Merge "coresight: stm: Remove spin lock usage for channel allocation" (4d7cba74) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/hwtracing/coresight/coresight-ost.c

+26 −15

Original line number	Diff line number	Diff line
		/* Copyright (c) 2012-2016, The Linux Foundation. All rights reserved.
		/* Copyright (c) 2012-2017, The Linux Foundation. All rights reserved.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 and
		@@ -30,19 +30,26 @@

		static struct stm_drvdata *stmdrvdata;

		static uint32_t stm_channel_alloc(uint32_t off)
		static uint32_t stm_channel_alloc(void)
		{
		struct stm_drvdata *drvdata = stmdrvdata;
		uint32_t ch;
		unsigned long flags;
		uint32_t ch, off, num_ch_per_cpu;
		int cpu;

		num_ch_per_cpu = drvdata->numsp/num_present_cpus();

		spin_lock_irqsave(&drvdata->spinlock, flags);
		do {
		cpu = get_cpu();

		off = num_ch_per_cpu * cpu;
		ch = find_next_zero_bit(drvdata->chs.bitmap,
		drvdata->numsp, off);
		} while ((ch < drvdata->numsp) &&
		test_and_set_bit(ch, drvdata->chs.bitmap));
		spin_unlock_irqrestore(&drvdata->spinlock, flags);
		if (unlikely(ch >= (off + num_ch_per_cpu))) {
		put_cpu();
		return drvdata->numsp;
		}

		set_bit(ch, drvdata->chs.bitmap);
		put_cpu();

		return ch;
		}
		@@ -65,11 +72,8 @@ static int stm_ost_send(void addr, const void data, uint32_t count)
		static void stm_channel_free(uint32_t ch)
		{
		struct stm_drvdata *drvdata = stmdrvdata;
		unsigned long flags;

		spin_lock_irqsave(&drvdata->spinlock, flags);
		clear_bit(ch, drvdata->chs.bitmap);
		spin_unlock_irqrestore(&drvdata->spinlock, flags);
		}

		static int stm_trace_ost_header(unsigned long ch_addr, uint32_t flags,
		@@ -146,7 +150,14 @@ static inline int __stm_trace(uint32_t flags, uint8_t entity_id,
		unsigned long ch_addr;

		/* allocate channel and get the channel address */
		ch = stm_channel_alloc(0);
		ch = stm_channel_alloc();
		if (unlikely(ch >= drvdata->numsp)) {
		drvdata->ch_alloc_fail_count++;
		dev_err_ratelimited(drvdata->dev,
		"Channel allocation failed %d",
		drvdata->ch_alloc_fail_count);
		return 0;
		}

		ch_addr = (unsigned long)stm_channel_addr(drvdata, ch);

drivers/hwtracing/coresight/coresight-stm.c

+2 −2

Original line number	Diff line number	Diff line
		/* Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
		/* Copyright (c) 2015-2017, The Linux Foundation. All rights reserved.
		*
		* Description: CoreSight System Trace Macrocell driver
		*
		@@ -729,7 +729,7 @@ static u32 stm_num_stimulus_port(struct stm_drvdata *drvdata)
		numsp &= 0x1ffff;
		if (!numsp)
		numsp = STM_32_CHANNEL;
		return numsp;
		return STM_32_CHANNEL;
		}

		static void stm_init_default_data(struct stm_drvdata *drvdata)

include/linux/coresight-stm.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -70,6 +70,7 @@ struct channel_space {
		* @stmheer: settings for register STMHEER.
		* @stmheter: settings for register STMHETER.
		* @stmhebsr: settings for register STMHEBSR.
		* @ch_alloc_fail_count: Number of ch allocation failures over time.
		*/
		struct stm_drvdata {
		void __iomem *base;
		@@ -90,6 +91,7 @@ struct stm_drvdata {
		u32 stmheer;
		u32 stmheter;
		u32 stmhebsr;
		u32 ch_alloc_fail_count;
		};

		#ifdef CONFIG_CORESIGHT_STM