From ae7617f0ef1820be033eef93859a6bb6174a843f Mon Sep 17 00:00:00 2001
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Date: Wed, 27 Sep 2017 17:41:38 +0100
Subject: [PATCH] drm/i915: Allow optimized platform checks
Git-commit: ae7617f0ef1820be033eef93859a6bb6174a843f
Patch-mainline: v4.15-rc1
References: FATE#322643 bsc#1055900
If we store the platform as a bitmask, and convert the
IS_PLATFORM macro to use it, we allow the compiler to
merge the IS_PLATFORM(a) || IS_PLATFORM(b) || ... checks
into a single conditional.
As a secondary benefit this saves almost 1k of text:
text data bss dec hex filename
-1460254 60014 3656 1523924 1740d4 drivers/gpu/drm/i915/i915.ko
+1459260 60026 3656 1522942 173cfe drivers/gpu/drm/i915/i915.ko
V2: Removed the infamous -1.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170927164138.15474-1-tvrtko.ursulin@linux.intel.com
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/i915/i915_drv.c | 4 ++++
drivers/gpu/drm/i915/i915_drv.h | 3 ++-
2 files changed, 6 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -870,6 +870,10 @@ static int i915_driver_init_early(struct
memcpy(device_info, match_info, sizeof(*device_info));
device_info->device_id = dev_priv->drm.pdev->device;
+ BUILD_BUG_ON(INTEL_MAX_PLATFORMS >
+ sizeof(device_info->platform_mask) * BITS_PER_BYTE);
+ device_info->platform_mask = BIT(device_info->platform);
+
BUG_ON(device_info->gen > sizeof(device_info->gen_mask) * BITS_PER_BYTE);
device_info->gen_mask = BIT(device_info->gen - 1);
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -860,6 +860,7 @@ struct intel_device_info {
u8 ring_mask; /* Rings supported by the HW */
enum intel_platform platform;
+ u32 platform_mask;
u32 display_mmio_offset;
@@ -2912,7 +2913,7 @@ intel_info(const struct drm_i915_private
#define IS_REVID(p, since, until) \
(INTEL_REVID(p) >= (since) && INTEL_REVID(p) <= (until))
-#define IS_PLATFORM(dev_priv, p) ((dev_priv)->info.platform == (p))
+#define IS_PLATFORM(dev_priv, p) ((dev_priv)->info.platform_mask & BIT(p))
#define IS_I830(dev_priv) IS_PLATFORM(dev_priv, INTEL_I830)
#define IS_I845G(dev_priv) IS_PLATFORM(dev_priv, INTEL_I845G)