drm/i915: dynamically allocate forcewake domains

We'd like to introduce a display uncore with no forcewake domains, so
let's avoid wasting memory and be ready to allocate only what we need.
Even without multiple uncore, we still don't need all the domains on all
gens.

v2: avoid hidden control flow, improve checks (Tvrtko), fix IVB special
case, add failure injection point
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190620010021.20637-6-daniele.ceraolospurio@intel.com

drivers/gpu/drm/i915/intel_uncore.c

@@ -344,7 +344,7 @@ intel_uncore_fw_release_timer(struct hrtimer *timer)
 {
 	struct intel_uncore_forcewake_domain *domain =
 	       container_of(timer, struct intel_uncore_forcewake_domain, timer);
-	struct intel_uncore *uncore = forcewake_domain_to_uncore(domain);
+	struct intel_uncore *uncore = domain->uncore;
 	unsigned long irqflags;
 
 	assert_rpm_device_not_suspended(uncore->rpm);
@@ -1293,23 +1293,27 @@ do { \
 	(uncore)->funcs.read_fw_domains = x##_reg_read_fw_domains; \
 } while (0)
 
-static void fw_domain_init(struct intel_uncore *uncore,
-			   enum forcewake_domain_id domain_id,
-			   i915_reg_t reg_set,
-			   i915_reg_t reg_ack)
+static int __fw_domain_init(struct intel_uncore *uncore,
+			    enum forcewake_domain_id domain_id,
+			    i915_reg_t reg_set,
+			    i915_reg_t reg_ack)
 {
 	struct intel_uncore_forcewake_domain *d;
 
-	if (WARN_ON(domain_id >= FW_DOMAIN_ID_COUNT))
-		return;
+	GEM_BUG_ON(domain_id >= FW_DOMAIN_ID_COUNT);
+	GEM_BUG_ON(uncore->fw_domain[domain_id]);
 
-	d = &uncore->fw_domain[domain_id];
+	if (i915_inject_load_failure())
+		return -ENOMEM;
 
-	WARN_ON(d->wake_count);
+	d = kzalloc(sizeof(*d), GFP_KERNEL);
+	if (!d)
+		return -ENOMEM;
 
 	WARN_ON(!i915_mmio_reg_valid(reg_set));
 	WARN_ON(!i915_mmio_reg_valid(reg_ack));
 
+	d->uncore = uncore;
 	d->wake_count = 0;
 	d->reg_set = uncore->regs + i915_mmio_reg_offset(reg_set);
 	d->reg_ack = uncore->regs + i915_mmio_reg_offset(reg_ack);
@@ -1326,7 +1330,6 @@ static void fw_domain_init(struct intel_uncore *uncore,
 	BUILD_BUG_ON(FORCEWAKE_MEDIA_VEBOX0 != (1 << FW_DOMAIN_ID_MEDIA_VEBOX0));
 	BUILD_BUG_ON(FORCEWAKE_MEDIA_VEBOX1 != (1 << FW_DOMAIN_ID_MEDIA_VEBOX1));
 
-
 	d->mask = BIT(domain_id);
 
 	hrtimer_init(&d->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
@@ -1335,6 +1338,10 @@ static void fw_domain_init(struct intel_uncore *uncore,
 	uncore->fw_domains |= BIT(domain_id);
 
 	fw_domain_reset(d);
+
+	uncore->fw_domain[domain_id] = d;
+
+	return 0;
 }
 
 static void fw_domain_fini(struct intel_uncore *uncore,
@@ -1342,29 +1349,41 @@ static void fw_domain_fini(struct intel_uncore *uncore,
 {
 	struct intel_uncore_forcewake_domain *d;
 
-	if (WARN_ON(domain_id >= FW_DOMAIN_ID_COUNT))
-		return;
+	GEM_BUG_ON(domain_id >= FW_DOMAIN_ID_COUNT);
 
-	d = &uncore->fw_domain[domain_id];
+	d = fetch_and_zero(&uncore->fw_domain[domain_id]);
+	if (!d)
+		return;
 
+	uncore->fw_domains &= ~BIT(domain_id);
 	WARN_ON(d->wake_count);
 	WARN_ON(hrtimer_cancel(&d->timer));
-	memset(d, 0, sizeof(*d));
+	kfree(d);
+}
 
-	uncore->fw_domains &= ~BIT(domain_id);
+static void intel_uncore_fw_domains_fini(struct intel_uncore *uncore)
+{
+	struct intel_uncore_forcewake_domain *d;
+	int tmp;
+
+	for_each_fw_domain(d, uncore, tmp)
+		fw_domain_fini(uncore, d->id);
 }
 
-static void intel_uncore_fw_domains_init(struct intel_uncore *uncore)
+static int intel_uncore_fw_domains_init(struct intel_uncore *uncore)
 {
 	struct drm_i915_private *i915 = uncore->i915;
+	int ret = 0;
 
 	GEM_BUG_ON(!intel_uncore_has_forcewake(uncore));
 
+#define fw_domain_init(uncore__, id__, set__, ack__) \
+	(ret ?: (ret = __fw_domain_init((uncore__), (id__), (set__), (ack__))))
+
 	if (INTEL_GEN(i915) >= 11) {
 		int i;
 
-		uncore->funcs.force_wake_get =
-			fw_domains_get_with_fallback;
+		uncore->funcs.force_wake_get = fw_domains_get_with_fallback;
 		uncore->funcs.force_wake_put = fw_domains_put;
 		fw_domain_init(uncore, FW_DOMAIN_ID_RENDER,
 			       FORCEWAKE_RENDER_GEN9,
@@ -1372,6 +1391,7 @@ static void intel_uncore_fw_domains_init(struct intel_uncore *uncore)
 		fw_domain_init(uncore, FW_DOMAIN_ID_BLITTER,
 			       FORCEWAKE_BLITTER_GEN9,
 			       FORCEWAKE_ACK_BLITTER_GEN9);
+
 		for (i = 0; i < I915_MAX_VCS; i++) {
 			if (!HAS_ENGINE(i915, _VCS(i)))
 				continue;
@@ -1389,8 +1409,7 @@ static void intel_uncore_fw_domains_init(struct intel_uncore *uncore)
 				       FORCEWAKE_ACK_MEDIA_VEBOX_GEN11(i));
 		}
 	} else if (IS_GEN_RANGE(i915, 9, 10)) {
-		uncore->funcs.force_wake_get =
-			fw_domains_get_with_fallback;
+		uncore->funcs.force_wake_get = fw_domains_get_with_fallback;
 		uncore->funcs.force_wake_put = fw_domains_put;
 		fw_domain_init(uncore, FW_DOMAIN_ID_RENDER,
 			       FORCEWAKE_RENDER_GEN9,
@@ -1439,8 +1458,10 @@ static void intel_uncore_fw_domains_init(struct intel_uncore *uncore)
 		__raw_uncore_write32(uncore, FORCEWAKE, 0);
 		__raw_posting_read(uncore, ECOBUS);
 
-		fw_domain_init(uncore, FW_DOMAIN_ID_RENDER,
-			       FORCEWAKE_MT, FORCEWAKE_MT_ACK);
+		ret = __fw_domain_init(uncore, FW_DOMAIN_ID_RENDER,
+				       FORCEWAKE_MT, FORCEWAKE_MT_ACK);
+		if (ret)
+			goto out;
 
 		spin_lock_irq(&uncore->lock);
 		fw_domains_get_with_thread_status(uncore, FORCEWAKE_RENDER);
@@ -1451,6 +1472,7 @@ static void intel_uncore_fw_domains_init(struct intel_uncore *uncore)
 		if (!(ecobus & FORCEWAKE_MT_ENABLE)) {
 			DRM_INFO("No MT forcewake available on Ivybridge, this can result in issues\n");
 			DRM_INFO("when using vblank-synced partial screen updates.\n");
+			fw_domain_fini(uncore, FW_DOMAIN_ID_RENDER);
 			fw_domain_init(uncore, FW_DOMAIN_ID_RENDER,
 				       FORCEWAKE, FORCEWAKE_ACK);
 		}
@@ -1462,8 +1484,16 @@ static void intel_uncore_fw_domains_init(struct intel_uncore *uncore)
 			       FORCEWAKE, FORCEWAKE_ACK);
 	}
 
+#undef fw_domain_init
+
 	/* All future platforms are expected to require complex power gating */
-	WARN_ON(uncore->fw_domains == 0);
+	WARN_ON(!ret && uncore->fw_domains == 0);
+
+out:
+	if (ret)
+		intel_uncore_fw_domains_fini(uncore);
+
+	return ret;
 }
 
 #define ASSIGN_FW_DOMAINS_TABLE(uncore, d) \
@@ -1564,13 +1594,17 @@ static void uncore_raw_init(struct intel_uncore *uncore)
 	}
 }
 
-static void uncore_forcewake_init(struct intel_uncore *uncore)
+static int uncore_forcewake_init(struct intel_uncore *uncore)
 {
 	struct drm_i915_private *i915 = uncore->i915;
+	int ret;
 
 	GEM_BUG_ON(!intel_uncore_has_forcewake(uncore));
 
-	intel_uncore_fw_domains_init(uncore);
+	ret = intel_uncore_fw_domains_init(uncore);
+	if (ret)
+		return ret;
+
 	forcewake_early_sanitize(uncore, 0);
 
 	if (IS_GEN_RANGE(i915, 6, 7)) {
@@ -1603,6 +1637,8 @@ static void uncore_forcewake_init(struct intel_uncore *uncore)
 
 	uncore->pmic_bus_access_nb.notifier_call = i915_pmic_bus_access_notifier;
 	iosf_mbi_register_pmic_bus_access_notifier(&uncore->pmic_bus_access_nb);
+
+	return 0;
 }
 
 int intel_uncore_init_mmio(struct intel_uncore *uncore)
@@ -1621,10 +1657,13 @@ int intel_uncore_init_mmio(struct intel_uncore *uncore)
 
 	uncore->unclaimed_mmio_check = 1;
 
-	if (!intel_uncore_has_forcewake(uncore))
+	if (!intel_uncore_has_forcewake(uncore)) {
 		uncore_raw_init(uncore);
-	else
-		uncore_forcewake_init(uncore);
+	} else {
+		ret = uncore_forcewake_init(uncore);
+		if (ret)
+			goto out_mmio_cleanup;
+	}
 
 	/* make sure fw funcs are set if and only if we have fw*/
 	GEM_BUG_ON(intel_uncore_has_forcewake(uncore) != !!uncore->funcs.force_wake_get);
@@ -1646,6 +1685,11 @@ int intel_uncore_init_mmio(struct intel_uncore *uncore)
 		DRM_DEBUG("unclaimed mmio detected on uncore init, clearing\n");
 
 	return 0;
+
+out_mmio_cleanup:
+	uncore_mmio_cleanup(uncore);
+
+	return ret;
 }
 
 /*
@@ -1691,6 +1735,7 @@ void intel_uncore_fini_mmio(struct intel_uncore *uncore)
 		iosf_mbi_unregister_pmic_bus_access_notifier_unlocked(
 			&uncore->pmic_bus_access_nb);
 		intel_uncore_forcewake_reset(uncore);
+		intel_uncore_fw_domains_fini(uncore);
 		iosf_mbi_punit_release();
 	}
 

drivers/gpu/drm/i915/intel_uncore.h

@@ -126,6 +126,7 @@ struct intel_uncore {
 	enum forcewake_domains fw_domains_saved; /* user domains saved for S3 */
 
 	struct intel_uncore_forcewake_domain {
+		struct intel_uncore *uncore;
 		enum forcewake_domain_id id;
 		enum forcewake_domains mask;
 		unsigned int wake_count;
@@ -133,7 +134,7 @@ struct intel_uncore {
 		struct hrtimer timer;
 		u32 __iomem *reg_set;
 		u32 __iomem *reg_ack;
-	} fw_domain[FW_DOMAIN_ID_COUNT];
+	} *fw_domain[FW_DOMAIN_ID_COUNT];
 
 	struct {
 		unsigned int count;
@@ -147,18 +148,12 @@ struct intel_uncore {
 
 /* Iterate over initialised fw domains */
 #define for_each_fw_domain_masked(domain__, mask__, uncore__, tmp__) \
-	for (tmp__ = (mask__); \
-	     tmp__ ? (domain__ = &(uncore__)->fw_domain[__mask_next_bit(tmp__)]), 1 : 0;)
+	for (tmp__ = (mask__); tmp__ ;) \
+		for_each_if(domain__ = (uncore__)->fw_domain[__mask_next_bit(tmp__)])
 
 #define for_each_fw_domain(domain__, uncore__, tmp__) \
 	for_each_fw_domain_masked(domain__, (uncore__)->fw_domains, uncore__, tmp__)
 
-static inline struct intel_uncore *
-forcewake_domain_to_uncore(const struct intel_uncore_forcewake_domain *d)
-{
-	return container_of(d, struct intel_uncore, fw_domain[d->id]);
-}
-
 static inline bool
 intel_uncore_has_forcewake(const struct intel_uncore *uncore)
 {