media: verisilicon: change confusingly named relaxed register access

The register abstraction has wrappers around both the normal writel()
and its writel_relaxed() counterpart, but this has led to a lot of users
ending up with the relaxed version.

There is sometimes a need to intentionally pick the relaxed accessor for
performance critical functions, but I noticed that each hantro_reg_write()
call also contains a non-relaxed readl(), which is typically much more
expensive than a writel, so there is little benefit here but an added
risk of missing a serialization against DMA.

To make this behave like other interfaces, use the normal accessor by
default and only provide the relaxed version as an alternative for
performance critical code. hantro_postproc.c is the only place that
used both the relaxed and normal writel, but this does not seem
cricital either, so change it all to the normal ones.

[hverkuil: fix function prototype alignment]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

Author: arndb

drivers/media/platform/verisilicon/hantro.h

@@ -441,14 +441,14 @@ static __always_inline void hantro_reg_write(struct hantro_dev *vpu,
 					     const struct hantro_reg *reg,
 					     u32 val)
 {
-	vdpu_write_relaxed(vpu, vdpu_read_mask(vpu, reg, val), reg->base);
+	vdpu_write(vpu, vdpu_read_mask(vpu, reg, val), reg->base);
 }
 
-static __always_inline void hantro_reg_write_s(struct hantro_dev *vpu,
-					       const struct hantro_reg *reg,
-					       u32 val)
+static __always_inline void hantro_reg_write_relaxed(struct hantro_dev *vpu,
+						     const struct hantro_reg *reg,
+						     u32 val)
 {
-	vdpu_write(vpu, vdpu_read_mask(vpu, reg, val), reg->base);
+	vdpu_write_relaxed(vpu, vdpu_read_mask(vpu, reg, val), reg->base);
 }
 
 void *hantro_get_ctrl(struct hantro_ctx *ctx, u32 id);

drivers/media/platform/verisilicon/hantro_postproc.c

@@ -21,11 +21,11 @@
 			 val); \
 }
 
-#define HANTRO_PP_REG_WRITE_S(vpu, reg_name, val) \
+#define HANTRO_PP_REG_WRITE_RELAXED(vpu, reg_name, val) \
 { \
-	hantro_reg_write_s(vpu, \
-			   &hantro_g1_postproc_regs.reg_name, \
-			   val); \
+	hantro_reg_write_relaxed(vpu, \
+				 &hantro_g1_postproc_regs.reg_name, \
+				 val); \
 }
 
 #define VPU_PP_IN_YUYV			0x0
@@ -72,7 +72,7 @@ static void hantro_postproc_g1_enable(struct hantro_ctx *ctx)
 	dma_addr_t dst_dma;
 
 	/* Turn on pipeline mode. Must be done first. */
-	HANTRO_PP_REG_WRITE_S(vpu, pipeline_en, 0x1);
+	HANTRO_PP_REG_WRITE(vpu, pipeline_en, 0x1);
 
 	src_pp_fmt = VPU_PP_IN_NV12;
 
@@ -242,7 +242,7 @@ static void hantro_postproc_g1_disable(struct hantro_ctx *ctx)
 {
 	struct hantro_dev *vpu = ctx->dev;
 
-	HANTRO_PP_REG_WRITE_S(vpu, pipeline_en, 0x0);
+	HANTRO_PP_REG_WRITE(vpu, pipeline_en, 0x0);
 }
 
 static void hantro_postproc_g2_disable(struct hantro_ctx *ctx)