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, 9 insertions, 9 deletions

diff --git a/drivers/gpu/drm/i915/intel_lrc.h b/drivers/gpu/drm/i915/intel_lrc.h
index 93668f8bfebc..97c16d87f33b 100644
--- a/drivers/gpu/drm/i915/intel_lrc.h
+++ b/drivers/gpu/drm/i915/intel_lrc.h
@@ -27,16 +27,16 @@
 #define GEN8_LR_CONTEXT_ALIGN 4096
 
 /* Execlists regs */
-#define RING_ELSP(ring)			((ring)->mmio_base+0x230)
-#define RING_EXECLIST_STATUS_LO(ring)	((ring)->mmio_base+0x234)
-#define RING_EXECLIST_STATUS_HI(ring)	((ring)->mmio_base+0x234 + 4)
-#define RING_CONTEXT_CONTROL(ring)	((ring)->mmio_base+0x244)
+#define RING_ELSP(ring)				_MMIO((ring)->mmio_base + 0x230)
+#define RING_EXECLIST_STATUS_LO(ring)		_MMIO((ring)->mmio_base + 0x234)
+#define RING_EXECLIST_STATUS_HI(ring)		_MMIO((ring)->mmio_base + 0x234 + 4)
+#define RING_CONTEXT_CONTROL(ring)		_MMIO((ring)->mmio_base + 0x244)
 #define	  CTX_CTRL_INHIBIT_SYN_CTX_SWITCH	(1 << 3)
 #define	  CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT	(1 << 0)
 #define   CTX_CTRL_RS_CTX_ENABLE                (1 << 1)
-#define RING_CONTEXT_STATUS_BUF_LO(ring, i)	((ring)->mmio_base+0x370 + (i) * 8)
-#define RING_CONTEXT_STATUS_BUF_HI(ring, i)	((ring)->mmio_base+0x370 + (i) * 8 + 4)
-#define RING_CONTEXT_STATUS_PTR(ring)	((ring)->mmio_base+0x3a0)
+#define RING_CONTEXT_STATUS_BUF_LO(ring, i)	_MMIO((ring)->mmio_base + 0x370 + (i) * 8)
+#define RING_CONTEXT_STATUS_BUF_HI(ring, i)	_MMIO((ring)->mmio_base + 0x370 + (i) * 8 + 4)
+#define RING_CONTEXT_STATUS_PTR(ring)		_MMIO((ring)->mmio_base + 0x3a0)
 
 /* Logical Rings */
 int intel_logical_ring_alloc_request_extras(struct drm_i915_gem_request *request);
@@ -69,9 +69,9 @@ static inline void intel_logical_ring_emit(struct intel_ringbuffer *ringbuf,
 	ringbuf->tail += 4;
 }
 static inline void intel_logical_ring_emit_reg(struct intel_ringbuffer *ringbuf,
-					       u32 reg)
+					       i915_reg_t reg)
 {
-	intel_logical_ring_emit(ringbuf, reg);
+	intel_logical_ring_emit(ringbuf, i915_mmio_reg_offset(reg));
 }
 
 /* Logical Ring Contexts */