[Intel-gfx] [RFC 1/2] drm/i915: add display uncore helpers

[Jani Nikula]

Add convenience helpers for the most common uncore operations with
struct drm_i915_private * as context rather than struct intel_uncore *.

The goal is to replace all instances of I915_READ(),
I915_POSTING_READ(), and I915_WRITE() in display/ with these, to finally
be able to get rid of the implicit dev_priv local parameter use.

The idea is that any non-u32 reads or writes are special enough that
they can use the intel_uncore_* functions directly.

Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>

---

Let the name bikeshedding commence! Some options are:

- intel_de_read, intel_de_write (this patch, de for display engine)
- intel_display_read, intel_display_write (too long I think)
- intel_read, intel_write
- i915_read, i915_write
- display_read, display_write
- ?

Here's a draft cocci patch that could be used on display/ subdir, en
masse:

@@
expression REG, OFFSET;
@@
- I915_READ(REG)
+ intel_de_read(dev_priv, REG)

@@
expression REG, OFFSET;
@@
- I915_POSTING_READ(REG)
+ intel_de_posting_read(dev_priv, REG)

@@
expression REG, OFFSET;
@@
- I915_WRITE(REG, OFFSET)
+ intel_de_write(dev_priv, REG, OFFSET)

Conveniently, we *know* dev_priv is everywhere the change is needed.

This enables us to make the s/dev_priv/i915/ rename on top. We also need
to discuss whether it's better to separate the steps to two (even if in
the same patch series) or if it's better to add the dev_priv parameter
as i915 directly.
---
 .../drm/i915/display/intel_display_uncore.h   | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 drivers/gpu/drm/i915/display/intel_display_uncore.h

diff --git a/drivers/gpu/drm/i915/display/intel_display_uncore.h b/drivers/gpu/drm/i915/display/intel_display_uncore.h
new file mode 100644
index 000000000000..e6c8c56fb0f9
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_display_uncore.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#ifndef __INTEL_DISPLAY_UNCORE_H__
+#define __INTEL_DISPLAY_UNCORE_H__
+
+#include "i915_drv.h"
+#include "i915_reg.h"
+#include "intel_uncore.h"
+
+static inline u32 intel_de_read(struct drm_i915_private *i915, i915_reg_t reg)
+{
+	return intel_uncore_read(&i915->uncore, reg);
+}
+
+static inline void intel_de_posting_read(struct drm_i915_private *i915,
+					 i915_reg_t reg)
+{
+	intel_uncore_posting_read(&i915->uncore, reg);
+}
+
+static inline void intel_de_write(struct drm_i915_private *i915, i915_reg_t reg,
+				  u32 val)
+{
+	intel_uncore_write(&i915->uncore, reg, val);
+}
+
+static inline void intel_de_rmw(struct drm_i915_private *i915, i915_reg_t reg,
+				u32 clear, u32 set)
+{
+	intel_uncore_rmw(&i915->uncore, reg, clear, set);
+}
+
+#endif /* __INTEL_DISPLAY_UNCORE_H__ */
-- 
2.20.1