ARM: 5841/1: a driver for on-chip ETM and ETB

This driver implements support for on-chip Embedded Tracing Macrocell and
Embedded Trace Buffer. It allows to trigger tracing of kernel execution flow
and exporting trace output to userspace via character device and a sysrq
combo.

Trace output can then be decoded by a fairly simple open source tool [1]
which is already sufficient to get the idea of what the kernel is doing.

[1]: http://github.com/virtuoso/etm2human

Signed-off-by: Alexander Shishkin <virtuoso@slind.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 165 insertions, 0 deletions

diff --git a/arch/arm/include/asm/hardware/coresight.h b/arch/arm/include/asm/hardware/coresight.h
new file mode 100644
index 000000000000..f82b25d4f73e
--- /dev/null
+++ b/arch/arm/include/asm/hardware/coresight.h
@@ -0,0 +1,165 @@
+/*
+ * linux/arch/arm/include/asm/hardware/coresight.h
+ *
+ * CoreSight components' registers
+ *
+ * Copyright (C) 2009 Nokia Corporation.
+ * Alexander Shishkin
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_HARDWARE_CORESIGHT_H
+#define __ASM_HARDWARE_CORESIGHT_H
+
+#define TRACER_ACCESSED_BIT     0
+#define TRACER_RUNNING_BIT      1
+#define TRACER_CYCLE_ACC_BIT    2
+#define TRACER_ACCESSED         BIT(TRACER_ACCESSED_BIT)
+#define TRACER_RUNNING          BIT(TRACER_RUNNING_BIT)
+#define TRACER_CYCLE_ACC        BIT(TRACER_CYCLE_ACC_BIT)
+
+struct tracectx {
+        unsigned int    etb_bufsz;
+        void __iomem    *etb_regs;
+        void __iomem    *etm_regs;
+        unsigned long   flags;
+        int             ncmppairs;
+        int             etm_portsz;
+        struct device   *dev;
+        struct clk      *emu_clk;
+        struct mutex    mutex;
+};
+
+#define TRACER_TIMEOUT 10000
+
+#define etm_writel(t, v, x) \
+        (__raw_writel((v), (t)->etm_regs + (x)))
+#define etm_readl(t, x) (__raw_readl((t)->etm_regs + (x)))
+
+/* CoreSight Management Registers */
+#define CSMR_LOCKACCESS 0xfb0
+#define CSMR_LOCKSTATUS 0xfb4
+#define CSMR_AUTHSTATUS 0xfb8
+#define CSMR_DEVID      0xfc8
+#define CSMR_DEVTYPE    0xfcc
+/* CoreSight Component Registers */
+#define CSCR_CLASS      0xff4
+
+#define CSCR_PRSR       0x314
+
+#define UNLOCK_MAGIC    0xc5acce55
+
+/* ETM control register, "ETM Architecture", 3.3.1 */
+#define ETMR_CTRL               0
+#define ETMCTRL_POWERDOWN       1
+#define ETMCTRL_PROGRAM         (1 << 10)
+#define ETMCTRL_PORTSEL         (1 << 11)
+#define ETMCTRL_DO_CONTEXTID    (3 << 14)
+#define ETMCTRL_PORTMASK1       (7 << 4)
+#define ETMCTRL_PORTMASK2       (1 << 21)
+#define ETMCTRL_PORTMASK        (ETMCTRL_PORTMASK1 | ETMCTRL_PORTMASK2)
+#define ETMCTRL_PORTSIZE(x) ((((x) & 7) << 4) | (!!((x) & 8)) << 21)
+#define ETMCTRL_DO_CPRT         (1 << 1)
+#define ETMCTRL_DATAMASK        (3 << 2)
+#define ETMCTRL_DATA_DO_DATA    (1 << 2)
+#define ETMCTRL_DATA_DO_ADDR    (1 << 3)
+#define ETMCTRL_DATA_DO_BOTH    (ETMCTRL_DATA_DO_DATA | ETMCTRL_DATA_DO_ADDR)
+#define ETMCTRL_BRANCH_OUTPUT   (1 << 8)
+#define ETMCTRL_CYCLEACCURATE   (1 << 12)
+
+/* ETM configuration code register */
+#define ETMR_CONFCODE           (0x04)
+
+/* ETM trace start/stop resource control register */
+#define ETMR_TRACESSCTRL        (0x18)
+
+/* ETM trigger event register */
+#define ETMR_TRIGEVT            (0x08)
+
+/* address access type register bits, "ETM architecture",
+ * table 3-27 */
+/* - access type */
+#define ETMAAT_IFETCH           0
+#define ETMAAT_IEXEC            1
+#define ETMAAT_IEXECPASS        2
+#define ETMAAT_IEXECFAIL        3
+#define ETMAAT_DLOADSTORE       4
+#define ETMAAT_DLOAD            5
+#define ETMAAT_DSTORE           6
+/* - comparison access size */
+#define ETMAAT_JAVA             (0 << 3)
+#define ETMAAT_THUMB            (1 << 3)
+#define ETMAAT_ARM              (3 << 3)
+/* - data value comparison control */
+#define ETMAAT_NOVALCMP         (0 << 5)
+#define ETMAAT_VALMATCH         (1 << 5)
+#define ETMAAT_VALNOMATCH       (3 << 5)
+/* - exact match */
+#define ETMAAT_EXACTMATCH       (1 << 7)
+/* - context id comparator control */
+#define ETMAAT_IGNCONTEXTID     (0 << 8)
+#define ETMAAT_VALUE1           (1 << 8)
+#define ETMAAT_VALUE2           (2 << 8)
+#define ETMAAT_VALUE3           (3 << 8)
+/* - security level control */
+#define ETMAAT_IGNSECURITY      (0 << 10)
+#define ETMAAT_NSONLY           (1 << 10)
+#define ETMAAT_SONLY            (2 << 10)
+
+#define ETMR_COMP_VAL(x)        (0x40 + (x) * 4)
+#define ETMR_COMP_ACC_TYPE(x)   (0x80 + (x) * 4)
+
+/* ETM status register, "ETM Architecture", 3.3.2 */
+#define ETMR_STATUS             (0x10)
+#define ETMST_OVERFLOW          (1 << 0)
+#define ETMST_PROGBIT           (1 << 1)
+#define ETMST_STARTSTOP         (1 << 2)
+#define ETMST_TRIGGER           (1 << 3)
+
+#define etm_progbit(t)          (etm_readl((t), ETMR_STATUS) & ETMST_PROGBIT)
+#define etm_started(t)          (etm_readl((t), ETMR_STATUS) & ETMST_STARTSTOP)
+#define etm_triggered(t)        (etm_readl((t), ETMR_STATUS) & ETMST_TRIGGER)
+
+#define ETMR_TRACEENCTRL2       0x1c
+#define ETMR_TRACEENCTRL        0x24
+#define ETMTE_INCLEXCL          (1 << 24)
+#define ETMR_TRACEENEVT         0x20
+#define ETMCTRL_OPTS            (ETMCTRL_DO_CPRT | \
+                                ETMCTRL_DATA_DO_ADDR | \
+                                ETMCTRL_BRANCH_OUTPUT | \
+                                ETMCTRL_DO_CONTEXTID)
+
+/* ETB registers, "CoreSight Components TRM", 9.3 */
+#define ETBR_DEPTH              0x04
+#define ETBR_STATUS             0x0c
+#define ETBR_READMEM            0x10
+#define ETBR_READADDR           0x14
+#define ETBR_WRITEADDR          0x18
+#define ETBR_TRIGGERCOUNT       0x1c
+#define ETBR_CTRL               0x20
+#define ETBR_FORMATTERCTRL      0x304
+#define ETBFF_ENFTC             1
+#define ETBFF_ENFCONT           (1 << 1)
+#define ETBFF_FONFLIN           (1 << 4)
+#define ETBFF_MANUAL_FLUSH      (1 << 6)
+#define ETBFF_TRIGIN            (1 << 8)
+#define ETBFF_TRIGEVT           (1 << 9)
+#define ETBFF_TRIGFL            (1 << 10)
+
+#define etb_writel(t, v, x) \
+        (__raw_writel((v), (t)->etb_regs + (x)))
+#define etb_readl(t, x) (__raw_readl((t)->etb_regs + (x)))
+
+#define etm_lock(t) do { etm_writel((t), 0, CSMR_LOCKACCESS); } while (0)
+#define etm_unlock(t) \
+        do { etm_writel((t), UNLOCK_MAGIC, CSMR_LOCKACCESS); } while (0)
+
+#define etb_lock(t) do { etb_writel((t), 0, CSMR_LOCKACCESS); } while (0)
+#define etb_unlock(t) \
+        do { etb_writel((t), UNLOCK_MAGIC, CSMR_LOCKACCESS); } while (0)
+
+#endif /* __ASM_HARDWARE_CORESIGHT_H */
+