[DO NOT MERGE ANYWHERE] Revert "mali_pixel: Implement SLC partition ref counting"

Revert submission 2753879-gpu-slcv2-gs201

Reason for revert: Prebuild did not land before cutoff

Reverted changes: /q/submissionid:2753879-gpu-slcv2-gs201

Bug: 329447972
Change-Id: I13716375afbe5be1ae04eb059ed24e8780e503cd

6 files changed, 5 insertions, 214 deletions

diff --git a/common/include/uapi/gpu/arm/midgard/platform/pixel/pixel_memory_group_manager.h b/common/include/uapi/gpu/arm/midgard/platform/pixel/pixel_memory_group_manager.h
index d410f7b..893cdca 100644
--- a/common/include/uapi/gpu/arm/midgard/platform/pixel/pixel_memory_group_manager.h
+++ b/common/include/uapi/gpu/arm/midgard/platform/pixel/pixel_memory_group_manager.h
@@ -7,8 +7,4 @@
 #ifndef _UAPI_PIXEL_MEMORY_GROUP_MANAGER_H_
 #define _UAPI_PIXEL_MEMORY_GROUP_MANAGER_H_
 
-void pixel_mgm_slc_inc_refcount(struct memory_group_manager_device* mgm_dev);
-
-void pixel_mgm_slc_dec_refcount(struct memory_group_manager_device* mgm_dev);
-
 #endif /* _UAPI_PIXEL_MEMORY_GROUP_MANAGER_H_ */
diff --git a/mali_kbase/platform/pixel/mali_kbase_config_platform.h b/mali_kbase/platform/pixel/mali_kbase_config_platform.h
index 47b1318..06b76ea 100644
--- a/mali_kbase/platform/pixel/mali_kbase_config_platform.h
+++ b/mali_kbase/platform/pixel/mali_kbase_config_platform.h
@@ -428,14 +428,12 @@ struct pixel_context {
 /**
  * struct pixel_platform_data - Per kbase_context Pixel specific platform data
  *
- * @kctx:     Handle to the parent kctx
- * @stats:    Tracks the dvfs metrics for the UID associated with this context
- * @slc_vote: Tracks whether this context is voting for slc
+ * @kctx:  Handle to the parent kctx
+ * @stats: Tracks the dvfs metrics for the UID associated with this context
  */
 struct pixel_platform_data {
 	struct kbase_context *kctx;
 	struct gpu_dvfs_metrics_uid_stats* stats;
-	int slc_vote;
 };
 
 #endif /* _KBASE_CONFIG_PLATFORM_H_ */
diff --git a/mali_kbase/platform/pixel/pixel_gpu_slc.c b/mali_kbase/platform/pixel/pixel_gpu_slc.c
index e8aae75..8e46be1 100644
--- a/mali_kbase/platform/pixel/pixel_gpu_slc.c
+++ b/mali_kbase/platform/pixel/pixel_gpu_slc.c
@@ -17,37 +17,6 @@
 #include "mali_kbase_config_platform.h"
 #include "pixel_gpu_slc.h"
 
-#include <uapi/gpu/arm/midgard/platform/pixel/pixel_memory_group_manager.h>
-
-/**
- * enum slc_vote_state - Whether a context is voting for SLC
- */
-enum slc_vote_state {
-	/** @IDLE: Idle, not voting for SLC */
-	IDLE   = 0,
-	/** @VOTING: Active, voting for SLC */
-	VOTING = 1,
-};
-
-/**
- * transition() - Try to transition from one value to another
- *
- * @v:   Value to transition
- * @old: Starting state to transition from
- * @new: Destination state to transition to
- *
- * Return: Whether the transition was successful
- */
-static bool transition(int *v, int old, int new)
-{
-	bool const cond = *v == old;
-
-	if (cond)
-		*v = new;
-
-	return cond;
-}
-
 /**
  * gpu_pixel_handle_buffer_liveness_update_ioctl() - See gpu_slc_liveness_update
  *
@@ -88,11 +57,7 @@ int gpu_slc_kctx_init(struct kbase_context *kctx)
  */
 void gpu_slc_kctx_term(struct kbase_context *kctx)
 {
-	struct pixel_platform_data *pd = kctx->platform_data;
-
-	/* Contexts can be terminated without being idled first */
-	if (transition(&pd->slc_vote, VOTING, IDLE))
-		pixel_mgm_slc_dec_refcount(kctx->kbdev->mgm_dev);
+	(void)kctx;
 }
 
 /**
@@ -102,12 +67,7 @@ void gpu_slc_kctx_term(struct kbase_context *kctx)
  */
 void gpu_slc_kctx_active(struct kbase_context *kctx)
 {
-	struct pixel_platform_data *pd = kctx->platform_data;
-
-	lockdep_assert_held(&kctx->kbdev->hwaccess_lock);
-
-	if (transition(&pd->slc_vote, IDLE, VOTING))
-		pixel_mgm_slc_inc_refcount(kctx->kbdev->mgm_dev);
+	(void)kctx;
 }
 
 /**
@@ -117,12 +77,7 @@ void gpu_slc_kctx_active(struct kbase_context *kctx)
  */
 void gpu_slc_kctx_idle(struct kbase_context *kctx)
 {
-	struct pixel_platform_data *pd = kctx->platform_data;
-
-	lockdep_assert_held(&kctx->kbdev->hwaccess_lock);
-
-	if (transition(&pd->slc_vote, VOTING, IDLE))
-		pixel_mgm_slc_dec_refcount(kctx->kbdev->mgm_dev);
+	(void)kctx;
 }
 
 /**
diff --git a/mali_pixel/memory_group_manager.c b/mali_pixel/memory_group_manager.c
index 03c6f74..4d92ea7 100644
--- a/mali_pixel/memory_group_manager.c
+++ b/mali_pixel/memory_group_manager.c
@@ -533,22 +533,6 @@ static vm_fault_t mgm_vmf_insert_pfn_prot(
 	return fault;
 }
 
-void pixel_mgm_slc_inc_refcount(struct memory_group_manager_device* mgm_dev)
-{
-	struct mgm_groups *const data = mgm_dev->data;
-
-	slc_inc_refcount(&data->slc_data);
-}
-EXPORT_SYMBOL_GPL(pixel_mgm_slc_inc_refcount);
-
-void pixel_mgm_slc_dec_refcount(struct memory_group_manager_device* mgm_dev)
-{
-	struct mgm_groups *const data = mgm_dev->data;
-
-	slc_dec_refcount(&data->slc_data);
-}
-EXPORT_SYMBOL_GPL(pixel_mgm_slc_dec_refcount);
-
 static int mgm_initialize_data(struct mgm_groups *mgm_data)
 {
 	int i, ret;
diff --git a/mali_pixel/pixel_slc.c b/mali_pixel/pixel_slc.c
index 78f1b74..62c6908 100644
--- a/mali_pixel/pixel_slc.c
+++ b/mali_pixel/pixel_slc.c
@@ -37,50 +37,6 @@
 #endif
 #define PBHA_BIT_MASK (0xf)
 
-#define PARTITION_DISABLE_HYSTERESIS (msecs_to_jiffies(100))
-
-
-/**
- * partition_required() - Determine whether we require a partition to be enabled
- *
- * @pt: The partition to check.
- *
- * Check whether a partition meets the requirements for being enabled.
- *
- * Return: True, if the partition is required to be enabled, otherwise false.
- */
-static bool partition_required(struct slc_partition *pt)
-{
-	lockdep_assert_held(&pt->lock);
-
-	return atomic_read(&pt->refcount);
-}
-
-/**
- * pixel_atomic_dec_and_lock_irqsave - lock on reaching reference count zero
- *
- * @val:   The atomic counter
- * @lock:  The spinlock in question
- * @flags: Storage for the current interrupt enable state
- *
- * Decrements @val by 1, if the result is 0, locks @lock.
- *
- * Return: True if the lock was taken, false for all other cases.
- */
-static int pixel_atomic_dec_and_lock_irqsave(atomic_t* val, spinlock_t* lock, unsigned long* flags)
-{
-	/* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
-	if (atomic_add_unless(val, -1, 1))
-		return 0;
-
-	/* Otherwise do it the slow way */
-	spin_lock_irqsave(lock, *flags);
-	if (atomic_dec_and_test(val))
-		return 1;
-	spin_unlock_irqrestore(lock, *flags);
-
-	return 0;
-}
 
 /**
  * slc_wipe_pbha - Clear any set PBHA bits from the pte.
@@ -148,84 +104,6 @@ static void disable_partition(struct slc_data *data, struct slc_partition *pt)
 }
 
 /**
- * queue_disable_worker - Queue a delayed partition disable op
- *
- * @data: The &struct slc_data tracking partition information.
- */
-static void queue_disable_worker(struct slc_data *data)
-{
-	queue_delayed_work(system_highpri_wq, &data->disable_work, PARTITION_DISABLE_HYSTERESIS);
-}
-
-/**
- * partition_disable_worker - Callback to lazily disable a partition
- *
- * @work: The &struct work_struct dequeued
- */
-static void partition_disable_worker(struct work_struct *work)
-{
-	struct slc_data* data = container_of(work, struct slc_data, disable_work.work);
-	struct slc_partition *pt = &data->partition;
-	unsigned long flags;
-
-	/* Complete any pending disable ops */
-	spin_lock_irqsave(&pt->lock, flags);
-
-	if (!partition_required(pt))
-		disable_partition(data, pt);
-
-	spin_unlock_irqrestore(&pt->lock, flags);
-}
-
-/**
- * slc_inc_refcount - Increase the partition reference count.
- *
- * @data: The &struct slc_data tracking partition information.
- *
- * If this is the first reference being taken, the partition will be enabled.
- */
-void slc_inc_refcount(struct slc_data *data)
-{
-	struct slc_partition *pt = &data->partition;
-
-	/* Try to re-enable the partition if this is the first reference */
-	if (atomic_inc_return(&pt->refcount) == 1) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&pt->lock, flags);
-
-		/* Enable the partition immediately if it's required */
-		if (partition_required(pt))
-			enable_partition(data, pt);
-
-		spin_unlock_irqrestore(&pt->lock, flags);
-	}
-}
-
-/**
- * slc_dec_refcount - Decrease the partition reference count.
- *
- * @data: The &struct slc_data tracking partition information.
- *
- * If this is the last reference being released, the partition will be disabled.
- */
-void slc_dec_refcount(struct slc_data *data)
-{
-	struct slc_partition *pt = &data->partition;
-	unsigned long flags;
-
-	/* Disable the partition if this was the last reference */
-	if (pixel_atomic_dec_and_lock_irqsave(&pt->refcount, &pt->lock, &flags)) {
-
-		/* Lazily disable the partition if it's no longer required */
-		if (!partition_required(pt))
-			queue_disable_worker(data);
-
-		spin_unlock_irqrestore(&pt->lock, flags);
-	}
-}
-
-/**
  * init_partition - Register and initialize a partition with the SLC driver.
  *
  * @data:  The &struct slc_data tracking partition information.
@@ -263,9 +141,7 @@ static int init_partition(struct slc_data *data, struct slc_partition *pt, u32 i
 		.ptid = ptid,
 		.pbha = pbha,
 		.enabled = false,
-		.refcount = ATOMIC_INIT(0),
 	};
-	spin_lock_init(&pt->lock);
 
 err_exit:
 	return err;
@@ -304,8 +180,6 @@ int slc_init_data(struct slc_data *data, struct device* dev)
 	/* Inherit the platform device */
 	data->dev = dev;
 
-	INIT_DELAYED_WORK(&data->disable_work, partition_disable_worker);
-
 	/* Register our node with the SLC driver.
 	 * This detects our partitions defined within the DT.
 	 */
@@ -335,9 +209,6 @@ err_exit:
  */
 void slc_term_data(struct slc_data *data)
 {
-	/* Ensure all pending disable ops are complete */
-	cancel_delayed_work_sync(&data->disable_work);
-
 	term_partition(data, &data->partition);
 
 	pt_client_unregister(data->pt_handle);
diff --git a/mali_pixel/pixel_slc.h b/mali_pixel/pixel_slc.h
index bcaf1ff..40b5ad7 100644
--- a/mali_pixel/pixel_slc.h
+++ b/mali_pixel/pixel_slc.h
@@ -45,12 +45,6 @@ struct slc_partition {
 
 	/** @enabled: Is the partition currently enabled */
 	bool enabled;
-
-	/** @refcount: Reference count for this partition */
-	atomic_t refcount;
-
-	/** @lock: Lock protecting enable/disable ops on this partition */
-	spinlock_t lock;
 };
 
 /**
@@ -65,9 +59,6 @@ struct slc_data {
 
 	/** @dev: Inherited pointer to device attached */
 	struct device *dev;
-
-	/** @disable_work: Work item used to queue lazy SLC partition disable ops. */
-	struct delayed_work disable_work;
 };
 
 int slc_init_data(struct slc_data *data, struct device* dev);
@@ -78,8 +69,4 @@ u64 slc_set_pbha(struct slc_data const *data, u64 pte);
 
 u64 slc_wipe_pbha(u64 pte);
 
-void slc_inc_refcount(struct slc_data *data);
-
-void slc_dec_refcount(struct slc_data *data);
-
 #endif /* _PIXEL_SLC_H_ */