staging: vc04_services: Move global memory mapped pointer

g_regs stores the remapped memory pointer for the vchiq platform.
It can be moved to struct vchiq_drv_mgmt instead of being global.

Adjust the affected functions accordingly. Pass vchiq_state pointer
wherever necessary to access struct vchiq_drv_mgmt.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Link: https://lore.kernel.org/r/20240412075743.60712-8-umang.jain@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Umang Jain

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c

@@ -129,8 +129,6 @@ struct vchiq_pagelist_info {
 	unsigned int scatterlist_mapped;
 };
 
-static void __iomem *g_regs;
-
 static int
 vchiq_blocking_bulk_transfer(struct vchiq_instance *instance, unsigned int handle, void *data,
 			     unsigned int size, enum vchiq_bulk_dir dir);
@@ -139,11 +137,14 @@ static irqreturn_t
 vchiq_doorbell_irq(int irq, void *dev_id)
 {
 	struct vchiq_state *state = dev_id;
+	struct vchiq_drv_mgmt *mgmt;
 	irqreturn_t ret = IRQ_NONE;
 	unsigned int status;
 
+	mgmt = dev_get_drvdata(state->dev);
+
 	/* Read (and clear) the doorbell */
-	status = readl(g_regs + BELL0);
+	status = readl(mgmt->regs + BELL0);
 
 	if (status & ARM_DS_ACTIVE) {  /* Was the doorbell rung? */
 		remote_event_pollall(state);
@@ -556,9 +557,9 @@ static int vchiq_platform_init(struct platform_device *pdev, struct vchiq_state
 	if (err)
 		return err;
 
-	g_regs = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(g_regs))
-		return PTR_ERR(g_regs);
+	drv_mgmt->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(drv_mgmt->regs))
+		return PTR_ERR(drv_mgmt->regs);
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq <= 0)
@@ -641,8 +642,10 @@ static struct vchiq_arm_state *vchiq_platform_get_arm_state(struct vchiq_state *
 }
 
 void
-remote_event_signal(struct remote_event *event)
+remote_event_signal(struct vchiq_state *state, struct remote_event *event)
 {
+	struct vchiq_drv_mgmt *mgmt = dev_get_drvdata(state->dev);
+
 	/*
 	 * Ensure that all writes to shared data structures have completed
 	 * before signalling the peer.
@@ -654,7 +657,7 @@ remote_event_signal(struct remote_event *event)
 	dsb(sy);         /* data barrier operation */
 
 	if (event->armed)
-		writel(0, g_regs + BELL2); /* trigger vc interrupt */
+		writel(0, mgmt->regs + BELL2); /* trigger vc interrupt */
 }
 
 int

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.h

@@ -50,6 +50,8 @@ struct vchiq_drv_mgmt {
 	char *fragments_base;
 	char *free_fragments;
 	unsigned int fragments_size;
+
+	void __iomem *regs;
 };
 
 struct user_service {

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c

@@ -691,7 +691,7 @@ reserve_space(struct vchiq_state *state, size_t space, int is_blocking)
 			/* But first, flush through the last slot. */
 			state->local_tx_pos = tx_pos;
 			local->tx_pos = tx_pos;
-			remote_event_signal(&state->remote->trigger);
+			remote_event_signal(state, &state->remote->trigger);
 
 			if (!is_blocking ||
 			    (wait_for_completion_interruptible(&state->slot_available_event)))
@@ -1124,7 +1124,7 @@ queue_message(struct vchiq_state *state, struct vchiq_service *service,
 	if (!(flags & QMFLAGS_NO_MUTEX_UNLOCK))
 		mutex_unlock(&state->slot_mutex);
 
-	remote_event_signal(&state->remote->trigger);
+	remote_event_signal(state, &state->remote->trigger);
 
 	return 0;
 }
@@ -1202,7 +1202,7 @@ queue_message_sync(struct vchiq_state *state, struct vchiq_service *service,
 		&svc_fourcc, VCHIQ_MSG_SRCPORT(msgid),
 		VCHIQ_MSG_DSTPORT(msgid), size);
 
-	remote_event_signal(&state->remote->sync_trigger);
+	remote_event_signal(state, &state->remote->sync_trigger);
 
 	if (VCHIQ_MSG_TYPE(msgid) != VCHIQ_MSG_PAUSE)
 		mutex_unlock(&state->sync_mutex);
@@ -1260,7 +1260,7 @@ release_slot(struct vchiq_state *state, struct vchiq_slot_info *slot_info,
 		 * A write barrier is necessary, but remote_event_signal
 		 * contains one.
 		 */
-		remote_event_signal(&state->remote->recycle);
+		remote_event_signal(state, &state->remote->recycle);
 	}
 
 	mutex_unlock(&state->recycle_mutex);
@@ -3240,7 +3240,7 @@ static void
 release_message_sync(struct vchiq_state *state, struct vchiq_header *header)
 {
 	header->msgid = VCHIQ_MSGID_PADDING;
-	remote_event_signal(&state->remote->sync_release);
+	remote_event_signal(state, &state->remote->sync_release);
 }
 
 int

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h

@@ -516,7 +516,7 @@ int vchiq_prepare_bulk_data(struct vchiq_instance *instance, struct vchiq_bulk *
 
 void vchiq_complete_bulk(struct vchiq_instance *instance, struct vchiq_bulk *bulk);
 
-void remote_event_signal(struct remote_event *event);
+void remote_event_signal(struct vchiq_state *state, struct remote_event *event);
 
 void vchiq_dump_platform_state(struct seq_file *f);