Re: [PATCH v6 2/3] drm/xe/sysctrl: Add system controller event support

[Raag Jadav <raag.jadav@intel.com>]

On Mon, Apr 27, 2026 at 02:20:59PM +0530, Tauro, Riana wrote:
> On 4/10/2026 3:57 PM, Raag Jadav wrote:
> > System controller reports different types of events to GFX endpoint for
> > different usecases, add initial support for them. This will be further
> > extended to service those usecases.
> > 
> > Signed-off-by: Raag Jadav <raag.jadav@intel.com>
> > Reviewed-by: Mallesh Koujalagi <mallesh.koujalagi@intel.com>
> > ---
> > v2: Handle unexpected response length (Mallesh)
> > v3: Handle event flood (Mallesh)
> > v6: Drop xe prefix from static functions (Riana)
> >      Don't fail on unexpected event (Riana)
> >      Move sysctrl commands to xe_sysctrl_mailbox_types.h (Riana)
> >      Add kernel doc (Riana)
> > ---
> >   drivers/gpu/drm/xe/Makefile                   |  1 +
> >   drivers/gpu/drm/xe/xe_sysctrl.c               | 11 +++
> >   drivers/gpu/drm/xe/xe_sysctrl.h               |  1 +
> >   drivers/gpu/drm/xe/xe_sysctrl_event.c         | 84 +++++++++++++++++++
> >   drivers/gpu/drm/xe/xe_sysctrl_event_types.h   | 57 +++++++++++++
> >   drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h | 18 ++++
> >   drivers/gpu/drm/xe/xe_sysctrl_types.h         |  3 +
> >   7 files changed, 175 insertions(+)
> >   create mode 100644 drivers/gpu/drm/xe/xe_sysctrl_event.c
> >   create mode 100644 drivers/gpu/drm/xe/xe_sysctrl_event_types.h
> > 
> > diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
> > index 7f03f06df186..9e6689c86797 100644
> > --- a/drivers/gpu/drm/xe/Makefile
> > +++ b/drivers/gpu/drm/xe/Makefile
> > @@ -125,6 +125,7 @@ xe-y += xe_bb.o \
> >   	xe_survivability_mode.o \
> >   	xe_sync.o \
> >   	xe_sysctrl.o \
> > +	xe_sysctrl_event.o \
> >   	xe_sysctrl_mailbox.o \
> >   	xe_tile.o \
> >   	xe_tile_sysfs.o \
> > diff --git a/drivers/gpu/drm/xe/xe_sysctrl.c b/drivers/gpu/drm/xe/xe_sysctrl.c
> > index 72ce0822cc6d..8fd791047f0a 100644
> > --- a/drivers/gpu/drm/xe/xe_sysctrl.c
> > +++ b/drivers/gpu/drm/xe/xe_sysctrl.c
> > @@ -12,6 +12,7 @@
> >   #include "regs/xe_sysctrl_regs.h"
> >   #include "xe_device.h"
> >   #include "xe_mmio.h"
> > +#include "xe_pm.h"
> >   #include "xe_soc_remapper.h"
> >   #include "xe_sysctrl.h"
> >   #include "xe_sysctrl_mailbox.h"
> > @@ -39,6 +40,12 @@ static void sysctrl_fini(void *arg)
> >   static void xe_sysctrl_work(struct work_struct *work)
> >   {
> > +	struct xe_sysctrl *sc = container_of(work, struct xe_sysctrl, work);
> > +	struct xe_device *xe = sc_to_xe(sc);
> > +
> > +	guard(xe_pm_runtime)(xe);
> > +	guard(mutex)(&sc->work_lock);
> > +	xe_sysctrl_event(sc);
> >   }
> >   /**
> > @@ -74,6 +81,10 @@ int xe_sysctrl_init(struct xe_device *xe)
> >   	if (ret)
> >   		return ret;
> > +	ret = devm_mutex_init(xe->drm.dev, &sc->work_lock);
> > +	if (ret)
> > +		return ret;
> > +
> >   	xe->soc_remapper.set_sysctrl_region(xe, SYSCTRL_MAILBOX_INDEX);
> >   	xe_sysctrl_mailbox_init(sc);
> >   	INIT_WORK(&sc->work, xe_sysctrl_work);
> > diff --git a/drivers/gpu/drm/xe/xe_sysctrl.h b/drivers/gpu/drm/xe/xe_sysctrl.h
> > index f7469bfc9324..090dffb6d55f 100644
> > --- a/drivers/gpu/drm/xe/xe_sysctrl.h
> > +++ b/drivers/gpu/drm/xe/xe_sysctrl.h
> > @@ -16,6 +16,7 @@ static inline struct xe_device *sc_to_xe(struct xe_sysctrl *sc)
> >   	return container_of(sc, struct xe_device, sc);
> >   }
> > +void xe_sysctrl_event(struct xe_sysctrl *sc);
> >   int xe_sysctrl_init(struct xe_device *xe);
> >   void xe_sysctrl_irq_handler(struct xe_device *xe, u32 master_ctl);
> >   void xe_sysctrl_pm_resume(struct xe_device *xe);
> > diff --git a/drivers/gpu/drm/xe/xe_sysctrl_event.c b/drivers/gpu/drm/xe/xe_sysctrl_event.c
> > new file mode 100644
> > index 000000000000..3edde46a9711
> > --- /dev/null
> > +++ b/drivers/gpu/drm/xe/xe_sysctrl_event.c
> > @@ -0,0 +1,84 @@
> > +// SPDX-License-Identifier: MIT
> > +/*
> > + * Copyright © 2026 Intel Corporation
> > + */
> > +
> > +#include "xe_device.h"
> > +#include "xe_irq.h"
> > +#include "xe_printk.h"
> > +#include "xe_sysctrl.h"
> > +#include "xe_sysctrl_event_types.h"
> > +#include "xe_sysctrl_mailbox.h"
> > +#include "xe_sysctrl_mailbox_types.h"
> > +
> > +static void get_pending_event(struct xe_sysctrl *sc, struct xe_sysctrl_mailbox_command *command)
> > +{
> > +	struct xe_sysctrl_event_response *response = command->data_out;
> > +	struct xe_device *xe = sc_to_xe(sc);
> > +	u32 count = XE_SYSCTRL_EVENT_FLOOD;
> > +	size_t len;
> > +	int ret;
> > +
> > +	do {
> > +		memset(response, 0, sizeof(*response));
> > +
> > +		ret = xe_sysctrl_send_command(sc, command, &len);
> > +		if (ret) {
> > +			xe_err(xe, "sysctrl: failed to get pending event %d\n", ret);
> > +			return;
> > +		}
> > +
> > +		if (len != sizeof(*response)) {
> > +			xe_err(xe, "sysctrl: unexpected event response length %zu\n", len);
> 
> Let's keep error logs consistent across patches. Since multiple people are
> working on different patches
> I found these logs better from the threshold series
> [v1,08/11] drm/xe/ras: Get error threshold support - Patchwork
> <https://patchwork.freedesktop.org/patch/719221/?series=165091&rev=1>
> 
> Example:
> 
> xe_err(xe, "sysctrl: get threshold  failed %d\n", ret);
> 
> xe_err(xe, "sysctrl: unexpected get threshold response size%zu (expected
> %zu)\n",
>            len, sizeof(response));
> 
> Let me know if this works. I'll incorporate the same in my patches

Yep, that's why I have those. The error message describes exactly what
happened instead of requiring me to open up specs or remembering random
command codes while debugging.

> > +			return;
> > +		}
> > +
> > +		if (response->event == XE_SYSCTRL_EVENT_THRESHOLD_CROSSED)
> > +			xe_warn(xe, "[RAS]: counter threshold crossed\n");
> > +		else
> > +			xe_err(xe, "sysctrl: unexpected event %#x\n", response->event);
> > +
> > +		if (!--count) {
> > +			xe_err(xe, "sysctrl: event flooding\n");
> > +			return;
> > +		}
> > +
> > +		xe_dbg(xe, "sysctrl: %u events pending\n", response->count);
> > +	} while (response->count);
> > +}
> > +
> > +static void event_request_prep(struct xe_device *xe, struct xe_sysctrl_app_msg_hdr *header,
> > +			       struct xe_sysctrl_event_request *request)
> > +{
> > +	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
> > +
> > +	header->data = REG_FIELD_PREP(APP_HDR_GROUP_ID_MASK, XE_SYSCTRL_GROUP_GFSP) |
> > +		       REG_FIELD_PREP(APP_HDR_COMMAND_MASK, XE_SYSCTRL_CMD_GET_PENDING_EVENT);
> > +
> > +	request->vector = xe_device_has_msix(xe) ? XE_IRQ_DEFAULT_MSIX : 0;
> > +	request->fn = PCI_FUNC(pdev->devfn);
> > +}
> > +
> > +/**
> > + * xe_sysctrl_event() - Handler for System Controller events
> > + * @sc: System Controller instance
> > + *
> > + * Handle events generated by System Controller.
> > + */
> > +void xe_sysctrl_event(struct xe_sysctrl *sc)
> > +{
> > +	struct xe_sysctrl_mailbox_command command = {};
> > +	struct xe_sysctrl_event_response response = {};
> > +	struct xe_sysctrl_event_request request = {};
> > +	struct xe_sysctrl_app_msg_hdr header = {};
> > +
> > +	event_request_prep(sc_to_xe(sc), &header, &request);
> > +
> > +	command.header = header;
> > +	command.data_in = &request;
> > +	command.data_in_len = sizeof(request);
> > +	command.data_out = &response;
> > +	command.data_out_len = sizeof(response);
> > +
> > +	get_pending_event(sc, &command);
> > +}
> > diff --git a/drivers/gpu/drm/xe/xe_sysctrl_event_types.h b/drivers/gpu/drm/xe/xe_sysctrl_event_types.h
> > new file mode 100644
> > index 000000000000..7066d7979f4a
> > --- /dev/null
> > +++ b/drivers/gpu/drm/xe/xe_sysctrl_event_types.h
> > @@ -0,0 +1,57 @@
> > +/* SPDX-License-Identifier: MIT */
> > +/*
> > + * Copyright © 2026 Intel Corporation
> > + */
> > +
> > +#ifndef _XE_SYSCTRL_EVENT_TYPES_H_
> > +#define _XE_SYSCTRL_EVENT_TYPES_H_
> > +
> > +#include <linux/types.h>
> > +
> > +#define XE_SYSCTRL_EVENT_DATA_LEN		59
> > +
> > +/* Modify as needed */
> > +#define XE_SYSCTRL_EVENT_FLOOD			16
> > +
> > +/**
> > + * enum xe_sysctrl_event - Events reported by System Controller
> > + *
> > + * @XE_SYSCTRL_EVENT_THRESHOLD_CROSSED: Error counter threshold crossed
> > + */
> > +enum xe_sysctrl_event {
> > +	XE_SYSCTRL_EVENT_THRESHOLD_CROSSED	= 0x01,
> > +};
> > +
> > +/**
> > + * struct xe_sysctrl_event_request - Request structure for pending event
> > + */
> > +struct xe_sysctrl_event_request {
> > +	/** @vector: MSI-X vector that was triggered */
> > +	u32 vector;
> > +	/** @fn: Function index (0-7) of PCIe device */
> > +	u32 fn:8;
> > +	/** @reserved: Reserved for future use */
> > +	u32 reserved:24;
> > +	/** @reserved2: Reserved for future use */
> > +	u32 reserved2[2];
> Nit: reserved1?

Sure.

> > +} __packed;
> > +
> > +/**
> > + * struct xe_sysctrl_event_response - Response structure for pending event
> > + */
> > +struct xe_sysctrl_event_response {
> > +	/** @count: Pending event count, decremented by fw on each response */
> 
> Might not be decremented  everytime if there is a new event

True. Will change it to "Pending event count after this response".

Raag

> > +	u32 count;
> > +	/** @event: Pending event */
> > +	enum xe_sysctrl_event event;
> > +	/** @timestamp: Timestamp of most recent event */
> > +	u64 timestamp;
> > +	/** @extended: Event has extended payload */
> > +	u32 extended:1;
> > +	/** @reserved: Reserved for future use */
> > +	u32 reserved:31;
> > +	/** @data: Generic event data */
> > +	u32 data[XE_SYSCTRL_EVENT_DATA_LEN];
> > +} __packed;
> > +
> > +#endif /* _XE_SYSCTRL_EVENT_TYPES_H_ */
> > diff --git a/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h b/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h
> > index 89456aec6097..84d7c647e743 100644
> > --- a/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h
> > +++ b/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h
> > @@ -10,6 +10,24 @@
> >   #include "abi/xe_sysctrl_abi.h"
> > +/**
> > + * enum xe_sysctrl_group - System Controller command groups
> > + *
> > + * @XE_SYSCTRL_GROUP_GFSP: GFSP group
> > + */
> > +enum xe_sysctrl_group {
> > +	XE_SYSCTRL_GROUP_GFSP			= 0x01,
> > +};
> > +
> > +/**
> > + * enum xe_sysctrl_gfsp_cmd - Commands supported by GFSP group
> > + *
> > + * @XE_SYSCTRL_CMD_GET_PENDING_EVENT: Retrieve pending event
> > + */
> > +enum xe_sysctrl_gfsp_cmd {
> > +	XE_SYSCTRL_CMD_GET_PENDING_EVENT	= 0x07,
> > +};
> > +
> >   /**
> >    * struct xe_sysctrl_mailbox_command - System Controller mailbox command
> >    */
> > diff --git a/drivers/gpu/drm/xe/xe_sysctrl_types.h b/drivers/gpu/drm/xe/xe_sysctrl_types.h
> > index 5f408d6491ef..95359af691c9 100644
> > --- a/drivers/gpu/drm/xe/xe_sysctrl_types.h
> > +++ b/drivers/gpu/drm/xe/xe_sysctrl_types.h
> > @@ -31,6 +31,9 @@ struct xe_sysctrl {
> >   	/** @work: Pending events worker */
> >   	struct work_struct work;
> > +
> > +	/** @work_lock: Mutex protecting pending events */
> > +	struct mutex work_lock;
> >   };
> >   #endif