[PATCH] drm/gma500: Replace kmap{,_atomic}() with page_address()

[Sumitra Sharma]

Remove unnecessary calls to kmap{,_atomic}() when acquiring
pages using GFP_DMA32.

The GFP_DMA32 uses the DMA32 zone to satisfy the allocation
requests. Therefore, pages allocated with GFP_DMA32 cannot
come from Highmem.

Avoid using calls to kmap_local_page() / kunmap_local() and
kmap() / kunmap() in the psb_mmu_alloc_pd function. Instead,
utilize page_address().

Remove the usage of kmap_atomic() / kunmap_atomic() in the
psb_mmu_alloc_pt function. Use page_address() instead.

Substitute kmap_atomic(pt->p) / kunmap_atomic(pt->v) calls
in the psb_mmu_pt_alloc_map_lock() and psb_mmu_pt_unmap_unlock()
functions with page_address(pt->p). This is possible as
pt = psb_mmu_alloc_pt(pd) allocates a page using
pt->p = alloc_page(GFP_DMA32).

Suggested-by: Ira Weiny <ira.we...@intel.com>
Signed-off-by: Sumitra Sharma <sumitraar...@gmail.com>
---
 drivers/gpu/drm/gma500/mmu.c | 17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/gma500/mmu.c b/drivers/gpu/drm/gma500/mmu.c
index a70b01ccdf70..59aa5661e56a 100644
--- a/drivers/gpu/drm/gma500/mmu.c
+++ b/drivers/gpu/drm/gma500/mmu.c
@@ -184,20 +184,15 @@ struct psb_mmu_pd *psb_mmu_alloc_pd(struct psb_mmu_driver 
*driver,
                pd->invalid_pte = 0;
        }
 
-       v = kmap_local_page(pd->dummy_pt);
+       v = page_address(pd->dummy_pt);
        for (i = 0; i < (PAGE_SIZE / sizeof(uint32_t)); ++i)
                v[i] = pd->invalid_pte;
 
-       kunmap_local(v);
-
-       v = kmap_local_page(pd->p);
+       v = page_address(pd->p);
        for (i = 0; i < (PAGE_SIZE / sizeof(uint32_t)); ++i)
                v[i] = pd->invalid_pde;
 
-       kunmap_local(v);
-
-       clear_page(kmap(pd->dummy_page));
-       kunmap(pd->dummy_page);
+       clear_page(page_address(pd->dummy_page));
 
        pd->tables = vmalloc_user(sizeof(struct psb_mmu_pt *) * 1024);
        if (!pd->tables)
@@ -279,7 +274,7 @@ static struct psb_mmu_pt *psb_mmu_alloc_pt(struct 
psb_mmu_pd *pd)
 
        spin_lock(lock);
 
-       v = kmap_atomic(pt->p);
+       v = page_address(pt->p);
        clf = (uint8_t *) v;
        ptes = (uint32_t *) v;
        for (i = 0; i < (PAGE_SIZE / sizeof(uint32_t)); ++i)
@@ -293,7 +288,6 @@ static struct psb_mmu_pt *psb_mmu_alloc_pt(struct 
psb_mmu_pd *pd)
                }
                mb();
        }
-       kunmap_atomic(v);
        spin_unlock(lock);
 
        pt->count = 0;
@@ -339,7 +333,7 @@ static struct psb_mmu_pt *psb_mmu_pt_alloc_map_lock(struct 
psb_mmu_pd *pd,
                        atomic_set(&pd->driver->needs_tlbflush, 1);
                }
        }
-       pt->v = kmap_atomic(pt->p);
+       pt->v = page_address(pt->p);
        return pt;
 }
 
@@ -365,7 +359,6 @@ static void psb_mmu_pt_unmap_unlock(struct psb_mmu_pt *pt)
        struct psb_mmu_pd *pd = pt->pd;
        uint32_t *v;
 
-       kunmap_atomic(pt->v);
        if (pt->count == 0) {
                v = kmap_atomic(pd->p);
                v[pt->index] = pd->invalid_pde;
-- 
2.25.1