Merge "mmc: host: Add Ring buffer logging for MMC." (7280bd07) · Commits · e / devices / android_kernel_sony_msm8998

drivers/mmc/core/Kconfig

+11 −0

Original line number	Diff line number	Diff line
		@@ -2,6 +2,17 @@
		# MMC core configuration
		#

		config MMC_RING_BUFFER
		bool "MMC_RING_BUFFER"
		depends on MMC
		default n
		help
		This enables the ring buffer tracing of significant
		events for mmc driver to provide command history for
		debugging purpose.

		If unsure, say N.

		config MMC_EMBEDDED_SDIO
		boolean "MMC embedded SDIO device support (EXPERIMENTAL)"
		help

drivers/mmc/core/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -10,3 +10,4 @@ mmc_core-y := core.o bus.o host.o \
		quirks.o slot-gpio.o
		mmc_core-$(CONFIG_OF) += pwrseq.o pwrseq_simple.o pwrseq_emmc.o
		mmc_core-$(CONFIG_DEBUG_FS) += debugfs.o
		obj-$(CONFIG_MMC_RING_BUFFER) += ring_buffer.o

drivers/mmc/core/host.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -26,6 +26,8 @@

		#include <linux/mmc/host.h>
		#include <linux/mmc/card.h>
		#include <linux/mmc/ring_buffer.h>

		#include <linux/mmc/slot-gpio.h>

		#include "core.h"
		@@ -869,6 +871,7 @@ int mmc_add_host(struct mmc_host *host)
		mmc_add_host_debugfs(host);
		#endif
		mmc_host_clk_sysfs_init(host);
		mmc_trace_init(host);

		err = sysfs_create_group(&host->class_dev.kobj, &clk_scaling_attr_grp);
		if (err)

drivers/mmc/core/ring_buffer.c

0 → 100644

+123 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (c) 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
		* only version 2 as published by the Free Software Foundation.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*/

		#include <linux/mmc/ring_buffer.h>
		#include <linux/mmc/host.h>

		void mmc_stop_tracing(struct mmc_host *mmc)
		{
		mmc->trace_buf.stop_tracing = true;
		}

		void mmc_trace_write(struct mmc_host *mmc,
		const char *fmt, ...)
		{
		unsigned int idx;
		va_list args;
		char *event;
		unsigned long flags;
		char str[MMC_TRACE_EVENT_SZ];

		if (unlikely(!mmc->trace_buf.data) \|\|
		unlikely(mmc->trace_buf.stop_tracing))
		return;

		/*
		* Here an increment and modulus is used to keep
		* index within array bounds. The cast to unsigned is
		* necessary so increment and rolover wraps to 0 correctly
		*/
		spin_lock_irqsave(&mmc->trace_buf.trace_lock, flags);
		mmc->trace_buf.wr_idx += 1;
		idx = ((unsigned int)mmc->trace_buf.wr_idx) &
		(MMC_TRACE_RBUF_NUM_EVENTS - 1);
		spin_unlock_irqrestore(&mmc->trace_buf.trace_lock, flags);

		/* Catch some unlikely machine specific wrap-around bug */
		if (unlikely(idx > (MMC_TRACE_RBUF_NUM_EVENTS - 1))) {
		pr_err("%s: %s: Invalid idx:%d for mmc trace, tracing stopped !\n",
		mmc_hostname(mmc), __func__, idx);
		mmc_stop_tracing(mmc);
		return;
		}

		event = &mmc->trace_buf.data[idx * MMC_TRACE_EVENT_SZ];
		va_start(args, fmt);
		snprintf(str, MMC_TRACE_EVENT_SZ, "<%d> %lld: %s: %s",
		raw_smp_processor_id(),
		ktime_to_ns(ktime_get()),
		mmc_hostname(mmc), fmt);
		memset(event, '\0', MMC_TRACE_EVENT_SZ);
		vscnprintf(event, MMC_TRACE_EVENT_SZ, str, args);
		va_end(args);
		}

		void mmc_trace_init(struct mmc_host *mmc)
		{
		BUILD_BUG_ON_NOT_POWER_OF_2(MMC_TRACE_RBUF_NUM_EVENTS);

		mmc->trace_buf.data = (char *)
		__get_free_pages(GFP_KERNEL\|__GFP_ZERO,
		MMC_TRACE_RBUF_SZ_ORDER);

		if (!mmc->trace_buf.data) {
		pr_err("%s: %s: Unable to allocate trace for mmc\n",
		__func__, mmc_hostname(mmc));
		return;
		}

		spin_lock_init(&mmc->trace_buf.trace_lock);
		mmc->trace_buf.wr_idx = -1;
		}

		void mmc_trace_free(struct mmc_host *mmc)
		{
		if (mmc->trace_buf.data)
		free_pages((unsigned long)mmc->trace_buf.data,
		MMC_TRACE_RBUF_SZ_ORDER);
		}

		void mmc_dump_trace_buffer(struct mmc_host mmc, struct seq_file s)
		{
		unsigned int idx, cur_idx;
		unsigned int N = MMC_TRACE_RBUF_NUM_EVENTS - 1;
		char *event;
		unsigned long flags;

		if (!mmc->trace_buf.data)
		return;

		spin_lock_irqsave(&mmc->trace_buf.trace_lock, flags);
		idx = ((unsigned int)mmc->trace_buf.wr_idx) & N;
		cur_idx = (idx + 1) & N;

		do {
		event = &mmc->trace_buf.data[cur_idx * MMC_TRACE_EVENT_SZ];
		if (s)
		seq_printf(s, "%s", (char *)event);
		else
		pr_err("%s", (char *)event);
		cur_idx = (cur_idx + 1) & N;
		if (cur_idx == idx) {
		event =
		&mmc->trace_buf.data[cur_idx * MMC_TRACE_EVENT_SZ];
		if (s)
		seq_printf(s, "latest_event: %s",
		(char *)event);
		else
		pr_err("latest_event: %s", (char *)event);
		break;
		}
		} while (1);
		spin_unlock_irqrestore(&mmc->trace_buf.trace_lock, flags);
		}

include/linux/mmc/host.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -22,6 +22,7 @@
		#include <linux/mmc/core.h>
		#include <linux/mmc/card.h>
		#include <linux/mmc/pm.h>
		#include <linux/mmc/ring_buffer.h>

		#define MMC_AUTOSUSPEND_DELAY_MS 3000

		@@ -571,6 +572,7 @@ struct mmc_host {
		} perf;
		bool perf_enable;
		#endif
		struct mmc_trace_buffer trace_buf;
		enum dev_state dev_status;
		bool wakeup_on_idle;
		struct mmc_cmdq_context_info cmdq_ctx;