v4.19.13 snapshot.
diff --git a/drivers/hwtracing/intel_th/sth.c b/drivers/hwtracing/intel_th/sth.c
new file mode 100644
index 0000000..4b7ae47
--- /dev/null
+++ b/drivers/hwtracing/intel_th/sth.c
@@ -0,0 +1,259 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel(R) Trace Hub Software Trace Hub support
+ *
+ * Copyright (C) 2014-2015 Intel Corporation.
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/stm.h>
+
+#include "intel_th.h"
+#include "sth.h"
+
+struct sth_device {
+	void __iomem	*base;
+	void __iomem	*channels;
+	phys_addr_t	channels_phys;
+	struct device	*dev;
+	struct stm_data	stm;
+	unsigned int	sw_nmasters;
+};
+
+static struct intel_th_channel __iomem *
+sth_channel(struct sth_device *sth, unsigned int master, unsigned int channel)
+{
+	struct intel_th_channel __iomem *sw_map = sth->channels;
+
+	return &sw_map[(master - sth->stm.sw_start) * sth->stm.sw_nchannels +
+		       channel];
+}
+
+static void sth_iowrite(void __iomem *dest, const unsigned char *payload,
+			unsigned int size)
+{
+	switch (size) {
+#ifdef CONFIG_64BIT
+	case 8:
+		writeq_relaxed(*(u64 *)payload, dest);
+		break;
+#endif
+	case 4:
+		writel_relaxed(*(u32 *)payload, dest);
+		break;
+	case 2:
+		writew_relaxed(*(u16 *)payload, dest);
+		break;
+	case 1:
+		writeb_relaxed(*(u8 *)payload, dest);
+		break;
+	default:
+		break;
+	}
+}
+
+static ssize_t notrace sth_stm_packet(struct stm_data *stm_data,
+				      unsigned int master,
+				      unsigned int channel,
+				      unsigned int packet,
+				      unsigned int flags,
+				      unsigned int size,
+				      const unsigned char *payload)
+{
+	struct sth_device *sth = container_of(stm_data, struct sth_device, stm);
+	struct intel_th_channel __iomem *out =
+		sth_channel(sth, master, channel);
+	u64 __iomem *outp = &out->Dn;
+	unsigned long reg = REG_STH_TRIG;
+
+#ifndef CONFIG_64BIT
+	if (size > 4)
+		size = 4;
+#endif
+
+	size = rounddown_pow_of_two(size);
+
+	switch (packet) {
+	/* Global packets (GERR, XSYNC, TRIG) are sent with register writes */
+	case STP_PACKET_GERR:
+		reg += 4;
+	case STP_PACKET_XSYNC:
+		reg += 8;
+	case STP_PACKET_TRIG:
+		if (flags & STP_PACKET_TIMESTAMPED)
+			reg += 4;
+		writeb_relaxed(*payload, sth->base + reg);
+		break;
+
+	case STP_PACKET_MERR:
+		if (size > 4)
+			size = 4;
+
+		sth_iowrite(&out->MERR, payload, size);
+		break;
+
+	case STP_PACKET_FLAG:
+		if (flags & STP_PACKET_TIMESTAMPED)
+			outp = (u64 __iomem *)&out->FLAG_TS;
+		else
+			outp = (u64 __iomem *)&out->FLAG;
+
+		size = 0;
+		writeb_relaxed(0, outp);
+		break;
+
+	case STP_PACKET_USER:
+		if (flags & STP_PACKET_TIMESTAMPED)
+			outp = &out->USER_TS;
+		else
+			outp = &out->USER;
+		sth_iowrite(outp, payload, size);
+		break;
+
+	case STP_PACKET_DATA:
+		outp = &out->Dn;
+
+		if (flags & STP_PACKET_TIMESTAMPED)
+			outp += 2;
+		if (flags & STP_PACKET_MARKED)
+			outp++;
+
+		sth_iowrite(outp, payload, size);
+		break;
+	default:
+		return -ENOTSUPP;
+	}
+
+	return size;
+}
+
+static phys_addr_t
+sth_stm_mmio_addr(struct stm_data *stm_data, unsigned int master,
+		  unsigned int channel, unsigned int nr_chans)
+{
+	struct sth_device *sth = container_of(stm_data, struct sth_device, stm);
+	phys_addr_t addr;
+
+	master -= sth->stm.sw_start;
+	addr = sth->channels_phys + (master * sth->stm.sw_nchannels + channel) *
+		sizeof(struct intel_th_channel);
+
+	if (offset_in_page(addr) ||
+	    offset_in_page(nr_chans * sizeof(struct intel_th_channel)))
+		return 0;
+
+	return addr;
+}
+
+static int sth_stm_link(struct stm_data *stm_data, unsigned int master,
+			 unsigned int channel)
+{
+	struct sth_device *sth = container_of(stm_data, struct sth_device, stm);
+
+	intel_th_set_output(to_intel_th_device(sth->dev), master);
+
+	return 0;
+}
+
+static int intel_th_sw_init(struct sth_device *sth)
+{
+	u32 reg;
+
+	reg = ioread32(sth->base + REG_STH_STHCAP1);
+	sth->stm.sw_nchannels = reg & 0xff;
+
+	reg = ioread32(sth->base + REG_STH_STHCAP0);
+	sth->stm.sw_start = reg & 0xffff;
+	sth->stm.sw_end = reg >> 16;
+
+	sth->sw_nmasters = sth->stm.sw_end - sth->stm.sw_start;
+	dev_dbg(sth->dev, "sw_start: %x sw_end: %x masters: %x nchannels: %x\n",
+		sth->stm.sw_start, sth->stm.sw_end, sth->sw_nmasters,
+		sth->stm.sw_nchannels);
+
+	return 0;
+}
+
+static int intel_th_sth_probe(struct intel_th_device *thdev)
+{
+	struct device *dev = &thdev->dev;
+	struct sth_device *sth;
+	struct resource *res;
+	void __iomem *base, *channels;
+	int err;
+
+	res = intel_th_device_get_resource(thdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	base = devm_ioremap(dev, res->start, resource_size(res));
+	if (!base)
+		return -ENOMEM;
+
+	res = intel_th_device_get_resource(thdev, IORESOURCE_MEM, 1);
+	if (!res)
+		return -ENODEV;
+
+	channels = devm_ioremap(dev, res->start, resource_size(res));
+	if (!channels)
+		return -ENOMEM;
+
+	sth = devm_kzalloc(dev, sizeof(*sth), GFP_KERNEL);
+	if (!sth)
+		return -ENOMEM;
+
+	sth->dev = dev;
+	sth->base = base;
+	sth->channels = channels;
+	sth->channels_phys = res->start;
+	sth->stm.name = dev_name(dev);
+	sth->stm.packet = sth_stm_packet;
+	sth->stm.mmio_addr = sth_stm_mmio_addr;
+	sth->stm.sw_mmiosz = sizeof(struct intel_th_channel);
+	sth->stm.link = sth_stm_link;
+
+	err = intel_th_sw_init(sth);
+	if (err)
+		return err;
+
+	err = stm_register_device(dev, &sth->stm, THIS_MODULE);
+	if (err) {
+		dev_err(dev, "stm_register_device failed\n");
+		return err;
+	}
+
+	dev_set_drvdata(dev, sth);
+
+	return 0;
+}
+
+static void intel_th_sth_remove(struct intel_th_device *thdev)
+{
+	struct sth_device *sth = dev_get_drvdata(&thdev->dev);
+
+	stm_unregister_device(&sth->stm);
+}
+
+static struct intel_th_driver intel_th_sth_driver = {
+	.probe	= intel_th_sth_probe,
+	.remove	= intel_th_sth_remove,
+	.driver	= {
+		.name	= "sth",
+		.owner	= THIS_MODULE,
+	},
+};
+
+module_driver(intel_th_sth_driver,
+	      intel_th_driver_register,
+	      intel_th_driver_unregister);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Intel(R) Trace Hub Software Trace Hub driver");
+MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@intel.com>");