[Intel-gfx] [PATCH] drm/i915: Introduce concept of a sub-platform
Chris Wilson
chris at chris-wilson.co.uk
Fri Mar 15 13:16:59 UTC 2019
Quoting Tvrtko Ursulin (2019-03-15 12:26:33)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>
> Concept of a sub-platform already exist in our code (like ULX and ULT
> platform variants and similar),implemented via the macros which check a
> list of device ids to determine a match.
>
> With this patch we consolidate device ids checking into a single function
> called during early driver load.
>
> A few low bits in the platform mask are reserved for sub-platform
> identification and defined as a per-platform namespace.
>
> At the same time it future proofs the platform_mask handling by preparing
> the code for easy extending, and tidies the very verbose WARN strings
> generated when IS_PLATFORM macros are embedded into a WARN type
> statements.
>
> The approach is also beneficial to driver size, with an combined shrink of
> code and strings of around 1.7 kiB.
>
> v2: Fixed IS_SUBPLATFORM. Updated commit msg.
> v3: Chris was right, there is an ordering problem.
>
> v4:
> * Catch-up with new sub-platforms.
> * Rebase for RUNTIME_INFO.
> * Drop subplatform mask union tricks and convert platform_mask to an
> array for extensibility.
>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Suggested-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> Cc: Jose Souza <jose.souza at intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.c | 7 +-
> drivers/gpu/drm/i915/i915_drv.h | 110 +++++++++++++++--------
> drivers/gpu/drm/i915/i915_pci.c | 2 +-
> drivers/gpu/drm/i915/intel_device_info.c | 79 ++++++++++++++++
> drivers/gpu/drm/i915/intel_device_info.h | 28 +++++-
> 5 files changed, 179 insertions(+), 47 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 0d743907e7bc..3218350cd225 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -863,6 +863,8 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv)
> if (i915_inject_load_failure())
> return -ENODEV;
>
> + intel_device_info_subplatform_init(dev_priv);
> +
> spin_lock_init(&dev_priv->irq_lock);
> spin_lock_init(&dev_priv->gpu_error.lock);
> mutex_init(&dev_priv->backlight_lock);
> @@ -1752,10 +1754,11 @@ static void i915_welcome_messages(struct drm_i915_private *dev_priv)
> if (drm_debug & DRM_UT_DRIVER) {
> struct drm_printer p = drm_debug_printer("i915 device info:");
>
> - drm_printf(&p, "pciid=0x%04x rev=0x%02x platform=%s gen=%i\n",
> + drm_printf(&p, "pciid=0x%04x rev=0x%02x platform=%s (%x) gen=%i\n",
> INTEL_DEVID(dev_priv),
> INTEL_REVID(dev_priv),
> intel_platform_name(INTEL_INFO(dev_priv)->platform),
> + RUNTIME_INFO(dev_priv)->platform_mask[INTEL_INFO(dev_priv)->platform / (BITS_PER_TYPE(RUNTIME_INFO(dev_priv)->platform_mask[0]) - INTEL_SUBPLATFORM_BITS)],
I hope that's a one-off!
> INTEL_GEN(dev_priv));
>
> intel_device_info_dump_flags(INTEL_INFO(dev_priv), &p);
> @@ -1798,8 +1801,6 @@ i915_driver_create(struct pci_dev *pdev, const struct pci_device_id *ent)
> memcpy(device_info, match_info, sizeof(*device_info));
> RUNTIME_INFO(i915)->device_id = pdev->device;
>
> - BUILD_BUG_ON(INTEL_MAX_PLATFORMS >
> - BITS_PER_TYPE(device_info->platform_mask));
> BUG_ON(device_info->gen > BITS_PER_TYPE(device_info->gen_mask));
>
> return i915;
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index dccb6006aabf..34282cf66cb0 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -2281,7 +2281,46 @@ static inline unsigned int i915_sg_segment_size(void)
> #define IS_REVID(p, since, until) \
> (INTEL_REVID(p) >= (since) && INTEL_REVID(p) <= (until))
>
> -#define IS_PLATFORM(dev_priv, p) (INTEL_INFO(dev_priv)->platform_mask & BIT(p))
> +#define __IS_PLATFORM(dev_priv, p) \
> +({ \
> + const unsigned int pbits__ = \
> + BITS_PER_TYPE(RUNTIME_INFO(dev_priv)->platform_mask[0]) - \
> + INTEL_SUBPLATFORM_BITS; \
> + const unsigned int pi__ = (p) / pbits__; \
> + const unsigned int pb__ = (p) % pbits__ + INTEL_SUBPLATFORM_BITS; \
Oh, p is a compile time constant, so these can all be evaluated at
compile time. So not a worry.
> +\
> + BUILD_BUG_ON(!__builtin_constant_p(p)); \
> +\
> + (RUNTIME_INFO(dev_priv)->platform_mask[pi__] & BIT(pb__)); \
> +})
> +
> +#define __IS_SUBPLATFORM(dev_priv, p, s) \
> +({ \
> + const unsigned int pbits__ = \
> + BITS_PER_TYPE(RUNTIME_INFO(dev_priv)->platform_mask[0]) - \
> + INTEL_SUBPLATFORM_BITS; \
> + const unsigned int pi__ = (p) / pbits__; \
> + const unsigned int pb__ = (p) % pbits__ + INTEL_SUBPLATFORM_BITS; \
> +\
> + BUILD_BUG_ON(!__builtin_constant_p(p)); \
> + BUILD_BUG_ON(!__builtin_constant_p(s)); \
> + BUILD_BUG_ON((s) >= INTEL_SUBPLATFORM_BITS); \
> +\
> + (RUNTIME_INFO(dev_priv)->platform_mask[pi__] & (BIT(pb__) | BIT(s))); \
> +})
> +
> +static inline bool
> +IS_PLATFORM(const struct drm_i915_private *i915, enum intel_platform p)
> +{
> + return __IS_PLATFORM(i915, p);
> +}
> +
> +static inline bool
> +IS_SUBPLATFORM(const struct drm_i915_private *i915,
> + enum intel_platform p, unsigned int s)
> +{
> + return __IS_SUBPLATFORM(i915, p, s);
> +}
Ok, that all makes sense as a custom bitmap.
> +void intel_device_info_subplatform_init(struct drm_i915_private *i915)
> +{
> + const unsigned int pbits =
> + BITS_PER_TYPE(RUNTIME_INFO(i915)->platform_mask[0]) -
> + INTEL_SUBPLATFORM_BITS;
> + const unsigned int pi = INTEL_INFO(i915)->platform / pbits;
> + const unsigned int pb =
> + INTEL_INFO(i915)->platform % pbits + INTEL_SUBPLATFORM_BITS;
> + struct intel_runtime_info *info = RUNTIME_INFO(i915);
> + u16 devid = INTEL_DEVID(i915);
> +
> + BUILD_BUG_ON(INTEL_MAX_PLATFORMS >
> + pbits * ARRAY_SIZE(RUNTIME_INFO(i915)->platform_mask));
> +
> + info->platform_mask[pi] = BIT(pb);
> +
> + if (IS_PINEVIEW(i915)) {
> + if (devid == 0xa001)
> + info->platform_mask[pi] |=
> + BIT(INTEL_SUBPLATFORM_PINEVIEW_G);
> + else if (devid == 0xa011)
> + info->platform_mask[pi] |=
> + BIT(INTEL_SUBPLATFORM_PINEVIEW_M);
if (IS_PINEVIEW(i915)) {
int subplatform = 0;
if (devid == 0xa001)
subplatform = INTEL_SUBPLATFORM_PINEVIEW_G;
else if (devid == 0xa001)
subplatform = INTEL_SUBPLATFORM_PINEVIEW_M;
else
MISSING_CASE(devid);
info->platform_mask[pi] |= BIT(subplatform);
WARN_ON(!IS_SUBPLATFORM(i915, INTEL_PLATFORM_PINEVIEW, subplatform));
}
So we catch missing ids, and validate subplatform against
SUBPLATFORM_BITS.
> /**
> * intel_device_info_runtime_init - initialize runtime info
> * @dev_priv: the i915 device
> diff --git a/drivers/gpu/drm/i915/intel_device_info.h b/drivers/gpu/drm/i915/intel_device_info.h
> index 047d10bdd455..b03fbd2e451a 100644
> --- a/drivers/gpu/drm/i915/intel_device_info.h
> +++ b/drivers/gpu/drm/i915/intel_device_info.h
> @@ -44,7 +44,7 @@ enum intel_platform {
> INTEL_I915G,
> INTEL_I915GM,
> INTEL_I945G,
> - INTEL_I945GM,
> + INTEL_I945GM = 8,
> INTEL_G33,
> INTEL_PINEVIEW,
> /* gen4 */
> @@ -55,7 +55,7 @@ enum intel_platform {
> /* gen5 */
> INTEL_IRONLAKE,
> /* gen6 */
> - INTEL_SANDYBRIDGE,
> + INTEL_SANDYBRIDGE = 16,
> /* gen7 */
> INTEL_IVYBRIDGE,
> INTEL_VALLEYVIEW,
> @@ -66,7 +66,7 @@ enum intel_platform {
> /* gen9 */
> INTEL_SKYLAKE,
> INTEL_BROXTON,
> - INTEL_KABYLAKE,
> + INTEL_KABYLAKE = 24,
Looks like you are just keeping a tally, and no I have no idea how to
add a comment to make that clear.
/* tally */
/* tally so far */
> INTEL_GEMINILAKE,
> INTEL_COFFEELAKE,
> /* gen10 */
> @@ -76,6 +76,24 @@ enum intel_platform {
> INTEL_MAX_PLATFORMS
> };
>
> +/*
> + * Subplatform bits share the same namespace per parent platform. In other words
> + * it is fine for the same bit to be used on multiple parent platforms.
> + */
> +
> +#define INTEL_SUBPLATFORM_BITS (3)
> +#define INTEL_SUBPLATFORM_IRONLAKE_M (0)
I can't believe you haven't done i852/i855! (Or whatever that variant
was called.)
Couldn't spot anything wrong, and so long as subplatform remains clear
in the error state, hint hint, I'm happy.
-Chris
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