[PATCH v3 10/11] platform/x86/intel/pmt: use a version struct

Michael J. Ruhl michael.j.ruhl at intel.com
Thu Jun 5 18:44:43 UTC 2025


In preparation for supporting multiple crashlog versions, use a struct
to keep bit offset info for the status and control bits.

Signed-off-by: Michael J. Ruhl <michael.j.ruhl at intel.com>
---
 drivers/platform/x86/intel/pmt/crashlog.c | 176 ++++++++++++++--------
 1 file changed, 112 insertions(+), 64 deletions(-)

diff --git a/drivers/platform/x86/intel/pmt/crashlog.c b/drivers/platform/x86/intel/pmt/crashlog.c
index 318d7a21f00e..fe6563721886 100644
--- a/drivers/platform/x86/intel/pmt/crashlog.c
+++ b/drivers/platform/x86/intel/pmt/crashlog.c
@@ -22,21 +22,6 @@
 /* Crashlog discovery header types */
 #define CRASH_TYPE_OOBMSM	1
 
-/* Control Flags */
-#define CRASHLOG_FLAG_DISABLE		BIT(28)
-
-/*
- * Bits 29 and 30 control the state of bit 31.
- *
- * Bit 29 will clear bit 31, if set, allowing a new crashlog to be captured.
- * Bit 30 will immediately trigger a crashlog to be generated, setting bit 31.
- * Bit 31 is the read-only status with a 1 indicating log is complete.
- */
-#define CRASHLOG_FLAG_TRIGGER_CLEAR	BIT(29)
-#define CRASHLOG_FLAG_TRIGGER_EXECUTE	BIT(30)
-#define CRASHLOG_FLAG_TRIGGER_COMPLETE	BIT(31)
-#define CRASHLOG_FLAG_TRIGGER_MASK	GENMASK(31, 28)
-
 /* Crashlog Discovery Header */
 #define CONTROL_OFFSET		0x0
 #define GUID_OFFSET		0x4
@@ -48,10 +33,63 @@
 /* size is in bytes */
 #define GET_SIZE(v)		((v) * sizeof(u32))
 
+/*
+ * Type 1 Version 0
+ * status and control registers are combined.
+ *
+ * Bits 29 and 30 control the state of bit 31.
+ * Bit 29 will clear bit 31, if set, allowing a new crashlog to be captured.
+ * Bit 30 will immediately trigger a crashlog to be generated, setting bit 31.
+ * Bit 31 is the read-only status with a 1 indicating log is complete.
+ */
+#define TYPE1_VER0_STATUS_OFFSET	0x00
+#define TYPE1_VER0_CONTROL_OFFSET	0x00
+
+#define TYPE1_VER0_DISABLE		BIT(28)
+#define TYPE1_VER0_CLEAR		BIT(29)
+#define TYPE1_VER0_EXECUTE		BIT(30)
+#define TYPE1_VER0_COMPLETE		BIT(31)
+#define TYPE1_VER0_TRIGGER_MASK		GENMASK(31, 28)
+
+/* After offset, order alphabetically, not bit ordered */
+struct crashlog_status {
+	u32 offset;
+	u32 clear;
+	u32 complete;
+	u32 disable;
+};
+
+struct crashlog_control {
+	u32 offset;
+	u32 trigger_mask;
+	u32 clear;
+	u32 disable;
+	u32 manual;
+};
+
+struct crashlog_info {
+	struct crashlog_status status;
+	struct crashlog_control control;
+};
+
+const struct crashlog_info crashlog_type1_ver0 = {
+	.status.offset = TYPE1_VER0_STATUS_OFFSET,
+	.status.clear = TYPE1_VER0_CLEAR,
+	.status.complete = TYPE1_VER0_COMPLETE,
+	.status.disable = TYPE1_VER0_DISABLE,
+
+	.control.offset = TYPE1_VER0_CONTROL_OFFSET,
+	.control.trigger_mask = TYPE1_VER0_TRIGGER_MASK,
+	.control.clear = TYPE1_VER0_CLEAR,
+	.control.disable = TYPE1_VER0_DISABLE,
+	.control.manual = TYPE1_VER0_EXECUTE,
+};
+
 struct crashlog_entry {
 	/* entry must be first member of struct */
 	struct intel_pmt_entry		entry;
 	struct mutex			control_mutex;
+	const struct crashlog_info	*info;
 };
 
 struct pmt_crashlog_priv {
@@ -59,74 +97,82 @@ struct pmt_crashlog_priv {
 	struct crashlog_entry	entry[];
 };
 
+/*
+ * This is the generic access to a PMT struct. So the use of
+ * struct crashlog_entry
+ * doesn't "make sense" here.
+ */
+static bool pmt_crashlog_supported(struct intel_pmt_entry *entry)
+{
+	u32 discovery_header = readl(entry->disc_table + CONTROL_OFFSET);
+	u32 crash_type, version;
+
+	crash_type = GET_TYPE(discovery_header);
+	version = GET_VERSION(discovery_header);
+
+	/*
+	 * Currently we only recognize OOBMSM version 0 devices.
+	 * We can ignore all other crashlog devices in the system.
+	 */
+	return crash_type == CRASH_TYPE_OOBMSM && version == 0;
+}
+
 /*
  * I/O
  */
+
 #define SET     true
 #define CLEAR   false
 
-static void read_modify_write(struct intel_pmt_entry *entry, u32 bit, bool set)
+static void read_modify_write(struct crashlog_entry *crashlog, u32 bit, bool set)
 {
-	u32 reg = readl(entry->disc_table + CONTROL_OFFSET);
+	const struct crashlog_control *control = &crashlog->info->control;
+	struct intel_pmt_entry *entry = &crashlog->entry;
+	u32 reg = readl(entry->disc_table + control->offset);
 
-	reg &= ~CRASHLOG_FLAG_TRIGGER_MASK;
+	reg &= ~control->trigger_mask;
 
 	if (set)
 		reg |= bit;
 	else
 		reg &= bit;
 
-	writel(reg, entry->disc_table + CONTROL_OFFSET);
+	writel(reg, entry->disc_table + control->offset);
 }
 
-static bool read_check(struct intel_pmt_entry *entry, u32 bit)
+static bool read_check(struct crashlog_entry *crashlog, u32 bit)
 {
-	u32 reg = readl(entry->disc_table + CONTROL_OFFSET);
+	const struct crashlog_status *status = &crashlog->info->status;
+	u32 reg = readl(crashlog->entry.disc_table + status->offset);
 
 	return !!(reg & bit);
 }
 
-static bool pmt_crashlog_complete(struct intel_pmt_entry *entry)
+static bool pmt_crashlog_complete(struct crashlog_entry *crashlog)
 {
 	/* return current value of the crashlog complete flag */
-	return read_check(entry, CRASHLOG_FLAG_TRIGGER_COMPLETE);
+	return read_check(crashlog, crashlog->info->status.complete);
 }
 
-static bool pmt_crashlog_disabled(struct intel_pmt_entry *entry)
+static bool pmt_crashlog_disabled(struct crashlog_entry *crashlog)
 {
 	/* return current value of the crashlog disabled flag */
-	return read_check(entry, CRASHLOG_FLAG_DISABLE);
-}
-
-static bool pmt_crashlog_supported(struct intel_pmt_entry *entry)
-{
-	u32 discovery_header = readl(entry->disc_table + CONTROL_OFFSET);
-	u32 crash_type, version;
-
-	crash_type = GET_TYPE(discovery_header);
-	version = GET_VERSION(discovery_header);
-
-	/*
-	 * Currently we only recognize OOBMSM version 0 devices.
-	 * We can ignore all other crashlog devices in the system.
-	 */
-	return crash_type == CRASH_TYPE_OOBMSM && version == 0;
+	return read_check(crashlog, crashlog->info->status.disable);
 }
 
-static void pmt_crashlog_set_disable(struct intel_pmt_entry *entry,
-				     bool disable)
+static void pmt_crashlog_set_disable(struct crashlog_entry *crashlog, bool disable)
 {
-	read_modify_write(entry, CRASHLOG_FLAG_DISABLE, disable);
+	read_modify_write(crashlog, crashlog->info->control.disable, disable);
 }
 
-static void pmt_crashlog_set_clear(struct intel_pmt_entry *entry)
+static void pmt_crashlog_set_clear(struct crashlog_entry *crashlog)
 {
-	read_modify_write(entry, CRASHLOG_FLAG_TRIGGER_CLEAR, SET);
+	read_modify_write(crashlog, crashlog->info->control.clear, SET);
 }
 
-static void pmt_crashlog_set_execute(struct intel_pmt_entry *entry)
+static void pmt_crashlog_set_execute(struct crashlog_entry *crashlog)
 {
-	read_modify_write(entry, CRASHLOG_FLAG_TRIGGER_EXECUTE, SET);
+	read_modify_write(crashlog, crashlog->info->control.manual, SET);
 }
 
 /*
@@ -135,8 +181,8 @@ static void pmt_crashlog_set_execute(struct intel_pmt_entry *entry)
 static ssize_t
 enable_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
-	struct intel_pmt_entry *entry = dev_get_drvdata(dev);
-	bool enabled = !pmt_crashlog_disabled(entry);
+	struct crashlog_entry *crashlog = dev_get_drvdata(dev);
+	bool enabled = !pmt_crashlog_disabled(crashlog);
 
 	return sprintf(buf, "%d\n", enabled);
 }
@@ -145,19 +191,19 @@ static ssize_t
 enable_store(struct device *dev, struct device_attribute *attr,
 	     const char *buf, size_t count)
 {
-	struct crashlog_entry *entry;
+	struct crashlog_entry *crashlog;
 	bool enabled;
 	int result;
 
-	entry = dev_get_drvdata(dev);
+	crashlog = dev_get_drvdata(dev);
 
 	result = kstrtobool(buf, &enabled);
 	if (result)
 		return result;
 
-	guard(mutex)(&entry->control_mutex);
+	guard(mutex)(&crashlog->control_mutex);
 
-	pmt_crashlog_set_disable(&entry->entry, !enabled);
+	pmt_crashlog_set_disable(crashlog, !enabled);
 
 	return count;
 }
@@ -166,11 +212,11 @@ static DEVICE_ATTR_RW(enable);
 static ssize_t
 trigger_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
-	struct intel_pmt_entry *entry;
+	struct crashlog_entry *crashlog;
 	bool trigger;
 
-	entry = dev_get_drvdata(dev);
-	trigger = pmt_crashlog_complete(entry);
+	crashlog = dev_get_drvdata(dev);
+	trigger = pmt_crashlog_complete(crashlog);
 
 	return sprintf(buf, "%d\n", trigger);
 }
@@ -179,32 +225,33 @@ static ssize_t
 trigger_store(struct device *dev, struct device_attribute *attr,
 	      const char *buf, size_t count)
 {
-	struct crashlog_entry *entry;
+	struct crashlog_entry *crashlog;
 	bool trigger;
 	int result;
 
-	entry = dev_get_drvdata(dev);
+	crashlog = dev_get_drvdata(dev);
 
 	result = kstrtobool(buf, &trigger);
 	if (result)
 		return result;
 
-	guard(mutex)(&entry->control_mutex);
+	guard(mutex)(&crashlog->control_mutex);
 
 	/* if device is currently disabled, return busy */
-	if (pmt_crashlog_disabled(&entry->entry))
+	if (pmt_crashlog_disabled(crashlog))
 		return -EBUSY;
 
 	if (!trigger) {
-		pmt_crashlog_set_clear(&entry->entry);
+		pmt_crashlog_set_clear(crashlog);
 		return count;
 	}
 
 	/* we cannot trigger a new crash if one is still pending */
-	if (pmt_crashlog_complete(&entry->entry))
+	if (pmt_crashlog_complete(crashlog))
 		return -EEXIST;
 
-	pmt_crashlog_set_execute(&entry->entry);
+	pmt_crashlog_set_execute(crashlog);
+
 
 	return count;
 }
@@ -230,9 +277,10 @@ static int pmt_crashlog_header_decode(struct intel_pmt_entry *entry,
 	if (!pmt_crashlog_supported(entry))
 		return 1;
 
-	/* initialize control mutex */
+	/* initialize the crashlog struct */
 	crashlog = container_of(entry, struct crashlog_entry, entry);
 	mutex_init(&crashlog->control_mutex);
+	crashlog->info = &crashlog_type1_ver0;
 
 	header->access_type = GET_ACCESS(readl(disc_table));
 	header->guid = readl(disc_table + GUID_OFFSET);
-- 
2.49.0



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