hwtracing: hisi_ptt: Add trace function support for HiSilicon PCIe Tune and Trace device

HiSilicon PCIe tune and trace device(PTT) is a PCIe Root Complex integrated
Endpoint(RCiEP) device, providing the capability to dynamically monitor and
tune the PCIe traffic and trace the TLP headers.

Add the driver for the device to enable the trace function. Register PMU
device of PTT trace, then users can use trace through perf command. The
driver makes use of perf AUX trace function and support the following
events to configure the trace:

- filter: select Root port or Endpoint to trace
- type: select the type of traced TLP headers
- direction: select the direction of traced TLP headers
- format: select the data format of the traced TLP headers

This patch initially add basic trace support of PTT device.
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20220816114414.4092-3-yangyicong@huawei.comSigned-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

drivers/Makefile

@@ -175,6 +175,7 @@ obj-$(CONFIG_USB4)		+= thunderbolt/
 obj-$(CONFIG_CORESIGHT)		+= hwtracing/coresight/
 obj-y				+= hwtracing/intel_th/
 obj-$(CONFIG_STM)		+= hwtracing/stm/
+obj-$(CONFIG_HISI_PTT)		+= hwtracing/ptt/
 obj-y				+= android/
 obj-$(CONFIG_NVMEM)		+= nvmem/
 obj-$(CONFIG_FPGA)		+= fpga/

drivers/hwtracing/Kconfig

@@ -5,4 +5,6 @@ source "drivers/hwtracing/stm/Kconfig"
 
 source "drivers/hwtracing/intel_th/Kconfig"
 
+source "drivers/hwtracing/ptt/Kconfig"
+
 endmenu

drivers/hwtracing/ptt/Kconfig

+# SPDX-License-Identifier: GPL-2.0-only
+config HISI_PTT
+	tristate "HiSilicon PCIe Tune and Trace Device"
+	depends on ARM64 || (COMPILE_TEST && 64BIT)
+	depends on PCI && HAS_DMA && HAS_IOMEM && PERF_EVENTS
+	help
+	  HiSilicon PCIe Tune and Trace device exists as a PCIe RCiEP
+	  device, and it provides support for PCIe traffic tuning and
+	  tracing TLP headers to the memory.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called hisi_ptt.

drivers/hwtracing/ptt/Makefile

+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_HISI_PTT) += hisi_ptt.o

drivers/hwtracing/ptt/hisi_ptt.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Driver for HiSilicon PCIe tune and trace device
+ *
+ * Copyright (c) 2022 HiSilicon Technologies Co., Ltd.
+ * Author: Yicong Yang <yangyicong@hisilicon.com>
+ */
+
+#ifndef _HISI_PTT_H
+#define _HISI_PTT_H
+
+#include <linux/bits.h>
+#include <linux/cpumask.h>
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <linux/perf_event.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#define DRV_NAME "hisi_ptt"
+
+/*
+ * The definition of the device registers and register fields.
+ */
+#define HISI_PTT_TRACE_ADDR_SIZE	0x0800
+#define HISI_PTT_TRACE_ADDR_BASE_LO_0	0x0810
+#define HISI_PTT_TRACE_ADDR_BASE_HI_0	0x0814
+#define HISI_PTT_TRACE_ADDR_STRIDE	0x8
+#define HISI_PTT_TRACE_CTRL		0x0850
+#define   HISI_PTT_TRACE_CTRL_EN	BIT(0)
+#define   HISI_PTT_TRACE_CTRL_RST	BIT(1)
+#define   HISI_PTT_TRACE_CTRL_RXTX_SEL	GENMASK(3, 2)
+#define   HISI_PTT_TRACE_CTRL_TYPE_SEL	GENMASK(7, 4)
+#define   HISI_PTT_TRACE_CTRL_DATA_FORMAT	BIT(14)
+#define   HISI_PTT_TRACE_CTRL_FILTER_MODE	BIT(15)
+#define   HISI_PTT_TRACE_CTRL_TARGET_SEL	GENMASK(31, 16)
+#define HISI_PTT_TRACE_INT_STAT		0x0890
+#define   HISI_PTT_TRACE_INT_STAT_MASK	GENMASK(3, 0)
+#define HISI_PTT_TRACE_INT_MASK		0x0894
+#define HISI_PTT_TRACE_WR_STS		0x08a0
+#define   HISI_PTT_TRACE_WR_STS_WRITE	GENMASK(27, 0)
+#define   HISI_PTT_TRACE_WR_STS_BUFFER	GENMASK(29, 28)
+#define HISI_PTT_TRACE_STS		0x08b0
+#define   HISI_PTT_TRACE_IDLE		BIT(0)
+#define HISI_PTT_DEVICE_RANGE		0x0fe0
+#define   HISI_PTT_DEVICE_RANGE_UPPER	GENMASK(31, 16)
+#define   HISI_PTT_DEVICE_RANGE_LOWER	GENMASK(15, 0)
+#define HISI_PTT_LOCATION		0x0fe8
+#define   HISI_PTT_CORE_ID		GENMASK(15, 0)
+#define   HISI_PTT_SICL_ID		GENMASK(31, 16)
+
+/* Parameters of PTT trace DMA part. */
+#define HISI_PTT_TRACE_DMA_IRQ			0
+#define HISI_PTT_TRACE_BUF_CNT			4
+#define HISI_PTT_TRACE_BUF_SIZE			SZ_4M
+#define HISI_PTT_TRACE_TOTAL_BUF_SIZE		(HISI_PTT_TRACE_BUF_SIZE * \
+						 HISI_PTT_TRACE_BUF_CNT)
+/* Wait time for hardware DMA to reset */
+#define HISI_PTT_RESET_TIMEOUT_US	10UL
+#define HISI_PTT_RESET_POLL_INTERVAL_US	1UL
+/* Poll timeout and interval for waiting hardware work to finish */
+#define HISI_PTT_WAIT_TRACE_TIMEOUT_US	100UL
+#define HISI_PTT_WAIT_POLL_INTERVAL_US	10UL
+
+#define HISI_PCIE_CORE_PORT_ID(devfn)	((PCI_SLOT(devfn) & 0x7) << 1)
+
+/* Definition of the PMU configs */
+#define HISI_PTT_PMU_FILTER_IS_PORT	BIT(19)
+#define HISI_PTT_PMU_FILTER_VAL_MASK	GENMASK(15, 0)
+#define HISI_PTT_PMU_DIRECTION_MASK	GENMASK(23, 20)
+#define HISI_PTT_PMU_TYPE_MASK		GENMASK(31, 24)
+#define HISI_PTT_PMU_FORMAT_MASK	GENMASK(35, 32)
+
+/**
+ * struct hisi_ptt_dma_buffer - Describe a single trace buffer of PTT trace.
+ *                              The detail of the data format is described
+ *                              in the documentation of PTT device.
+ * @dma:   DMA address of this buffer visible to the device
+ * @addr:  virtual address of this buffer visible to the cpu
+ */
+struct hisi_ptt_dma_buffer {
+	dma_addr_t dma;
+	void *addr;
+};
+
+/**
+ * struct hisi_ptt_trace_ctrl - Control and status of PTT trace
+ * @trace_buf: array of the trace buffers for holding the trace data.
+ *             the length will be HISI_PTT_TRACE_BUF_CNT.
+ * @handle:    perf output handle of current trace session
+ * @buf_index: the index of current using trace buffer
+ * @on_cpu:    current tracing cpu
+ * @started:   current trace status, true for started
+ * @is_port:   whether we're tracing root port or not
+ * @direction: direction of the TLP headers to trace
+ * @filter:    filter value for tracing the TLP headers
+ * @format:    format of the TLP headers to trace
+ * @type:      type of the TLP headers to trace
+ */
+struct hisi_ptt_trace_ctrl {
+	struct hisi_ptt_dma_buffer *trace_buf;
+	struct perf_output_handle handle;
+	u32 buf_index;
+	int on_cpu;
+	bool started;
+	bool is_port;
+	u32 direction:2;
+	u32 filter:16;
+	u32 format:1;
+	u32 type:4;
+};
+
+/**
+ * struct hisi_ptt_filter_desc - Descriptor of the PTT trace filter
+ * @list:    entry of this descriptor in the filter list
+ * @is_port: the PCI device of the filter is a Root Port or not
+ * @devid:   the PCI device's devid of the filter
+ */
+struct hisi_ptt_filter_desc {
+	struct list_head list;
+	bool is_port;
+	u16 devid;
+};
+
+/**
+ * struct hisi_ptt_pmu_buf - Descriptor of the AUX buffer of PTT trace
+ * @length:   size of the AUX buffer
+ * @nr_pages: number of pages of the AUX buffer
+ * @base:     start address of AUX buffer
+ * @pos:      position in the AUX buffer to commit traced data
+ */
+struct hisi_ptt_pmu_buf {
+	size_t length;
+	int nr_pages;
+	void *base;
+	long pos;
+};
+
+/**
+ * struct hisi_ptt - Per PTT device data
+ * @trace_ctrl:   the control information of PTT trace
+ * @hotplug_node: node for register cpu hotplug event
+ * @hisi_ptt_pmu: the pum device of trace
+ * @iobase:       base IO address of the device
+ * @pdev:         pci_dev of this PTT device
+ * @pmu_lock:     lock to serialize the perf process
+ * @upper_bdf:    the upper BDF range of the PCI devices managed by this PTT device
+ * @lower_bdf:    the lower BDF range of the PCI devices managed by this PTT device
+ * @port_filters: the filter list of root ports
+ * @req_filters:  the filter list of requester ID
+ * @port_mask:    port mask of the managed root ports
+ */
+struct hisi_ptt {
+	struct hisi_ptt_trace_ctrl trace_ctrl;
+	struct hlist_node hotplug_node;
+	struct pmu hisi_ptt_pmu;
+	void __iomem *iobase;
+	struct pci_dev *pdev;
+	spinlock_t pmu_lock;
+	u32 upper_bdf;
+	u32 lower_bdf;
+
+	/*
+	 * The trace TLP headers can either be filtered by certain
+	 * root port, or by the requester ID. Organize the filters
+	 * by @port_filters and @req_filters here. The mask of all
+	 * the valid ports is also cached for doing sanity check
+	 * of user input.
+	 */
+	struct list_head port_filters;
+	struct list_head req_filters;
+	u16 port_mask;
+};
+
+#define to_hisi_ptt(pmu) container_of(pmu, struct hisi_ptt, hisi_ptt_pmu)
+
+#endif /* _HISI_PTT_H */