[PATCH net-next 2/4] cxgb4: Add support for cim_la entry in debugfs

[Hariprasad Shenai <hariprasad@chelsio.com>]

The CIM LA captures the embedded processor’s internal state. Optionally, it can
also trace the flow of data in and out of the embedded processor. Therefore, the
CIM LA output contains detailed information of what code the embedded processor
executed prior to the CIM LA capture.

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
---
 drivers/net/ethernet/chelsio/cxgb4/cxgb4.h         |    7 +
 drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c |  129 +++++++++++++++++++-
 drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.h |   12 ++
 drivers/net/ethernet/chelsio/cxgb4/t4_hw.c         |  120 ++++++++++++++++++
 drivers/net/ethernet/chelsio/cxgb4/t4_hw.h         |    4 +
 drivers/net/ethernet/chelsio/cxgb4/t4_regs.h       |   14 ++
 6 files changed, 284 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h b/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
index 081b7ef..d8a62cc 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
@@ -297,6 +297,8 @@ struct adapter_params {
 	struct devlog_params devlog;
 	enum pcie_memwin drv_memwin;
 
+	unsigned int cim_la_size;
+
 	unsigned int sf_size;             /* serial flash size in bytes */
 	unsigned int sf_nsec;             /* # of flash sectors */
 	unsigned int sf_fw_start;         /* start of FW image in flash */
@@ -1013,6 +1015,11 @@ int t4_mc_read(struct adapter *adap, int idx, u32 addr, __be32 *data,
 	       u64 *parity);
 int t4_edc_read(struct adapter *adap, int idx, u32 addr, __be32 *data,
 		u64 *parity);
+int t4_cim_read(struct adapter *adap, unsigned int addr, unsigned int n,
+		unsigned int *valp);
+int t4_cim_write(struct adapter *adap, unsigned int addr, unsigned int n,
+		 const unsigned int *valp);
+int t4_cim_read_la(struct adapter *adap, u32 *la_buf, unsigned int *wrptr);
 const char *t4_get_port_type_description(enum fw_port_type port_type);
 void t4_get_port_stats(struct adapter *adap, int idx, struct port_stats *p);
 void t4_read_mtu_tbl(struct adapter *adap, u16 *mtus, u8 *mtu_log);
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
index 0704af5..04b490e 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
@@ -43,8 +43,132 @@
 #include "cxgb4_debugfs.h"
 #include "l2t.h"
 
-/* Firmware Device Log dump.
- */
+/* generic seq_file support for showing a table of size rows x width. */
+static void *seq_tab_get_idx(struct seq_tab *tb, loff_t pos)
+{
+	pos -= tb->skip_first;
+	return pos >= tb->rows ? NULL : &tb->data[pos * tb->width];
+}
+
+static void *seq_tab_start(struct seq_file *seq, loff_t *pos)
+{
+	struct seq_tab *tb = seq->private;
+
+	if (tb->skip_first && *pos == 0)
+		return SEQ_START_TOKEN;
+
+	return seq_tab_get_idx(tb, *pos);
+}
+
+static void *seq_tab_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	v = seq_tab_get_idx(seq->private, *pos + 1);
+	if (v)
+		++*pos;
+	return v;
+}
+
+static void seq_tab_stop(struct seq_file *seq, void *v)
+{
+}
+
+static int seq_tab_show(struct seq_file *seq, void *v)
+{
+	const struct seq_tab *tb = seq->private;
+
+	return tb->show(seq, v, ((char *)v - tb->data) / tb->width);
+}
+
+static const struct seq_operations seq_tab_ops = {
+	.start = seq_tab_start,
+	.next  = seq_tab_next,
+	.stop  = seq_tab_stop,
+	.show  = seq_tab_show
+};
+
+struct seq_tab *seq_open_tab(struct file *f, unsigned int rows,
+			     unsigned int width, unsigned int have_header,
+			     int (*show)(struct seq_file *seq, void *v, int i))
+{
+	struct seq_tab *p;
+
+	p = __seq_open_private(f, &seq_tab_ops, sizeof(*p) + rows * width);
+	if (p) {
+		p->show = show;
+		p->rows = rows;
+		p->width = width;
+		p->skip_first = have_header != 0;
+	}
+	return p;
+}
+
+static int cim_la_show(struct seq_file *seq, void *v, int idx)
+{
+	if (v == SEQ_START_TOKEN)
+		seq_puts(seq, "Status   Data      PC     LS0Stat  LS0Addr "
+			 "            LS0Data\n");
+	else {
+		const u32 *p = v;
+
+		seq_printf(seq,
+			   "  %02x  %x%07x %x%07x %08x %08x %08x%08x%08x%08x\n",
+			   (p[0] >> 4) & 0xff, p[0] & 0xf, p[1] >> 4,
+			   p[1] & 0xf, p[2] >> 4, p[2] & 0xf, p[3], p[4], p[5],
+			   p[6], p[7]);
+	}
+	return 0;
+}
+
+static int cim_la_show_3in1(struct seq_file *seq, void *v, int idx)
+{
+	if (v == SEQ_START_TOKEN) {
+		seq_puts(seq, "Status   Data      PC\n");
+	} else {
+		const u32 *p = v;
+
+		seq_printf(seq, "  %02x   %08x %08x\n", p[5] & 0xff, p[6],
+			   p[7]);
+		seq_printf(seq, "  %02x   %02x%06x %02x%06x\n",
+			   (p[3] >> 8) & 0xff, p[3] & 0xff, p[4] >> 8,
+			   p[4] & 0xff, p[5] >> 8);
+		seq_printf(seq, "  %02x   %x%07x %x%07x\n", (p[0] >> 4) & 0xff,
+			   p[0] & 0xf, p[1] >> 4, p[1] & 0xf, p[2] >> 4);
+	}
+	return 0;
+}
+
+static int cim_la_open(struct inode *inode, struct file *file)
+{
+	int ret;
+	unsigned int cfg;
+	struct seq_tab *p;
+	struct adapter *adap = inode->i_private;
+
+	ret = t4_cim_read(adap, UP_UP_DBG_LA_CFG, 1, &cfg);
+	if (ret)
+		return ret;
+
+	p = seq_open_tab(file, adap->params.cim_la_size / 8, 8 * sizeof(u32), 1,
+			 cfg & UPDBGLACAPTPCONLY ?
+			 cim_la_show_3in1 : cim_la_show);
+	if (!p)
+		return -ENOMEM;
+
+	ret = t4_cim_read_la(adap, (u32 *)p->data, NULL);
+	if (ret)
+		seq_release_private(inode, file);
+	return ret;
+}
+
+static const struct file_operations cim_la_fops = {
+	.owner   = THIS_MODULE,
+	.open    = cim_la_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = seq_release_private
+};
+
+/* Firmware Device Log dump. */
 static const char * const devlog_level_strings[] = {
 	[FW_DEVLOG_LEVEL_EMERG]		= "EMERG",
 	[FW_DEVLOG_LEVEL_CRIT]		= "CRIT",
@@ -320,6 +444,7 @@ int t4_setup_debugfs(struct adapter *adap)
 	u32 size;
 
 	static struct t4_debugfs_entry t4_debugfs_files[] = {
+		{ "cim_la", &cim_la_fops, S_IRUSR, 0 },
 		{ "devlog", &devlog_fops, S_IRUSR, 0 },
 		{ "l2t", &t4_l2t_fops, S_IRUSR, 0},
 	};
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.h b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.h
index a3d8867..70fcbc9 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.h
@@ -44,6 +44,18 @@ struct t4_debugfs_entry {
 	unsigned char data;
 };
 
+struct seq_tab {
+	int (*show)(struct seq_file *seq, void *v, int idx);
+	unsigned int rows;        /* # of entries */
+	unsigned char width;      /* size in bytes of each entry */
+	unsigned char skip_first; /* whether the first line is a header */
+	char data[0];             /* the table data */
+};
+
+struct seq_tab *seq_open_tab(struct file *f, unsigned int rows,
+			     unsigned int width, unsigned int have_header,
+			     int (*show)(struct seq_file *seq, void *v, int i));
+
 int t4_setup_debugfs(struct adapter *adap);
 void add_debugfs_files(struct adapter *adap,
 		       struct t4_debugfs_entry *files,
diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
index 1fff149..81e1ef2 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
@@ -3953,6 +3953,7 @@ int t4_prep_adapter(struct adapter *adapter)
 		return -EINVAL;
 	}
 
+	adapter->params.cim_la_size = CIMLA_SIZE;
 	init_cong_ctrl(adapter->params.a_wnd, adapter->params.b_wnd);
 
 	/*
@@ -4125,3 +4126,122 @@ int t4_port_init(struct adapter *adap, int mbox, int pf, int vf)
 	}
 	return 0;
 }
+
+/**
+ *	t4_cim_read - read a block from CIM internal address space
+ *	@adap: the adapter
+ *	@addr: the start address within the CIM address space
+ *	@n: number of words to read
+ *	@valp: where to store the result
+ *
+ *	Reads a block of 4-byte words from the CIM intenal address space.
+ */
+int t4_cim_read(struct adapter *adap, unsigned int addr, unsigned int n,
+		unsigned int *valp)
+{
+	int ret = 0;
+
+	if (t4_read_reg(adap, CIM_HOST_ACC_CTRL) & HOSTBUSY)
+		return -EBUSY;
+
+	for ( ; !ret && n--; addr += 4) {
+		t4_write_reg(adap, CIM_HOST_ACC_CTRL, addr);
+		ret = t4_wait_op_done(adap, CIM_HOST_ACC_CTRL, HOSTBUSY,
+				      0, 5, 2);
+		if (!ret)
+			*valp++ = t4_read_reg(adap, CIM_HOST_ACC_DATA);
+	}
+	return ret;
+}
+
+/**
+ *	t4_cim_write - write a block into CIM internal address space
+ *	@adap: the adapter
+ *	@addr: the start address within the CIM address space
+ *	@n: number of words to write
+ *	@valp: set of values to write
+ *
+ *	Writes a block of 4-byte words into the CIM intenal address space.
+ */
+int t4_cim_write(struct adapter *adap, unsigned int addr, unsigned int n,
+		 const unsigned int *valp)
+{
+	int ret = 0;
+
+	if (t4_read_reg(adap, CIM_HOST_ACC_CTRL) & HOSTBUSY)
+		return -EBUSY;
+
+	for ( ; !ret && n--; addr += 4) {
+		t4_write_reg(adap, CIM_HOST_ACC_DATA, *valp++);
+		t4_write_reg(adap, CIM_HOST_ACC_CTRL, addr | HOSTWRITE);
+		ret = t4_wait_op_done(adap, CIM_HOST_ACC_CTRL, HOSTBUSY,
+				      0, 5, 2);
+	}
+	return ret;
+}
+
+static int t4_cim_write1(struct adapter *adap, unsigned int addr,
+			 unsigned int val)
+{
+	return t4_cim_write(adap, addr, 1, &val);
+}
+
+/**
+ *	t4_cim_read_la - read CIM LA capture buffer
+ *	@adap: the adapter
+ *	@la_buf: where to store the LA data
+ *	@wrptr: the HW write pointer within the capture buffer
+ *
+ *	Reads the contents of the CIM LA buffer with the most recent entry at
+ *	the end	of the returned data and with the entry at @wrptr first.
+ *	We try to leave the LA in the running state we find it in.
+ */
+int t4_cim_read_la(struct adapter *adap, u32 *la_buf, unsigned int *wrptr)
+{
+	int i, ret;
+	unsigned int cfg, val, idx;
+
+	ret = t4_cim_read(adap, UP_UP_DBG_LA_CFG, 1, &cfg);
+	if (ret)
+		return ret;
+
+	if (cfg & UPDBGLAEN) {                /* LA is running, freeze it */
+		ret = t4_cim_write1(adap, UP_UP_DBG_LA_CFG, 0);
+		if (ret)
+			return ret;
+	}
+
+	ret = t4_cim_read(adap, UP_UP_DBG_LA_CFG, 1, &val);
+	if (ret)
+		goto restart;
+
+	idx = UPDBGLAWRPTR_GET(val);
+	if (wrptr)
+		*wrptr = idx;
+
+	for (i = 0; i < adap->params.cim_la_size; i++) {
+		ret = t4_cim_write1(adap, UP_UP_DBG_LA_CFG,
+				    UPDBGLARDPTR(idx) | UPDBGLARDEN);
+		if (ret)
+			break;
+		ret = t4_cim_read(adap, UP_UP_DBG_LA_CFG, 1, &val);
+		if (ret)
+			break;
+		if (val & UPDBGLARDEN) {
+			ret = -ETIMEDOUT;
+			break;
+		}
+		ret = t4_cim_read(adap, UP_UP_DBG_LA_DATA, 1, &la_buf[i]);
+		if (ret)
+			break;
+		idx = (idx + 1) & UPDBGLARDPTR_MASK;
+	}
+restart:
+	if (cfg & UPDBGLAEN) {
+		int r = t4_cim_write1(adap, UP_UP_DBG_LA_CFG,
+				      cfg & ~UPDBGLARDEN);
+		if (!ret)
+			ret = r;
+	}
+	return ret;
+}
diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.h b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.h
index 5e5eee6..bcc925b 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.h
@@ -56,6 +56,10 @@ enum {
 };
 
 enum {
+	CIMLA_SIZE     = 2048,  /* # of 32-bit words in CIM LA */
+};
+
+enum {
 	SF_PAGE_SIZE = 256,           /* serial flash page size */
 	SF_SEC_SIZE = 64 * 1024,      /* serial flash sector size */
 };
diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_regs.h b/drivers/net/ethernet/chelsio/cxgb4/t4_regs.h
index a1024db..4f6d6fa 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/t4_regs.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4_regs.h
@@ -1331,4 +1331,18 @@
 #define S_FT_VNID_ID_VLD                16
 #define V_FT_VNID_ID_VLD(x)             ((x) << S_FT_VNID_ID_VLD)
 
+/* registers for module CIM */
+#define CIM_HOST_ACC_CTRL	0x7b50
+#define CIM_HOST_ACC_DATA	0x7b54
+#define UP_UP_DBG_LA_CFG	0x140
+#define HOSTBUSY	(1U << 17)
+#define HOSTWRITE	(1U << 16)
+#define UPDBGLAEN	(1U << 0)
+#define UPDBGLARDEN	(1U << 1)
+#define UP_UP_DBG_LA_DATA	0x144
+#define UPDBGLARDPTR_MASK	0xfffU
+#define UPDBGLARDPTR(x)	((x) << 2)
+#define UPDBGLAWRPTR_GET(x)	(((x) >> 16) & 0xfffU)
+#define UPDBGLACAPTPCONLY	(1U << 30)
+
 #endif /* __T4_REGS_H */
-- 
1.7.1