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	Contrib clone of linux	matthias

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path: root/fs/file_table.c

Age	Commit message (Expand)	Author
2012-12-20	fs: Fix imbalance in freeze protection in mark_files_ro()	Jan Kara
2012-10-10	lglock: add DEFINE_STATIC_LGLOCK()	Lai Jiangshan
2012-10-02	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/...	Linus Torvalds
2012-09-26	take fget() and friends to fs/file.c	Al Viro
2012-09-07	vfs: move ima_file_free before releasing the file	Mimi Zohar
2012-07-31	fs: Add freezing handling to mnt_want_write() / mnt_drop_write()	Jan Kara
2012-07-29	uninline file_free_rcu()	Al Viro
2012-07-22	switch fput to task_work_add	Al Viro
2012-07-14	mark_files_ro(): don't bother with mntget/mntput	Al Viro
2012-05-29	brlocks/lglocks: API cleanups	Andi Kleen
2012-05-29	brlocks/lglocks: turn into functions	Andi Kleen
2012-03-20	vfs: drop_file_write_access() made static	Al Viro
2012-01-06	vfs: prevent remount read-only if pending removes	Miklos Szeredi
2011-07-26	atomic: use <linux/atomic.h>	Arun Sharma
2011-03-16	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vir...	Linus Torvalds
2011-03-16	fix cdev leak on O_PATH final fput()	Miklos Szeredi
2011-03-16	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmo...	Linus Torvalds
2011-03-15	Allow passing O_PATH descriptors via SCM_RIGHTS datagrams	Al Viro
2011-03-15	New kind of open files - "location only".	Al Viro
2011-03-08	Merge branch 'master'; commit 'v2.6.38-rc7' into next	James Morris
2011-02-10	IMA: maintain i_readcount in the VFS layer	Mimi Zohar
2011-02-04	CRED: Fix kernel panic upon security_file_alloc() failure.	Tetsuo Handa
2011-01-17	fs: Remove unlikely() from fget_light()	Steven Rostedt
2010-10-26	fs: allow for more than 2^31 files	Eric Dumazet
2010-08-18	fs: scale files_lock	Nick Piggin
2010-08-18	fs: cleanup files_lock locking	Nick Piggin
2010-08-12	Revert "fsnotify: store struct file not struct path"	Linus Torvalds
2010-08-11	vfs: improve comment describing fget_light()	Tony Battersby
2010-07-28	vfs/fsnotify: fsnotify_close can delay the final work in fput	Eric Paris
2010-05-27	get rid of the magic around f_count in aio	Al Viro
2010-03-06	vfs: take f_lock on modifying f_mode after open time	Wu Fengguang
2010-02-07	Take ima_file_free() to proper place.	Al Viro
2009-12-22	alloc_file(): simplify handling of mnt_clone_write() errors	Roland Dreier
2009-12-16	re-export alloc_file()	Roland Dreier
2009-12-16	Untangling ima mess, part 1: alloc_file()	Al Viro
2009-12-16	fs: move get_empty_filp() deffinition to internal.h	Eric Paris
2009-12-16	switch alloc_file() to passing struct path	Al Viro
2009-12-16	get rid of init_file()	Al Viro
2009-12-16	unexport get_empty_filp()	Al Viro
2009-10-25	LSM: imbed ima calls in the security hooks	Mimi Zohar
2009-09-24	sysctl: remove "struct file *" argument of ->proc_handler	Alexey Dobriyan
2009-06-11	fs: move mark_files_ro into file_table.c	npiggin@suse.de
2009-06-11	fs: introduce mnt_clone_write	npiggin@suse.de
2009-03-30	trivial: remove unused variable 'path' in alloc_file()	Tero Roponen
2009-03-26	Merge branch 'bkl-removal' of git://git.lwn.net/linux-2.6	Linus Torvalds
2009-03-16	Rename struct file->f_ep_lock	Jonathan Corbet
2009-02-06	Merge branch 'master' into next	James Morris
2009-02-06	integrity: IMA hooks	Mimi Zohar
2008-12-31	filp_cachep can be static in fs/file_table.c	Eric Dumazet
2008-11-14	CRED: Use creds in file structs	David Howells

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generated by cgit v1.2.3 (git 2.25.1) at 2024-09-11 11:31:27 +0000

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
 *
 * Description: CoreSight Embedded Trace Buffer driver
 */

#include <linux/atomic.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/pm_runtime.h>
#include <linux/seq_file.h>
#include <linux/coresight.h>
#include <linux/amba/bus.h>
#include <linux/clk.h>
#include <linux/circ_buf.h>
#include <linux/mm.h>
#include <linux/perf_event.h>


#include "coresight-priv.h"
#include "coresight-etm-perf.h"

#define ETB_RAM_DEPTH_REG	0x004
#define ETB_STATUS_REG		0x00c
#define ETB_RAM_READ_DATA_REG	0x010
#define ETB_RAM_READ_POINTER	0x014
#define ETB_RAM_WRITE_POINTER	0x018
#define ETB_TRG			0x01c
#define ETB_CTL_REG		0x020
#define ETB_RWD_REG		0x024
#define ETB_FFSR		0x300
#define ETB_FFCR		0x304
#define ETB_ITMISCOP0		0xee0
#define ETB_ITTRFLINACK		0xee4
#define ETB_ITTRFLIN		0xee8
#define ETB_ITATBDATA0		0xeeC
#define ETB_ITATBCTR2		0xef0
#define ETB_ITATBCTR1		0xef4
#define ETB_ITATBCTR0		0xef8

/* register description */
/* STS - 0x00C */
#define ETB_STATUS_RAM_FULL	BIT(0)
/* CTL - 0x020 */
#define ETB_CTL_CAPT_EN		BIT(0)
/* FFCR - 0x304 */
#define ETB_FFCR_EN_FTC		BIT(0)
#define ETB_FFCR_FON_MAN	BIT(6)
#define ETB_FFCR_STOP_FI	BIT(12)
#define ETB_FFCR_STOP_TRIGGER	BIT(13)

#define ETB_FFCR_BIT		6
#define ETB_FFSR_BIT		1
#define ETB_FRAME_SIZE_WORDS	4

DEFINE_CORESIGHT_DEVLIST(etb_devs, "etb");

/**
 * struct etb_drvdata - specifics associated to an ETB component
 * @base:	memory mapped base address for this component.
 * @atclk:	optional clock for the core parts of the ETB.
 * @csdev:	component vitals needed by the framework.
 * @miscdev:	specifics to handle "/dev/xyz.etb" entry.
 * @spinlock:	only one at a time pls.
 * @reading:	synchronise user space access to etb buffer.
 * @pid:	Process ID of the process being monitored by the session
 *		that is using this component.
 * @buf:	area of memory where ETB buffer content gets sent.
 * @mode:	this ETB is being used.
 * @buffer_depth: size of @buf.
 * @trigger_cntr: amount of words to store after a trigger.
 */
struct etb_drvdata {
	void __iomem		*base;
	struct clk		*atclk;
	struct coresight_device	*csdev;
	struct miscdevice	miscdev;
	spinlock_t		spinlock;
	local_t			reading;
	pid_t			pid;
	u8			*buf;
	u32			mode;
	u32			buffer_depth;
	u32			trigger_cntr;
};

static int etb_set_buffer(struct coresight_device *csdev,
			  struct perf_output_handle *handle);

static inline unsigned int etb_get_buffer_depth(struct etb_drvdata *drvdata)
{
	return readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
}

static void __etb_enable_hw(struct etb_drvdata *drvdata)
{
	int i;
	u32 depth;

	CS_UNLOCK(drvdata->base);

	depth = drvdata->buffer_depth;
	/* reset write RAM pointer address */
	writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
	/* clear entire RAM buffer */
	for (i = 0; i < depth; i++)
		writel_relaxed(0x0, drvdata->base + ETB_RWD_REG);

	/* reset write RAM pointer address */
	writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
	/* reset read RAM pointer address */
	writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);

	writel_relaxed(drvdata->trigger_cntr, drvdata->base + ETB_TRG);
	writel_relaxed(ETB_FFCR_EN_FTC | ETB_FFCR_STOP_TRIGGER,
		       drvdata->base + ETB_FFCR);
	/* ETB trace capture enable */
	writel_relaxed(ETB_CTL_CAPT_EN, drvdata->base + ETB_CTL_REG);

	CS_LOCK(drvdata->base);
}

static int etb_enable_hw(struct etb_drvdata *drvdata)
{
	int rc = coresight_claim_device(drvdata->base);

	if (rc)
		return rc;

	__etb_enable_hw(drvdata);
	return 0;
}

static int etb_enable_sysfs(struct coresight_device *csdev)
{
	int ret = 0;
	unsigned long flags;
	struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);

	spin_lock_irqsave(&drvdata->spinlock, flags);

	/* Don't messup with perf sessions. */
	if (drvdata->mode == CS_MODE_PERF) {
		ret = -EBUSY;
		goto out;
	}

	if (drvdata->mode == CS_MODE_DISABLED) {
		ret = etb_enable_hw(drvdata);
		if (ret)
			goto out;

		drvdata->mode = CS_MODE_SYSFS;
	}

	atomic_inc(csdev->refcnt);
out:
	spin_unlock_irqrestore(&drvdata->spinlock, flags);
	return ret;
}

static int etb_enable_perf(struct coresight_device *csdev, void *data)
{
	int ret = 0;
	pid_t pid;
	unsigned long flags;
	struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
	struct perf_output_handle *handle = data;

	spin_lock_irqsave(&drvdata->spinlock, flags);

	/* No need to continue if the component is already in used by sysFS. */
	if (drvdata->mode == CS_MODE_SYSFS) {
		ret = -EBUSY;
		goto out;
	}

	/* Get a handle on the pid of the process to monitor */
	pid = task_pid_nr(handle->event->owner);

	if (drvdata->pid != -1 && drvdata->pid != pid) {
		ret = -EBUSY;
		goto out;
	}

	/*
	 * No HW configuration is needed if the sink is already in
	 * use for this session.
	 */
	if (drvdata->pid == pid) {
		atomic_inc(csdev->refcnt);
		goto out;
	}

	/*
	 * We don't have an internal state to clean up if we fail to setup
	 * the perf buffer. So we can perform the step before we turn the
	 * ETB on and leave without cleaning up.
	 */
	ret = etb_set_buffer(csdev, handle);
	if (ret)
		goto out;

	ret = etb_enable_hw(drvdata);
	if (!ret) {
		/* Associate with monitored process. */
		drvdata->pid = pid;
		drvdata->mode = CS_MODE_PERF;
		atomic_inc(csdev->refcnt);
	}

out:
	spin_unlock_irqrestore(&drvdata->spinlock, flags);
	return ret;
}

static int