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, 6 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
index 6c32ca32f448..465d5bb125d4 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/drivers/gpu/drm/i915/intel_psr.c
@@ -80,7 +80,7 @@ static void intel_psr_write_vsc(struct intel_dp *intel_dp,
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *crtc = to_intel_crtc(dig_port->base.base.crtc);
 	enum transcoder cpu_transcoder = crtc->config->cpu_transcoder;
-	u32 ctl_reg = HSW_TVIDEO_DIP_CTL(cpu_transcoder);
+	i915_reg_t ctl_reg = HSW_TVIDEO_DIP_CTL(cpu_transcoder);
 	uint32_t *data = (uint32_t *) vsc_psr;
 	unsigned int i;
 
@@ -151,8 +151,8 @@ static void vlv_psr_enable_sink(struct intel_dp *intel_dp)
 			   DP_PSR_ENABLE | DP_PSR_MAIN_LINK_ACTIVE);
 }
 
-static uint32_t psr_aux_ctl_reg(struct drm_i915_private *dev_priv,
-				enum port port)
+static i915_reg_t psr_aux_ctl_reg(struct drm_i915_private *dev_priv,
+				       enum port port)
 {
 	if (INTEL_INFO(dev_priv)->gen >= 9)
 		return DP_AUX_CH_CTL(port);
@@ -160,8 +160,8 @@ static uint32_t psr_aux_ctl_reg(struct drm_i915_private *dev_priv,
 		return EDP_PSR_AUX_CTL;
 }
 
-static uint32_t psr_aux_data_reg(struct drm_i915_private *dev_priv,
-				 enum port port, int index)
+static i915_reg_t psr_aux_data_reg(struct drm_i915_private *dev_priv,
+					enum port port, int index)
 {
 	if (INTEL_INFO(dev_priv)->gen >= 9)
 		return DP_AUX_CH_DATA(port, index);
@@ -175,7 +175,7 @@ static void hsw_psr_enable_sink(struct intel_dp *intel_dp)
 	struct drm_device *dev = dig_port->base.base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	uint32_t aux_clock_divider;
-	uint32_t aux_ctl_reg;
+	i915_reg_t aux_ctl_reg;
 	int precharge = 0x3;
 	static const uint8_t aux_msg[] = {
 		[0] = DP_AUX_NATIVE_WRITE << 4,