988257cfcb
The first read from ETM OS save and restore register after the power down bit deassertion returns garbage. Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Alexander Shishkin <virtuoso@slind.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
644 lines
13 KiB
C
644 lines
13 KiB
C
/*
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* linux/arch/arm/kernel/etm.c
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*
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* Driver for ARM's Embedded Trace Macrocell and Embedded Trace Buffer.
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*
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* Copyright (C) 2009 Nokia Corporation.
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* Alexander Shishkin
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/io.h>
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#include <linux/sysrq.h>
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#include <linux/device.h>
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#include <linux/clk.h>
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#include <linux/amba/bus.h>
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#include <linux/fs.h>
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#include <linux/uaccess.h>
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#include <linux/miscdevice.h>
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#include <linux/vmalloc.h>
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#include <linux/mutex.h>
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#include <asm/hardware/coresight.h>
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#include <asm/sections.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Alexander Shishkin");
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static struct tracectx tracer;
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static inline bool trace_isrunning(struct tracectx *t)
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{
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return !!(t->flags & TRACER_RUNNING);
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}
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static int etm_setup_address_range(struct tracectx *t, int n,
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unsigned long start, unsigned long end, int exclude, int data)
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{
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u32 flags = ETMAAT_ARM | ETMAAT_IGNCONTEXTID | ETMAAT_NSONLY | \
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ETMAAT_NOVALCMP;
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if (n < 1 || n > t->ncmppairs)
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return -EINVAL;
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/* comparators and ranges are numbered starting with 1 as opposed
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* to bits in a word */
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n--;
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if (data)
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flags |= ETMAAT_DLOADSTORE;
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else
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flags |= ETMAAT_IEXEC;
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/* first comparator for the range */
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etm_writel(t, flags, ETMR_COMP_ACC_TYPE(n * 2));
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etm_writel(t, start, ETMR_COMP_VAL(n * 2));
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/* second comparator is right next to it */
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etm_writel(t, flags, ETMR_COMP_ACC_TYPE(n * 2 + 1));
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etm_writel(t, end, ETMR_COMP_VAL(n * 2 + 1));
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flags = exclude ? ETMTE_INCLEXCL : 0;
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etm_writel(t, flags | (1 << n), ETMR_TRACEENCTRL);
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return 0;
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}
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static int trace_start(struct tracectx *t)
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{
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u32 v;
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unsigned long timeout = TRACER_TIMEOUT;
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etb_unlock(t);
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etb_writel(t, 0, ETBR_FORMATTERCTRL);
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etb_writel(t, 1, ETBR_CTRL);
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etb_lock(t);
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/* configure etm */
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v = ETMCTRL_OPTS | ETMCTRL_PROGRAM | ETMCTRL_PORTSIZE(t->etm_portsz);
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if (t->flags & TRACER_CYCLE_ACC)
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v |= ETMCTRL_CYCLEACCURATE;
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etm_unlock(t);
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etm_writel(t, v, ETMR_CTRL);
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while (!(etm_readl(t, ETMR_CTRL) & ETMCTRL_PROGRAM) && --timeout)
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;
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if (!timeout) {
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dev_dbg(t->dev, "Waiting for progbit to assert timed out\n");
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etm_lock(t);
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return -EFAULT;
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}
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etm_setup_address_range(t, 1, (unsigned long)_stext,
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(unsigned long)_etext, 0, 0);
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etm_writel(t, 0, ETMR_TRACEENCTRL2);
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etm_writel(t, 0, ETMR_TRACESSCTRL);
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etm_writel(t, 0x6f, ETMR_TRACEENEVT);
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v &= ~ETMCTRL_PROGRAM;
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v |= ETMCTRL_PORTSEL;
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etm_writel(t, v, ETMR_CTRL);
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timeout = TRACER_TIMEOUT;
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while (etm_readl(t, ETMR_CTRL) & ETMCTRL_PROGRAM && --timeout)
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;
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if (!timeout) {
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dev_dbg(t->dev, "Waiting for progbit to deassert timed out\n");
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etm_lock(t);
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return -EFAULT;
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}
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etm_lock(t);
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t->flags |= TRACER_RUNNING;
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return 0;
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}
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static int trace_stop(struct tracectx *t)
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{
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unsigned long timeout = TRACER_TIMEOUT;
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etm_unlock(t);
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etm_writel(t, 0x440, ETMR_CTRL);
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while (!(etm_readl(t, ETMR_CTRL) & ETMCTRL_PROGRAM) && --timeout)
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;
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if (!timeout) {
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dev_dbg(t->dev, "Waiting for progbit to assert timed out\n");
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etm_lock(t);
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return -EFAULT;
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}
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etm_lock(t);
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etb_unlock(t);
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etb_writel(t, ETBFF_MANUAL_FLUSH, ETBR_FORMATTERCTRL);
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timeout = TRACER_TIMEOUT;
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while (etb_readl(t, ETBR_FORMATTERCTRL) &
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ETBFF_MANUAL_FLUSH && --timeout)
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;
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if (!timeout) {
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dev_dbg(t->dev, "Waiting for formatter flush to commence "
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"timed out\n");
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etb_lock(t);
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return -EFAULT;
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}
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etb_writel(t, 0, ETBR_CTRL);
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etb_lock(t);
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t->flags &= ~TRACER_RUNNING;
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return 0;
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}
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static int etb_getdatalen(struct tracectx *t)
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{
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u32 v;
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int rp, wp;
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v = etb_readl(t, ETBR_STATUS);
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if (v & 1)
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return t->etb_bufsz;
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rp = etb_readl(t, ETBR_READADDR);
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wp = etb_readl(t, ETBR_WRITEADDR);
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if (rp > wp) {
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etb_writel(t, 0, ETBR_READADDR);
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etb_writel(t, 0, ETBR_WRITEADDR);
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return 0;
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}
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return wp - rp;
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}
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/* sysrq+v will always stop the running trace and leave it at that */
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static void etm_dump(void)
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{
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struct tracectx *t = &tracer;
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u32 first = 0;
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int length;
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if (!t->etb_regs) {
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printk(KERN_INFO "No tracing hardware found\n");
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return;
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}
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if (trace_isrunning(t))
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trace_stop(t);
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etb_unlock(t);
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length = etb_getdatalen(t);
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if (length == t->etb_bufsz)
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first = etb_readl(t, ETBR_WRITEADDR);
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etb_writel(t, first, ETBR_READADDR);
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printk(KERN_INFO "Trace buffer contents length: %d\n", length);
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printk(KERN_INFO "--- ETB buffer begin ---\n");
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for (; length; length--)
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printk("%08x", cpu_to_be32(etb_readl(t, ETBR_READMEM)));
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printk(KERN_INFO "\n--- ETB buffer end ---\n");
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/* deassert the overflow bit */
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etb_writel(t, 1, ETBR_CTRL);
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etb_writel(t, 0, ETBR_CTRL);
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etb_writel(t, 0, ETBR_TRIGGERCOUNT);
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etb_writel(t, 0, ETBR_READADDR);
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etb_writel(t, 0, ETBR_WRITEADDR);
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etb_lock(t);
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}
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static void sysrq_etm_dump(int key, struct tty_struct *tty)
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{
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dev_dbg(tracer.dev, "Dumping ETB buffer\n");
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etm_dump();
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}
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static struct sysrq_key_op sysrq_etm_op = {
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.handler = sysrq_etm_dump,
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.help_msg = "ETM buffer dump",
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.action_msg = "etm",
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};
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static int etb_open(struct inode *inode, struct file *file)
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{
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if (!tracer.etb_regs)
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return -ENODEV;
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file->private_data = &tracer;
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return nonseekable_open(inode, file);
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}
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static ssize_t etb_read(struct file *file, char __user *data,
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size_t len, loff_t *ppos)
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{
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int total, i;
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long length;
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struct tracectx *t = file->private_data;
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u32 first = 0;
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u32 *buf;
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mutex_lock(&t->mutex);
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if (trace_isrunning(t)) {
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length = 0;
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goto out;
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}
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etb_unlock(t);
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total = etb_getdatalen(t);
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if (total == t->etb_bufsz)
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first = etb_readl(t, ETBR_WRITEADDR);
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etb_writel(t, first, ETBR_READADDR);
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length = min(total * 4, (int)len);
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buf = vmalloc(length);
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dev_dbg(t->dev, "ETB buffer length: %d\n", total);
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dev_dbg(t->dev, "ETB status reg: %x\n", etb_readl(t, ETBR_STATUS));
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for (i = 0; i < length / 4; i++)
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buf[i] = etb_readl(t, ETBR_READMEM);
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/* the only way to deassert overflow bit in ETB status is this */
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etb_writel(t, 1, ETBR_CTRL);
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etb_writel(t, 0, ETBR_CTRL);
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etb_writel(t, 0, ETBR_WRITEADDR);
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etb_writel(t, 0, ETBR_READADDR);
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etb_writel(t, 0, ETBR_TRIGGERCOUNT);
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etb_lock(t);
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length -= copy_to_user(data, buf, length);
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vfree(buf);
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out:
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mutex_unlock(&t->mutex);
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return length;
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}
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static int etb_release(struct inode *inode, struct file *file)
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{
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/* there's nothing to do here, actually */
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return 0;
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}
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static const struct file_operations etb_fops = {
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.owner = THIS_MODULE,
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.read = etb_read,
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.open = etb_open,
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.release = etb_release,
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};
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static struct miscdevice etb_miscdev = {
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.name = "tracebuf",
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.minor = 0,
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.fops = &etb_fops,
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};
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static int __init etb_probe(struct amba_device *dev, struct amba_id *id)
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{
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struct tracectx *t = &tracer;
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int ret = 0;
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ret = amba_request_regions(dev, NULL);
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if (ret)
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goto out;
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t->etb_regs = ioremap_nocache(dev->res.start, resource_size(&dev->res));
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if (!t->etb_regs) {
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ret = -ENOMEM;
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goto out_release;
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}
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amba_set_drvdata(dev, t);
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etb_miscdev.parent = &dev->dev;
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ret = misc_register(&etb_miscdev);
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if (ret)
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goto out_unmap;
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t->emu_clk = clk_get(&dev->dev, "emu_src_ck");
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if (IS_ERR(t->emu_clk)) {
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dev_dbg(&dev->dev, "Failed to obtain emu_src_ck.\n");
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return -EFAULT;
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}
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clk_enable(t->emu_clk);
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etb_unlock(t);
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t->etb_bufsz = etb_readl(t, ETBR_DEPTH);
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dev_dbg(&dev->dev, "Size: %x\n", t->etb_bufsz);
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/* make sure trace capture is disabled */
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etb_writel(t, 0, ETBR_CTRL);
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etb_writel(t, 0x1000, ETBR_FORMATTERCTRL);
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etb_lock(t);
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dev_dbg(&dev->dev, "ETB AMBA driver initialized.\n");
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out:
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return ret;
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out_unmap:
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amba_set_drvdata(dev, NULL);
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iounmap(t->etb_regs);
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out_release:
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amba_release_regions(dev);
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return ret;
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}
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static int etb_remove(struct amba_device *dev)
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{
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struct tracectx *t = amba_get_drvdata(dev);
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amba_set_drvdata(dev, NULL);
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iounmap(t->etb_regs);
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t->etb_regs = NULL;
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clk_disable(t->emu_clk);
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clk_put(t->emu_clk);
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amba_release_regions(dev);
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return 0;
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}
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static struct amba_id etb_ids[] = {
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{
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.id = 0x0003b907,
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.mask = 0x0007ffff,
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},
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{ 0, 0 },
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};
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static struct amba_driver etb_driver = {
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.drv = {
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.name = "etb",
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.owner = THIS_MODULE,
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},
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.probe = etb_probe,
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.remove = etb_remove,
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.id_table = etb_ids,
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};
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/* use a sysfs file "trace_running" to start/stop tracing */
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static ssize_t trace_running_show(struct kobject *kobj,
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struct kobj_attribute *attr,
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char *buf)
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{
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return sprintf(buf, "%x\n", trace_isrunning(&tracer));
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}
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static ssize_t trace_running_store(struct kobject *kobj,
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struct kobj_attribute *attr,
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const char *buf, size_t n)
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{
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unsigned int value;
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int ret;
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if (sscanf(buf, "%u", &value) != 1)
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return -EINVAL;
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mutex_lock(&tracer.mutex);
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ret = value ? trace_start(&tracer) : trace_stop(&tracer);
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mutex_unlock(&tracer.mutex);
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return ret ? : n;
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}
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static struct kobj_attribute trace_running_attr =
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__ATTR(trace_running, 0644, trace_running_show, trace_running_store);
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static ssize_t trace_info_show(struct kobject *kobj,
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struct kobj_attribute *attr,
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char *buf)
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{
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u32 etb_wa, etb_ra, etb_st, etb_fc, etm_ctrl, etm_st;
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int datalen;
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etb_unlock(&tracer);
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datalen = etb_getdatalen(&tracer);
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etb_wa = etb_readl(&tracer, ETBR_WRITEADDR);
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etb_ra = etb_readl(&tracer, ETBR_READADDR);
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etb_st = etb_readl(&tracer, ETBR_STATUS);
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etb_fc = etb_readl(&tracer, ETBR_FORMATTERCTRL);
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etb_lock(&tracer);
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etm_unlock(&tracer);
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etm_ctrl = etm_readl(&tracer, ETMR_CTRL);
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etm_st = etm_readl(&tracer, ETMR_STATUS);
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etm_lock(&tracer);
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return sprintf(buf, "Trace buffer len: %d\nComparator pairs: %d\n"
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"ETBR_WRITEADDR:\t%08x\n"
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"ETBR_READADDR:\t%08x\n"
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"ETBR_STATUS:\t%08x\n"
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"ETBR_FORMATTERCTRL:\t%08x\n"
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"ETMR_CTRL:\t%08x\n"
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"ETMR_STATUS:\t%08x\n",
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datalen,
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tracer.ncmppairs,
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etb_wa,
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etb_ra,
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etb_st,
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etb_fc,
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etm_ctrl,
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etm_st
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);
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}
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static struct kobj_attribute trace_info_attr =
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__ATTR(trace_info, 0444, trace_info_show, NULL);
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static ssize_t trace_mode_show(struct kobject *kobj,
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struct kobj_attribute *attr,
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char *buf)
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{
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return sprintf(buf, "%d %d\n",
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!!(tracer.flags & TRACER_CYCLE_ACC),
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tracer.etm_portsz);
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}
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static ssize_t trace_mode_store(struct kobject *kobj,
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struct kobj_attribute *attr,
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const char *buf, size_t n)
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{
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unsigned int cycacc, portsz;
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if (sscanf(buf, "%u %u", &cycacc, &portsz) != 2)
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return -EINVAL;
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mutex_lock(&tracer.mutex);
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if (cycacc)
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tracer.flags |= TRACER_CYCLE_ACC;
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else
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tracer.flags &= ~TRACER_CYCLE_ACC;
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tracer.etm_portsz = portsz & 0x0f;
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mutex_unlock(&tracer.mutex);
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return n;
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}
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static struct kobj_attribute trace_mode_attr =
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__ATTR(trace_mode, 0644, trace_mode_show, trace_mode_store);
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static int __init etm_probe(struct amba_device *dev, struct amba_id *id)
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{
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struct tracectx *t = &tracer;
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int ret = 0;
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if (t->etm_regs) {
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dev_dbg(&dev->dev, "ETM already initialized\n");
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ret = -EBUSY;
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goto out;
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}
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ret = amba_request_regions(dev, NULL);
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if (ret)
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goto out;
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t->etm_regs = ioremap_nocache(dev->res.start, resource_size(&dev->res));
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if (!t->etm_regs) {
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ret = -ENOMEM;
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goto out_release;
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}
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amba_set_drvdata(dev, t);
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|
|
mutex_init(&t->mutex);
|
|
t->dev = &dev->dev;
|
|
t->flags = TRACER_CYCLE_ACC;
|
|
t->etm_portsz = 1;
|
|
|
|
etm_unlock(t);
|
|
(void)etm_readl(t, ETMMR_PDSR);
|
|
/* dummy first read */
|
|
(void)etm_readl(&tracer, ETMMR_OSSRR);
|
|
|
|
t->ncmppairs = etm_readl(t, ETMR_CONFCODE) & 0xf;
|
|
etm_writel(t, 0x440, ETMR_CTRL);
|
|
etm_lock(t);
|
|
|
|
ret = sysfs_create_file(&dev->dev.kobj,
|
|
&trace_running_attr.attr);
|
|
if (ret)
|
|
goto out_unmap;
|
|
|
|
/* failing to create any of these two is not fatal */
|
|
ret = sysfs_create_file(&dev->dev.kobj, &trace_info_attr.attr);
|
|
if (ret)
|
|
dev_dbg(&dev->dev, "Failed to create trace_info in sysfs\n");
|
|
|
|
ret = sysfs_create_file(&dev->dev.kobj, &trace_mode_attr.attr);
|
|
if (ret)
|
|
dev_dbg(&dev->dev, "Failed to create trace_mode in sysfs\n");
|
|
|
|
dev_dbg(t->dev, "ETM AMBA driver initialized.\n");
|
|
|
|
out:
|
|
return ret;
|
|
|
|
out_unmap:
|
|
amba_set_drvdata(dev, NULL);
|
|
iounmap(t->etm_regs);
|
|
|
|
out_release:
|
|
amba_release_regions(dev);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int etm_remove(struct amba_device *dev)
|
|
{
|
|
struct tracectx *t = amba_get_drvdata(dev);
|
|
|
|
amba_set_drvdata(dev, NULL);
|
|
|
|
iounmap(t->etm_regs);
|
|
t->etm_regs = NULL;
|
|
|
|
amba_release_regions(dev);
|
|
|
|
sysfs_remove_file(&dev->dev.kobj, &trace_running_attr.attr);
|
|
sysfs_remove_file(&dev->dev.kobj, &trace_info_attr.attr);
|
|
sysfs_remove_file(&dev->dev.kobj, &trace_mode_attr.attr);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct amba_id etm_ids[] = {
|
|
{
|
|
.id = 0x0003b921,
|
|
.mask = 0x0007ffff,
|
|
},
|
|
{ 0, 0 },
|
|
};
|
|
|
|
static struct amba_driver etm_driver = {
|
|
.drv = {
|
|
.name = "etm",
|
|
.owner = THIS_MODULE,
|
|
},
|
|
.probe = etm_probe,
|
|
.remove = etm_remove,
|
|
.id_table = etm_ids,
|
|
};
|
|
|
|
static int __init etm_init(void)
|
|
{
|
|
int retval;
|
|
|
|
retval = amba_driver_register(&etb_driver);
|
|
if (retval) {
|
|
printk(KERN_ERR "Failed to register etb\n");
|
|
return retval;
|
|
}
|
|
|
|
retval = amba_driver_register(&etm_driver);
|
|
if (retval) {
|
|
amba_driver_unregister(&etb_driver);
|
|
printk(KERN_ERR "Failed to probe etm\n");
|
|
return retval;
|
|
}
|
|
|
|
/* not being able to install this handler is not fatal */
|
|
(void)register_sysrq_key('v', &sysrq_etm_op);
|
|
|
|
return 0;
|
|
}
|
|
|
|
device_initcall(etm_init);
|
|
|