msm: kgsl: Add GPU snapshot support

Add support for snapshotting the state of the GPU in a binary format. The
snapshot can be pulled from sysfs and parsed off-target.  The advantage is
that far more information can be encapsulated in a snapshot then can be
printed on the console during a hang.  Snapshots are automatically created
during a hang, or can be manually triggered by writing 'trigger'
in /sys/class/kgsl/kgsl-<n>/snapshot where n is either the 2D or 3D device.
Snapshot data can be pulled from 'dump' in the same directory.

Change-Id: Ic0dedbad1c8473b3b109582b95a8771b0d341f05
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
diff --git a/drivers/gpu/msm/kgsl_snapshot.h b/drivers/gpu/msm/kgsl_snapshot.h
new file mode 100644
index 0000000..4fdc8a1
--- /dev/null
+++ b/drivers/gpu/msm/kgsl_snapshot.h
@@ -0,0 +1,259 @@
+/* Copyright (c) 2012, Code Aurora Forum. 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.
+ *
+ */
+
+#ifndef _KGSL_SNAPSHOT_H_
+#define _KGSL_SNAPSHOT_H_
+
+#include <linux/types.h>
+
+/* Snapshot header */
+
+#define SNAPSHOT_MAGIC 0x504D0001
+
+/* GPU ID scheme:
+ * [16:31] - core identifer (0x0002 for 2D or 0x0003 for 3D)
+ * [00:16] - GPU specific identifier
+ */
+
+struct kgsl_snapshot_header {
+	__u32 magic; /* Magic identifier */
+	__u32 gpuid; /* GPU ID - see above */
+} __packed;
+
+/* Section header */
+#define SNAPSHOT_SECTION_MAGIC 0xABCD
+
+struct kgsl_snapshot_section_header {
+	__u16 magic; /* Magic identifier */
+	__u16 id;    /* Type of section */
+	__u32 size;  /* Size of the section including this header */
+} __packed;
+
+/* Section identifiers */
+#define KGSL_SNAPSHOT_SECTION_OS           0x0101
+#define KGSL_SNAPSHOT_SECTION_REGS         0x0201
+#define KGSL_SNAPSHOT_SECTION_RB           0x0301
+#define KGSL_SNAPSHOT_SECTION_IB           0x0401
+#define KGSL_SNAPSHOT_SECTION_INDEXED_REGS 0x0501
+#define KGSL_SNAPSHOT_SECTION_ISTORE       0x0801
+#define KGSL_SNAPSHOT_SECTION_DEBUG        0x0901
+#define KGSL_SNAPSHOT_SECTION_END          0xFFFF
+
+/* OS sub-section header */
+#define KGSL_SNAPSHOT_OS_LINUX             0x0001
+
+/* Linux OS specific information */
+
+#define SNAPSHOT_STATE_HUNG 0
+#define SNAPSHOT_STATE_RUNNING 1
+
+struct kgsl_snapshot_linux {
+	int osid;                   /* subsection OS identifier */
+	int state;		    /* 1 if the thread is running, 0 for hung */
+	__u32 seconds;		    /* Unix timestamp for the snapshot */
+	__u32 power_flags;            /* Current power flags */
+	__u32 power_level;            /* Current power level */
+	__u32 power_interval_timeout; /* Power interval timeout */
+	__u32 grpclk;                 /* Current GP clock value */
+	__u32 busclk;		    /* Current busclk value */
+	__u32 ptbase;		    /* Current ptbase */
+	__u32 pid;		    /* PID of the process that owns the PT */
+	__u32 current_context;	    /* ID of the current context */
+	__u32 ctxtcount;	    /* Number of contexts appended to section */
+	unsigned char release[32];  /* kernel release */
+	unsigned char version[32];  /* kernel version */
+	unsigned char comm[16];	    /* Name of the process that owns the PT */
+} __packed;
+
+/*
+ * This structure contains a record of an active context.
+ * These are appended one after another in the OS section below
+ * the header above
+ */
+
+struct kgsl_snapshot_linux_context {
+	__u32 id;			/* The context ID */
+	__u32 timestamp_queued;		/* The last queued timestamp */
+	__u32 timestamp_retired;	/* The last timestamp retired by HW */
+};
+
+/* Ringbuffer sub-section header */
+struct kgsl_snapshot_rb {
+	int start;  /* dword at the start of the dump */
+	int end;    /* dword at the end of the dump */
+	int rbsize; /* Size (in dwords) of the ringbuffer */
+	int wptr;   /* Current index of the CPU write pointer */
+	int rptr;   /* Current index of the GPU read pointer */
+	int count;  /* Number of dwords in the dump */
+} __packed;
+
+/* Indirect buffer sub-section header */
+struct kgsl_snapshot_ib {
+	__u32 gpuaddr; /* GPU address of the the IB */
+	__u32 ptbase;  /* Base for the pagetable the GPU address is valid in */
+	int size;    /* Size of the IB */
+} __packed;
+
+/* Register sub-section header */
+struct kgsl_snapshot_regs {
+	__u32 count; /* Number of register pairs in the section */
+} __packed;
+
+/* Indexed register sub-section header */
+struct kgsl_snapshot_indexed_regs {
+	__u32 index_reg; /* Offset of the index register for this section */
+	__u32 data_reg;  /* Offset of the data register for this section */
+	int start;     /* Starting index */
+	int count;     /* Number of dwords in the data */
+} __packed;
+
+/* Istore sub-section header */
+struct kgsl_snapshot_istore {
+	int count;   /* Number of instructions in the istore */
+} __packed;
+
+/* Debug data sub-section header */
+
+#define SNAPSHOT_DEBUG_SX         1
+#define SNAPSHOT_DEBUG_CP         2
+#define SNAPSHOT_DEBUG_SQ         3
+#define SNAPSHOT_DEBUG_SQTHREAD   4
+#define SNAPSHOT_DEBUG_MIU        5
+
+struct kgsl_snapshot_debug {
+	int type;    /* Type identifier for the attached tata */
+	int size;   /* Size of the section in bytes */
+} __packed;
+
+#ifdef __KERNEL__
+
+/* Allocate 512K for each device snapshot */
+#define KGSL_SNAPSHOT_MEMSIZE (512 * 1024)
+
+struct kgsl_device;
+/*
+ * A helper macro to print out "not enough memory functions" - this
+ * makes it easy to standardize the messages as well as cut down on
+ * the number of strings in the binary
+ */
+
+#define SNAPSHOT_ERR_NOMEM(_d, _s) \
+	KGSL_DRV_ERR((_d), \
+	"snapshot: not enough snapshot memory for section %s\n", (_s))
+
+/*
+ * kgsl_snapshot_add_section - Add a new section to the GPU snapshot
+ * @device - the KGSL device being snapshotted
+ * @id - the section id
+ * @snapshot - pointer to the memory for the snapshot
+ * @remain - pointer to the number of bytes left in the snapshot region
+ * @func - Function pointer to fill the section
+ * @priv - Priv pointer to pass to the function
+ *
+ * Set up a KGSL snapshot header by filling the memory with the callback
+ * function and adding the standard section header
+ */
+
+static inline void *kgsl_snapshot_add_section(struct kgsl_device *device,
+	u16 id, void *snapshot, int *remain,
+	int (*func)(struct kgsl_device *, void *, int, void *), void *priv)
+{
+	struct kgsl_snapshot_section_header *header = snapshot;
+	void *data = snapshot + sizeof(*header);
+	int ret = 0;
+
+	/*
+	 * Sanity check to make sure there is enough for the header.  The
+	 * callback will check to make sure there is enough for the rest
+	 * of the data.  If there isn't enough room then don't advance the
+	 * pointer.
+	 */
+
+	if (*remain < sizeof(*header))
+		return snapshot;
+
+	/* It is legal to have no function (i.e. - make an empty section) */
+
+	if (func) {
+		ret = func(device, data, *remain, priv);
+
+		/*
+		 * If there wasn't enough room for the data then don't bother
+		 * setting up the header.
+		 */
+
+		if (ret == 0)
+			return snapshot;
+	}
+
+	header->magic = SNAPSHOT_SECTION_MAGIC;
+	header->id = id;
+	header->size = ret + sizeof(*header);
+
+	/* Decrement the room left in the snapshot region */
+	*remain -= header->size;
+	/* Advance the pointer to the end of the next function */
+	return snapshot + header->size;
+}
+
+/* A common helper function to dump a range of registers.  This will be used in
+ * the GPU specific devices like this:
+ *
+ * struct kgsl_snapshot_registers priv;
+ * priv.regs = registers_array;;
+ * priv.count = num_registers;
+ *
+ * kgsl_snapshot_add_section(device, KGSL_SNAPSHOT_SECTION_REGS, snapshot,
+ *	remain, kgsl_snapshot_dump_regs, &priv).
+ *
+ * Pass in an array of register range pairs in the form of:
+ * start reg, stop reg
+ * All the registers between start and stop inclusive will be dumped
+ */
+
+struct kgsl_snapshot_registers {
+	unsigned int *regs;  /* Pointer to the array of register ranges */
+	int count;	     /* Number of entries in the array */
+};
+
+int kgsl_snapshot_dump_regs(struct kgsl_device *device, void *snapshot,
+	int remain, void *priv);
+
+/*
+ * A common helper function to dump a set of indexed registers. Use it
+ * like this:
+ *
+ * struct kgsl_snapshot_indexed_registers priv;
+ * priv.index = REG_INDEX;
+ * priv.data = REG_DATA;
+ * priv.count = num_registers
+ *
+ * kgsl_snapshot_add_section(device, KGSL_SNAPSHOT_SECTION_INDEXED_REGS,
+ *	snapshot, remain, kgsl_snapshot_dump_indexed_regs, &priv).
+ *
+ * The callback function will write an index from 0 to priv.count to
+ * the index register and read the data from the data register.
+ */
+
+struct kgsl_snapshot_indexed_registers {
+	unsigned int index; /* Offset of the index register */
+	unsigned int data;  /* Offset of the data register */
+	unsigned int start;	/* Index to start with */
+	unsigned int count; /* Number of values to read from the pair */
+};
+
+int kgsl_snapshot_dump_indexed_regs(struct kgsl_device *device,
+	void *snapshot, int remain, void *priv);
+
+#endif
+#endif