Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1f7466c6 authored by Anup Patel's avatar Anup Patel Committed by Jassi Brar
Browse files

mailbox: bcm-flexrm-mailbox: Use bitmap instead of IDA 



Currently, we are using IDA library for managing IDs
on a FlexRM ring. The IDA library dynamically allocates
memory for underlying data structures which can cause
potential locking issue when allocating/free IDs from
flexrm_new_request() and flexrm_process_completions().

To tackle this, we replace use of IDA with bitmap for
each FlexRM ring and also protect the bitmap with FlexRM
ring lock.

Signed-off-by: default avatarAnup Patel <anup.patel@broadcom.com>
Signed-off-by: default avatarJassi Brar <jaswinder.singh@linaro.org>
parent 6d2061b9

drivers/mailbox/bcm-flexrm-mailbox.c

+19 −17
Original line number Diff line number Diff line
@@ -18,13 +18,13 @@ 
#include <asm/barrier.h>

#include <asm/byteorder.h>

#include <linux/atomic.h>

#include <linux/bitmap.h>

#include <linux/debugfs.h>

#include <linux/delay.h>

#include <linux/device.h>

#include <linux/dma-mapping.h>

#include <linux/dmapool.h>

#include <linux/err.h>

#include <linux/idr.h>

#include <linux/interrupt.h>

#include <linux/kernel.h>

#include <linux/mailbox_controller.h>
@@ -265,7 +265,6 @@ struct flexrm_ring { 
	cpumask_t irq_aff_hint;

	unsigned int msi_timer_val;

	unsigned int msi_count_threshold;

	struct ida requests_ida;

	struct brcm_message *requests[RING_MAX_REQ_COUNT];

	void *bd_base;

	dma_addr_t bd_dma_base;
@@ -277,6 +276,7 @@ struct flexrm_ring { 
	atomic_t msg_cmpl_count;

	/* Protected members */

	spinlock_t lock;

	DECLARE_BITMAP(requests_bmap, RING_MAX_REQ_COUNT);

	struct brcm_message *last_pending_msg;

	u32 cmpl_read_offset;

};
@@ -994,10 +994,10 @@ static int flexrm_new_request(struct flexrm_ring *ring, 
	msg->error = 0;



	/* If no requests possible then save data pointer and goto done. */

	reqid = ida_simple_get(&ring->requests_ida, 0,

				RING_MAX_REQ_COUNT, GFP_KERNEL);

	if (reqid < 0) {

	spin_lock_irqsave(&ring->lock, flags);

	reqid = bitmap_find_free_region(ring->requests_bmap,

					RING_MAX_REQ_COUNT, 0);

	if (reqid < 0) {

		if (batch_msg)

			ring->last_pending_msg = batch_msg;

		else
@@ -1005,13 +1005,16 @@ static int flexrm_new_request(struct flexrm_ring *ring, 
		spin_unlock_irqrestore(&ring->lock, flags);

		return 0;

	}

	spin_unlock_irqrestore(&ring->lock, flags);

	ring->requests[reqid] = msg;



	/* Do DMA mappings for the message */

	ret = flexrm_dma_map(ring->mbox->dev, msg);

	if (ret < 0) {

		ring->requests[reqid] = NULL;

		ida_simple_remove(&ring->requests_ida, reqid);

		spin_lock_irqsave(&ring->lock, flags);

		bitmap_release_region(ring->requests_bmap, reqid, 0);

		spin_unlock_irqrestore(&ring->lock, flags);

		return ret;

	}
@@ -1088,7 +1091,9 @@ static int flexrm_new_request(struct flexrm_ring *ring, 
	if (exit_cleanup) {

		flexrm_dma_unmap(ring->mbox->dev, msg);

		ring->requests[reqid] = NULL;

		ida_simple_remove(&ring->requests_ida, reqid);

		spin_lock_irqsave(&ring->lock, flags);

		bitmap_release_region(ring->requests_bmap, reqid, 0);

		spin_unlock_irqrestore(&ring->lock, flags);

	}



	return ret;
@@ -1163,7 +1168,9 @@ static int flexrm_process_completions(struct flexrm_ring *ring) 


		/* Release reqid for recycling */

		ring->requests[reqid] = NULL;

		ida_simple_remove(&ring->requests_ida, reqid);

		spin_lock_irqsave(&ring->lock, flags);

		bitmap_release_region(ring->requests_bmap, reqid, 0);

		spin_unlock_irqrestore(&ring->lock, flags);



		/* Unmap DMA mappings */

		flexrm_dma_unmap(ring->mbox->dev, msg);
@@ -1414,7 +1421,6 @@ static void flexrm_shutdown(struct mbox_chan *chan) 


		/* Release reqid for recycling */

		ring->requests[reqid] = NULL;

		ida_simple_remove(&ring->requests_ida, reqid);



		/* Unmap DMA mappings */

		flexrm_dma_unmap(ring->mbox->dev, msg);
@@ -1424,6 +1430,9 @@ static void flexrm_shutdown(struct mbox_chan *chan) 
		mbox_chan_received_data(chan, msg);

	}



	/* Clear requests bitmap */

	bitmap_zero(ring->requests_bmap, RING_MAX_REQ_COUNT);



	/* Release IRQ */

	if (ring->irq_requested) {

		irq_set_affinity_hint(ring->irq, NULL);
@@ -1581,7 +1590,6 @@ static int flexrm_mbox_probe(struct platform_device *pdev) 
		ring->irq_requested = false;

		ring->msi_timer_val = MSI_TIMER_VAL_MASK;

		ring->msi_count_threshold = 0x1;

		ida_init(&ring->requests_ida);

		memset(ring->requests, 0, sizeof(ring->requests));

		ring->bd_base = NULL;

		ring->bd_dma_base = 0;
@@ -1590,6 +1598,7 @@ static int flexrm_mbox_probe(struct platform_device *pdev) 
		atomic_set(&ring->msg_send_count, 0);

		atomic_set(&ring->msg_cmpl_count, 0);

		spin_lock_init(&ring->lock);

		bitmap_zero(ring->requests_bmap, RING_MAX_REQ_COUNT);

		ring->last_pending_msg = NULL;

		ring->cmpl_read_offset = 0;

	}
@@ -1701,9 +1710,7 @@ static int flexrm_mbox_probe(struct platform_device *pdev) 


static int flexrm_mbox_remove(struct platform_device *pdev)

{

	int index;

	struct device *dev = &pdev->dev;

	struct flexrm_ring *ring;

	struct flexrm_mbox *mbox = platform_get_drvdata(pdev);



	mbox_controller_unregister(&mbox->controller);
@@ -1715,11 +1722,6 @@ static int flexrm_mbox_remove(struct platform_device *pdev) 
	dma_pool_destroy(mbox->cmpl_pool);

	dma_pool_destroy(mbox->bd_pool);



	for (index = 0; index < mbox->num_rings; index++) {

		ring = &mbox->rings[index];

		ida_destroy(&ring->requests_ida);

	}



	return 0;

}