drm/i915/gen9: Removed byte swapping for csr firmware

This patch contains the changes to remove the byte
swapping logic introduced with old dmc firmware.
While debugging PC10 entry issue for skylake found
with latest dmc firmware version 1.18 without byte
swapping dmc is working fine and able to enter PC10.

Note that apparently this was changed with dmc version 1.0 and earlier
ones indeed are byteswapped like this ...

v1: Initial version.

v2: Corrected firmware size during memcpy(). (Suggested by Sunil)

Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Signed-off-by: Vathsala Nagaraju <vathsala.nagaraju@intel.com>
Reviewed-by: A.Sunil Kamath <sunil.kamath@intel.com>
[danvet: Add note that this only holds for released dmc firmware.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -742,7 +742,7 @@ enum csr_state {
 
 struct intel_csr {
 	const char *fw_path;
-	__be32 *dmc_payload;
+	uint32_t *dmc_payload;
 	uint32_t dmc_fw_size;
 	uint32_t mmio_count;
 	uint32_t mmioaddr[8];

drivers/gpu/drm/i915/intel_csr.c

@@ -244,7 +244,7 @@ void intel_csr_load_status_set(struct drm_i915_private *dev_priv,
 void intel_csr_load_program(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	__be32 *payload = dev_priv->csr.dmc_payload;
+	u32 *payload = dev_priv->csr.dmc_payload;
 	uint32_t i, fw_size;
 
 	if (!IS_GEN9(dev)) {
@@ -256,7 +256,7 @@ void intel_csr_load_program(struct drm_device *dev)
 	fw_size = dev_priv->csr.dmc_fw_size;
 	for (i = 0; i < fw_size; i++)
 		I915_WRITE(CSR_PROGRAM_BASE + i * 4,
-			(u32 __force)payload[i]);
+			payload[i]);
 
 	for (i = 0; i < dev_priv->csr.mmio_count; i++) {
 		I915_WRITE(dev_priv->csr.mmioaddr[i],
@@ -279,7 +279,7 @@ static void finish_csr_load(const struct firmware *fw, void *context)
 	char substepping = intel_get_substepping(dev);
 	uint32_t dmc_offset = CSR_DEFAULT_FW_OFFSET, readcount = 0, nbytes;
 	uint32_t i;
-	__be32 *dmc_payload;
+	uint32_t *dmc_payload;
 	bool fw_loaded = false;
 
 	if (!fw) {
@@ -375,15 +375,7 @@ static void finish_csr_load(const struct firmware *fw, void *context)
 	}
 
 	dmc_payload = csr->dmc_payload;
-	for (i = 0; i < dmc_header->fw_size; i++) {
-		uint32_t *tmp = (u32 *)&fw->data[readcount + i * 4];
-		/*
-		 * The firmware payload is an array of 32 bit words stored in
-		 * little-endian format in the firmware image and programmed
-		 * as 32 bit big-endian format to memory.
-		 */
-		dmc_payload[i] = cpu_to_be32(*tmp);
-	}
+	memcpy(dmc_payload, &fw->data[readcount], nbytes);
 
 	/* load csr program during system boot, as needed for DC states */
 	intel_csr_load_program(dev);