drm/i915: Define bitmasks for ilk pfit window pos/size

Define and use the bitmasks for the x/y components
of the ilk+ panel filter window pos/size registers.

Note that we stick to the full 16 bit mask even though
the actual hardware limits are lower (and somewhat
platform dependent). BDW is actually limited to
13 bits horizontal and 12 bits vertical, with the high
bits being hardwired to zero. HSW should have the same
limits as BDW. And pre-HSW should be limited to 12bits
in both directions as that's already the limit of the
transcoder timing registers. Curiously on HSW and earlier
platforms all 16 bits can actually be set, but presumably
the hardware ignores the high bits.

v2: Switch back to full 16bit masks since that's what
    we use transcoder timign regs and PIPESRC as well

Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230426135019.7603-2-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/display/intel_display.c

@@ -812,8 +812,10 @@ static void ilk_pfit_enable(const struct intel_crtc_state *crtc_state)
 	else
 		intel_de_write_fw(dev_priv, PF_CTL(pipe), PF_ENABLE |
 				  PF_FILTER_MED_3x3);
-	intel_de_write_fw(dev_priv, PF_WIN_POS(pipe), x << 16 | y);
-	intel_de_write_fw(dev_priv, PF_WIN_SZ(pipe), width << 16 | height);
+	intel_de_write_fw(dev_priv, PF_WIN_POS(pipe),
+			  PF_WIN_XPOS(x) | PF_WIN_YPOS(y));
+	intel_de_write_fw(dev_priv, PF_WIN_SZ(pipe),
+			  PF_WIN_XSIZE(width) | PF_WIN_YSIZE(height));
 }
 
 static void intel_crtc_dpms_overlay_disable(struct intel_crtc *crtc)
@@ -3246,8 +3248,10 @@ static void ilk_get_pfit_config(struct intel_crtc_state *crtc_state)
 	size = intel_de_read(dev_priv, PF_WIN_SZ(crtc->pipe));
 
 	drm_rect_init(&crtc_state->pch_pfit.dst,
-		      pos >> 16, pos & 0xffff,
-		      size >> 16, size & 0xffff);
+		      REG_FIELD_GET(PF_WIN_XPOS_MASK, pos),
+		      REG_FIELD_GET(PF_WIN_YPOS_MASK, pos),
+		      REG_FIELD_GET(PF_WIN_XSIZE_MASK, size),
+		      REG_FIELD_GET(PF_WIN_YSIZE_MASK, size));
 
 	/*
 	 * We currently do not free assignements of panel fitters on

drivers/gpu/drm/i915/i915_reg.h

@@ -4015,8 +4015,16 @@
 #define   PF_FILTER_EDGE_SOFTEN		REG_FIELD_PREP(PF_FILTER_EDGE_MASK, 3)
 #define _PFA_WIN_SZ		0x68074
 #define _PFB_WIN_SZ		0x68874
+#define   PF_WIN_XSIZE_MASK	REG_GENMASK(31, 16)
+#define   PF_WIN_XSIZE(w)	REG_FIELD_PREP(PF_WIN_XSIZE_MASK, (w))
+#define   PF_WIN_YSIZE_MASK	REG_GENMASK(15, 0)
+#define   PF_WIN_YSIZE(h)	REG_FIELD_PREP(PF_WIN_YSIZE_MASK, (h))
 #define _PFA_WIN_POS		0x68070
 #define _PFB_WIN_POS		0x68870
+#define   PF_WIN_XPOS_MASK	REG_GENMASK(31, 16)
+#define   PF_WIN_XPOS(x)	REG_FIELD_PREP(PF_WIN_XPOS_MASK, (x))
+#define   PF_WIN_YPOS_MASK	REG_GENMASK(15, 0)
+#define   PF_WIN_YPOS(y)	REG_FIELD_PREP(PF_WIN_YPOS_MASK, (y))
 #define _PFA_VSCALE		0x68084
 #define _PFB_VSCALE		0x68884
 #define _PFA_HSCALE		0x68090