1 files changed, 390 insertions, 0 deletions

diff --git a/arch/mips/sibyte/sb1250/bcm1250_tbprof.c b/arch/mips/sibyte/sb1250/bcm1250_tbprof.c
new file mode 100644
index 000000000000..7f813ae9eaff
--- /dev/null
+++ b/arch/mips/sibyte/sb1250/bcm1250_tbprof.c
@@ -0,0 +1,390 @@
+/*
+ * Copyright (C) 2001, 2002, 2003 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#define SBPROF_TB_DEBUG 0
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/reboot.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/sibyte/sb1250.h>
+#include <asm/sibyte/sb1250_regs.h>
+#include <asm/sibyte/sb1250_scd.h>
+#include <asm/sibyte/sb1250_int.h>
+#include <asm/sibyte/trace_prof.h>
+
+#define DEVNAME "bcm1250_tbprof"
+
+static struct sbprof_tb sbp;
+
+#define TB_FULL (sbp.next_tb_sample == MAX_TB_SAMPLES)
+
+/************************************************************************
+ * Support for ZBbus sampling using the trace buffer
+ *
+ * We use the SCD performance counter interrupt, caused by a Zclk counter
+ * overflow, to trigger the start of tracing.
+ *
+ * We set the trace buffer to sample everything and freeze on
+ * overflow.
+ *
+ * We map the interrupt for trace_buffer_freeze to handle it on CPU 0.
+ *
+ ************************************************************************/
+
+static u_int64_t tb_period;
+
+static void arm_tb(void)
+{
+        u_int64_t scdperfcnt;
+        u_int64_t next = (1ULL << 40) - tb_period;
+        u_int64_t tb_options = M_SCD_TRACE_CFG_FREEZE_FULL;
+        /* Generate an SCD_PERFCNT interrupt in TB_PERIOD Zclks to
+           trigger start of trace.  XXX vary sampling period */
+        bus_writeq(0, IOADDR(A_SCD_PERF_CNT_1));
+        scdperfcnt = bus_readq(IOADDR(A_SCD_PERF_CNT_CFG));
+        /* Unfortunately, in Pass 2 we must clear all counters to knock down
+           a previous interrupt request.  This means that bus profiling
+           requires ALL of the SCD perf counters. */
+        bus_writeq((scdperfcnt & ~M_SPC_CFG_SRC1) | // keep counters 0,2,3 as is
+                   M_SPC_CFG_ENABLE |            // enable counting
+                   M_SPC_CFG_CLEAR |             // clear all counters
+                   V_SPC_CFG_SRC1(1),            // counter 1 counts cycles
+                   IOADDR(A_SCD_PERF_CNT_CFG));
+        bus_writeq(next, IOADDR(A_SCD_PERF_CNT_1));
+        /* Reset the trace buffer */
+        bus_writeq(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
+#if 0 && defined(M_SCD_TRACE_CFG_FORCECNT)
+        /* XXXKW may want to expose control to the data-collector */
+        tb_options |= M_SCD_TRACE_CFG_FORCECNT;
+#endif
+        bus_writeq(tb_options, IOADDR(A_SCD_TRACE_CFG));
+        sbp.tb_armed = 1;
+}
+
+static irqreturn_t sbprof_tb_intr(int irq, void *dev_id, struct pt_regs *regs)
+{
+        int i;
+        DBG(printk(DEVNAME ": tb_intr\n"));
+        if (sbp.next_tb_sample < MAX_TB_SAMPLES) {
+                /* XXX should use XKPHYS to make writes bypass L2 */
+                u_int64_t *p = sbp.sbprof_tbbuf[sbp.next_tb_sample++];
+                /* Read out trace */
+                bus_writeq(M_SCD_TRACE_CFG_START_READ, IOADDR(A_SCD_TRACE_CFG));
+                __asm__ __volatile__ ("sync" : : : "memory");
+                /* Loop runs backwards because bundles are read out in reverse order */
+                for (i = 256 * 6; i > 0; i -= 6) {
+                        // Subscripts decrease to put bundle in the order
+                        //   t0 lo, t0 hi, t1 lo, t1 hi, t2 lo, t2 hi
+                        p[i-1] = bus_readq(IOADDR(A_SCD_TRACE_READ)); // read t2 hi
+                        p[i-2] = bus_readq(IOADDR(A_SCD_TRACE_READ)); // read t2 lo
+                        p[i-3] = bus_readq(IOADDR(A_SCD_TRACE_READ)); // read t1 hi
+                        p[i-4] = bus_readq(IOADDR(A_SCD_TRACE_READ)); // read t1 lo
+                        p[i-5] = bus_readq(IOADDR(A_SCD_TRACE_READ)); // read t0 hi
+                        p[i-6] = bus_readq(IOADDR(A_SCD_TRACE_READ)); // read t0 lo
+                }
+                if (!sbp.tb_enable) {
+                        DBG(printk(DEVNAME ": tb_intr shutdown\n"));
+                        bus_writeq(M_SCD_TRACE_CFG_RESET,
+                                   IOADDR(A_SCD_TRACE_CFG));
+                        sbp.tb_armed = 0;
+                        wake_up(&sbp.tb_sync);
+                } else {
+                        arm_tb();       // knock down current interrupt and get another one later
+                }
+        } else {
+                /* No more trace buffer samples */
+                DBG(printk(DEVNAME ": tb_intr full\n"));
+                bus_writeq(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
+                sbp.tb_armed = 0;
+                if (!sbp.tb_enable) {
+                        wake_up(&sbp.tb_sync);
+                }
+                wake_up(&sbp.tb_read);
+        }
+        return IRQ_HANDLED;
+}
+
+static irqreturn_t sbprof_pc_intr(int irq, void *dev_id, struct pt_regs *regs)
+{
+        printk(DEVNAME ": unexpected pc_intr");
+        return IRQ_NONE;
+}
+
+int sbprof_zbprof_start(struct file *filp)
+{
+        u_int64_t scdperfcnt;
+
+        if (sbp.tb_enable)
+                return -EBUSY;
+
+        DBG(printk(DEVNAME ": starting\n"));
+
+        sbp.tb_enable = 1;
+        sbp.next_tb_sample = 0;
+        filp->f_pos = 0;
+
+        if (request_irq
+            (K_INT_TRACE_FREEZE, sbprof_tb_intr, 0, DEVNAME " trace freeze", &sbp)) {
+                return -EBUSY;
+        }
+        /* Make sure there isn't a perf-cnt interrupt waiting */
+        scdperfcnt = bus_readq(IOADDR(A_SCD_PERF_CNT_CFG));
+        /* Disable and clear counters, override SRC_1 */
+        bus_writeq((scdperfcnt & ~(M_SPC_CFG_SRC1 | M_SPC_CFG_ENABLE)) |
+                   M_SPC_CFG_ENABLE |
+                   M_SPC_CFG_CLEAR |
+                   V_SPC_CFG_SRC1(1),
+                   IOADDR(A_SCD_PERF_CNT_CFG));
+
+        /* We grab this interrupt to prevent others from trying to use
+           it, even though we don't want to service the interrupts
+           (they only feed into the trace-on-interrupt mechanism) */
+        if (request_irq
+            (K_INT_PERF_CNT, sbprof_pc_intr, 0, DEVNAME " scd perfcnt", &sbp)) {
+                free_irq(K_INT_TRACE_FREEZE, &sbp);
+                return -EBUSY;
+        }
+
+        /* I need the core to mask these, but the interrupt mapper to
+           pass them through.  I am exploiting my knowledge that
+           cp0_status masks out IP[5]. krw */
+        bus_writeq(K_INT_MAP_I3,
+                   IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) +
+                          (K_INT_PERF_CNT << 3)));
+
+        /* Initialize address traps */
+        bus_writeq(0, IOADDR(A_ADDR_TRAP_UP_0));
+        bus_writeq(0, IOADDR(A_ADDR_TRAP_UP_1));
+        bus_writeq(0, IOADDR(A_ADDR_TRAP_UP_2));
+        bus_writeq(0, IOADDR(A_ADDR_TRAP_UP_3));
+
+        bus_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_0));
+        bus_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_1));
+        bus_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_2));
+        bus_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_3));
+
+        bus_writeq(0, IOADDR(A_ADDR_TRAP_CFG_0));
+        bus_writeq(0, IOADDR(A_ADDR_TRAP_CFG_1));
+        bus_writeq(0, IOADDR(A_ADDR_TRAP_CFG_2));
+        bus_writeq(0, IOADDR(A_ADDR_TRAP_CFG_3));
+
+        /* Initialize Trace Event 0-7 */
+        //                              when interrupt
+        bus_writeq(M_SCD_TREVT_INTERRUPT, IOADDR(A_SCD_TRACE_EVENT_0));
+        bus_writeq(0, IOADDR(A_SCD_TRACE_EVENT_1));
+        bus_writeq(0, IOADDR(A_SCD_TRACE_EVENT_2));
+        bus_writeq(0, IOADDR(A_SCD_TRACE_EVENT_3));
+        bus_writeq(0, IOADDR(A_SCD_TRACE_EVENT_4));
+        bus_writeq(0, IOADDR(A_SCD_TRACE_EVENT_5));
+        bus_writeq(0, IOADDR(A_SCD_TRACE_EVENT_6));
+        bus_writeq(0, IOADDR(A_SCD_TRACE_EVENT_7));
+
+        /* Initialize Trace Sequence 0-7 */
+        //                                   Start on event 0 (interrupt)
+        bus_writeq(V_SCD_TRSEQ_FUNC_START | 0x0fff,
+                   IOADDR(A_SCD_TRACE_SEQUENCE_0));
+        //                        dsamp when d used | asamp when a used
+        bus_writeq(M_SCD_TRSEQ_ASAMPLE | M_SCD_TRSEQ_DSAMPLE |
+                   K_SCD_TRSEQ_TRIGGER_ALL,
+                   IOADDR(A_SCD_TRACE_SEQUENCE_1));
+        bus_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_2));
+        bus_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_3));
+        bus_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_4));
+        bus_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_5));
+        bus_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_6));
+        bus_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_7));
+
+        /* Now indicate the PERF_CNT interrupt as a trace-relevant interrupt */
+        bus_writeq((1ULL << K_INT_PERF_CNT),
+                   IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_TRACE)));
+
+        arm_tb();
+
+        DBG(printk(DEVNAME ": done starting\n"));
+
+        return 0;
+}
+
+int sbprof_zbprof_stop(void)
+{
+        DBG(printk(DEVNAME ": stopping\n"));
+
+        if (sbp.tb_enable) {
+                sbp.tb_enable = 0;
+                /* XXXKW there is a window here where the intr handler
+                   may run, see the disable, and do the wake_up before
+                   this sleep happens. */
+                if (sbp.tb_armed) {
+                        DBG(printk(DEVNAME ": wait for disarm\n"));
+                        interruptible_sleep_on(&sbp.tb_sync);
+                        DBG(printk(DEVNAME ": disarm complete\n"));
+                }
+                free_irq(K_INT_TRACE_FREEZE, &sbp);
+                free_irq(K_INT_PERF_CNT, &sbp);
+        }
+
+        DBG(printk(DEVNAME ": done stopping\n"));
+
+        return 0;
+}
+
+static int sbprof_tb_open(struct inode *inode, struct file *filp)
+{
+        int minor;
+
+        minor = iminor(inode);
+        if (minor != 0) {
+                return -ENODEV;
+        }
+        if (sbp.open) {
+                return -EBUSY;
+        }
+
+        memset(&sbp, 0, sizeof(struct sbprof_tb));
+        sbp.sbprof_tbbuf = vmalloc(MAX_TBSAMPLE_BYTES);
+        if (!sbp.sbprof_tbbuf) {
+                return -ENOMEM;
+        }
+        memset(sbp.sbprof_tbbuf, 0, MAX_TBSAMPLE_BYTES);
+        init_waitqueue_head(&sbp.tb_sync);
+        init_waitqueue_head(&sbp.tb_read);
+        sbp.open = 1;
+
+        return 0;
+}
+
+static int sbprof_tb_release(struct inode *inode, struct file *filp)
+{
+        int minor;
+
+        minor = iminor(inode);
+        if (minor != 0 || !sbp.open) {
+                return -ENODEV;
+        }
+
+        if (sbp.tb_armed || sbp.tb_enable) {
+                sbprof_zbprof_stop();
+        }
+
+        vfree(sbp.sbprof_tbbuf);
+        sbp.open = 0;
+
+        return 0;
+}
+
+static ssize_t sbprof_tb_read(struct file *filp, char *buf,
+                              size_t size, loff_t *offp)
+{
+        int cur_sample, sample_off, cur_count, sample_left;
+        char *src;
+        int   count   =  0;
+        char *dest    =  buf;
+        long  cur_off = *offp;
+
+        count = 0;
+        cur_sample = cur_off / TB_SAMPLE_SIZE;
+        sample_off = cur_off % TB_SAMPLE_SIZE;
+        sample_left = TB_SAMPLE_SIZE - sample_off;
+        while (size && (cur_sample < sbp.next_tb_sample)) {
+                cur_count = size < sample_left ? size : sample_left;
+                src = (char *)(((long)sbp.sbprof_tbbuf[cur_sample])+sample_off);
+                copy_to_user(dest, src, cur_count);
+                DBG(printk(DEVNAME ": read from sample %d, %d bytes\n",
+                           cur_sample, cur_count));
+                size -= cur_count;
+                sample_left -= cur_count;
+                if (!sample_left) {
+                        cur_sample++;
+                        sample_off = 0;
+                        sample_left = TB_SAMPLE_SIZE;
+                } else {
+                        sample_off += cur_count;
+                }
+                cur_off += cur_count;
+                dest += cur_count;
+                count += cur_count;
+        }
+        *offp = cur_off;
+
+        return count;
+}
+
+static int sbprof_tb_ioctl(struct inode *inode,
+                           struct file *filp,
+                           unsigned int command,
+                           unsigned long arg)
+{
+        int error = 0;
+
+        switch (command) {
+        case SBPROF_ZBSTART:
+                error = sbprof_zbprof_start(filp);
+                break;
+        case SBPROF_ZBSTOP:
+                error = sbprof_zbprof_stop();
+                break;
+        case SBPROF_ZBWAITFULL:
+                interruptible_sleep_on(&sbp.tb_read);
+                /* XXXKW check if interrupted? */
+                return put_user(TB_FULL, (int *) arg);
+        default:
+                error = -EINVAL;
+                break;
+        }
+
+        return error;
+}
+
+static struct file_operations sbprof_tb_fops = {
+        .owner          = THIS_MODULE,
+        .open           = sbprof_tb_open,
+        .release        = sbprof_tb_release,
+        .read           = sbprof_tb_read,
+        .ioctl          = sbprof_tb_ioctl,
+        .mmap           = NULL,
+};
+
+static int __init sbprof_tb_init(void)
+{
+        if (register_chrdev(SBPROF_TB_MAJOR, DEVNAME, &sbprof_tb_fops)) {
+                printk(KERN_WARNING DEVNAME ": initialization failed (dev %d)\n",
+                       SBPROF_TB_MAJOR);
+                return -EIO;
+        }
+        sbp.open = 0;
+        tb_period = zbbus_mhz * 10000LL;
+        printk(KERN_INFO DEVNAME ": initialized - tb_period = %lld\n", tb_period);
+        return 0;
+}
+
+static void __exit sbprof_tb_cleanup(void)
+{
+        unregister_chrdev(SBPROF_TB_MAJOR, DEVNAME);
+}
+
+module_init(sbprof_tb_init);
+module_exit(sbprof_tb_cleanup);