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From:   Suzuki K Poulose <suzuki.poulose@arm.com>
To:     linux-arm-kernel@lists.infradead.org
Cc:     linux-kernel@vger.kernel.org, mathieu.poirier@linaro.org,
        mike.leach@linaro.org, robert.walker@arm.com, mark.rutland@arm.com,
        will.deacon@arm.com, robin.murphy@arm.com, sudeep.holla@arm.com,
        frowand.list@gmail.com, robh@kernel.org, john.horley@arm.com,
        Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: [PATCH v2 04/27] coresight: Introduce support for Coresight Addrss Translation Unit
Date:   Tue,  1 May 2018 10:10:34 +0100
Message-Id: <1525165857-11096-5-git-send-email-suzuki.poulose@arm.com>
In-Reply-To: <1525165857-11096-1-git-send-email-suzuki.poulose@arm.com>
References: <1525165857-11096-1-git-send-email-suzuki.poulose@arm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Add the initial support for Coresight Address Translation Unit, which
augments the TMC in Coresight SoC-600 by providing an improved Scatter
Gather mechanism. CATU is always connected to a single TMC-ETR and
converts the AXI address with a translated address (from a given SG
table with specific format). The CATU should be programmed in pass
through mode and enabled if the ETR doesn't translation by CATU.

This patch provides mechanism to enable/disable the CATU always in the
pass through mode.

We reuse the existing ports mechanism to link the TMC-ETR to the
connected CATU.

i.e, TMC-ETR:output_port0 -> CATU:input_port0

Reference manual for  CATU component is avilable in version r2p0 of :
"Arm Coresight System-on-Chip SoC-600 Technical Reference Manual",
under Section 4.9.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 drivers/hwtracing/coresight/Kconfig             |  10 ++
 drivers/hwtracing/coresight/Makefile            |   1 +
 drivers/hwtracing/coresight/coresight-catu.c    | 195 ++++++++++++++++++++++++
 drivers/hwtracing/coresight/coresight-catu.h    |  89 +++++++++++
 drivers/hwtracing/coresight/coresight-tmc-etr.c |  26 ++++
 drivers/hwtracing/coresight/coresight-tmc.h     |  27 ++++
 include/linux/coresight.h                       |   1 +
 7 files changed, 349 insertions(+)
 create mode 100644 drivers/hwtracing/coresight/coresight-catu.c
 create mode 100644 drivers/hwtracing/coresight/coresight-catu.h

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index ef9cb3c..21f638f 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -31,6 +31,16 @@ config CORESIGHT_LINK_AND_SINK_TMC
 	  complies with the generic implementation of the component without
 	  special enhancement or added features.
 
+config CORESIGHT_CATU
+	bool "Coresight Address Translation Unit (CATU) driver"
+	depends on CORESIGHT_LINK_AND_SINK_TMC
+	help
+	   Enable support for the Coresight Address Translation Unit (CATU).
+	   CATU supports a scatter gather table of 4K pages, with forward/backward
+	   lookup. CATU helps TMC ETR to use large physically non-contiguous trace
+	   buffer by translating the addersses used by ETR to the corresponding
+	   physical adderss by looking up the table.
+
 config CORESIGHT_SINK_TPIU
 	bool "Coresight generic TPIU driver"
 	depends on CORESIGHT_LINKS_AND_SINKS
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index 61db9dd..41870de 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -18,3 +18,4 @@ obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o \
 obj-$(CONFIG_CORESIGHT_DYNAMIC_REPLICATOR) += coresight-dynamic-replicator.o
 obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o
 obj-$(CONFIG_CORESIGHT_CPU_DEBUG) += coresight-cpu-debug.o
+obj-$(CONFIG_CORESIGHT_CATU) += coresight-catu.o
diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c
new file mode 100644
index 0000000..2cd69a6
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-catu.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright (C) 2017 ARM Limited. All rights reserved.
+ *
+ * Coresight Address Translation Unit support
+ *
+ * Author: Suzuki K Poulose <suzuki.poulose@arm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/amba/bus.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#include "coresight-catu.h"
+#include "coresight-priv.h"
+
+#define csdev_to_catu_drvdata(csdev)	\
+	dev_get_drvdata(csdev->dev.parent)
+
+coresight_simple_reg32(struct catu_drvdata, control, CATU_CONTROL);
+coresight_simple_reg32(struct catu_drvdata, status, CATU_STATUS);
+coresight_simple_reg32(struct catu_drvdata, mode, CATU_MODE);
+coresight_simple_reg32(struct catu_drvdata, axictrl, CATU_AXICTRL);
+coresight_simple_reg32(struct catu_drvdata, irqen, CATU_IRQEN);
+coresight_simple_reg64(struct catu_drvdata, sladdr,
+		       CATU_SLADDRLO, CATU_SLADDRHI);
+coresight_simple_reg64(struct catu_drvdata, inaddr,
+		       CATU_INADDRLO, CATU_INADDRHI);
+
+static struct attribute *catu_mgmt_attrs[] = {
+	&dev_attr_control.attr,
+	&dev_attr_status.attr,
+	&dev_attr_mode.attr,
+	&dev_attr_axictrl.attr,
+	&dev_attr_irqen.attr,
+	&dev_attr_sladdr.attr,
+	&dev_attr_inaddr.attr,
+	NULL,
+};
+
+static const struct attribute_group catu_mgmt_group = {
+	.attrs = catu_mgmt_attrs,
+	.name = "mgmt",
+};
+
+static const struct attribute_group *catu_groups[] = {
+	&catu_mgmt_group,
+	NULL,
+};
+
+
+static inline int catu_wait_for_ready(struct catu_drvdata *drvdata)
+{
+	return coresight_timeout(drvdata->base,
+				 CATU_STATUS, CATU_STATUS_READY, 1);
+}
+
+static int catu_enable_hw(struct catu_drvdata *drvdata, void *__unused)
+{
+	u32 control;
+
+	if (catu_wait_for_ready(drvdata))
+		dev_warn(drvdata->dev, "Timeout while waiting for READY\n");
+
+	control = catu_read_control(drvdata);
+	if (control & BIT(CATU_CONTROL_ENABLE)) {
+		dev_warn(drvdata->dev, "CATU is already enabled\n");
+		return -EBUSY;
+	}
+
+	control |= BIT(CATU_CONTROL_ENABLE);
+	catu_write_mode(drvdata, CATU_MODE_PASS_THROUGH);
+	catu_write_control(drvdata, control);
+	dev_dbg(drvdata->dev, "Enabled in Pass through mode\n");
+	return 0;
+}
+
+static int catu_enable(struct coresight_device *csdev, void *data)
+{
+	int rc;
+	struct catu_drvdata *catu_drvdata = csdev_to_catu_drvdata(csdev);
+
+	CS_UNLOCK(catu_drvdata->base);
+	rc = catu_enable_hw(catu_drvdata, data);
+	CS_LOCK(catu_drvdata->base);
+	return rc;
+}
+
+static int catu_disable_hw(struct catu_drvdata *drvdata)
+{
+	int rc = 0;
+
+	if (catu_wait_for_ready(drvdata)) {
+		dev_info(drvdata->dev, "Timeout while waiting for READY\n");
+		rc = -EAGAIN;
+	}
+
+	catu_write_control(drvdata, 0);
+	dev_dbg(drvdata->dev, "Disabled\n");
+	return rc;
+}
+
+static int catu_disable(struct coresight_device *csdev, void *__unused)
+{
+	int rc;
+	struct catu_drvdata *catu_drvdata = csdev_to_catu_drvdata(csdev);
+
+	CS_UNLOCK(catu_drvdata->base);
+	rc = catu_disable_hw(catu_drvdata);
+	CS_LOCK(catu_drvdata->base);
+
+	return rc;
+}
+
+const struct coresight_ops_helper catu_helper_ops = {
+	.enable = catu_enable,
+	.disable = catu_disable,
+};
+
+const struct coresight_ops catu_ops = {
+	.helper_ops = &catu_helper_ops,
+};
+
+static int catu_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	int ret = 0;
+	struct catu_drvdata *drvdata;
+	struct coresight_desc catu_desc;
+	struct coresight_platform_data *pdata = NULL;
+	struct device *dev = &adev->dev;
+	struct device_node *np = dev->of_node;
+	void __iomem *base;
+
+	if (np) {
+		pdata = of_get_coresight_platform_data(dev, np);
+		if (IS_ERR(pdata)) {
+			ret = PTR_ERR(pdata);
+			goto out;
+		}
+		dev->platform_data = pdata;
+	}
+
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	drvdata->dev = dev;
+	dev_set_drvdata(dev, drvdata);
+	base = devm_ioremap_resource(dev, &adev->res);
+	if (IS_ERR(base)) {
+		ret = PTR_ERR(base);
+		goto out;
+	}
+
+	drvdata->base = base;
+	catu_desc.pdata = pdata;
+	catu_desc.dev = dev;
+	catu_desc.groups = catu_groups;
+	catu_desc.type = CORESIGHT_DEV_TYPE_HELPER;
+	catu_desc.subtype.helper_subtype = CORESIGHT_DEV_SUBTYPE_HELPER_CATU;
+	catu_desc.ops = &catu_ops;
+	drvdata->csdev = coresight_register(&catu_desc);
+	if (IS_ERR(drvdata->csdev))
+		ret = PTR_ERR(drvdata->csdev);
+	if (!ret)
+		dev_info(drvdata->dev, "initialized\n");
+out:
+	pm_runtime_put(&adev->dev);
+	return ret;
+}
+
+static struct amba_id catu_ids[] = {
+	{
+		.id	= 0x000bb9ee,
+		.mask	= 0x000fffff,
+	},
+	{},
+};
+
+static struct amba_driver catu_driver = {
+	.drv = {
+		.name			= "coresight-catu",
+		.owner			= THIS_MODULE,
+		.suppress_bind_attrs	= true,
+	},
+	.probe				= catu_probe,
+	.id_table			= catu_ids,
+};
+
+builtin_amba_driver(catu_driver);
diff --git a/drivers/hwtracing/coresight/coresight-catu.h b/drivers/hwtracing/coresight/coresight-catu.h
new file mode 100644
index 0000000..cd58d6f
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-catu.h
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Copyright (C) 2017 ARM Limited. All rights reserved.
+ *
+ * Author: Suzuki K Poulose <suzuki.poulose@arm.com>
+ *
+ */
+
+#ifndef _CORESIGHT_CATU_H
+#define _CORESIGHT_CATU_H
+
+#include "coresight-priv.h"
+
+/* Register offset from base */
+#define CATU_CONTROL		0x000
+#define CATU_MODE		0x004
+#define CATU_AXICTRL		0x008
+#define CATU_IRQEN		0x00c
+#define CATU_SLADDRLO		0x020
+#define CATU_SLADDRHI		0x024
+#define CATU_INADDRLO		0x028
+#define CATU_INADDRHI		0x02c
+#define CATU_STATUS		0x100
+#define CATU_DEVARCH		0xfbc
+
+#define CATU_CONTROL_ENABLE	0
+
+#define CATU_MODE_PASS_THROUGH	0U
+#define CATU_MODE_TRANSLATE	1U
+
+#define CATU_STATUS_READY	8
+#define CATU_STATUS_ADRERR	0
+#define CATU_STATUS_AXIERR	4
+
+
+#define CATU_IRQEN_ON		0x1
+#define CATU_IRQEN_OFF		0x0
+
+
+struct catu_drvdata {
+	struct device *dev;
+	void __iomem *base;
+	struct coresight_device *csdev;
+	int irq;
+};
+
+#define CATU_REG32(name, offset)					\
+static inline u32							\
+catu_read_##name(struct catu_drvdata *drvdata)				\
+{									\
+	return coresight_read_reg_pair(drvdata->base, offset, -1);	\
+}									\
+static inline void							\
+catu_write_##name(struct catu_drvdata *drvdata, u32 val)		\
+{									\
+	coresight_write_reg_pair(drvdata->base, val, offset, -1);	\
+}
+
+#define CATU_REG_PAIR(name, lo_off, hi_off)				\
+static inline u64							\
+catu_read_##name(struct catu_drvdata *drvdata)				\
+{									\
+	return coresight_read_reg_pair(drvdata->base, lo_off, hi_off);	\
+}									\
+static inline void							\
+catu_write_##name(struct catu_drvdata *drvdata, u64 val)		\
+{									\
+	coresight_write_reg_pair(drvdata->base, val, lo_off, hi_off);	\
+}
+
+CATU_REG32(control, CATU_CONTROL);
+CATU_REG32(mode, CATU_MODE);
+CATU_REG_PAIR(sladdr, CATU_SLADDRLO, CATU_SLADDRHI)
+CATU_REG_PAIR(inaddr, CATU_INADDRLO, CATU_INADDRHI)
+
+static inline bool coresight_is_catu_device(struct coresight_device *csdev)
+{
+	enum coresight_dev_subtype_helper subtype;
+
+	/* Make the checkpatch happy */
+	subtype = csdev->subtype.helper_subtype;
+
+	return IS_ENABLED(CONFIG_CORESIGHT_CATU) &&
+	       csdev->type == CORESIGHT_DEV_TYPE_HELPER &&
+	       subtype == CORESIGHT_DEV_SUBTYPE_HELPER_CATU;
+}
+
+#endif
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 68fbc8f..9b0c620 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -17,9 +17,26 @@
 
 #include <linux/coresight.h>
 #include <linux/dma-mapping.h>
+#include "coresight-catu.h"
 #include "coresight-priv.h"
 #include "coresight-tmc.h"
 
+static inline void tmc_etr_enable_catu(struct tmc_drvdata *drvdata)
+{
+	struct coresight_device *catu = tmc_etr_get_catu_device(drvdata);
+
+	if (catu && helper_ops(catu)->enable)
+		helper_ops(catu)->enable(catu, NULL);
+}
+
+static inline void tmc_etr_disable_catu(struct tmc_drvdata *drvdata)
+{
+	struct coresight_device *catu = tmc_etr_get_catu_device(drvdata);
+
+	if (catu && helper_ops(catu)->disable)
+		helper_ops(catu)->disable(catu, NULL);
+}
+
 static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata)
 {
 	u32 axictl, sts;
@@ -27,6 +44,12 @@ static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata)
 	/* Zero out the memory to help with debug */
 	memset(drvdata->vaddr, 0, drvdata->size);
 
+	/*
+	 * If this ETR is connected to a CATU, enable it before we turn
+	 * this on
+	 */
+	tmc_etr_enable_catu(drvdata);
+
 	CS_UNLOCK(drvdata->base);
 
 	/* Wait for TMCSReady bit to be set */
@@ -116,6 +139,9 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
 	tmc_disable_hw(drvdata);
 
 	CS_LOCK(drvdata->base);
+
+	/* Disable CATU device if this ETR is connected to one */
+	tmc_etr_disable_catu(drvdata);
 }
 
 static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 8df7a81..cdff853 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -19,6 +19,7 @@
 #define _CORESIGHT_TMC_H
 
 #include <linux/miscdevice.h>
+#include "coresight-catu.h"
 
 #define TMC_RSZ			0x004
 #define TMC_STS			0x00c
@@ -222,4 +223,30 @@ static inline bool tmc_etr_has_cap(struct tmc_drvdata *drvdata, u32 cap)
 	return !!(drvdata->etr_caps & cap);
 }
 
+/*
+ * TMC ETR could be connected to a CATU device, which can provide address
+ * translation service. This is represented by the Output port of the TMC
+ * (ETR) connected to the input port of the CATU.
+ *
+ * Returns	: coresight_device ptr for the CATU device if a CATU is found.
+ *		: NULL otherwise.
+ */
+static inline struct coresight_device *
+tmc_etr_get_catu_device(struct tmc_drvdata *drvdata)
+{
+	int i;
+	struct coresight_device *tmp, *etr = drvdata->csdev;
+
+	if (!IS_ENABLED(CONFIG_CORESIGHT_CATU))
+		return NULL;
+
+	for (i = 0; i < etr->nr_outport; i++) {
+		tmp = etr->conns[0].child_dev;
+		if (tmp && coresight_is_catu_device(tmp))
+			return tmp;
+	}
+
+	return NULL;
+}
+
 #endif
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 5e926f7..c0e1568 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -72,6 +72,7 @@ enum coresight_dev_subtype_source {
 
 enum coresight_dev_subtype_helper {
 	CORESIGHT_DEV_SUBTYPE_HELPER_NONE,
+	CORESIGHT_DEV_SUBTYPE_HELPER_CATU,
 };
 
 /**
-- 
2.7.4