644
--- a/drivers/staging/gma500/psb_gtt.c
+++ b/drivers/staging/gma500/psb_gtt.c
@@ -79,7 +79,6 @@ u32 *psb_gtt_entry(struct drm_device *dev, struct gtt_range *r)
static int psb_gtt_insert(struct drm_device *dev, struct gtt_range *r)
{
u32 *gtt_slot, pte;
- int numpages = resource_size(&r->resource) >> PAGE_SHIFT;
struct page **pages;
int i;

@@ -94,10 +93,10 @@ static int psb_gtt_insert(struct drm_device *dev, struct gtt_range *r)
pages = r->pages;

/* Make sure changes are visible to the GPU */
- set_pages_array_uc(pages, numpages);
+ set_pages_array_uc(pages, r->npage);

/* Write our page entries into the GTT itself */
- for (i = 0; i < numpages; i++) {
+ for (i = 0; i < r->npage; i++) {
pte = psb_gtt_mask_pte(page_to_pfn(*pages++), 0/*type*/);
iowrite32(pte, gtt_slot++);
}
@@ -120,7 +119,6 @@ static void psb_gtt_remove(struct drm_device *dev, struct gtt_range *r)
{
struct drm_psb_private *dev_priv = dev->dev_private;
u32 *gtt_slot, pte;
- int numpages = resource_size(&r->resource) >> PAGE_SHIFT;
int i;

WARN_ON(r->stolen);
@@ -128,10 +126,10 @@ static void psb_gtt_remove(struct drm_device *dev, struct gtt_range *r)
gtt_slot = psb_gtt_entry(dev, r);
pte = psb_gtt_mask_pte(page_to_pfn(dev_priv->scratch_page), 0);;

- for (i = 0; i < numpages; i++)
+ for (i = 0; i < r->npage; i++)
iowrite32(pte, gtt_slot++);
ioread32(gtt_slot - 1);
- set_pages_array_wb(r->pages, numpages);
+ set_pages_array_wb(r->pages, r->npage);
}

/**
@@ -149,7 +147,7 @@ static int psb_gtt_attach_pages(struct gtt_range *gt)
struct address_space *mapping;
int i;
struct page *p;
- int pages = resource_size(&gt->resource) >> PAGE_SHIFT;
+ int pages = gt->gem.size / PAGE_SIZE;

WARN_ON(gt->pages);

@@ -160,6 +158,8 @@ static int psb_gtt_attach_pages(struct gtt_range *gt)
gt->pages = kmalloc(pages * sizeof(struct page *), GFP_KERNEL);
if (gt->pages == NULL)
return -ENOMEM;
+ gt->npage = pages;
+
for (i = 0; i < pages; i++) {
/* FIXME: review flags later */
p = read_cache_page_gfp(mapping, i,
@@ -191,9 +191,7 @@ err:
static void psb_gtt_detach_pages(struct gtt_range *gt)
{
int i;
- int pages = resource_size(&gt->resource) >> PAGE_SHIFT;
-
- for (i = 0; i < pages; i++) {
+ for (i = 0; i < gt->npage; i++) {
/* FIXME: do we need to force dirty */
set_page_dirty(gt->pages[i]);
/* Undo the reference we took when populating the table */
diff --git a/drivers/staging/gma500/psb_gtt.h b/drivers/staging/gma500/psb_gtt.h
index 535ae00..37287eb 100644
--- a/drivers/staging/gma500/psb_gtt.h
+++ b/drivers/staging/gma500/psb_gtt.h
@@ -46,9 +46,10 @@ struct gtt_range {
struct kref kref;
struct drm_gem_object gem; /* GEM high level stuff */
int in_gart; /* Currently in the GART (ref ct) */
- bool stolen; /* Backed from stolen RAM */
- bool mmapping; /* Is mmappable */
+ bool stolen; /* Backed from stolen RAM */
+ bool mmapping; /* Is mmappable */
struct page **pages; /* Backing pages if present */
+ int npage; /* Number of backing pages */
};

extern struct gtt_range *psb_gtt_alloc_range(struct drm_device *dev, int len,

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