[PATCH 07/10] platform/x86/intel/pmt: use a version struct
Ruhl, Michael J
michael.j.ruhl at intel.com
Mon Jun 2 17:57:30 UTC 2025
>-----Original Message-----
>From: Ilpo Järvinen <ilpo.jarvinen at linux.intel.com>
>Sent: Saturday, May 31, 2025 1:46 AM
>To: Ruhl, Michael J <michael.j.ruhl at intel.com>
>Cc: platform-driver-x86 at vger.kernel.org; intel-xe at lists.freedesktop.org; Hans
>de Goede <hdegoede at redhat.com>; De Marchi, Lucas
><lucas.demarchi at intel.com>; Vivi, Rodrigo <rodrigo.vivi at intel.com>
>Subject: Re: [PATCH 07/10] platform/x86/intel/pmt: use a version struct
>
>On Fri, 30 May 2025, Michael J. Ruhl wrote:
>
>> 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 | 177 ++++++++++++++--------
>> 1 file changed, 113 insertions(+), 64 deletions(-)
>>
>> diff --git a/drivers/platform/x86/intel/pmt/crashlog.c
>b/drivers/platform/x86/intel/pmt/crashlog.c
>> index 09cd0a1346f3..e6eea8809a56 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 = CONTROL_OFFSET,
>> + .status.clear = TYPE1_VER0_CLEAR,
>> + .status.complete = TYPE1_VER0_COMPLETE,
>> + .status.disable = TYPE1_VER0_DISABLE,
>> +
>> + .control.offset = 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 {
>> @@ -60,24 +98,10 @@ struct pmt_crashlog_priv {
>> };
>>
>> /*
>> - * I/O
>> + * 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_complete(struct intel_pmt_entry *entry)
>> -{
>> - u32 control = readl(entry->disc_table + CONTROL_OFFSET);
>> -
>> - /* return current value of the crashlog complete flag */
>> - return !!(control & CRASHLOG_FLAG_TRIGGER_COMPLETE);
>> -}
>> -
>> -static bool pmt_crashlog_disabled(struct intel_pmt_entry *entry)
>> -{
>> - u32 control = readl(entry->disc_table + CONTROL_OFFSET);
>> -
>> - /* return current value of the crashlog disabled flag */
>> - return !!(control & CRASHLOG_FLAG_DISABLE);
>> -}
>> -
>> static bool pmt_crashlog_supported(struct intel_pmt_entry *entry)
>> {
>> u32 discovery_header = readl(entry->disc_table + CONTROL_OFFSET);
>> @@ -93,40 +117,64 @@ static bool pmt_crashlog_supported(struct
>intel_pmt_entry *entry)
>> return crash_type == CRASH_TYPE_OOBMSM && version == 0;
>> }
>>
>> +/*
>> + * I/O
>> + */
>> +static bool pmt_crashlog_complete(struct intel_pmt_entry *entry,
>> + const struct crashlog_status *status)
>
>I didn't fine comb this change but IMO it would be better to pass just
>crashlog_info here, the same applies to the other functions too taking
>just one of the substructs.
The issue I ran into was that the info and entry are separate members... So I would pass crashlog_entry
and then do this:
static bool pmt_crashlog_complete(struct crashlog_entry *crashlog)
{
struct intel_pmt_entry *entry = &crashlog->entry;
struct crashlog_status *status = &crashlog->info->status;
int reg = readl(entry->disc_table + status->offset;
return !!(reg & status->complete);
}
If that is preferred, I will update.
M
>Overall, this change looks definitely better than the earlier version
>that was based on those if () constructs. Good work! :-)
I agree. This is a lot cleaner than the previous attempt. Thanks for the hints! 😊
M
>> +{
>> + u32 reg = readl(entry->disc_table + status->offset);
>> +
>> + /* return current value of the crashlog complete flag */
>> + return !!(reg & status->complete);
>> +}
>> +
>> +static bool pmt_crashlog_disabled(struct intel_pmt_entry *entry,
>> + const struct crashlog_status *status)
>> +{
>> + u32 reg = readl(entry->disc_table + status->offset);
>> +
>> + /* return current value of the crashlog disabled flag */
>> + return !!(reg & status->disable);
>> +}
>> +
>> static void pmt_crashlog_set_disable(struct intel_pmt_entry *entry,
>> + const struct crashlog_control *control,
>> bool disable)
>> {
>> - u32 control = readl(entry->disc_table + CONTROL_OFFSET);
>> + u32 reg = readl(entry->disc_table + control->offset);
>>
>> /* clear trigger bits so we are only modifying disable flag */
>> - control &= ~CRASHLOG_FLAG_TRIGGER_MASK;
>> + reg &= ~control->trigger_mask;
>>
>> if (disable)
>> - control |= CRASHLOG_FLAG_DISABLE;
>> + reg |= control->disable;
>> else
>> - control &= ~CRASHLOG_FLAG_DISABLE;
>> + reg &= ~control->disable;
>>
>> - writel(control, entry->disc_table + CONTROL_OFFSET);
>> + writel(reg, entry->disc_table + control->offset);
>> }
>>
>> -static void pmt_crashlog_set_clear(struct intel_pmt_entry *entry)
>> +static void pmt_crashlog_set_clear(struct intel_pmt_entry *entry,
>> + const struct crashlog_control *control)
>> {
>> - u32 control = readl(entry->disc_table + CONTROL_OFFSET);
>> + u32 reg = readl(entry->disc_table + control->offset);
>>
>> - control &= ~CRASHLOG_FLAG_TRIGGER_MASK;
>> - control |= CRASHLOG_FLAG_TRIGGER_CLEAR;
>> + reg &= ~control->trigger_mask;
>> + reg |= control->clear;
>>
>> - writel(control, entry->disc_table + CONTROL_OFFSET);
>> + writel(reg, entry->disc_table + control->offset);
>> }
>>
>> -static void pmt_crashlog_set_execute(struct intel_pmt_entry *entry)
>> +static void pmt_crashlog_set_execute(struct intel_pmt_entry *entry,
>> + const struct crashlog_control *control)
>> {
>> - u32 control = readl(entry->disc_table + CONTROL_OFFSET);
>> + u32 reg = readl(entry->disc_table + control->offset);
>>
>> - control &= ~CRASHLOG_FLAG_TRIGGER_MASK;
>> - control |= CRASHLOG_FLAG_TRIGGER_EXECUTE;
>> + reg &= ~control->trigger_mask;
>> + reg |= control->manual;
>>
>> - writel(control, entry->disc_table + CONTROL_OFFSET);
>> + writel(reg, entry->disc_table + control->offset);
>> }
>>
>> /*
>> @@ -135,8 +183,8 @@ 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);
>> - int enabled = !pmt_crashlog_disabled(entry);
>> + struct crashlog_entry *crashlog = dev_get_drvdata(dev);
>> + int enabled = !pmt_crashlog_disabled(&crashlog->entry, &crashlog-
>>info->status);
>>
>> return sprintf(buf, "%d\n", enabled);
>> }
>> @@ -145,19 +193,19 @@ 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->entry, &crashlog->info->control,
>!enabled);
>>
>> return count;
>> }
>> @@ -166,11 +214,11 @@ 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;
>> int trigger;
>>
>> - entry = dev_get_drvdata(dev);
>> - trigger = pmt_crashlog_complete(entry);
>> + crashlog = dev_get_drvdata(dev);
>> + trigger = pmt_crashlog_complete(&crashlog->entry, &crashlog->info-
>>status);
>>
>> return sprintf(buf, "%d\n", trigger);
>> }
>> @@ -179,32 +227,32 @@ 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 (!trigger) {
>> - pmt_crashlog_set_clear(&entry->entry);
>> + pmt_crashlog_set_clear(&crashlog->entry, &crashlog->info-
>>control);
>> return count;
>> }
>>
>> /* we cannot trigger a new crash if one is still pending */
>> - if (pmt_crashlog_complete(&entry->entry))
>> + if (pmt_crashlog_complete(&crashlog->entry, &crashlog->info-
>>status))
>> return -EEXIST;
>>
>> /* if device is currently disabled, return busy */
>> - if (pmt_crashlog_disabled(&entry->entry))
>> + if (pmt_crashlog_disabled(&crashlog->entry, &crashlog->info->status))
>> return -EBUSY;
>>
>> - pmt_crashlog_set_execute(&entry->entry);
>> + pmt_crashlog_set_execute(&crashlog->entry, &crashlog->info-
>>control);
>>
>> return count;
>> }
>> @@ -230,9 +278,10 @@ 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);
>>
>
>--
> i.
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