msm: kgsl: remove readl/writel use for dma memory

For dma_alloc_coherent() you don't need writel/readl because
it's just a plain old void *. Linux tries very hard to make a
distinction between io memory (void __iomem *) and memory
(void *) so that drivers are portable to architectures that
don't have a way to access registers via pointer dereferences.
You can see http://lwn.net/Articles/102232/ and the Linus rant
http://lwn.net/Articles/102240/ here for more details behind
the motivation.

Change-Id: I3da075c30304e4adf321cfb3edb1baa4a93fc2ce
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>

drivers/gpu/msm/adreno_ringbuffer.h

@@ -64,7 +64,7 @@ struct adreno_ringbuffer {
 
 #define GSL_RB_WRITE(ring, gpuaddr, data) \
 	do { \
-		writel_relaxed(data, ring); \
+		*ring = data; \
 		wmb(); \
 		kgsl_cffdump_setmem(gpuaddr, data, 4); \
 		ring++; \
@@ -93,7 +93,7 @@ struct adreno_ringbuffer {
 #define GSL_RB_CNTL_NO_UPDATE 0x0 /* enable */
 #define GSL_RB_GET_READPTR(rb, data) \
 	do { \
-		*(data) = readl_relaxed(&(rb)->memptrs->rptr); \
+		*(data) = rb->memptrs->rptr; \
 	} while (0)
 #else
 #define GSL_RB_CNTL_NO_UPDATE 0x1 /* disable */

drivers/gpu/msm/kgsl_gpummu.c

@@ -382,15 +382,16 @@ static inline void
 kgsl_pt_map_set(struct kgsl_gpummu_pt *pt, uint32_t pte, uint32_t val)
 {
 	uint32_t *baseptr = (uint32_t *)pt->base.hostptr;
-
-	writel_relaxed(val, &baseptr[pte]);
+	BUG_ON(pte*sizeof(uint32_t) >= pt->base.size);
+	baseptr[pte] = val;
 }
 
 static inline uint32_t
 kgsl_pt_map_get(struct kgsl_gpummu_pt *pt, uint32_t pte)
 {
 	uint32_t *baseptr = (uint32_t *)pt->base.hostptr;
-	return readl_relaxed(&baseptr[pte]) & GSL_PT_PAGE_ADDR_MASK;
+	BUG_ON(pte*sizeof(uint32_t) >= pt->base.size);
+	return baseptr[pte] & GSL_PT_PAGE_ADDR_MASK;
 }
 
 static unsigned int kgsl_gpummu_pt_get_flags(struct kgsl_pagetable *pt,

drivers/gpu/msm/kgsl_sharedmem.c

@@ -636,13 +636,17 @@ kgsl_sharedmem_readl(const struct kgsl_memdesc *memdesc,
 			uint32_t *dst,
 			unsigned int offsetbytes)
 {
+	uint32_t *src;
 	BUG_ON(memdesc == NULL || memdesc->hostptr == NULL || dst == NULL);
-	WARN_ON(offsetbytes + sizeof(unsigned int) > memdesc->size);
+	WARN_ON(offsetbytes % sizeof(uint32_t) != 0);
+	if (offsetbytes % sizeof(uint32_t) != 0)
+		return -EINVAL;
 
-	if (offsetbytes + sizeof(unsigned int) > memdesc->size)
+	WARN_ON(offsetbytes + sizeof(uint32_t) > memdesc->size);
+	if (offsetbytes + sizeof(uint32_t) > memdesc->size)
 		return -ERANGE;
-
-	*dst = readl_relaxed(memdesc->hostptr + offsetbytes);
+	src = (uint32_t *)(memdesc->hostptr + offsetbytes);
+	*dst = *src;
 	return 0;
 }
 EXPORT_SYMBOL(kgsl_sharedmem_readl);
@@ -652,12 +656,19 @@ kgsl_sharedmem_writel(const struct kgsl_memdesc *memdesc,
 			unsigned int offsetbytes,
 			uint32_t src)
 {
+	uint32_t *dst;
 	BUG_ON(memdesc == NULL || memdesc->hostptr == NULL);
-	BUG_ON(offsetbytes + sizeof(unsigned int) > memdesc->size);
+	WARN_ON(offsetbytes % sizeof(uint32_t) != 0);
+	if (offsetbytes % sizeof(uint32_t) != 0)
+		return -EINVAL;
 
+	WARN_ON(offsetbytes + sizeof(uint32_t) > memdesc->size);
+	if (offsetbytes + sizeof(uint32_t) > memdesc->size)
+		return -ERANGE;
 	kgsl_cffdump_setmem(memdesc->gpuaddr + offsetbytes,
-		src, sizeof(uint));
-	writel_relaxed(src, memdesc->hostptr + offsetbytes);
+		src, sizeof(uint32_t));
+	dst = (uint32_t *)(memdesc->hostptr + offsetbytes);
+	*dst = src;
 	return 0;
 }
 EXPORT_SYMBOL(kgsl_sharedmem_writel);