[PATCH 0/2] TPMI debugfs suport

[PATCH 0/2] TPMI debugfs suport

[Srinivas Pandruvada]

The first patch provides interface to read feature status. This is
generic patch to be used by other feature drivers.
The second patch patch add support for debugfs. Debugfs also display
feature status using the first patch.

Srinivas Pandruvada (2):
  platform/x86/intel/tpmi: Read feature control status
  platform/x86/intel/tpmi: Add debugfs interface

 drivers/platform/x86/intel/tpmi.c | 392 +++++++++++++++++++++++++++++-
 include/linux/intel_tpmi.h        |   2 +
 2 files changed, 387 insertions(+), 7 deletions(-)

-- 
2.38.1

[PATCH 1/2] platform/x86/intel/tpmi: Read feature control status

[Srinivas Pandruvada]

Some of the PM features can be locked or disabled. In that case, write
interface can be locked.

This status is read via a mailbox. There is one TPMI ID which provides
base address for interface and data register for mail box operation.
The mailbox operations is defined in the TPMI specification. Refer to
https://github.com/intel/tpmi_power_management/ for TPMI specifications.

An API is exposed to feature drivers to read feature control status.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
As suggested by Dan Williams changed ioremap to devm_ioremap() after
review by Andy.

 drivers/platform/x86/intel/tpmi.c | 147 ++++++++++++++++++++++++++++++
 include/linux/intel_tpmi.h        |   2 +
 2 files changed, 149 insertions(+)

diff --git a/drivers/platform/x86/intel/tpmi.c b/drivers/platform/x86/intel/tpmi.c
index a5227951decc..9545e9cdb924 100644
--- a/drivers/platform/x86/intel/tpmi.c
+++ b/drivers/platform/x86/intel/tpmi.c
@@ -47,8 +47,11 @@
  */
 
 #include <linux/auxiliary_bus.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>
 #include <linux/intel_tpmi.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 
@@ -98,6 +101,7 @@ struct intel_tpmi_pm_feature {
  * @feature_count:	Number of TPMI of TPMI instances pointed by tpmi_features
  * @pfs_start:		Start of PFS offset for the TPMI instances in this device
  * @plat_info:		Stores platform info which can be used by the client drivers
+ * @tpmi_control_mem:	Memory mapped IO for getting control information
  *
  * Stores the information for all TPMI devices enumerated from a single PCI device.
  */
@@ -107,6 +111,7 @@ struct intel_tpmi_info {
 	int feature_count;
 	u64 pfs_start;
 	struct intel_tpmi_plat_info plat_info;
+	void __iomem *tpmi_control_mem;
 };
 
 /**
@@ -139,6 +144,7 @@ enum intel_tpmi_id {
 	TPMI_ID_PEM = 1, /* Power and Perf excursion Monitor */
 	TPMI_ID_UNCORE = 2, /* Uncore Frequency Scaling */
 	TPMI_ID_SST = 5, /* Speed Select Technology */
+	TPMI_CONTROL_ID = 0x80, /* Special ID for getting feature status */
 	TPMI_INFO_ID = 0x81, /* Special ID for PCI BDF and Package ID information */
 };
 
@@ -175,6 +181,144 @@ struct resource *tpmi_get_resource_at_index(struct auxiliary_device *auxdev, int
 }
 EXPORT_SYMBOL_NS_GPL(tpmi_get_resource_at_index, INTEL_TPMI);
 
+/* TPMI Control Interface */
+
+#define TPMI_CONTROL_STATUS_OFFSET	0x00
+#define TPMI_COMMAND_OFFSET		0x08
+#define TPMI_DATA_OFFSET		0x0C
+/*
+ * Spec is calling for max 1 seconds to get ownership at the worst
+ * case. Read at 10 ms timeouts and repeat up to 1 second.
+ */
+#define TPMI_CONTROL_TIMEOUT_US		(10 * USEC_PER_MSEC)
+#define TPMI_CONTROL_TIMEOUT_MAX_US	USEC_PER_SEC
+
+#define TPMI_RB_TIMEOUT_US		(10 * USEC_PER_MSEC)
+#define TPMI_RB_TIMEOUT_MAX_US		USEC_PER_SEC
+
+#define TPMI_OWNER_NONE			0
+#define TPMI_OWNER_IN_BAND		1
+
+#define TPMI_GENMASK_OWNER	GENMASK_ULL(5, 4)
+#define TPMI_GENMASK_STATUS	GENMASK_ULL(15, 8)
+
+#define TPMI_GET_STATE_CMD		0x10
+#define TPMI_GET_STATE_CMD_DATA_OFFSET	8
+#define TPMI_CMD_DATA_OFFSET		32
+#define TPMI_CMD_PKT_LEN_OFFSET		16
+#define TPMI_CMD_PKT_LEN		2
+#define TPMI_CONTROL_RB_BIT		0
+#define TPMI_CONTROL_CPL_BIT		6
+#define TPMI_CMD_STATUS_SUCCESS		0x40
+#define TPMI_GET_STATUS_BIT_ENABLE	0
+#define TPMI_GET_STATUS_BIT_LOCKED	31
+
+/* Mutex to complete get feature status without interruption */
+static DEFINE_MUTEX(tpmi_dev_lock);
+
+static int tpmi_wait_for_owner(struct intel_tpmi_info *tpmi_info, u8 owner)
+{
+	u64 control;
+
+	return read_poll_timeout(readq, control, owner == FIELD_GET(TPMI_GENMASK_OWNER, control),
+				 TPMI_CONTROL_TIMEOUT_US, TPMI_CONTROL_TIMEOUT_MAX_US, false,
+				 tpmi_info->tpmi_control_mem + TPMI_CONTROL_STATUS_OFFSET);
+}
+
+static int tpmi_read_feature_status(struct intel_tpmi_info *tpmi_info, int feature_id,
+				    int *locked, int *disabled)
+{
+	u64 control, data;
+	int ret;
+
+	if (!tpmi_info->tpmi_control_mem)
+		return -EFAULT;
+
+	mutex_lock(&tpmi_dev_lock);
+
+	ret = tpmi_wait_for_owner(tpmi_info, TPMI_OWNER_NONE);
+	if (ret)
+		goto err_unlock;
+
+	/* set command id to 0x10 for TPMI_GET_STATE */
+	data = TPMI_GET_STATE_CMD;
+	/* 32 bits for DATA offset and +8 for feature_id field */
+	data |= ((u64)feature_id << (TPMI_CMD_DATA_OFFSET + TPMI_GET_STATE_CMD_DATA_OFFSET));
+
+	/* Write at command offset for qword access */
+	writeq(data, tpmi_info->tpmi_control_mem + TPMI_COMMAND_OFFSET);
+
+	ret = tpmi_wait_for_owner(tpmi_info, TPMI_OWNER_IN_BAND);
+	if (ret)
+		goto err_unlock;
+
+	/* Set Run Busy and packet length of 2 dwords */
+	writeq(BIT_ULL(TPMI_CONTROL_RB_BIT) | (TPMI_CMD_PKT_LEN << TPMI_CMD_PKT_LEN_OFFSET),
+	       tpmi_info->tpmi_control_mem + TPMI_CONTROL_STATUS_OFFSET);
+
+	ret = read_poll_timeout(readq, control, !(control & BIT_ULL(TPMI_CONTROL_RB_BIT)),
+				TPMI_RB_TIMEOUT_US, TPMI_RB_TIMEOUT_MAX_US, false,
+				tpmi_info->tpmi_control_mem + TPMI_CONTROL_STATUS_OFFSET);
+	if (ret)
+		goto done_proc;
+
+	control = FIELD_GET(TPMI_GENMASK_STATUS, control);
+	if (control != TPMI_CMD_STATUS_SUCCESS) {
+		ret = -EBUSY;
+		goto done_proc;
+	}
+
+	data = readq(tpmi_info->tpmi_control_mem + TPMI_COMMAND_OFFSET);
+	data >>= TPMI_CMD_DATA_OFFSET; /* Upper 32 bits are for TPMI_DATA */
+
+	*disabled = 0;
+	*locked = 0;
+
+	if (!(data & BIT_ULL(TPMI_GET_STATUS_BIT_ENABLE)))
+		*disabled = 1;
+
+	if (data & BIT_ULL(TPMI_GET_STATUS_BIT_LOCKED))
+		*locked = 1;
+
+	ret = 0;
+
+done_proc:
+	/* SET CPL "completion"bit */
+	writeq(BIT_ULL(TPMI_CONTROL_CPL_BIT),
+	       tpmi_info->tpmi_control_mem + TPMI_CONTROL_STATUS_OFFSET);
+
+err_unlock:
+	mutex_unlock(&tpmi_dev_lock);
+
+	return ret;
+}
+
+int tpmi_get_feature_status(struct auxiliary_device *auxdev, int feature_id,
+			    int *locked, int *disabled)
+{
+	struct intel_vsec_device *intel_vsec_dev = dev_to_ivdev(auxdev->dev.parent);
+	struct intel_tpmi_info *tpmi_info = auxiliary_get_drvdata(&intel_vsec_dev->auxdev);
+
+	return tpmi_read_feature_status(tpmi_info, feature_id, locked, disabled);
+}
+EXPORT_SYMBOL_NS_GPL(tpmi_get_feature_status, INTEL_TPMI);
+
+static void tpmi_set_control_base(struct auxiliary_device *auxdev,
+				  struct intel_tpmi_info *tpmi_info,
+				  struct intel_tpmi_pm_feature *pfs)
+{
+	void __iomem *mem;
+	u16 size;
+
+	size = pfs->pfs_header.num_entries * pfs->pfs_header.entry_size * 4;
+	mem = devm_ioremap(&auxdev->dev, pfs->vsec_offset, size);
+	if (!mem)
+		return;
+
+	/* mem is pointing to TPMI CONTROL base */
+	tpmi_info->tpmi_control_mem = mem;
+}
+
 static const char *intel_tpmi_name(enum intel_tpmi_id id)
 {
 	switch (id) {
@@ -367,6 +511,9 @@ static int intel_vsec_tpmi_init(struct auxiliary_device *auxdev)
 		 */
 		if (pfs->pfs_header.tpmi_id == TPMI_INFO_ID)
 			tpmi_process_info(tpmi_info, pfs);
+
+		if (pfs->pfs_header.tpmi_id == TPMI_CONTROL_ID)
+			tpmi_set_control_base(auxdev, tpmi_info, pfs);
 	}
 
 	tpmi_info->pfs_start = pfs_start;
diff --git a/include/linux/intel_tpmi.h b/include/linux/intel_tpmi.h
index f505788c05da..04d937ad4dc4 100644
--- a/include/linux/intel_tpmi.h
+++ b/include/linux/intel_tpmi.h
@@ -27,4 +27,6 @@ struct intel_tpmi_plat_info *tpmi_get_platform_data(struct auxiliary_device *aux
 struct resource *tpmi_get_resource_at_index(struct auxiliary_device *auxdev, int index);
 int tpmi_get_resource_count(struct auxiliary_device *auxdev);
 
+int tpmi_get_feature_status(struct auxiliary_device *auxdev, int feature_id, int *locked,
+			    int *disabled);
 #endif
-- 
2.38.1

[PATCH 2/2] platform/x86/intel/tpmi: Add debugfs interface

[Srinivas Pandruvada]

Add debugfs interface for debugging TPMI configuration and register
contents. This shows PFS (PM Feature structure) for each TPMI device.

For each feature shows full register contents and allows to modify
register at an offset.

There is a help file, which explains debugfs contents and operations.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/platform/x86/intel/tpmi.c | 245 +++++++++++++++++++++++++++++-
 1 file changed, 238 insertions(+), 7 deletions(-)

diff --git a/drivers/platform/x86/intel/tpmi.c b/drivers/platform/x86/intel/tpmi.c
index 9545e9cdb924..9ec9c56bca68 100644
--- a/drivers/platform/x86/intel/tpmi.c
+++ b/drivers/platform/x86/intel/tpmi.c
@@ -48,12 +48,14 @@
 
 #include <linux/auxiliary_bus.h>
 #include <linux/bitfield.h>
+#include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/intel_tpmi.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/string_helpers.h>
 
 #include "vsec.h"
 
@@ -86,12 +88,14 @@ struct intel_tpmi_pfs_entry {
  * @vsec_offset: Starting MMIO address for this feature in bytes. Essentially
  *		 this offset = "Address" from VSEC header + PFS Capability
  *		 offset for this feature entry.
+ * @vsec_dev:	Pointer to intel_vsec_device structure for this TPMI device
  *
  * Represents TPMI instance information for one TPMI ID.
  */
 struct intel_tpmi_pm_feature {
 	struct intel_tpmi_pfs_entry pfs_header;
 	unsigned int vsec_offset;
+	struct intel_vsec_device *vsec_dev;
 };
 
 /**
@@ -102,6 +106,7 @@ struct intel_tpmi_pm_feature {
  * @pfs_start:		Start of PFS offset for the TPMI instances in this device
  * @plat_info:		Stores platform info which can be used by the client drivers
  * @tpmi_control_mem:	Memory mapped IO for getting control information
+ * @dbgfs_dir:		debugfs entry pointer
  *
  * Stores the information for all TPMI devices enumerated from a single PCI device.
  */
@@ -112,6 +117,7 @@ struct intel_tpmi_info {
 	u64 pfs_start;
 	struct intel_tpmi_plat_info plat_info;
 	void __iomem *tpmi_control_mem;
+	struct dentry *dbgfs_dir;
 };
 
 /**
@@ -303,6 +309,222 @@ int tpmi_get_feature_status(struct auxiliary_device *auxdev, int feature_id,
 }
 EXPORT_SYMBOL_NS_GPL(tpmi_get_feature_status, INTEL_TPMI);
 
+static int tpmi_help_show(struct seq_file *s, void *unused)
+{
+	const char *help =
+		"TPMI debugfs help\n"
+		"There will be multiple instances of debugfs folders, one for each package\n"
+		"E.g. tpmi-0000:00:03.1\n"
+		"Attributes:\n"
+		"\tpfs_dump: Shows all PFS entries. Refer to TPMI spec for details\n"
+		"\tEach of the TPMI ID will have its folder for read/write register access\n"
+		"\tThe name of the folder suffixed with tpmi ID\n"
+		"\tEach folder contains two entries\n"
+		"\tmem_dump and mem_write\n"
+		"\tmem_dump: Show register contents of full PFS for all TPMI instances\n"
+		"\tThe total size will be pfs->entry_size * pfs->number of entries * 4\n"
+		"\tmem_write: Allows to write at any offset. Hardware ignores writes on read only memory\n"
+		"\tRead/write is at offset multiples of 4\n"
+		"\tThe format is instance:offset:contents\n"
+		"\tThe values are in hex\n"
+		"\t\tExample: echo 0,0x20,0xff > mem_write\n"
+		"\t\tExample: echo 1,64,64 > mem_write\n";
+
+	seq_puts(s, help);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(tpmi_help);
+
+static int tpmi_pfs_dbg_show(struct seq_file *s, void *unused)
+{
+	struct intel_tpmi_info *tpmi_info = s->private;
+	int i, ret;
+
+	seq_printf(s, "tpmi PFS start offset 0x:%llx\n", tpmi_info->pfs_start);
+	seq_puts(s, "tpmi_id\t\tnum_entries\tentry_size\t\tcap_offset\tattribute\tfull_base_pointer_for_memmap\tlocked\tdisabled\n");
+	for (i = 0; i < tpmi_info->feature_count; ++i) {
+		struct intel_tpmi_pm_feature *pfs;
+		int locked, disabled;
+
+		pfs = &tpmi_info->tpmi_features[i];
+		ret = tpmi_read_feature_status(tpmi_info, pfs->pfs_header.tpmi_id, &locked, &disabled);
+		if (ret) {
+			locked = 'U';
+			disabled = 'U';
+		} else {
+			disabled = disabled ? 'Y' : 'N';
+			locked = locked ? 'Y' : 'N';
+		}
+		seq_printf(s, "0x%02x\t\t0x%02x\t\t0x%06x\t\t0x%04x\t\t0x%02x\t\t0x%x\t\t\t%c\t%c\n",
+			   pfs->pfs_header.tpmi_id, pfs->pfs_header.num_entries, pfs->pfs_header.entry_size,
+			   pfs->pfs_header.cap_offset, pfs->pfs_header.attribute, pfs->vsec_offset, locked, disabled);
+	}
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(tpmi_pfs_dbg);
+
+#define MEM_DUMP_COLUMN_COUNT	8
+
+static int tpmi_mem_dump_show(struct seq_file *s, void *unused)
+{
+	size_t row_size = MEM_DUMP_COLUMN_COUNT * sizeof(u32);
+	struct intel_tpmi_pm_feature *pfs = s->private;
+	int count, ret = 0;
+	void __iomem *mem;
+	u16 size;
+	u32 off;
+
+	off = pfs->vsec_offset;
+
+	mutex_lock(&tpmi_dev_lock);
+
+	for (count = 0; count < pfs->pfs_header.num_entries; ++count) {
+		u8 *buffer;
+
+		size = pfs->pfs_header.entry_size * sizeof(u32);
+		buffer = kmalloc(size, GFP_KERNEL);
+		if (!buffer) {
+			ret = -ENOMEM;
+			goto done_mem_show;
+		}
+
+		seq_printf(s, "TPMI Instance:%d offset:0x%x\n", count, off);
+
+		mem = ioremap(off, size);
+		if (!mem) {
+			ret = -ENOMEM;
+			kfree(buffer);
+			goto done_mem_show;
+		}
+
+		memcpy_fromio(buffer, mem, size);
+
+		seq_hex_dump(s, " ", DUMP_PREFIX_OFFSET, row_size, sizeof(u32), buffer, size, false);
+
+		iounmap(mem);
+		kfree(buffer);
+
+		off += size;
+	}
+
+done_mem_show:
+	mutex_unlock(&tpmi_dev_lock);
+
+	return ret;
+}
+DEFINE_SHOW_ATTRIBUTE(tpmi_mem_dump);
+
+static ssize_t mem_write(struct file *file, const char __user *userbuf, size_t len, loff_t *ppos)
+{
+	struct seq_file *m = file->private_data;
+	struct intel_tpmi_pm_feature *pfs = m->private;
+	u32 addr, value, punit;
+	u32 num_elems, *array;
+	void __iomem *mem;
+	u16 size;
+	int ret;
+
+	ret = parse_int_array_user(userbuf, len, (int **)&array);
+	if (ret < 0)
+		return ret;
+
+	num_elems = *array;
+	if (num_elems != 3) {
+		ret = -EINVAL;
+		goto exit_write;
+	}
+
+	punit = array[1];
+	addr = array[2];
+	value = array[3];
+
+	if (punit >= pfs->pfs_header.num_entries) {
+		ret = -EINVAL;
+		goto exit_write;
+	}
+
+	size = pfs->pfs_header.entry_size * sizeof(u32);
+	if (addr >= size) {
+		ret = -EINVAL;
+		goto exit_write;
+	}
+
+	mutex_lock(&tpmi_dev_lock);
+
+	mem = ioremap(pfs->vsec_offset + (punit * size), size);
+	if (!mem) {
+		ret = -ENOMEM;
+		goto unlock_mem_write;
+	}
+
+	writel(value, mem + addr);
+
+	iounmap(mem);
+
+	ret = len;
+
+unlock_mem_write:
+	mutex_unlock(&tpmi_dev_lock);
+
+exit_write:
+	kfree(array);
+
+	return ret;
+}
+
+static int mem_write_show(struct seq_file *s, void *unused)
+{
+	return 0;
+}
+
+static int mem_write_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, mem_write_show, inode->i_private);
+}
+
+static const struct file_operations mem_write_ops = {
+	.open           = mem_write_open,
+	.read           = seq_read,
+	.write          = mem_write,
+	.llseek         = seq_lseek,
+	.release        = single_release,
+};
+
+#define tpmi_to_dev(info)	(&info->vsec_dev->pcidev->dev)
+
+static void tpmi_dbgfs_register(struct intel_tpmi_info *tpmi_info)
+{
+	struct dentry *top_dir;
+	char name[64];
+	int i;
+
+	snprintf(name, sizeof(name), "tpmi-%s", dev_name(tpmi_to_dev(tpmi_info)));
+	top_dir = debugfs_create_dir(name, NULL);
+	if (IS_ERR_OR_NULL(top_dir))
+		return;
+
+	tpmi_info->dbgfs_dir = top_dir;
+
+	debugfs_create_file("pfs_dump", 0444, top_dir, tpmi_info,
+			    &tpmi_pfs_dbg_fops);
+	debugfs_create_file("help", 0444, top_dir, NULL, &tpmi_help_fops);
+	for (i = 0; i < tpmi_info->feature_count; ++i) {
+		struct intel_tpmi_pm_feature *pfs;
+		struct dentry *dir;
+
+		pfs = &tpmi_info->tpmi_features[i];
+		snprintf(name, sizeof(name), "tpmi-id-%02x", pfs->pfs_header.tpmi_id);
+		dir = debugfs_create_dir(name, top_dir);
+
+		debugfs_create_file("mem_dump", 0444, dir, pfs,
+				    &tpmi_mem_dump_fops);
+		debugfs_create_file("mem_write", 0644, dir, pfs,
+				    &mem_write_ops);
+	}
+}
+
 static void tpmi_set_control_base(struct auxiliary_device *auxdev,
 				  struct intel_tpmi_info *tpmi_info,
 				  struct intel_tpmi_pm_feature *pfs)
@@ -458,7 +680,7 @@ static int intel_vsec_tpmi_init(struct auxiliary_device *auxdev)
 	struct pci_dev *pci_dev = vsec_dev->pcidev;
 	struct intel_tpmi_info *tpmi_info;
 	u64 pfs_start = 0;
-	int i;
+	int ret, i;
 
 	tpmi_info = devm_kzalloc(&auxdev->dev, sizeof(*tpmi_info), GFP_KERNEL);
 	if (!tpmi_info)
@@ -481,6 +703,7 @@ static int intel_vsec_tpmi_init(struct auxiliary_device *auxdev)
 		int size, ret;
 
 		pfs = &tpmi_info->tpmi_features[i];
+		pfs->vsec_dev = vsec_dev;
 
 		res = &vsec_dev->resource[i];
 		if (!res)
@@ -520,7 +743,13 @@ static int intel_vsec_tpmi_init(struct auxiliary_device *auxdev)
 
 	auxiliary_set_drvdata(auxdev, tpmi_info);
 
-	return tpmi_create_devices(tpmi_info);
+	ret = tpmi_create_devices(tpmi_info);
+	if (ret)
+		return ret;
+
+	tpmi_dbgfs_register(tpmi_info);
+
+	return 0;
 }
 
 static int tpmi_probe(struct auxiliary_device *auxdev,
@@ -529,11 +758,12 @@ static int tpmi_probe(struct auxiliary_device *auxdev,
 	return intel_vsec_tpmi_init(auxdev);
 }
 
-/*
- * Remove callback is not needed currently as there is no
- * cleanup required. All memory allocs are device managed. All
- * devices created by this modules are also device managed.
- */
+static void tpmi_remove(struct auxiliary_device *auxdev)
+{
+	struct intel_tpmi_info *tpmi_info = auxiliary_get_drvdata(auxdev);
+
+	debugfs_remove_recursive(tpmi_info->dbgfs_dir);
+}
 
 static const struct auxiliary_device_id tpmi_id_table[] = {
 	{ .name = "intel_vsec.tpmi" },
@@ -544,6 +774,7 @@ MODULE_DEVICE_TABLE(auxiliary, tpmi_id_table);
 static struct auxiliary_driver tpmi_aux_driver = {
 	.id_table	= tpmi_id_table,
 	.probe		= tpmi_probe,
+	.remove         = tpmi_remove,
 };
 
 module_auxiliary_driver(tpmi_aux_driver);
-- 
2.38.1

Re: [PATCH 1/2] platform/x86/intel/tpmi: Read feature control status

[Ilpo Järvinen]

On Thu, 15 Jun 2023, Srinivas Pandruvada wrote:

> Some of the PM features can be locked or disabled. In that case, write
> interface can be locked.
> 
> This status is read via a mailbox. There is one TPMI ID which provides
> base address for interface and data register for mail box operation.
> The mailbox operations is defined in the TPMI specification. Refer to
> https://github.com/intel/tpmi_power_management/ for TPMI specifications.
> 
> An API is exposed to feature drivers to read feature control status.
> 
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> As suggested by Dan Williams changed ioremap to devm_ioremap() after
> review by Andy.
> 
>  drivers/platform/x86/intel/tpmi.c | 147 ++++++++++++++++++++++++++++++
>  include/linux/intel_tpmi.h        |   2 +
>  2 files changed, 149 insertions(+)
> 
> diff --git a/drivers/platform/x86/intel/tpmi.c b/drivers/platform/x86/intel/tpmi.c
> index a5227951decc..9545e9cdb924 100644
> --- a/drivers/platform/x86/intel/tpmi.c
> +++ b/drivers/platform/x86/intel/tpmi.c
> @@ -47,8 +47,11 @@
>   */
>  
>  #include <linux/auxiliary_bus.h>
> +#include <linux/bitfield.h>
> +#include <linux/delay.h>
>  #include <linux/intel_tpmi.h>
>  #include <linux/io.h>
> +#include <linux/iopoll.h>
>  #include <linux/module.h>
>  #include <linux/pci.h>
>  
> @@ -98,6 +101,7 @@ struct intel_tpmi_pm_feature {
>   * @feature_count:	Number of TPMI of TPMI instances pointed by tpmi_features
>   * @pfs_start:		Start of PFS offset for the TPMI instances in this device
>   * @plat_info:		Stores platform info which can be used by the client drivers
> + * @tpmi_control_mem:	Memory mapped IO for getting control information
>   *
>   * Stores the information for all TPMI devices enumerated from a single PCI device.
>   */
> @@ -107,6 +111,7 @@ struct intel_tpmi_info {
>  	int feature_count;
>  	u64 pfs_start;
>  	struct intel_tpmi_plat_info plat_info;
> +	void __iomem *tpmi_control_mem;
>  };
>  
>  /**
> @@ -139,6 +144,7 @@ enum intel_tpmi_id {
>  	TPMI_ID_PEM = 1, /* Power and Perf excursion Monitor */
>  	TPMI_ID_UNCORE = 2, /* Uncore Frequency Scaling */
>  	TPMI_ID_SST = 5, /* Speed Select Technology */
> +	TPMI_CONTROL_ID = 0x80, /* Special ID for getting feature status */
>  	TPMI_INFO_ID = 0x81, /* Special ID for PCI BDF and Package ID information */
>  };
>  
> @@ -175,6 +181,144 @@ struct resource *tpmi_get_resource_at_index(struct auxiliary_device *auxdev, int
>  }
>  EXPORT_SYMBOL_NS_GPL(tpmi_get_resource_at_index, INTEL_TPMI);
>  
> +/* TPMI Control Interface */
> +
> +#define TPMI_CONTROL_STATUS_OFFSET	0x00
> +#define TPMI_COMMAND_OFFSET		0x08
> +#define TPMI_DATA_OFFSET		0x0C
> +/*
> + * Spec is calling for max 1 seconds to get ownership at the worst
> + * case. Read at 10 ms timeouts and repeat up to 1 second.
> + */
> +#define TPMI_CONTROL_TIMEOUT_US		(10 * USEC_PER_MSEC)
> +#define TPMI_CONTROL_TIMEOUT_MAX_US	USEC_PER_SEC
> +
> +#define TPMI_RB_TIMEOUT_US		(10 * USEC_PER_MSEC)
> +#define TPMI_RB_TIMEOUT_MAX_US		USEC_PER_SEC
> +
> +#define TPMI_OWNER_NONE			0
> +#define TPMI_OWNER_IN_BAND		1
> +
> +#define TPMI_GENMASK_OWNER	GENMASK_ULL(5, 4)
> +#define TPMI_GENMASK_STATUS	GENMASK_ULL(15, 8)
> +
> +#define TPMI_GET_STATE_CMD		0x10
> +#define TPMI_GET_STATE_CMD_DATA_OFFSET	8
> +#define TPMI_CMD_DATA_OFFSET		32
> +#define TPMI_CMD_PKT_LEN_OFFSET		16
> +#define TPMI_CMD_PKT_LEN		2
> +#define TPMI_CONTROL_RB_BIT		0
> +#define TPMI_CONTROL_CPL_BIT		6
> +#define TPMI_CMD_STATUS_SUCCESS		0x40
> +#define TPMI_GET_STATUS_BIT_ENABLE	0
> +#define TPMI_GET_STATUS_BIT_LOCKED	31
> +
> +/* Mutex to complete get feature status without interruption */
> +static DEFINE_MUTEX(tpmi_dev_lock);
> +
> +static int tpmi_wait_for_owner(struct intel_tpmi_info *tpmi_info, u8 owner)
> +{
> +	u64 control;
> +
> +	return read_poll_timeout(readq, control, owner == FIELD_GET(TPMI_GENMASK_OWNER, control),
> +				 TPMI_CONTROL_TIMEOUT_US, TPMI_CONTROL_TIMEOUT_MAX_US, false,
> +				 tpmi_info->tpmi_control_mem + TPMI_CONTROL_STATUS_OFFSET);
> +}
> +
> +static int tpmi_read_feature_status(struct intel_tpmi_info *tpmi_info, int feature_id,
> +				    int *locked, int *disabled)
> +{
> +	u64 control, data;
> +	int ret;
> +
> +	if (!tpmi_info->tpmi_control_mem)
> +		return -EFAULT;
> +
> +	mutex_lock(&tpmi_dev_lock);
> +
> +	ret = tpmi_wait_for_owner(tpmi_info, TPMI_OWNER_NONE);
> +	if (ret)
> +		goto err_unlock;
> +
> +	/* set command id to 0x10 for TPMI_GET_STATE */
> +	data = TPMI_GET_STATE_CMD;
> +	/* 32 bits for DATA offset and +8 for feature_id field */
> +	data |= ((u64)feature_id << (TPMI_CMD_DATA_OFFSET + TPMI_GET_STATE_CMD_DATA_OFFSET));

This looks like you should add the GENMASK_ULL() for the fields and use 
FIELD_PREP() instead of adding all those OFFSET defines + custom shifting.

> +
> +	/* Write at command offset for qword access */
> +	writeq(data, tpmi_info->tpmi_control_mem + TPMI_COMMAND_OFFSET);
> +
> +	ret = tpmi_wait_for_owner(tpmi_info, TPMI_OWNER_IN_BAND);
> +	if (ret)
> +		goto err_unlock;
> +
> +	/* Set Run Busy and packet length of 2 dwords */
> +	writeq(BIT_ULL(TPMI_CONTROL_RB_BIT) | (TPMI_CMD_PKT_LEN << TPMI_CMD_PKT_LEN_OFFSET),

Define using BIT_ULL(0) instead. Use FIELD_PREP().

I'd drop _BIT from the define name but I leave it up to you, it just 
makes your lines longer w/o much added value.

> +	       tpmi_info->tpmi_control_mem + TPMI_CONTROL_STATUS_OFFSET);
> +
> +	ret = read_poll_timeout(readq, control, !(control & BIT_ULL(TPMI_CONTROL_RB_BIT)),
> +				TPMI_RB_TIMEOUT_US, TPMI_RB_TIMEOUT_MAX_US, false,
> +				tpmi_info->tpmi_control_mem + TPMI_CONTROL_STATUS_OFFSET);
> +	if (ret)
> +		goto done_proc;
> +
> +	control = FIELD_GET(TPMI_GENMASK_STATUS, control);
> +	if (control != TPMI_CMD_STATUS_SUCCESS) {
> +		ret = -EBUSY;
> +		goto done_proc;
> +	}
> +
> +	data = readq(tpmi_info->tpmi_control_mem + TPMI_COMMAND_OFFSET);
> +	data >>= TPMI_CMD_DATA_OFFSET; /* Upper 32 bits are for TPMI_DATA */

Define the field with GENMASK() and use FIELD_GET().

> +
> +	*disabled = 0;
> +	*locked = 0;
> +
> +	if (!(data & BIT_ULL(TPMI_GET_STATUS_BIT_ENABLE)))

Put BIT_ULL() into the define.

Perhaps drop _BIT_ from the name.

> +		*disabled = 1;
> +
> +	if (data & BIT_ULL(TPMI_GET_STATUS_BIT_LOCKED))

Ditto.

> +		*locked = 1;
> +
> +	ret = 0;
> +
> +done_proc:
> +	/* SET CPL "completion"bit */

Missing space.

> +	writeq(BIT_ULL(TPMI_CONTROL_CPL_BIT),

BIT_ULL() to define.

> +	       tpmi_info->tpmi_control_mem + TPMI_CONTROL_STATUS_OFFSET);
> +
> +err_unlock:
> +	mutex_unlock(&tpmi_dev_lock);
> +
> +	return ret;
> +}
> +
> +int tpmi_get_feature_status(struct auxiliary_device *auxdev, int feature_id,
> +			    int *locked, int *disabled)
> +{
> +	struct intel_vsec_device *intel_vsec_dev = dev_to_ivdev(auxdev->dev.parent);
> +	struct intel_tpmi_info *tpmi_info = auxiliary_get_drvdata(&intel_vsec_dev->auxdev);
> +
> +	return tpmi_read_feature_status(tpmi_info, feature_id, locked, disabled);
> +}
> +EXPORT_SYMBOL_NS_GPL(tpmi_get_feature_status, INTEL_TPMI);
> +
> +static void tpmi_set_control_base(struct auxiliary_device *auxdev,
> +				  struct intel_tpmi_info *tpmi_info,
> +				  struct intel_tpmi_pm_feature *pfs)
> +{
> +	void __iomem *mem;
> +	u16 size;
> +
> +	size = pfs->pfs_header.num_entries * pfs->pfs_header.entry_size * 4;

Can this overflow u16? Where does pfs_header content originate from? If 
from HW, how is it the input validated?

-- 
 i.


> +	mem = devm_ioremap(&auxdev->dev, pfs->vsec_offset, size);
> +	if (!mem)
> +		return;
> +
> +	/* mem is pointing to TPMI CONTROL base */
> +	tpmi_info->tpmi_control_mem = mem;
> +}
> +
>  static const char *intel_tpmi_name(enum intel_tpmi_id id)
>  {
>  	switch (id) {
> @@ -367,6 +511,9 @@ static int intel_vsec_tpmi_init(struct auxiliary_device *auxdev)
>  		 */
>  		if (pfs->pfs_header.tpmi_id == TPMI_INFO_ID)
>  			tpmi_process_info(tpmi_info, pfs);
> +
> +		if (pfs->pfs_header.tpmi_id == TPMI_CONTROL_ID)
> +			tpmi_set_control_base(auxdev, tpmi_info, pfs);
>  	}
>  
>  	tpmi_info->pfs_start = pfs_start;
> diff --git a/include/linux/intel_tpmi.h b/include/linux/intel_tpmi.h
> index f505788c05da..04d937ad4dc4 100644
> --- a/include/linux/intel_tpmi.h
> +++ b/include/linux/intel_tpmi.h
> @@ -27,4 +27,6 @@ struct intel_tpmi_plat_info *tpmi_get_platform_data(struct auxiliary_device *aux
>  struct resource *tpmi_get_resource_at_index(struct auxiliary_device *auxdev, int index);
>  int tpmi_get_resource_count(struct auxiliary_device *auxdev);
>  
> +int tpmi_get_feature_status(struct auxiliary_device *auxdev, int feature_id, int *locked,
> +			    int *disabled);
>  #endif
> 

Re: [PATCH 2/2] platform/x86/intel/tpmi: Add debugfs interface

[Ilpo Järvinen]

On Thu, 15 Jun 2023, Srinivas Pandruvada wrote:

> Add debugfs interface for debugging TPMI configuration and register
> contents. This shows PFS (PM Feature structure) for each TPMI device.
> 
> For each feature shows full register contents and allows to modify
> register at an offset.
> 
> There is a help file, which explains debugfs contents and operations.
> 
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  drivers/platform/x86/intel/tpmi.c | 245 +++++++++++++++++++++++++++++-
>  1 file changed, 238 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/platform/x86/intel/tpmi.c b/drivers/platform/x86/intel/tpmi.c
> index 9545e9cdb924..9ec9c56bca68 100644
> --- a/drivers/platform/x86/intel/tpmi.c
> +++ b/drivers/platform/x86/intel/tpmi.c
> @@ -48,12 +48,14 @@
>  
>  #include <linux/auxiliary_bus.h>
>  #include <linux/bitfield.h>
> +#include <linux/debugfs.h>
>  #include <linux/delay.h>
>  #include <linux/intel_tpmi.h>
>  #include <linux/io.h>
>  #include <linux/iopoll.h>
>  #include <linux/module.h>
>  #include <linux/pci.h>
> +#include <linux/string_helpers.h>
>  
>  #include "vsec.h"
>  
> @@ -86,12 +88,14 @@ struct intel_tpmi_pfs_entry {
>   * @vsec_offset: Starting MMIO address for this feature in bytes. Essentially
>   *		 this offset = "Address" from VSEC header + PFS Capability
>   *		 offset for this feature entry.
> + * @vsec_dev:	Pointer to intel_vsec_device structure for this TPMI device
>   *
>   * Represents TPMI instance information for one TPMI ID.
>   */
>  struct intel_tpmi_pm_feature {
>  	struct intel_tpmi_pfs_entry pfs_header;
>  	unsigned int vsec_offset;
> +	struct intel_vsec_device *vsec_dev;
>  };
>  
>  /**
> @@ -102,6 +106,7 @@ struct intel_tpmi_pm_feature {
>   * @pfs_start:		Start of PFS offset for the TPMI instances in this device
>   * @plat_info:		Stores platform info which can be used by the client drivers
>   * @tpmi_control_mem:	Memory mapped IO for getting control information
> + * @dbgfs_dir:		debugfs entry pointer
>   *
>   * Stores the information for all TPMI devices enumerated from a single PCI device.
>   */
> @@ -112,6 +117,7 @@ struct intel_tpmi_info {
>  	u64 pfs_start;
>  	struct intel_tpmi_plat_info plat_info;
>  	void __iomem *tpmi_control_mem;
> +	struct dentry *dbgfs_dir;
>  };
>  
>  /**
> @@ -303,6 +309,222 @@ int tpmi_get_feature_status(struct auxiliary_device *auxdev, int feature_id,
>  }
>  EXPORT_SYMBOL_NS_GPL(tpmi_get_feature_status, INTEL_TPMI);
>  
> +static int tpmi_help_show(struct seq_file *s, void *unused)
> +{
> +	const char *help =
> +		"TPMI debugfs help\n"
> +		"There will be multiple instances of debugfs folders, one for each package\n"
> +		"E.g. tpmi-0000:00:03.1\n"
> +		"Attributes:\n"
> +		"\tpfs_dump: Shows all PFS entries. Refer to TPMI spec for details\n"
> +		"\tEach of the TPMI ID will have its folder for read/write register access\n"
> +		"\tThe name of the folder suffixed with tpmi ID\n"
> +		"\tEach folder contains two entries\n"
> +		"\tmem_dump and mem_write\n"
> +		"\tmem_dump: Show register contents of full PFS for all TPMI instances\n"
> +		"\tThe total size will be pfs->entry_size * pfs->number of entries * 4\n"
> +		"\tmem_write: Allows to write at any offset. Hardware ignores writes on read only memory\n"
> +		"\tRead/write is at offset multiples of 4\n"
> +		"\tThe format is instance:offset:contents\n"
> +		"\tThe values are in hex\n"
> +		"\t\tExample: echo 0,0x20,0xff > mem_write\n"
> +		"\t\tExample: echo 1,64,64 > mem_write\n";
> +
> +	seq_puts(s, help);

The appropriate place to this kinda information would seem to be:

Documentation/ABI/testing/debugfs-... file.

> +
> +	return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(tpmi_help);
> +
> +static int tpmi_pfs_dbg_show(struct seq_file *s, void *unused)
> +{
> +	struct intel_tpmi_info *tpmi_info = s->private;
> +	int i, ret;
> +
> +	seq_printf(s, "tpmi PFS start offset 0x:%llx\n", tpmi_info->pfs_start);
> +	seq_puts(s, "tpmi_id\t\tnum_entries\tentry_size\t\tcap_offset\tattribute\tfull_base_pointer_for_memmap\tlocked\tdisabled\n");
> +	for (i = 0; i < tpmi_info->feature_count; ++i) {
> +		struct intel_tpmi_pm_feature *pfs;
> +		int locked, disabled;
> +
> +		pfs = &tpmi_info->tpmi_features[i];
> +		ret = tpmi_read_feature_status(tpmi_info, pfs->pfs_header.tpmi_id, &locked, &disabled);
> +		if (ret) {
> +			locked = 'U';
> +			disabled = 'U';
> +		} else {
> +			disabled = disabled ? 'Y' : 'N';
> +			locked = locked ? 'Y' : 'N';
> +		}
> +		seq_printf(s, "0x%02x\t\t0x%02x\t\t0x%06x\t\t0x%04x\t\t0x%02x\t\t0x%x\t\t\t%c\t%c\n",

The last hex is just %x (not %08x), is it intentional?

> +			   pfs->pfs_header.tpmi_id, pfs->pfs_header.num_entries, pfs->pfs_header.entry_size,
> +			   pfs->pfs_header.cap_offset, pfs->pfs_header.attribute, pfs->vsec_offset, locked, disabled);

Please split parameters to 100 columns (I'm okay with the string 
exceeding it).

It would help here if you add pointer also to pfs_header struct. ;-)

> +	}
> +
> +	return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(tpmi_pfs_dbg);
> +
> +#define MEM_DUMP_COLUMN_COUNT	8
> +
> +static int tpmi_mem_dump_show(struct seq_file *s, void *unused)
> +{
> +	size_t row_size = MEM_DUMP_COLUMN_COUNT * sizeof(u32);
> +	struct intel_tpmi_pm_feature *pfs = s->private;
> +	int count, ret = 0;
> +	void __iomem *mem;
> +	u16 size;
> +	u32 off;
> +
> +	off = pfs->vsec_offset;
> +
> +	mutex_lock(&tpmi_dev_lock);
> +
> +	for (count = 0; count < pfs->pfs_header.num_entries; ++count) {
> +		u8 *buffer;

Why only this is declared here? I see no consistency based on 
variable usage/scope.

> +		size = pfs->pfs_header.entry_size * sizeof(u32);

Can this overflow?

> +		buffer = kmalloc(size, GFP_KERNEL);
> +		if (!buffer) {
> +			ret = -ENOMEM;
> +			goto done_mem_show;
> +		}
> +
> +		seq_printf(s, "TPMI Instance:%d offset:0x%x\n", count, off);
> +
> +		mem = ioremap(off, size);
> +		if (!mem) {
> +			ret = -ENOMEM;
> +			kfree(buffer);
> +			goto done_mem_show;
> +		}
> +
> +		memcpy_fromio(buffer, mem, size);
> +
> +		seq_hex_dump(s, " ", DUMP_PREFIX_OFFSET, row_size, sizeof(u32), buffer, size, false);
> +
> +		iounmap(mem);
> +		kfree(buffer);
> +
> +		off += size;
> +	}
> +
> +done_mem_show:
> +	mutex_unlock(&tpmi_dev_lock);
> +
> +	return ret;
> +}
> +DEFINE_SHOW_ATTRIBUTE(tpmi_mem_dump);
> +
> +static ssize_t mem_write(struct file *file, const char __user *userbuf, size_t len, loff_t *ppos)
> +{
> +	struct seq_file *m = file->private_data;
> +	struct intel_tpmi_pm_feature *pfs = m->private;
> +	u32 addr, value, punit;
> +	u32 num_elems, *array;
> +	void __iomem *mem;
> +	u16 size;
> +	int ret;
> +
> +	ret = parse_int_array_user(userbuf, len, (int **)&array);
> +	if (ret < 0)
> +		return ret;
> +
> +	num_elems = *array;
> +	if (num_elems != 3) {
> +		ret = -EINVAL;
> +		goto exit_write;
> +	}
> +
> +	punit = array[1];
> +	addr = array[2];
> +	value = array[3];
> +
> +	if (punit >= pfs->pfs_header.num_entries) {
> +		ret = -EINVAL;
> +		goto exit_write;
> +	}
> +
> +	size = pfs->pfs_header.entry_size * sizeof(u32);

There's no consistency in the code, some places do: entry_size * 4 and 
here it's entry_size * sizeof(u32). Please convert all of them to the 
latter one. You need to do one additional patch to convert the existing 
users but that's perfectly fine as an additional cleanup patch (don't 
try to put it either of these patches "while at it").

> +	if (addr >= size) {
> +		ret = -EINVAL;
> +		goto exit_write;
> +	}
> +
> +	mutex_lock(&tpmi_dev_lock);
> +
> +	mem = ioremap(pfs->vsec_offset + (punit * size), size);

Unnecessary parenthesis.

> +	if (!mem) {
> +		ret = -ENOMEM;
> +		goto unlock_mem_write;
> +	}
> +
> +	writel(value, mem + addr);
> +
> +	iounmap(mem);
> +
> +	ret = len;
> +
> +unlock_mem_write:
> +	mutex_unlock(&tpmi_dev_lock);
> +
> +exit_write:
> +	kfree(array);
> +
> +	return ret;
> +}
> +
> +static int mem_write_show(struct seq_file *s, void *unused)
> +{
> +	return 0;
> +}
> +
> +static int mem_write_open(struct inode *inode, struct file *file)
> +{
> +	return single_open(file, mem_write_show, inode->i_private);
> +}
> +
> +static const struct file_operations mem_write_ops = {
> +	.open           = mem_write_open,
> +	.read           = seq_read,
> +	.write          = mem_write,
> +	.llseek         = seq_lseek,
> +	.release        = single_release,
> +};
> +
> +#define tpmi_to_dev(info)	(&info->vsec_dev->pcidev->dev)
> +
> +static void tpmi_dbgfs_register(struct intel_tpmi_info *tpmi_info)
> +{
> +	struct dentry *top_dir;
> +	char name[64];
> +	int i;
> +
> +	snprintf(name, sizeof(name), "tpmi-%s", dev_name(tpmi_to_dev(tpmi_info)));
> +	top_dir = debugfs_create_dir(name, NULL);
> +	if (IS_ERR_OR_NULL(top_dir))
> +		return;
> +
> +	tpmi_info->dbgfs_dir = top_dir;
> +
> +	debugfs_create_file("pfs_dump", 0444, top_dir, tpmi_info,
> +			    &tpmi_pfs_dbg_fops);

One line.

> +	debugfs_create_file("help", 0444, top_dir, NULL, &tpmi_help_fops);
> +	for (i = 0; i < tpmi_info->feature_count; ++i) {
> +		struct intel_tpmi_pm_feature *pfs;
> +		struct dentry *dir;
> +
> +		pfs = &tpmi_info->tpmi_features[i];
> +		snprintf(name, sizeof(name), "tpmi-id-%02x", pfs->pfs_header.tpmi_id);
> +		dir = debugfs_create_dir(name, top_dir);
> +
> +		debugfs_create_file("mem_dump", 0444, dir, pfs,
> +				    &tpmi_mem_dump_fops);
> +		debugfs_create_file("mem_write", 0644, dir, pfs,
> +				    &mem_write_ops);

These too can be put to one line.


-- 
 i.

> +	}
> +}
> +
>  static void tpmi_set_control_base(struct auxiliary_device *auxdev,
>  				  struct intel_tpmi_info *tpmi_info,
>  				  struct intel_tpmi_pm_feature *pfs)
> @@ -458,7 +680,7 @@ static int intel_vsec_tpmi_init(struct auxiliary_device *auxdev)
>  	struct pci_dev *pci_dev = vsec_dev->pcidev;
>  	struct intel_tpmi_info *tpmi_info;
>  	u64 pfs_start = 0;
> -	int i;
> +	int ret, i;
>  
>  	tpmi_info = devm_kzalloc(&auxdev->dev, sizeof(*tpmi_info), GFP_KERNEL);
>  	if (!tpmi_info)
> @@ -481,6 +703,7 @@ static int intel_vsec_tpmi_init(struct auxiliary_device *auxdev)
>  		int size, ret;
>  
>  		pfs = &tpmi_info->tpmi_features[i];
> +		pfs->vsec_dev = vsec_dev;
>  
>  		res = &vsec_dev->resource[i];
>  		if (!res)
> @@ -520,7 +743,13 @@ static int intel_vsec_tpmi_init(struct auxiliary_device *auxdev)
>  
>  	auxiliary_set_drvdata(auxdev, tpmi_info);
>  
> -	return tpmi_create_devices(tpmi_info);
> +	ret = tpmi_create_devices(tpmi_info);
> +	if (ret)
> +		return ret;
> +
> +	tpmi_dbgfs_register(tpmi_info);
> +
> +	return 0;
>  }
>  
>  static int tpmi_probe(struct auxiliary_device *auxdev,
> @@ -529,11 +758,12 @@ static int tpmi_probe(struct auxiliary_device *auxdev,
>  	return intel_vsec_tpmi_init(auxdev);
>  }
>  
> -/*
> - * Remove callback is not needed currently as there is no
> - * cleanup required. All memory allocs are device managed. All
> - * devices created by this modules are also device managed.
> - */
> +static void tpmi_remove(struct auxiliary_device *auxdev)
> +{
> +	struct intel_tpmi_info *tpmi_info = auxiliary_get_drvdata(auxdev);
> +
> +	debugfs_remove_recursive(tpmi_info->dbgfs_dir);
> +}
>  
>  static const struct auxiliary_device_id tpmi_id_table[] = {
>  	{ .name = "intel_vsec.tpmi" },
> @@ -544,6 +774,7 @@ MODULE_DEVICE_TABLE(auxiliary, tpmi_id_table);
>  static struct auxiliary_driver tpmi_aux_driver = {
>  	.id_table	= tpmi_id_table,
>  	.probe		= tpmi_probe,
> +	.remove         = tpmi_remove,
>  };
>  
>  module_auxiliary_driver(tpmi_aux_driver);
> 

Re: [PATCH 1/2] platform/x86/intel/tpmi: Read feature control status

[srinivas pandruvada]

On Fri, 2023-06-16 at 10:13 +0300, Ilpo Järvinen wrote:
> On Thu, 15 Jun 2023, Srinivas Pandruvada wrote:
> 
> > 

[...]

> > +       /* set command id to 0x10 for TPMI_GET_STATE */
> > +       data = TPMI_GET_STATE_CMD;
> > +       /* 32 bits for DATA offset and +8 for feature_id field */
> > +       data |= ((u64)feature_id << (TPMI_CMD_DATA_OFFSET +
> > TPMI_GET_STATE_CMD_DATA_OFFSET));
> 
> This looks like you should add the GENMASK_ULL() for the fields and
> use 
> FIELD_PREP() instead of adding all those OFFSET defines + custom
> shifting.

You mean, I should change one shift instruction, to FIELD_PREP()
which will use three instructions to shift, sub and AND?
((typeof(_mask))(_val) << __bf_shf(_mask)) & (_mask);

> 
> > +
> > +       /* Write at command offset for qword access */
> > +       writeq(data, tpmi_info->tpmi_control_mem +
> > TPMI_COMMAND_OFFSET);
> > +
> > +       ret = tpmi_wait_for_owner(tpmi_info, TPMI_OWNER_IN_BAND);
> > +       if (ret)
> > +               goto err_unlock;
> > +
> > +       /* Set Run Busy and packet length of 2 dwords */
> > +       writeq(BIT_ULL(TPMI_CONTROL_RB_BIT) | (TPMI_CMD_PKT_LEN <<
> > TPMI_CMD_PKT_LEN_OFFSET),
> 
> Define using BIT_ULL(0) instead. Use FIELD_PREP().


This code will run only on X86 64 bit, not a common device driver which
will run in any architecture.
Please let me know why FIELD_PREP() is better.


> 
> I'd drop _BIT from the define name but I leave it up to you, it just 
> makes your lines longer w/o much added value.
> 
> > +              tpmi_info->tpmi_control_mem +
> > TPMI_CONTROL_STATUS_OFFSET);
> > +
> > +       ret = read_poll_timeout(readq, control, !(control &
> > BIT_ULL(TPMI_CONTROL_RB_BIT)),
> > +                               TPMI_RB_TIMEOUT_US,
> > TPMI_RB_TIMEOUT_MAX_US, false,
> > +                               tpmi_info->tpmi_control_mem +
> > TPMI_CONTROL_STATUS_OFFSET);
> > +       if (ret)
> > +               goto done_proc;
> > +
> > +       control = FIELD_GET(TPMI_GENMASK_STATUS, control);
> > +       if (control != TPMI_CMD_STATUS_SUCCESS) {
> > +               ret = -EBUSY;
> > +               goto done_proc;
> > +       }
> > +
> > +       data = readq(tpmi_info->tpmi_control_mem +
> > TPMI_COMMAND_OFFSET);
> > +       data >>= TPMI_CMD_DATA_OFFSET; /* Upper 32 bits are for
> > TPMI_DATA */
> 
> Define the field with GENMASK() and use FIELD_GET().
> 
Again 3 instructions instead of 1.

> > +
> > +       *disabled = 0;
> > +       *locked = 0;
> > +
> > +       if (!(data & BIT_ULL(TPMI_GET_STATUS_BIT_ENABLE)))
> 
> Put BIT_ULL() into the define.
Good idea.

> 
> Perhaps drop _BIT_ from the name.
I can do that.

> 
> > +               *disabled = 1;
> > +
> > +       if (data & BIT_ULL(TPMI_GET_STATUS_BIT_LOCKED))
> 
> Ditto.
> 
> > +               *locked = 1;
> > +
> > +       ret = 0;
> > +
> > +done_proc:
> > +       /* SET CPL "completion"bit */
> 
> Missing space.
> 
OK

> > +       writeq(BIT_ULL(TPMI_CONTROL_CPL_BIT),
> 
> BIT_ULL() to define.
> 
> > +              tpmi_info->tpmi_control_mem +
> > TPMI_CONTROL_STATUS_OFFSET);
> > +
> > +err_unlock:
> > +       mutex_unlock(&tpmi_dev_lock);
> > +
> > +       return ret;
> > +}
> > +
> > +int tpmi_get_feature_status(struct auxiliary_device *auxdev, int
> > feature_id,
> > +                           int *locked, int *disabled)
> > +{
> > +       struct intel_vsec_device *intel_vsec_dev =
> > dev_to_ivdev(auxdev->dev.parent);
> > +       struct intel_tpmi_info *tpmi_info =
> > auxiliary_get_drvdata(&intel_vsec_dev->auxdev);
> > +
> > +       return tpmi_read_feature_status(tpmi_info, feature_id,
> > locked, disabled);
> > +}
> > +EXPORT_SYMBOL_NS_GPL(tpmi_get_feature_status, INTEL_TPMI);
> > +
> > +static void tpmi_set_control_base(struct auxiliary_device *auxdev,
> > +                                 struct intel_tpmi_info
> > *tpmi_info,
> > +                                 struct intel_tpmi_pm_feature
> > *pfs)
> > +{
> > +       void __iomem *mem;
> > +       u16 size;
> > +
> > +       size = pfs->pfs_header.num_entries * pfs-
> > >pfs_header.entry_size * 4;
> 
> Can this overflow u16? Where does pfs_header content originate from?
We can add a check, but this is coming from a trusted and validated x86
core (Not an add on IP), which not only driver uses but all PM IP in
the hardware.

Thanks,
Srinivas

> If 
> from HW, how is it the input validated?
> 

Re: [PATCH 2/2] platform/x86/intel/tpmi: Add debugfs interface

[srinivas pandruvada]

On Fri, 2023-06-16 at 10:46 +0300, Ilpo Järvinen wrote:
> On Thu, 15 Jun 2023, Srinivas Pandruvada wrote:
> 
> > 

[...]

> > +       seq_puts(s, help);
> 
> The appropriate place to this kinda information would seem to be:
> 
> Documentation/ABI/testing/debugfs-... file.

I prefer to add to Documentation.
But this is for validation folks, who struggle to get documentation,
will ask you 10 question before using. Hence added here.

But I don't have strong preference here. I can move to doc area.


> 
> > +
> > +       return 0;
> > +}
> > +DEFINE_SHOW_ATTRIBUTE(tpmi_help);
> > +
> > +static int tpmi_pfs_dbg_show(struct seq_file *s, void *unused)
> > +{
> > +       struct intel_tpmi_info *tpmi_info = s->private;
> > +       int i, ret;
> > +
> > +       seq_printf(s, "tpmi PFS start offset 0x:%llx\n", tpmi_info-
> > >pfs_start);
> > +       seq_puts(s,
> > "tpmi_id\t\tnum_entries\tentry_size\t\tcap_offset\tattribute\tfull_
> > base_pointer_for_memmap\tlocked\tdisabled\n");
> > +       for (i = 0; i < tpmi_info->feature_count; ++i) {
> > +               struct intel_tpmi_pm_feature *pfs;
> > +               int locked, disabled;
> > +
> > +               pfs = &tpmi_info->tpmi_features[i];
> > +               ret = tpmi_read_feature_status(tpmi_info, pfs-
> > >pfs_header.tpmi_id, &locked, &disabled);
> > +               if (ret) {
> > +                       locked = 'U';
> > +                       disabled = 'U';
> > +               } else {
> > +                       disabled = disabled ? 'Y' : 'N';
> > +                       locked = locked ? 'Y' : 'N';
> > +               }
> > +               seq_printf(s,
> > "0x%02x\t\t0x%02x\t\t0x%06x\t\t0x%04x\t\t0x%02x\t\t0x%x\t\t\t%c\t%c
> > \n",
> 
> The last hex is just %x (not %08x), is it intentional?
Not intentional.

> 
> > +                          pfs->pfs_header.tpmi_id, pfs-
> > >pfs_header.num_entries, pfs->pfs_header.entry_size,
> > +                          pfs->pfs_header.cap_offset, pfs-
> > >pfs_header.attribute, pfs->vsec_offset, locked, disabled);
> 
> Please split parameters to 100 columns (I'm okay with the string 
> exceeding it).
> 
> It would help here if you add pointer also to pfs_header struct. ;-)
> 
Will think about it if useful.

> > +       }
> > +
> > +       return 0;
> > +}
> > +DEFINE_SHOW_ATTRIBUTE(tpmi_pfs_dbg);
> > +
> > +#define MEM_DUMP_COLUMN_COUNT  8
> > +
> > +static int tpmi_mem_dump_show(struct seq_file *s, void *unused)
> > +{
> > +       size_t row_size = MEM_DUMP_COLUMN_COUNT * sizeof(u32);
> > +       struct intel_tpmi_pm_feature *pfs = s->private;
> > +       int count, ret = 0;
> > +       void __iomem *mem;
> > +       u16 size;
> > +       u32 off;
> > +
> > +       off = pfs->vsec_offset;
> > +
> > +       mutex_lock(&tpmi_dev_lock);
> > +
> > +       for (count = 0; count < pfs->pfs_header.num_entries;
> > ++count) {
> > +               u8 *buffer;
> 
> Why only this is declared here? I see no consistency based on 
> variable usage/scope.
I will fix this.

> 
> > +               size = pfs->pfs_header.entry_size * sizeof(u32);
> 
> Can this overflow?
No. Coming from a trusted architectural source. The system will not
pass BIOS if they are wrong.

> 
> > +               buffer = kmalloc(size, GFP_KERNEL);
> > +               if (!buffer) {
> > +                       ret = -ENOMEM;
> > +                       goto done_mem_show;
> > +               }
> > +
> > +               seq_printf(s, "TPMI Instance:%d offset:0x%x\n",
> > count, off);
> > +
> > +               mem = ioremap(off, size);
> > +               if (!mem) {
> > +                       ret = -ENOMEM;
> > +                       kfree(buffer);
> > +                       goto done_mem_show;
> > +               }
> > +
> > +               memcpy_fromio(buffer, mem, size);
> > +
> > +               seq_hex_dump(s, " ", DUMP_PREFIX_OFFSET, row_size,
> > sizeof(u32), buffer, size, false);
> > +
> > +               iounmap(mem);
> > +               kfree(buffer);
> > +
> > +               off += size;
> > +       }
> > +
> > +done_mem_show:
> > +       mutex_unlock(&tpmi_dev_lock);
> > +
> > +       return ret;
> > +}
> > +DEFINE_SHOW_ATTRIBUTE(tpmi_mem_dump);
> > +
> > +static ssize_t mem_write(struct file *file, const char __user
> > *userbuf, size_t len, loff_t *ppos)
> > +{
> > +       struct seq_file *m = file->private_data;
> > +       struct intel_tpmi_pm_feature *pfs = m->private;
> > +       u32 addr, value, punit;
> > +       u32 num_elems, *array;
> > +       void __iomem *mem;
> > +       u16 size;
> > +       int ret;
> > +
> > +       ret = parse_int_array_user(userbuf, len, (int **)&array);
> > +       if (ret < 0)
> > +               return ret;
> > +
> > +       num_elems = *array;
> > +       if (num_elems != 3) {
> > +               ret = -EINVAL;
> > +               goto exit_write;
> > +       }
> > +
> > +       punit = array[1];
> > +       addr = array[2];
> > +       value = array[3];
> > +
> > +       if (punit >= pfs->pfs_header.num_entries) {
> > +               ret = -EINVAL;
> > +               goto exit_write;
> > +       }
> > +
> > +       size = pfs->pfs_header.entry_size * sizeof(u32);
> 
> There's no consistency in the code, some places do: entry_size * 4
> and 
> here it's entry_size * sizeof(u32). Please convert all of them to the
> latter one. You need to do one additional patch to convert the
> existing 
> users but that's perfectly fine as an additional cleanup patch (don't
> try to put it either of these patches "while at it").
Good idea.

> 
> > +       if (addr >= size) {
> > +               ret = -EINVAL;
> > +               goto exit_write;
> > +       }
> > +
> > +       mutex_lock(&tpmi_dev_lock);
> > +
> > +       mem = ioremap(pfs->vsec_offset + (punit * size), size);
> 
> Unnecessary parenthesis.
ok

> 
> > +       if (!mem) {
> > +               ret = -ENOMEM;
> > +               goto unlock_mem_write;
> > +       }
> > +
> > +       writel(value, mem + addr);
> > +
> > +       iounmap(mem);
> > +
> > +       ret = len;
> > +
> > +unlock_mem_write:
> > +       mutex_unlock(&tpmi_dev_lock);
> > +
> > +exit_write:
> > +       kfree(array);
> > +
> > +       return ret;
> > +}
> > +
> > +static int mem_write_show(struct seq_file *s, void *unused)
> > +{
> > +       return 0;
> > +}
> > +
> > +static int mem_write_open(struct inode *inode, struct file *file)
> > +{
> > +       return single_open(file, mem_write_show, inode->i_private);
> > +}
> > +
> > +static const struct file_operations mem_write_ops = {
> > +       .open           = mem_write_open,
> > +       .read           = seq_read,
> > +       .write          = mem_write,
> > +       .llseek         = seq_lseek,
> > +       .release        = single_release,
> > +};
> > +
> > +#define tpmi_to_dev(info)      (&info->vsec_dev->pcidev->dev)
> > +
> > +static void tpmi_dbgfs_register(struct intel_tpmi_info *tpmi_info)
> > +{
> > +       struct dentry *top_dir;
> > +       char name[64];
> > +       int i;
> > +
> > +       snprintf(name, sizeof(name), "tpmi-%s",
> > dev_name(tpmi_to_dev(tpmi_info)));
> > +       top_dir = debugfs_create_dir(name, NULL);
> > +       if (IS_ERR_OR_NULL(top_dir))
> > +               return;
> > +
> > +       tpmi_info->dbgfs_dir = top_dir;
> > +
> > +       debugfs_create_file("pfs_dump", 0444, top_dir, tpmi_info,
> > +                           &tpmi_pfs_dbg_fops);
> 
> One line.
OK

> 
> > +       debugfs_create_file("help", 0444, top_dir, NULL,
> > &tpmi_help_fops);
> > +       for (i = 0; i < tpmi_info->feature_count; ++i) {
> > +               struct intel_tpmi_pm_feature *pfs;
> > +               struct dentry *dir;
> > +
> > +               pfs = &tpmi_info->tpmi_features[i];
> > +               snprintf(name, sizeof(name), "tpmi-id-%02x", pfs-
> > >pfs_header.tpmi_id);
> > +               dir = debugfs_create_dir(name, top_dir);
> > +
> > +               debugfs_create_file("mem_dump", 0444, dir, pfs,
> > +                                   &tpmi_mem_dump_fops);
> > +               debugfs_create_file("mem_write", 0644, dir, pfs,
> > +                                   &mem_write_ops);
> 
> These too can be put to one line.
> 
OK

Thanks,
Srinivas

>