drivers/gpu/drm/xe/xe_pcode.c - linux - Git at Google

 // SPDX-License-Identifier: MIT
 /*
  * Copyright © 2022 Intel Corporation
  */

 #include "xe_pcode.h"

 #include <linux/delay.h>
 #include <linux/errno.h>

 #include <drm/drm_managed.h>

 #include "xe_gt.h"
 #include "xe_mmio.h"
 #include "xe_pcode_api.h"

 /**
  * DOC: PCODE
  *
  * Xe PCODE is the component responsible for interfacing with the PCODE
  * firmware.
  * It shall provide a very simple ABI to other Xe components, but be the
  * single and consolidated place that will communicate with PCODE. All read
  * and write operations to PCODE will be internal and private to this component.
  *
  * What's next:
  * - PCODE hw metrics
  * - PCODE for display operations
  */

 static int pcode_mailbox_status(struct xe_gt *gt)
 {
 	u32 err;
 	static const struct pcode_err_decode err_decode[] = {
 		[PCODE_ILLEGAL_CMD] = {-ENXIO, "Illegal Command"},
 		[PCODE_TIMEOUT] = {-ETIMEDOUT, "Timed out"},
 		[PCODE_ILLEGAL_DATA] = {-EINVAL, "Illegal Data"},
 		[PCODE_ILLEGAL_SUBCOMMAND] = {-ENXIO, "Illegal Subcommand"},
 		[PCODE_LOCKED] = {-EBUSY, "PCODE Locked"},
 		[PCODE_GT_RATIO_OUT_OF_RANGE] = {-EOVERFLOW,
 			"GT ratio out of range"},
 		[PCODE_REJECTED] = {-EACCES, "PCODE Rejected"},
 		[PCODE_ERROR_MASK] = {-EPROTO, "Unknown"},
 	};

 	lockdep_assert_held(&gt->pcode.lock);

 	err = xe_mmio_read32(gt, PCODE_MAILBOX) & PCODE_ERROR_MASK;
 	if (err) {
 		drm_err(&gt_to_xe(gt)->drm, "PCODE Mailbox failed: %d %s", err,
 			err_decode[err].str ?: "Unknown");
 		return err_decode[err].errno ?: -EPROTO;
 	}

 	return 0;
 }

 static int pcode_mailbox_rw(struct xe_gt *gt, u32 mbox, u32 *data0, u32 *data1,
 			    unsigned int timeout_ms, bool return_data,
 			    bool atomic)
 {
 	int err;

 	if (gt_to_xe(gt)->info.skip_pcode)
 		return 0;

 	lockdep_assert_held(&gt->pcode.lock);

 	if ((xe_mmio_read32(gt, PCODE_MAILBOX) & PCODE_READY) != 0)
 		return -EAGAIN;

 	xe_mmio_write32(gt, PCODE_DATA0, *data0);
 	xe_mmio_write32(gt, PCODE_DATA1, data1 ? *data1 : 0);
 	xe_mmio_write32(gt, PCODE_MAILBOX, PCODE_READY | mbox);

 	err = xe_mmio_wait32(gt, PCODE_MAILBOX, PCODE_READY, 0,
 			     timeout_ms * 1000, NULL, atomic);
 	if (err)
 		return err;

 	if (return_data) {
 		*data0 = xe_mmio_read32(gt, PCODE_DATA0);
 		if (data1)
 			*data1 = xe_mmio_read32(gt, PCODE_DATA1);
 	}

 	return pcode_mailbox_status(gt);
 }

 int xe_pcode_write_timeout(struct xe_gt *gt, u32 mbox, u32 data, int timeout)
 {
 	int err;

 	mutex_lock(&gt->pcode.lock);
 	err = pcode_mailbox_rw(gt, mbox, &data, NULL, timeout, false, false);
 	mutex_unlock(&gt->pcode.lock);

 	return err;
 }

 int xe_pcode_read(struct xe_gt *gt, u32 mbox, u32 *val, u32 *val1)
 {
 	int err;

 	mutex_lock(&gt->pcode.lock);
 	err = pcode_mailbox_rw(gt, mbox, val, val1, 1, true, false);
 	mutex_unlock(&gt->pcode.lock);

 	return err;
 }

 static int xe_pcode_try_request(struct xe_gt *gt, u32 mbox,
 				u32 request, u32 reply_mask, u32 reply,
 				u32 *status, bool atomic, int timeout_us)
 {
 	int slept, wait = 10;

 	for (slept = 0; slept < timeout_us; slept += wait) {
 		*status = pcode_mailbox_rw(gt, mbox, &request, NULL, 1, true,
 					   atomic);
 		if ((*status == 0) && ((request & reply_mask) == reply))
 			return 0;

 		if (atomic)
 			udelay(wait);
 		else
 			usleep_range(wait, wait << 1);
 		wait <<= 1;
 	}

 	return -ETIMEDOUT;
 }

 /**
  * xe_pcode_request - send PCODE request until acknowledgment
  * @gt: gt
  * @mbox: PCODE mailbox ID the request is targeted for
  * @request: request ID
  * @reply_mask: mask used to check for request acknowledgment
  * @reply: value used to check for request acknowledgment
  * @timeout_base_ms: timeout for polling with preemption enabled
  *
  * Keep resending the @request to @mbox until PCODE acknowledges it, PCODE
  * reports an error or an overall timeout of @timeout_base_ms+50 ms expires.
  * The request is acknowledged once the PCODE reply dword equals @reply after
  * applying @reply_mask. Polling is first attempted with preemption enabled
  * for @timeout_base_ms and if this times out for another 50 ms with
  * preemption disabled.
  *
  * Returns 0 on success, %-ETIMEDOUT in case of a timeout, <0 in case of some
  * other error as reported by PCODE.
  */
 int xe_pcode_request(struct xe_gt *gt, u32 mbox, u32 request,
 		      u32 reply_mask, u32 reply, int timeout_base_ms)
 {
 	u32 status;
 	int ret;

 	mutex_lock(&gt->pcode.lock);

 	ret = xe_pcode_try_request(gt, mbox, request, reply_mask, reply, &status,
 				   false, timeout_base_ms * 1000);
 	if (!ret)
 		goto out;

 	/*
 	 * The above can time out if the number of requests was low (2 in the
 	 * worst case) _and_ PCODE was busy for some reason even after a
 	 * (queued) request and @timeout_base_ms delay. As a workaround retry
 	 * the poll with preemption disabled to maximize the number of
 	 * requests. Increase the timeout from @timeout_base_ms to 50ms to
 	 * account for interrupts that could reduce the number of these
 	 * requests, and for any quirks of the PCODE firmware that delays
 	 * the request completion.
 	 */
 	drm_err(&gt_to_xe(gt)->drm,
 		"PCODE timeout, retrying with preemption disabled\n");
 	drm_WARN_ON_ONCE(&gt_to_xe(gt)->drm, timeout_base_ms > 1);
 	preempt_disable();
 	ret = xe_pcode_try_request(gt, mbox, request, reply_mask, reply, &status,
 				   true, timeout_base_ms * 1000);
 	preempt_enable();

 out:
 	mutex_unlock(&gt->pcode.lock);
 	return status ? status : ret;
 }
 /**
  * xe_pcode_init_min_freq_table - Initialize PCODE's QOS frequency table
  * @gt: gt instance
  * @min_gt_freq: Minimal (RPn) GT frequency in units of 50MHz.
  * @max_gt_freq: Maximal (RP0) GT frequency in units of 50MHz.
  *
  * This function initialize PCODE's QOS frequency table for a proper minimal
  * frequency/power steering decision, depending on the current requested GT
  * frequency. For older platforms this was a more complete table including
  * the IA freq. However for the latest platforms this table become a simple
  * 1-1 Ring vs GT frequency. Even though, without setting it, PCODE might
  * not take the right decisions for some memory frequencies and affect latency.
  *
  * It returns 0 on success, and -ERROR number on failure, -EINVAL if max
  * frequency is higher then the minimal, and other errors directly translated
  * from the PCODE Error returs:
  * - -ENXIO: "Illegal Command"
  * - -ETIMEDOUT: "Timed out"
  * - -EINVAL: "Illegal Data"
  * - -ENXIO, "Illegal Subcommand"
  * - -EBUSY: "PCODE Locked"
  * - -EOVERFLOW, "GT ratio out of range"
  * - -EACCES, "PCODE Rejected"
  * - -EPROTO, "Unknown"
  */
 int xe_pcode_init_min_freq_table(struct xe_gt *gt, u32 min_gt_freq,
 				 u32 max_gt_freq)
 {
 	int ret;
 	u32 freq;

 	if (!gt_to_xe(gt)->info.has_llc)
 		return 0;

 	if (max_gt_freq <= min_gt_freq)
 		return -EINVAL;

 	mutex_lock(&gt->pcode.lock);
 	for (freq = min_gt_freq; freq <= max_gt_freq; freq++) {
 		u32 data = freq << PCODE_FREQ_RING_RATIO_SHIFT | freq;

 		ret = pcode_mailbox_rw(gt, PCODE_WRITE_MIN_FREQ_TABLE,
 				       &data, NULL, 1, false, false);
 		if (ret)
 			goto unlock;
 	}

 unlock:
 	mutex_unlock(&gt->pcode.lock);
 	return ret;
 }

 /**
  * xe_pcode_init - Ensure PCODE is initialized
  * @gt: gt instance
  *
  * This function ensures that PCODE is properly initialized. To be called during
  * probe and resume paths.
  *
  * It returns 0 on success, and -error number on failure.
  */
 int xe_pcode_init(struct xe_gt *gt)
 {
 	u32 status, request = DGFX_GET_INIT_STATUS;
 	int timeout_us = 180000000; /* 3 min */
 	int ret;

 	if (gt_to_xe(gt)->info.skip_pcode)
 		return 0;

 	if (!IS_DGFX(gt_to_xe(gt)))
 		return 0;

 	mutex_lock(&gt->pcode.lock);
 	ret = xe_pcode_try_request(gt, DGFX_PCODE_STATUS, request,
 				   DGFX_INIT_STATUS_COMPLETE,
 				   DGFX_INIT_STATUS_COMPLETE,
 				   &status, false, timeout_us);
 	mutex_unlock(&gt->pcode.lock);

 	if (ret)
 		drm_err(&gt_to_xe(gt)->drm,
 			"PCODE initialization timedout after: 3 min\n");

 	return ret;
 }

 /**
  * xe_pcode_probe - Prepare xe_pcode and also ensure PCODE is initialized.
  * @gt: gt instance
  *
  * This function initializes the xe_pcode component, and when needed, it ensures
  * that PCODE has properly performed its initialization and it is really ready
  * to go. To be called once only during probe.
  *
  * It returns 0 on success, and -error number on failure.
  */
 int xe_pcode_probe(struct xe_gt *gt)
 {
 	drmm_mutex_init(&gt_to_xe(gt)->drm, &gt->pcode.lock);

 	if (gt_to_xe(gt)->info.skip_pcode)
 		return 0;

 	if (!IS_DGFX(gt_to_xe(gt)))
 		return 0;

 	return xe_pcode_init(gt);
 }
	// SPDX-License-Identifier: MIT
	/*
	* Copyright © 2022 Intel Corporation
	*/

	#include "xe_pcode.h"

	#include <linux/delay.h>
	#include <linux/errno.h>

	#include <drm/drm_managed.h>

	#include "xe_gt.h"
	#include "xe_mmio.h"
	#include "xe_pcode_api.h"

	/**
	* DOC: PCODE
	*
	* Xe PCODE is the component responsible for interfacing with the PCODE
	* firmware.
	* It shall provide a very simple ABI to other Xe components, but be the
	* single and consolidated place that will communicate with PCODE. All read
	* and write operations to PCODE will be internal and private to this component.
	*
	* What's next:
	* - PCODE hw metrics
	* - PCODE for display operations
	*/

	static int pcode_mailbox_status(struct xe_gt *gt)
	{
	u32 err;
	static const struct pcode_err_decode err_decode[] = {
	[PCODE_ILLEGAL_CMD] = {-ENXIO, "Illegal Command"},
	[PCODE_TIMEOUT] = {-ETIMEDOUT, "Timed out"},
	[PCODE_ILLEGAL_DATA] = {-EINVAL, "Illegal Data"},
	[PCODE_ILLEGAL_SUBCOMMAND] = {-ENXIO, "Illegal Subcommand"},
	[PCODE_LOCKED] = {-EBUSY, "PCODE Locked"},
	[PCODE_GT_RATIO_OUT_OF_RANGE] = {-EOVERFLOW,
	"GT ratio out of range"},
	[PCODE_REJECTED] = {-EACCES, "PCODE Rejected"},
	[PCODE_ERROR_MASK] = {-EPROTO, "Unknown"},
	};

	lockdep_assert_held(&gt->pcode.lock);

	err = xe_mmio_read32(gt, PCODE_MAILBOX) & PCODE_ERROR_MASK;
	if (err) {
	drm_err(&gt_to_xe(gt)->drm, "PCODE Mailbox failed: %d %s", err,
	err_decode[err].str ?: "Unknown");
	return err_decode[err].errno ?: -EPROTO;
	}

	return 0;
	}

	static int pcode_mailbox_rw(struct xe_gt gt, u32 mbox, u32 data0, u32 *data1,
	unsigned int timeout_ms, bool return_data,
	bool atomic)
	{
	int err;

	if (gt_to_xe(gt)->info.skip_pcode)
	return 0;

	lockdep_assert_held(&gt->pcode.lock);

	if ((xe_mmio_read32(gt, PCODE_MAILBOX) & PCODE_READY) != 0)
	return -EAGAIN;

	xe_mmio_write32(gt, PCODE_DATA0, *data0);
	xe_mmio_write32(gt, PCODE_DATA1, data1 ? *data1 : 0);
	xe_mmio_write32(gt, PCODE_MAILBOX, PCODE_READY \| mbox);

	err = xe_mmio_wait32(gt, PCODE_MAILBOX, PCODE_READY, 0,
	timeout_ms * 1000, NULL, atomic);
	if (err)
	return err;

	if (return_data) {
	*data0 = xe_mmio_read32(gt, PCODE_DATA0);
	if (data1)
	*data1 = xe_mmio_read32(gt, PCODE_DATA1);
	}

	return pcode_mailbox_status(gt);
	}

	int xe_pcode_write_timeout(struct xe_gt *gt, u32 mbox, u32 data, int timeout)
	{
	int err;

	mutex_lock(&gt->pcode.lock);
	err = pcode_mailbox_rw(gt, mbox, &data, NULL, timeout, false, false);
	mutex_unlock(&gt->pcode.lock);

	return err;
	}

	int xe_pcode_read(struct xe_gt gt, u32 mbox, u32 val, u32 *val1)
	{
	int err;

	mutex_lock(&gt->pcode.lock);
	err = pcode_mailbox_rw(gt, mbox, val, val1, 1, true, false);
	mutex_unlock(&gt->pcode.lock);

	return err;
	}

	static int xe_pcode_try_request(struct xe_gt *gt, u32 mbox,
	u32 request, u32 reply_mask, u32 reply,
	u32 *status, bool atomic, int timeout_us)
	{
	int slept, wait = 10;

	for (slept = 0; slept < timeout_us; slept += wait) {
	*status = pcode_mailbox_rw(gt, mbox, &request, NULL, 1, true,
	atomic);
	if ((*status == 0) && ((request & reply_mask) == reply))
	return 0;

	if (atomic)
	udelay(wait);
	else
	usleep_range(wait, wait << 1);
	wait <<= 1;
	}

	return -ETIMEDOUT;
	}

	/**
	* xe_pcode_request - send PCODE request until acknowledgment
	* @gt: gt
	* @mbox: PCODE mailbox ID the request is targeted for
	* @request: request ID
	* @reply_mask: mask used to check for request acknowledgment
	* @reply: value used to check for request acknowledgment
	* @timeout_base_ms: timeout for polling with preemption enabled
	*
	* Keep resending the @request to @mbox until PCODE acknowledges it, PCODE
	* reports an error or an overall timeout of @timeout_base_ms+50 ms expires.
	* The request is acknowledged once the PCODE reply dword equals @reply after
	* applying @reply_mask. Polling is first attempted with preemption enabled
	* for @timeout_base_ms and if this times out for another 50 ms with
	* preemption disabled.
	*
	* Returns 0 on success, %-ETIMEDOUT in case of a timeout, <0 in case of some
	* other error as reported by PCODE.
	*/
	int xe_pcode_request(struct xe_gt *gt, u32 mbox, u32 request,
	u32 reply_mask, u32 reply, int timeout_base_ms)
	{
	u32 status;
	int ret;

	mutex_lock(&gt->pcode.lock);

	ret = xe_pcode_try_request(gt, mbox, request, reply_mask, reply, &status,
	false, timeout_base_ms * 1000);
	if (!ret)
	goto out;

	/*
	* The above can time out if the number of requests was low (2 in the
	* worst case) _and_ PCODE was busy for some reason even after a
	* (queued) request and @timeout_base_ms delay. As a workaround retry
	* the poll with preemption disabled to maximize the number of
	* requests. Increase the timeout from @timeout_base_ms to 50ms to
	* account for interrupts that could reduce the number of these
	* requests, and for any quirks of the PCODE firmware that delays
	* the request completion.
	*/
	drm_err(&gt_to_xe(gt)->drm,
	"PCODE timeout, retrying with preemption disabled\n");
	drm_WARN_ON_ONCE(&gt_to_xe(gt)->drm, timeout_base_ms > 1);
	preempt_disable();
	ret = xe_pcode_try_request(gt, mbox, request, reply_mask, reply, &status,
	true, timeout_base_ms * 1000);
	preempt_enable();

	out:
	mutex_unlock(&gt->pcode.lock);
	return status ? status : ret;
	}
	/**
	* xe_pcode_init_min_freq_table - Initialize PCODE's QOS frequency table
	* @gt: gt instance
	* @min_gt_freq: Minimal (RPn) GT frequency in units of 50MHz.
	* @max_gt_freq: Maximal (RP0) GT frequency in units of 50MHz.
	*
	* This function initialize PCODE's QOS frequency table for a proper minimal
	* frequency/power steering decision, depending on the current requested GT
	* frequency. For older platforms this was a more complete table including
	* the IA freq. However for the latest platforms this table become a simple
	* 1-1 Ring vs GT frequency. Even though, without setting it, PCODE might
	* not take the right decisions for some memory frequencies and affect latency.
	*
	* It returns 0 on success, and -ERROR number on failure, -EINVAL if max
	* frequency is higher then the minimal, and other errors directly translated
	* from the PCODE Error returs:
	* - -ENXIO: "Illegal Command"
	* - -ETIMEDOUT: "Timed out"
	* - -EINVAL: "Illegal Data"
	* - -ENXIO, "Illegal Subcommand"
	* - -EBUSY: "PCODE Locked"
	* - -EOVERFLOW, "GT ratio out of range"
	* - -EACCES, "PCODE Rejected"
	* - -EPROTO, "Unknown"
	*/
	int xe_pcode_init_min_freq_table(struct xe_gt *gt, u32 min_gt_freq,
	u32 max_gt_freq)
	{
	int ret;
	u32 freq;

	if (!gt_to_xe(gt)->info.has_llc)
	return 0;

	if (max_gt_freq <= min_gt_freq)
	return -EINVAL;

	mutex_lock(&gt->pcode.lock);
	for (freq = min_gt_freq; freq <= max_gt_freq; freq++) {
	u32 data = freq << PCODE_FREQ_RING_RATIO_SHIFT \| freq;

	ret = pcode_mailbox_rw(gt, PCODE_WRITE_MIN_FREQ_TABLE,
	&data, NULL, 1, false, false);
	if (ret)
	goto unlock;
	}

	unlock:
	mutex_unlock(&gt->pcode.lock);
	return ret;
	}

	/**
	* xe_pcode_init - Ensure PCODE is initialized
	* @gt: gt instance
	*
	* This function ensures that PCODE is properly initialized. To be called during
	* probe and resume paths.
	*
	* It returns 0 on success, and -error number on failure.
	*/
	int xe_pcode_init(struct xe_gt *gt)
	{
	u32 status, request = DGFX_GET_INIT_STATUS;
	int timeout_us = 180000000; /* 3 min */
	int ret;

	if (gt_to_xe(gt)->info.skip_pcode)
	return 0;

	if (!IS_DGFX(gt_to_xe(gt)))
	return 0;

	mutex_lock(&gt->pcode.lock);
	ret = xe_pcode_try_request(gt, DGFX_PCODE_STATUS, request,
	DGFX_INIT_STATUS_COMPLETE,
	DGFX_INIT_STATUS_COMPLETE,
	&status, false, timeout_us);
	mutex_unlock(&gt->pcode.lock);

	if (ret)
	drm_err(&gt_to_xe(gt)->drm,
	"PCODE initialization timedout after: 3 min\n");

	return ret;
	}

	/**
	* xe_pcode_probe - Prepare xe_pcode and also ensure PCODE is initialized.
	* @gt: gt instance
	*
	* This function initializes the xe_pcode component, and when needed, it ensures
	* that PCODE has properly performed its initialization and it is really ready
	* to go. To be called once only during probe.
	*
	* It returns 0 on success, and -error number on failure.
	*/
	int xe_pcode_probe(struct xe_gt *gt)
	{
	drmm_mutex_init(&gt_to_xe(gt)->drm, &gt->pcode.lock);

	if (gt_to_xe(gt)->info.skip_pcode)
	return 0;

	if (!IS_DGFX(gt_to_xe(gt)))
	return 0;

	return xe_pcode_init(gt);
	}