Re: [PATCH v4 2/8] hwtracing: Add trace function support for HiSilicon PCIe Tune and Trace device
From: John Garry
Date: Tue Feb 22 2022 - 06:06:43 EST
On 21/02/2022 08:43, Yicong Yang wrote:
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.
This patch adds basic function of trace, including the device's
probe and initialization, functions for trace buffer allocation
and trace enable/disable, register an interrupt handler to
simply response to the DMA events. The user interface of trace
will be added in the following patch.
Fill commit message lines upto 75 characters
Signed-off-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
---
drivers/Makefile | 1 +
drivers/hwtracing/Kconfig | 2 +
drivers/hwtracing/ptt/Kconfig | 11 +
drivers/hwtracing/ptt/Makefile | 2 +
drivers/hwtracing/ptt/hisi_ptt.c | 370 +++++++++++++++++++++++++++++++
drivers/hwtracing/ptt/hisi_ptt.h | 149 +++++++++++++
6 files changed, 535 insertions(+)
create mode 100644 drivers/hwtracing/ptt/Kconfig
create mode 100644 drivers/hwtracing/ptt/Makefile
create mode 100644 drivers/hwtracing/ptt/hisi_ptt.c
create mode 100644 drivers/hwtracing/ptt/hisi_ptt.h
diff --git a/drivers/Makefile b/drivers/Makefile
index a110338c860c..ab3411e4eba5 100644
--- a/drivers/Makefile
+++ b/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-$(CONFIG_ANDROID) += android/
obj-$(CONFIG_NVMEM) += nvmem/
obj-$(CONFIG_FPGA) += fpga/
diff --git a/drivers/hwtracing/Kconfig b/drivers/hwtracing/Kconfig
index 13085835a636..911ee977103c 100644
--- a/drivers/hwtracing/Kconfig
+++ b/drivers/hwtracing/Kconfig
@@ -5,4 +5,6 @@ source "drivers/hwtracing/stm/Kconfig"
source "drivers/hwtracing/intel_th/Kconfig"
+source "drivers/hwtracing/ptt/Kconfig"
+
endmenu
diff --git a/drivers/hwtracing/ptt/Kconfig b/drivers/hwtracing/ptt/Kconfig
new file mode 100644
index 000000000000..41fa83921a07
--- /dev/null
+++ b/drivers/hwtracing/ptt/Kconfig
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config HISI_PTT
+ tristate "HiSilicon PCIe Tune and Trace Device"
+ depends on ARM64 && PCI && HAS_DMA && HAS_IOMEM
why no compile test support?
+ help
+ HiSilicon PCIe Tune and Trace Device exists as a PCIe RCiEP
+ device, and it provides support for PCIe traffic tuning and
+ tracing TLP headers to the memory.
+
+ This driver can also be built as a module. If so, the module
+ will be called hisi_ptt.
diff --git a/drivers/hwtracing/ptt/Makefile b/drivers/hwtracing/ptt/Makefile
new file mode 100644
index 000000000000..908c09a98161
--- /dev/null
+++ b/drivers/hwtracing/ptt/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_HISI_PTT) += hisi_ptt.o
diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c
new file mode 100644
index 000000000000..a5b4f09ccd1e
--- /dev/null
+++ b/drivers/hwtracing/ptt/hisi_ptt.c
@@ -0,0 +1,370 @@
+// 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@xxxxxxxxxxxxx>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/dma-iommu.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iommu.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/sysfs.h>
+
+#include "hisi_ptt.h"
+
+static u16 hisi_ptt_get_filter_val(struct pci_dev *pdev)
+{
+ if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT)
+ return BIT(HISI_PCIE_CORE_PORT_ID(PCI_SLOT(pdev->devfn)));
+
+ return PCI_DEVID(pdev->bus->number, pdev->devfn);
+}
+
+static int hisi_ptt_wait_trace_hw_idle(struct hisi_ptt *hisi_ptt)
+{
+ u32 val;
+
+ return readl_poll_timeout_atomic(hisi_ptt->iobase + HISI_PTT_TRACE_STS,
+ val, val & HISI_PTT_TRACE_IDLE,
+ HISI_PTT_WAIT_POLL_INTERVAL_US,
+ HISI_PTT_WAIT_TIMEOUT_US);
+}
+
+static int hisi_ptt_wait_dma_reset_done(struct hisi_ptt *hisi_ptt)
+{
+ u32 val;
+
+ return readl_poll_timeout_atomic(hisi_ptt->iobase + HISI_PTT_TRACE_WR_STS,
+ val, !val, HISI_PTT_RESET_POLL_INTERVAL_US,
+ HISI_PTT_RESET_TIMEOUT_US);
+}
+
+static void hisi_ptt_free_trace_buf(struct hisi_ptt *hisi_ptt)
+{
+ struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
+ struct device *dev = &hisi_ptt->pdev->dev;
+ int i;
+
+ if (!ctrl->trace_buf)
+ return;
+
+ for (i = 0; i < HISI_PTT_TRACE_BUF_CNT; i++)
it's good practice to use {} for if-else or similar in the loop
+ if (ctrl->trace_buf[i].addr)
+ dma_free_coherent(dev, HISI_PTT_TRACE_BUF_SIZE,
+ ctrl->trace_buf[i].addr,
+ ctrl->trace_buf[i].dma);
+
+ kfree(ctrl->trace_buf);
+ ctrl->trace_buf = NULL;
+}
+
+static int hisi_ptt_alloc_trace_buf(struct hisi_ptt *hisi_ptt)
+{
+ struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
+ struct device *dev = &hisi_ptt->pdev->dev;
+ int i;
+
+ hisi_ptt->trace_ctrl.buf_index = 0;
+
+ /* If the trace buffer has already been allocated, zero it. */
+ if (ctrl->trace_buf) {
+ for (i = 0; i < HISI_PTT_TRACE_BUF_CNT; i++)
+ memset(ctrl->trace_buf[i].addr, 0, HISI_PTT_TRACE_BUF_SIZE);
+ return 0;
+ }
+
+ ctrl->trace_buf = kcalloc(HISI_PTT_TRACE_BUF_CNT, sizeof(struct hisi_ptt_dma_buffer),
+ GFP_KERNEL);
+ if (!ctrl->trace_buf)
+ return -ENOMEM;
+
+ for (i = 0; i < HISI_PTT_TRACE_BUF_CNT; ++i) {
+ ctrl->trace_buf[i].addr = dma_alloc_coherent(dev, HISI_PTT_TRACE_BUF_SIZE,
+ &ctrl->trace_buf[i].dma,
+ GFP_KERNEL);
dmam_alloc_coherent() would mean that we can drop the manual frees
+ if (!ctrl->trace_buf[i].addr) {
+ hisi_ptt_free_trace_buf(hisi_ptt);
+ return -ENOMEM;
+ }
+ }
+
+ return 0;
+}
+
+static void hisi_ptt_trace_end(struct hisi_ptt *hisi_ptt)
+{
+ writel(0, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+ hisi_ptt->trace_ctrl.status = HISI_PTT_TRACE_STATUS_OFF;
+}
+
+static int hisi_ptt_trace_start(struct hisi_ptt *hisi_ptt)
+{
+ struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
+ u32 val;
+ int i;
+
+ /* Check device idle before start trace */
+ if (hisi_ptt_wait_trace_hw_idle(hisi_ptt)) {
hisi_ptt_wait_trace_hw_idle() is a bit of an odd odd, as I would expect
it to return true when idle
+ pci_err(hisi_ptt->pdev, "Failed to start trace, the device is still busy.\n");
+ return -EBUSY;
+ }
+
+ /* Reset the DMA before start tracing */
+ val = readl(hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+ val |= HISI_PTT_TRACE_CTRL_RST;
+ writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+
+ hisi_ptt_wait_dma_reset_done(hisi_ptt);
+
+ val = readl(hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+ val &= ~HISI_PTT_TRACE_CTRL_RST;
+ writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+
+ /* Clear the interrupt status */
+ writel(HISI_PTT_TRACE_INT_STAT_MASK, hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
+ writel(0, hisi_ptt->iobase + HISI_PTT_TRACE_INT_MASK);
+
+ /* Configure the trace DMA buffer */
+ for (i = 0; i < HISI_PTT_TRACE_BUF_CNT; i++) {
+ writel(lower_32_bits(ctrl->trace_buf[i].dma),
+ hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_BASE_LO_0 +
+ i * HISI_PTT_TRACE_ADDR_STRIDE);
+ writel(upper_32_bits(ctrl->trace_buf[i].dma),
+ hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_BASE_HI_0 +
+ i * HISI_PTT_TRACE_ADDR_STRIDE);
+ }
+ writel(HISI_PTT_TRACE_BUF_SIZE, hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_SIZE);
+
+ /* Set the trace control register */
+ val = FIELD_PREP(HISI_PTT_TRACE_CTRL_TYPE_SEL, ctrl->type);
+ val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_RXTX_SEL, ctrl->direction);
+ val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_DATA_FORMAT, ctrl->format);
+ val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_TARGET_SEL, hisi_ptt->trace_ctrl.filter);
+ if (!hisi_ptt->trace_ctrl.is_port)
+ val |= HISI_PTT_TRACE_CTRL_FILTER_MODE;
+
+ /* Start the Trace */
+ val |= HISI_PTT_TRACE_CTRL_EN;
+ writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+
+ ctrl->status = HISI_PTT_TRACE_STATUS_ON;
+
+ return 0;
+}
+
+static irqreturn_t hisi_ptt_irq(int irq, void *context)
as I said before (I forget the reply), it's odd to add an empty handler.
+{
+ struct hisi_ptt *hisi_ptt = context;
+ u32 status;
+
+ status = readl(hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
+ if (!(status & HISI_PTT_TRACE_INT_STAT_MASK))
+ return IRQ_NONE;
+
+ return IRQ_HANDLED;
+}
+