drm/gma500: Move GTT locking into GTT helpers

Acquire the GTT mutex in psb_gtt_{insert,remove}_pages(). Remove
locking from callers. Also remove the GTT locking around the resume
code. Resume does not run concurrently with other GTT operations.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220308195222.13471-4-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/gma500/gem.c b/drivers/gpu/drm/gma500/gem.c
index 026ce11..2f44535 100644 (file)
--- a/drivers/gpu/drm/gma500/gem.c
+++ b/drivers/gpu/drm/gma500/gem.c
@@ -35,15 +35,13 @@ int psb_gem_pin(struct psb_gem_object *pobj)
        if (drm_WARN_ONCE(dev, ret, "dma_resv_lock() failed, ret=%d\n", ret))
                return ret;
 
-       mutex_lock(&dev_priv->gtt_mutex);
-
        if (pobj->in_gart || pobj->stolen)
                goto out; /* already mapped */
 
        pages = drm_gem_get_pages(obj);
        if (IS_ERR(pages)) {
                ret = PTR_ERR(pages);
-               goto err_mutex_unlock;
+               goto err_dma_resv_unlock;
        }
 
        npages = obj->size / PAGE_SIZE;
@@ -59,13 +57,11 @@ int psb_gem_pin(struct psb_gem_object *pobj)
 
 out:
        ++pobj->in_gart;
-       mutex_unlock(&dev_priv->gtt_mutex);
        dma_resv_unlock(obj->resv);
 
        return 0;
 
-err_mutex_unlock:
-       mutex_unlock(&dev_priv->gtt_mutex);
+err_dma_resv_unlock:
        dma_resv_unlock(obj->resv);
        return ret;
 }
@@ -83,8 +79,6 @@ void psb_gem_unpin(struct psb_gem_object *pobj)
        if (drm_WARN_ONCE(dev, ret, "dma_resv_lock() failed, ret=%d\n", ret))
                return;
 
-       mutex_lock(&dev_priv->gtt_mutex);
-
        WARN_ON(!pobj->in_gart);
 
        --pobj->in_gart;
@@ -105,7 +99,6 @@ void psb_gem_unpin(struct psb_gem_object *pobj)
        pobj->pages = NULL;
 
 out:
-       mutex_unlock(&dev_priv->gtt_mutex);
        dma_resv_unlock(obj->resv);
 }
 

diff --git a/drivers/gpu/drm/gma500/gtt.c b/drivers/gpu/drm/gma500/gtt.c
index 309ffe9..4202e88 100644 (file)
--- a/drivers/gpu/drm/gma500/gtt.c
+++ b/drivers/gpu/drm/gma500/gtt.c
@@ -74,11 +74,7 @@ static u32 __iomem *psb_gtt_entry(struct drm_psb_private *pdev, const struct res
        return pdev->gtt_map + (offset >> PAGE_SHIFT);
 }
 
-/*
- * Take our preallocated GTT range and insert the GEM object into
- * the GTT. This is protected via the gtt mutex which the caller
- * must hold.
- */
+/* Acquires GTT mutex internally. */
 void psb_gtt_insert_pages(struct drm_psb_private *pdev, const struct resource *res,
                          struct page **pages)
 {
@@ -86,6 +82,8 @@ void psb_gtt_insert_pages(struct drm_psb_private *pdev, const struct resource *r
        u32 __iomem *gtt_slot;
        u32 pte;
 
+       mutex_lock(&pdev->gtt_mutex);
+
        /* Write our page entries into the GTT itself */
 
        npages = resource_size(res) >> PAGE_SHIFT;
@@ -98,19 +96,19 @@ void psb_gtt_insert_pages(struct drm_psb_private *pdev, const struct resource *r
 
        /* Make sure all the entries are set before we return */
        ioread32(gtt_slot - 1);
+
+       mutex_unlock(&pdev->gtt_mutex);
 }
 
-/*
- * Remove a preallocated GTT range from the GTT. Overwrite all the
- * page table entries with the dummy page. This is protected via the gtt
- * mutex which the caller must hold.
- */
+/* Acquires GTT mutex internally. */
 void psb_gtt_remove_pages(struct drm_psb_private *pdev, const struct resource *res)
 {
        resource_size_t npages, i;
        u32 __iomem *gtt_slot;
        u32 pte;
 
+       mutex_lock(&pdev->gtt_mutex);
+
        /* Install scratch page for the resource */
 
        pte = psb_gtt_mask_pte(page_to_pfn(pdev->scratch_page), PSB_MMU_CACHED_MEMORY);
@@ -123,6 +121,8 @@ void psb_gtt_remove_pages(struct drm_psb_private *pdev, const struct resource *r
 
        /* Make sure all the entries are set before we return */
        ioread32(gtt_slot - 1);
+
+       mutex_unlock(&pdev->gtt_mutex);
 }
 
 static void psb_gtt_alloc(struct drm_device *dev)
@@ -306,8 +306,6 @@ int psb_gtt_restore(struct drm_device *dev)
        struct psb_gem_object *pobj;
        unsigned int restored = 0, total = 0, size = 0;
 
-       /* On resume, the gtt_mutex is already initialized */
-       mutex_lock(&dev_priv->gtt_mutex);
        psb_gtt_init(dev, 1);
 
        while (r != NULL) {
@@ -325,7 +323,7 @@ int psb_gtt_restore(struct drm_device *dev)
                r = r->sibling;
                total++;
        }
-       mutex_unlock(&dev_priv->gtt_mutex);
+
        DRM_DEBUG_DRIVER("Restored %u of %u gtt ranges (%u KB)", restored,
                         total, (size / 1024));