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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, coresight@lists.linaro.org,
        mathieu.poirier@linaro.org, leo.yan@linaro.org,
        mike.leach@linaro.org, anshuman.khandual@arm.com,
        Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: [PATCH v6 03/26] coresight: Introduce device access abstraction
Date:   Thu,  7 Jan 2021 12:38:36 +0000
Message-Id: <20210107123859.674252-4-suzuki.poulose@arm.com>
In-Reply-To: <20210107123859.674252-1-suzuki.poulose@arm.com>
References: <20210107123859.674252-1-suzuki.poulose@arm.com>
MIME-Version: 1.0
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We are about to introduce support for sysreg access to ETMv4.4+
component. Since there are generic routines that access the
registers (e.g, CS_LOCK/UNLOCK , claim/disclaim operations, timeout)
and in order to preserve the logic of these operations at a
single place we introduce an abstraction layer for the accesses
to a given device.

Cc: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
Change since v3
 - Dropped csa argument to read()/write().
 - Addressed comments on spacing and adding labels for the #if #else #endifs.
   (Mathieu)
---
 drivers/hwtracing/coresight/coresight-catu.c  |   1 +
 drivers/hwtracing/coresight/coresight-core.c  |  43 ++++
 .../hwtracing/coresight/coresight-cti-core.c  |   1 +
 drivers/hwtracing/coresight/coresight-etb10.c |   1 +
 .../coresight/coresight-etm3x-core.c          |   1 +
 .../coresight/coresight-etm4x-core.c          |   1 +
 .../hwtracing/coresight/coresight-funnel.c    |   1 +
 .../coresight/coresight-replicator.c          |   1 +
 drivers/hwtracing/coresight/coresight-stm.c   |   1 +
 .../hwtracing/coresight/coresight-tmc-core.c  |   1 +
 drivers/hwtracing/coresight/coresight-tpiu.c  |   1 +
 include/linux/coresight.h                     | 198 +++++++++++++++++-
 12 files changed, 248 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c
index a61313f320bd..867c932c7b26 100644
--- a/drivers/hwtracing/coresight/coresight-catu.c
+++ b/drivers/hwtracing/coresight/coresight-catu.c
@@ -551,6 +551,7 @@ static int catu_probe(struct amba_device *adev, const struct amba_id *id)
 	dev->platform_data = pdata;
 
 	drvdata->base = base;
+	catu_desc.access = CSDEV_ACCESS_IOMEM(base);
 	catu_desc.pdata = pdata;
 	catu_desc.dev = dev;
 	catu_desc.groups = catu_groups;
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 4ba801dffcb7..a38af8f0831b 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1458,6 +1458,48 @@ int coresight_timeout(void __iomem *addr, u32 offset, int position, int value)
 }
 EXPORT_SYMBOL_GPL(coresight_timeout);
 
+u32 coresight_relaxed_read32(struct coresight_device *csdev, u32 offset)
+{
+	return csdev_access_relaxed_read32(&csdev->access, offset);
+}
+
+u32 coresight_read32(struct coresight_device *csdev, u32 offset)
+{
+	return csdev_access_read32(&csdev->access, offset);
+}
+
+void coresight_relaxed_write32(struct coresight_device *csdev,
+			       u32 val, u32 offset)
+{
+	csdev_access_relaxed_write32(&csdev->access, val, offset);
+}
+
+void coresight_write32(struct coresight_device *csdev, u32 val, u32 offset)
+{
+	csdev_access_write32(&csdev->access, val, offset);
+}
+
+u64 coresight_relaxed_read64(struct coresight_device *csdev, u32 offset)
+{
+	return csdev_access_relaxed_read64(&csdev->access, offset);
+}
+
+u64 coresight_read64(struct coresight_device *csdev, u32 offset)
+{
+	return csdev_access_read64(&csdev->access, offset);
+}
+
+void coresight_relaxed_write64(struct coresight_device *csdev,
+			       u64 val, u32 offset)
+{
+	csdev_access_relaxed_write64(&csdev->access, val, offset);
+}
+
+void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset)
+{
+	csdev_access_write64(&csdev->access, val, offset);
+}
+
 /*
  * coresight_release_platform_data: Release references to the devices connected
  * to the output port of this device.
@@ -1522,6 +1564,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)
 	csdev->type = desc->type;
 	csdev->subtype = desc->subtype;
 	csdev->ops = desc->ops;
+	csdev->access = desc->access;
 	csdev->orphan = false;
 
 	csdev->dev.type = &coresight_dev_type[desc->type];
diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c
index 61dbc1afd8da..b38a8db5f252 100644
--- a/drivers/hwtracing/coresight/coresight-cti-core.c
+++ b/drivers/hwtracing/coresight/coresight-cti-core.c
@@ -870,6 +870,7 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
 		return PTR_ERR(base);
 
 	drvdata->base = base;
+	cti_desc.access = CSDEV_ACCESS_IOMEM(base);
 
 	dev_set_drvdata(dev, drvdata);
 
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index 0cf6f0b947b6..cc742561a986 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -757,6 +757,7 @@ static int etb_probe(struct amba_device *adev, const struct amba_id *id)
 		return PTR_ERR(base);
 
 	drvdata->base = base;
+	desc.access = CSDEV_ACCESS_IOMEM(base);
 
 	spin_lock_init(&drvdata->spinlock);
 
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
index 5bf5a5a4ce6d..3b7837cbe376 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
@@ -839,6 +839,7 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
 		return PTR_ERR(base);
 
 	drvdata->base = base;
+	desc.access = CSDEV_ACCESS_IOMEM(base);
 
 	spin_lock_init(&drvdata->spinlock);
 
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index cce65fc0c9aa..ebd41bb7ce1c 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -1626,6 +1626,7 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
 		return PTR_ERR(base);
 
 	drvdata->base = base;
+	desc.access = CSDEV_ACCESS_IOMEM(base);
 
 	spin_lock_init(&drvdata->spinlock);
 
diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
index 071c723227db..8f7c40d7d8d6 100644
--- a/drivers/hwtracing/coresight/coresight-funnel.c
+++ b/drivers/hwtracing/coresight/coresight-funnel.c
@@ -242,6 +242,7 @@ static int funnel_probe(struct device *dev, struct resource *res)
 		}
 		drvdata->base = base;
 		desc.groups = coresight_funnel_groups;
+		desc.access = CSDEV_ACCESS_IOMEM(base);
 	}
 
 	dev_set_drvdata(dev, drvdata);
diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
index 7e2a2b7f503f..205756fab729 100644
--- a/drivers/hwtracing/coresight/coresight-replicator.c
+++ b/drivers/hwtracing/coresight/coresight-replicator.c
@@ -254,6 +254,7 @@ static int replicator_probe(struct device *dev, struct resource *res)
 		}
 		drvdata->base = base;
 		desc.groups = replicator_groups;
+		desc.access = CSDEV_ACCESS_IOMEM(base);
 	}
 
 	if (fwnode_property_present(dev_fwnode(dev),
diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
index 99791773f682..41d9a922c2d4 100644
--- a/drivers/hwtracing/coresight/coresight-stm.c
+++ b/drivers/hwtracing/coresight/coresight-stm.c
@@ -884,6 +884,7 @@ static int stm_probe(struct amba_device *adev, const struct amba_id *id)
 	if (IS_ERR(base))
 		return PTR_ERR(base);
 	drvdata->base = base;
+	desc.access = CSDEV_ACCESS_IOMEM(base);
 
 	ret = stm_get_stimulus_area(dev, &ch_res);
 	if (ret)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
index 8169dff5a9f6..e61b75be66b6 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-core.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
@@ -456,6 +456,7 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
 	}
 
 	drvdata->base = base;
+	desc.access = CSDEV_ACCESS_IOMEM(base);
 
 	spin_lock_init(&drvdata->spinlock);
 
diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c
index d5dfee9ee556..6ca396799883 100644
--- a/drivers/hwtracing/coresight/coresight-tpiu.c
+++ b/drivers/hwtracing/coresight/coresight-tpiu.c
@@ -149,6 +149,7 @@ static int tpiu_probe(struct amba_device *adev, const struct amba_id *id)
 		return PTR_ERR(base);
 
 	drvdata->base = base;
+	desc.access = CSDEV_ACCESS_IOMEM(base);
 
 	/* Disable tpiu to support older devices */
 	tpiu_disable_hw(drvdata);
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 7d3c87e5b97c..d3aa328639cd 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -7,6 +7,7 @@
 #define _LINUX_CORESIGHT_H
 
 #include <linux/device.h>
+#include <linux/io.h>
 #include <linux/perf_event.h>
 #include <linux/sched.h>
 
@@ -114,6 +115,36 @@ struct coresight_platform_data {
 	struct coresight_connection *conns;
 };
 
+/**
+ * struct csdev_access - Abstraction of a CoreSight device access.
+ *
+ * @io_mem	: True if the device has memory mapped I/O
+ * @base	: When io_mem == true, base address of the component
+ * @read	: Read from the given "offset" of the given instance.
+ * @write	: Write "val" to the given "offset".
+ */
+struct csdev_access {
+	bool io_mem;
+	union {
+		void __iomem *base;
+		struct {
+			u64 (*read)(u32 offset,
+				    bool relaxed,
+				    bool _64bit);
+			void (*write)(u64 val,
+				      u32 offset,
+				      bool relaxed,
+				      bool _64bit);
+		};
+	};
+};
+
+#define CSDEV_ACCESS_IOMEM(_addr)		\
+	((struct csdev_access)	{		\
+		.io_mem		= true,		\
+		.base		= (_addr),	\
+	})
+
 /**
  * struct coresight_desc - description of a component required from drivers
  * @type:	as defined by @coresight_dev_type.
@@ -125,6 +156,7 @@ struct coresight_platform_data {
  * @groups:	operations specific to this component. These will end up
  *		in the component's sysfs sub-directory.
  * @name:	name for the coresight device, also shown under sysfs.
+ * @access:	Describe access to the device
  */
 struct coresight_desc {
 	enum coresight_dev_type type;
@@ -134,6 +166,7 @@ struct coresight_desc {
 	struct device *dev;
 	const struct attribute_group **groups;
 	const char *name;
+	struct csdev_access access;
 };
 
 /**
@@ -173,7 +206,8 @@ struct coresight_sysfs_link {
  * @type:	as defined by @coresight_dev_type.
  * @subtype:	as defined by @coresight_dev_subtype.
  * @ops:	generic operations for this component, as defined
-		by @coresight_ops.
+ *		by @coresight_ops.
+ * @access:	Device i/o access abstraction for this device.
  * @dev:	The device entity associated to this component.
  * @refcnt:	keep track of what is in use.
  * @orphan:	true if the component has connections that haven't been linked.
@@ -195,6 +229,7 @@ struct coresight_device {
 	enum coresight_dev_type type;
 	union coresight_dev_subtype subtype;
 	const struct coresight_ops *ops;
+	struct csdev_access access;
 	struct device dev;
 	atomic_t *refcnt;
 	bool orphan;
@@ -326,6 +361,104 @@ struct coresight_ops {
 };
 
 #if IS_ENABLED(CONFIG_CORESIGHT)
+
+static inline u32 csdev_access_relaxed_read32(struct csdev_access *csa,
+					      u32 offset)
+{
+	if (likely(csa->io_mem))
+		return readl_relaxed(csa->base + offset);
+
+	return csa->read(offset, true, false);
+}
+
+static inline u32 csdev_access_read32(struct csdev_access *csa, u32 offset)
+{
+	if (likely(csa->io_mem))
+		return readl(csa->base + offset);
+
+	return csa->read(offset, false, false);
+}
+
+static inline void csdev_access_relaxed_write32(struct csdev_access *csa,
+						u32 val, u32 offset)
+{
+	if (likely(csa->io_mem))
+		writel_relaxed(val, csa->base + offset);
+	else
+		csa->write(val, offset, true, false);
+}
+
+static inline void csdev_access_write32(struct csdev_access *csa, u32 val, u32 offset)
+{
+	if (likely(csa->io_mem))
+		writel(val, csa->base + offset);
+	else
+		csa->write(val, offset, false, false);
+}
+
+#ifdef CONFIG_64BIT
+
+static inline u64 csdev_access_relaxed_read64(struct csdev_access *csa,
+					      u32 offset)
+{
+	if (likely(csa->io_mem))
+		return readq_relaxed(csa->base + offset);
+
+	return csa->read(offset, true, true);
+}
+
+static inline u64 csdev_access_read64(struct csdev_access *csa, u32 offset)
+{
+	if (likely(csa->io_mem))
+		return readq(csa->base + offset);
+
+	return csa->read(offset, false, true);
+}
+
+static inline void csdev_access_relaxed_write64(struct csdev_access *csa,
+						u64 val, u32 offset)
+{
+	if (likely(csa->io_mem))
+		writeq_relaxed(val, csa->base + offset);
+	else
+		csa->write(val, offset, true, true);
+}
+
+static inline void csdev_access_write64(struct csdev_access *csa, u64 val, u32 offset)
+{
+	if (likely(csa->io_mem))
+		writeq(val, csa->base + offset);
+	else
+		csa->write(val, offset, false, true);
+}
+
+#else	/* !CONFIG_64BIT */
+
+static inline u64 csdev_access_relaxed_read64(struct csdev_access *csa,
+					   u32 offset)
+{
+	WARN_ON(1);
+	return 0;
+}
+
+static inline u64 csdev_access_read64(struct csdev_access *csa, u32 offset)
+{
+	WARN_ON(1);
+	return 0;
+}
+
+static inline void csdev_access_relaxed_write64(struct csdev_access *csa,
+						u64 val, u32 offset)
+{
+	WARN_ON(1);
+}
+
+static inline void csdev_access_write64(struct csdev_access *csa, u64 val, u32 offset)
+{
+	WARN_ON(1);
+}
+#endif	/* CONFIG_64BIT */
+
 extern struct coresight_device *
 coresight_register(struct coresight_desc *desc);
 extern void coresight_unregister(struct coresight_device *csdev);
@@ -343,6 +476,20 @@ extern char *coresight_alloc_device_name(struct coresight_dev_list *devs,
 					 struct device *dev);
 
 extern bool coresight_loses_context_with_cpu(struct device *dev);
+
+u32 coresight_relaxed_read32(struct coresight_device *csdev, u32 offset);
+u32 coresight_read32(struct coresight_device *csdev, u32 offset);
+void coresight_write32(struct coresight_device *csdev, u32 val, u32 offset);
+void coresight_relaxed_write32(struct coresight_device *csdev,
+			       u32 val,
+			       u32 offset);
+u64 coresight_relaxed_read64(struct coresight_device *csdev, u32 offset);
+u64 coresight_read64(struct coresight_device *csdev, u32 offset);
+void coresight_relaxed_write64(struct coresight_device *csdev,
+			       u64 val, u32 offset);
+void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset);
+
+
 #else
 static inline struct coresight_device *
 coresight_register(struct coresight_desc *desc) { return NULL; }
@@ -369,10 +516,55 @@ static inline bool coresight_loses_context_with_cpu(struct device *dev)
 {
 	return false;
 }
-#endif
+
+static inline u32 coresight_relaxed_read32(struct coresight_device *csdev, u32 offset)
+{
+	WARN_ON_ONCE(1);
+	return 0;
+}
+
+static inline u32 coresight_read32(struct coresight_device *csdev, u32 offset)
+{
+	WARN_ON_ONCE(1);
+	return 0;
+}
+
+static inline void coresight_write32(struct coresight_device *csdev, u32 val, u32 offset)
+{
+}
+
+static inline void coresight_relaxed_write32(struct coresight_device *csdev,
+					     u32 val, u32 offset)
+{
+}
+
+static inline u64 coresight_relaxed_read64(struct coresight_device *csdev,
+					   u32 offset)
+{
+	WARN_ON_ONCE(1);
+	return 0;
+}
+
+static inline u64 coresight_read64(struct coresight_device *csdev, u32 offset)
+{
+	WARN_ON_ONCE(1);
+	return 0;
+}
+
+static inline void coresight_relaxed_write64(struct coresight_device *csdev,
+					     u64 val,
+					     u32 offset)
+{
+}
+
+static inline void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset)
+{
+}
+
+#endif		/* IS_ENABLED(CONFIG_CORESIGHT) */
 
 extern int coresight_get_cpu(struct device *dev);
 
 struct coresight_platform_data *coresight_get_platform_data(struct device *dev);
 
-#endif
+#endif		/* _LINUX_COREISGHT_H */
-- 
2.24.1