drm/i915: Type safe register read/write

Make I915_READ and I915_WRITE more type safe by wrapping the register
offset in a struct. This should eliminate most of the fumbles we've had
with misplaced parens.

This only takes care of normal mmio registers. We could extend the idea
to other register types and define each with its own struct. That way
you wouldn't be able to accidentally pass the wrong thing to a specific
register access function.

The gpio_reg setup is probably the ugliest thing left. But I figure I'd
just leave it for now, and wait for some divine inspiration to strike
before making it nice.

As for the generated code, it's actually a bit better sometimes. Eg.
looking at i915_irq_handler(), we can see the following change:
  lea    0x70024(%rdx,%rax,1),%r9d
  mov    $0x1,%edx
- movslq %r9d,%r9
- mov    %r9,%rsi
- mov    %r9,-0x58(%rbp)
- callq  *0xd8(%rbx)
+ mov    %r9d,%esi
+ mov    %r9d,-0x48(%rbp)
 callq  *0xd8(%rbx)

So previously gcc thought the register offset might be signed and
decided to sign extend it, just in case. The rest appears to be
mostly just minor shuffling of instructions.

v2: i915_mmio_reg_{offset,equal,valid}() helpers added
    s/_REG/_MMIO/ in the register defines
    mo more switch statements left to worry about
    ring_emit stuff got sorted in a prep patch
    cmd parser, lrc context and w/a batch buildup also in prep patch
    vgpu stuff cleaned up and moved to a prep patch
    all other unrelated changes split out
v3: Rebased due to BXT DSI/BLC, MOCS, etc.
v4: Rebased due to churn, s/i915_mmio_reg_t/i915_reg_t/

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1447853606-2751-1-git-send-email-ville.syrjala@linux.intel.com

1 files changed, 29 insertions, 26 deletions

diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 47d3f5a..fd86cef 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -113,10 +113,11 @@ static u32 hsw_infoframe_enable(enum hdmi_infoframe_type type)
 	}
 }
 
-static u32 hsw_dip_data_reg(struct drm_i915_private *dev_priv,
-			    enum transcoder cpu_transcoder,
-			    enum hdmi_infoframe_type type,
-			    int i)
+static i915_reg_t
+hsw_dip_data_reg(struct drm_i915_private *dev_priv,
+		 enum transcoder cpu_transcoder,
+		 enum hdmi_infoframe_type type,
+		 int i)
 {
 	switch (type) {
 	case HDMI_INFOFRAME_TYPE_AVI:
@@ -127,7 +128,7 @@ static u32 hsw_dip_data_reg(struct drm_i915_private *dev_priv,
 		return HSW_TVIDEO_DIP_VS_DATA(cpu_transcoder, i);
 	default:
 		DRM_DEBUG_DRIVER("unknown info frame type %d\n", type);
-		return 0;
+		return INVALID_MMIO_REG;
 	}
 }
 
@@ -193,8 +194,9 @@ static void ibx_write_infoframe(struct drm_encoder *encoder,
 	struct drm_device *dev = encoder->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
-	int i, reg = TVIDEO_DIP_CTL(intel_crtc->pipe);
+	i915_reg_t reg = TVIDEO_DIP_CTL(intel_crtc->pipe);
 	u32 val = I915_READ(reg);
+	int i;
 
 	WARN(!(val & VIDEO_DIP_ENABLE), "Writing DIP with CTL reg disabled\n");
 
@@ -229,7 +231,7 @@ static bool ibx_infoframe_enabled(struct drm_encoder *encoder)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
 	struct intel_digital_port *intel_dig_port = enc_to_dig_port(encoder);
-	int reg = TVIDEO_DIP_CTL(intel_crtc->pipe);
+	i915_reg_t reg = TVIDEO_DIP_CTL(intel_crtc->pipe);
 	u32 val = I915_READ(reg);
 
 	if ((val & VIDEO_DIP_ENABLE) == 0)
@@ -251,8 +253,9 @@ static void cpt_write_infoframe(struct drm_encoder *encoder,
 	struct drm_device *dev = encoder->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
-	int i, reg = TVIDEO_DIP_CTL(intel_crtc->pipe);
+	i915_reg_t reg = TVIDEO_DIP_CTL(intel_crtc->pipe);
 	u32 val = I915_READ(reg);
+	int i;
 
 	WARN(!(val & VIDEO_DIP_ENABLE), "Writing DIP with CTL reg disabled\n");
 
@@ -289,8 +292,7 @@ static bool cpt_infoframe_enabled(struct drm_encoder *encoder)
 	struct drm_device *dev = encoder->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
-	int reg = TVIDEO_DIP_CTL(intel_crtc->pipe);
-	u32 val = I915_READ(reg);
+	u32 val = I915_READ(TVIDEO_DIP_CTL(intel_crtc->pipe));
 
 	if ((val & VIDEO_DIP_ENABLE) == 0)
 		return false;
@@ -308,8 +310,9 @@ static void vlv_write_infoframe(struct drm_encoder *encoder,
 	struct drm_device *dev = encoder->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
-	int i, reg = VLV_TVIDEO_DIP_CTL(intel_crtc->pipe);
+	i915_reg_t reg = VLV_TVIDEO_DIP_CTL(intel_crtc->pipe);
 	u32 val = I915_READ(reg);
+	int i;
 
 	WARN(!(val & VIDEO_DIP_ENABLE), "Writing DIP with CTL reg disabled\n");
 
@@ -344,8 +347,7 @@ static bool vlv_infoframe_enabled(struct drm_encoder *encoder)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
 	struct intel_digital_port *intel_dig_port = enc_to_dig_port(encoder);
-	int reg = VLV_TVIDEO_DIP_CTL(intel_crtc->pipe);
-	u32 val = I915_READ(reg);
+	u32 val = I915_READ(VLV_TVIDEO_DIP_CTL(intel_crtc->pipe));
 
 	if ((val & VIDEO_DIP_ENABLE) == 0)
 		return false;
@@ -367,13 +369,13 @@ static void hsw_write_infoframe(struct drm_encoder *encoder,
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
 	enum transcoder cpu_transcoder = intel_crtc->config->cpu_transcoder;
-	u32 ctl_reg = HSW_TVIDEO_DIP_CTL(cpu_transcoder);
-	u32 data_reg;
+	i915_reg_t ctl_reg = HSW_TVIDEO_DIP_CTL(cpu_transcoder);
+	i915_reg_t data_reg;
 	int i;
 	u32 val = I915_READ(ctl_reg);
 
 	data_reg = hsw_dip_data_reg(dev_priv, cpu_transcoder, type, 0);
-	if (data_reg == 0)
+	if (i915_mmio_reg_valid(data_reg))
 		return;
 
 	val &= ~hsw_infoframe_enable(type);
@@ -401,8 +403,7 @@ static bool hsw_infoframe_enabled(struct drm_encoder *encoder)
 	struct drm_device *dev = encoder->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
-	u32 ctl_reg = HSW_TVIDEO_DIP_CTL(intel_crtc->config->cpu_transcoder);
-	u32 val = I915_READ(ctl_reg);
+	u32 val = I915_READ(HSW_TVIDEO_DIP_CTL(intel_crtc->config->cpu_transcoder));
 
 	return val & (VIDEO_DIP_ENABLE_VSC_HSW | VIDEO_DIP_ENABLE_AVI_HSW |
 		      VIDEO_DIP_ENABLE_GCP_HSW | VIDEO_DIP_ENABLE_VS_HSW |
@@ -513,7 +514,7 @@ static void g4x_set_infoframes(struct drm_encoder *encoder,
 	struct drm_i915_private *dev_priv = encoder->dev->dev_private;
 	struct intel_digital_port *intel_dig_port = enc_to_dig_port(encoder);
 	struct intel_hdmi *intel_hdmi = &intel_dig_port->hdmi;
-	u32 reg = VIDEO_DIP_CTL;
+	i915_reg_t reg = VIDEO_DIP_CTL;
 	u32 val = I915_READ(reg);
 	u32 port = VIDEO_DIP_PORT(intel_dig_port->port);
 
@@ -633,7 +634,8 @@ static bool intel_hdmi_set_gcp_infoframe(struct drm_encoder *encoder)
 {
 	struct drm_i915_private *dev_priv = encoder->dev->dev_private;
 	struct intel_crtc *crtc = to_intel_crtc(encoder->crtc);
-	u32 reg, val = 0;
+	i915_reg_t reg;
+	u32 val = 0;
 
 	if (HAS_DDI(dev_priv))
 		reg = HSW_TVIDEO_DIP_GCP(crtc->config->cpu_transcoder);
@@ -666,7 +668,7 @@ static void ibx_set_infoframes(struct drm_encoder *encoder,
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
 	struct intel_digital_port *intel_dig_port = enc_to_dig_port(encoder);
 	struct intel_hdmi *intel_hdmi = &intel_dig_port->hdmi;
-	u32 reg = TVIDEO_DIP_CTL(intel_crtc->pipe);
+	i915_reg_t reg = TVIDEO_DIP_CTL(intel_crtc->pipe);
 	u32 val = I915_READ(reg);
 	u32 port = VIDEO_DIP_PORT(intel_dig_port->port);
 
@@ -717,7 +719,7 @@ static void cpt_set_infoframes(struct drm_encoder *encoder,
 	struct drm_i915_private *dev_priv = encoder->dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
 	struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(encoder);
-	u32 reg = TVIDEO_DIP_CTL(intel_crtc->pipe);
+	i915_reg_t reg = TVIDEO_DIP_CTL(intel_crtc->pipe);
 	u32 val = I915_READ(reg);
 
 	assert_hdmi_port_disabled(intel_hdmi);
@@ -760,7 +762,7 @@ static void vlv_set_infoframes(struct drm_encoder *encoder,
 	struct intel_digital_port *intel_dig_port = enc_to_dig_port(encoder);
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
 	struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(encoder);
-	u32 reg = VLV_TVIDEO_DIP_CTL(intel_crtc->pipe);
+	i915_reg_t reg = VLV_TVIDEO_DIP_CTL(intel_crtc->pipe);
 	u32 val = I915_READ(reg);
 	u32 port = VIDEO_DIP_PORT(intel_dig_port->port);
 
@@ -811,7 +813,7 @@ static void hsw_set_infoframes(struct drm_encoder *encoder,
 	struct drm_i915_private *dev_priv = encoder->dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
 	struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(encoder);
-	u32 reg = HSW_TVIDEO_DIP_CTL(intel_crtc->config->cpu_transcoder);
+	i915_reg_t reg = HSW_TVIDEO_DIP_CTL(intel_crtc->config->cpu_transcoder);
 	u32 val = I915_READ(reg);
 
 	assert_hdmi_port_disabled(intel_hdmi);
@@ -2138,7 +2140,8 @@ void intel_hdmi_init_connector(struct intel_digital_port *intel_dig_port,
 	}
 }
 
-void intel_hdmi_init(struct drm_device *dev, int hdmi_reg, enum port port)
+void intel_hdmi_init(struct drm_device *dev,
+		     i915_reg_t hdmi_reg, enum port port)
 {
 	struct intel_digital_port *intel_dig_port;
 	struct intel_encoder *intel_encoder;
@@ -2209,7 +2212,7 @@ void intel_hdmi_init(struct drm_device *dev, int hdmi_reg, enum port port)
 
 	intel_dig_port->port = port;
 	intel_dig_port->hdmi.hdmi_reg = hdmi_reg;
-	intel_dig_port->dp.output_reg = 0;
+	intel_dig_port->dp.output_reg = INVALID_MMIO_REG;
 
 	intel_hdmi_init_connector(intel_dig_port, intel_connector);
 }