[PATCH v9 04/26] drm/xe: Error handling in xe_force_wake_get()
Nirmoy Das
nirmoy.das at linux.intel.com
Mon Oct 14 08:32:13 UTC 2024
On 10/14/2024 9:55 AM, Himal Prasad Ghimiray wrote:
> If an acknowledgment timeout occurs for a forcewake domain awake
> request, do not increment the reference count for the domain. This
> ensures that subsequent _get calls do not incorrectly assume the domain
> is awake. The return value is a mask of domains that got refcounted,
> and these domains need to be provided for subsequent xe_force_wake_put
> call.
>
> While at it, add simple kernel-doc for xe_force_wake_get()
>
> v3
> - Use explicit type for mask (Michal/Badal)
> - Improve kernel-doc (Michal)
> - Use unsigned int instead of abusing enum (Michal)
>
> v5
> - Use unsigned int for return (MattB/Badal/Rodrigo)
> - use xe_gt_WARN for domain awake ack failure (Badal/Rodrigo)
>
> v6
> - Change XE_FORCEWAKE_ALL to single bit, this helps accommodate
> actually refcounted domains in return. (Michal)
> - Modify commit message and warn message (Badal)
> - Remove unnecessary information in kernel-doc (Michal)
>
> v7
> - Add assert condition for valid input domains (Badal)
>
> v9
> - Update kernel-doc and simplify conditions (Michal)
>
> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Badal Nilawar <badal.nilawar at intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> Cc: Nirmoy Das <nirmoy.das at intel.com>
> Reviewed-by: Badal Nilawar <badal.nilawar at intel.com>
> Reviewed-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
I am bit too late to this party :)
Reviewed-by: Nirmoy Das <nirmoy.das at intel.com>
> ---
> drivers/gpu/drm/xe/xe_force_wake.c | 52 +++++++++++++++++++-----
> drivers/gpu/drm/xe/xe_force_wake.h | 4 +-
> drivers/gpu/drm/xe/xe_force_wake_types.h | 2 +-
> 3 files changed, 45 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_force_wake.c b/drivers/gpu/drm/xe/xe_force_wake.c
> index ac0419da7173..d36ed4f8bdbe 100644
> --- a/drivers/gpu/drm/xe/xe_force_wake.c
> +++ b/drivers/gpu/drm/xe/xe_force_wake.c
> @@ -154,29 +154,61 @@ static int domain_sleep_wait(struct xe_gt *gt,
> (ffs(tmp__) - 1))) && \
> domain__->reg_ctl.addr)
>
> -int xe_force_wake_get(struct xe_force_wake *fw,
> - enum xe_force_wake_domains domains)
> +/**
> + * xe_force_wake_get() : Increase the domain refcount
> + * @fw: struct xe_force_wake
> + * @domains: forcewake domains to get refcount on
> + *
> + * This function wakes up @domains if they are asleep and takes references.
> + * If requested domain is XE_FORCEWAKE_ALL then only applicable/initialized
> + * domains will be considered for refcount and it is a caller responsibility
> + * to check returned ref if it includes any specific domain by using
> + * xe_force_wake_ref_has_domain() function. Caller must call
> + * xe_force_wake_put() function to decrease incremented refcounts.
> + *
> + * Return: opaque reference to woken domains or zero if none of requested
> + * domains were awake.
> + */
> +unsigned int xe_force_wake_get(struct xe_force_wake *fw,
> + enum xe_force_wake_domains domains)
> {
> struct xe_gt *gt = fw->gt;
> struct xe_force_wake_domain *domain;
> - enum xe_force_wake_domains tmp, woken = 0;
> + unsigned int ref_incr = 0, awake_rqst = 0, awake_failed = 0;
> + unsigned int tmp, ref_rqst;
> unsigned long flags;
> - int ret = 0;
>
> + xe_gt_assert(gt, is_power_of_2(domains));
> + xe_gt_assert(gt, domains <= XE_FORCEWAKE_ALL);
> + xe_gt_assert(gt, domains == XE_FORCEWAKE_ALL || fw->initialized_domains & domains);
> +
> + ref_rqst = (domains == XE_FORCEWAKE_ALL) ? fw->initialized_domains : domains;
> spin_lock_irqsave(&fw->lock, flags);
> - for_each_fw_domain_masked(domain, domains, fw, tmp) {
> + for_each_fw_domain_masked(domain, ref_rqst, fw, tmp) {
> if (!domain->ref++) {
> - woken |= BIT(domain->id);
> + awake_rqst |= BIT(domain->id);
> domain_wake(gt, domain);
> }
> + ref_incr |= BIT(domain->id);
> }
> - for_each_fw_domain_masked(domain, woken, fw, tmp) {
> - ret |= domain_wake_wait(gt, domain);
> + for_each_fw_domain_masked(domain, awake_rqst, fw, tmp) {
> + if (domain_wake_wait(gt, domain) == 0) {
> + fw->awake_domains |= BIT(domain->id);
> + } else {
> + awake_failed |= BIT(domain->id);
> + --domain->ref;
> + }
> }
> - fw->awake_domains |= woken;
> + ref_incr &= ~awake_failed;
> spin_unlock_irqrestore(&fw->lock, flags);
>
> - return ret;
> + xe_gt_WARN(gt, awake_failed, "Forcewake domain%s %#x failed to acknowledge awake request\n",
> + str_plural(hweight_long(awake_failed)), awake_failed);
> +
> + if (domains == XE_FORCEWAKE_ALL && ref_incr == fw->initialized_domains)
> + ref_incr |= XE_FORCEWAKE_ALL;
> +
> + return ref_incr;
> }
>
> int xe_force_wake_put(struct xe_force_wake *fw,
> diff --git a/drivers/gpu/drm/xe/xe_force_wake.h b/drivers/gpu/drm/xe/xe_force_wake.h
> index 1608a55edc84..75fa1a19797c 100644
> --- a/drivers/gpu/drm/xe/xe_force_wake.h
> +++ b/drivers/gpu/drm/xe/xe_force_wake.h
> @@ -15,8 +15,8 @@ void xe_force_wake_init_gt(struct xe_gt *gt,
> struct xe_force_wake *fw);
> void xe_force_wake_init_engines(struct xe_gt *gt,
> struct xe_force_wake *fw);
> -int xe_force_wake_get(struct xe_force_wake *fw,
> - enum xe_force_wake_domains domains);
> +unsigned int xe_force_wake_get(struct xe_force_wake *fw,
> + enum xe_force_wake_domains domains);
> int xe_force_wake_put(struct xe_force_wake *fw,
> enum xe_force_wake_domains domains);
>
> diff --git a/drivers/gpu/drm/xe/xe_force_wake_types.h b/drivers/gpu/drm/xe/xe_force_wake_types.h
> index fde17dc3d01e..899fbbcb3ea9 100644
> --- a/drivers/gpu/drm/xe/xe_force_wake_types.h
> +++ b/drivers/gpu/drm/xe/xe_force_wake_types.h
> @@ -48,7 +48,7 @@ enum xe_force_wake_domains {
> XE_FW_MEDIA_VEBOX2 = BIT(XE_FW_DOMAIN_ID_MEDIA_VEBOX2),
> XE_FW_MEDIA_VEBOX3 = BIT(XE_FW_DOMAIN_ID_MEDIA_VEBOX3),
> XE_FW_GSC = BIT(XE_FW_DOMAIN_ID_GSC),
> - XE_FORCEWAKE_ALL = BIT(XE_FW_DOMAIN_ID_COUNT) - 1
> + XE_FORCEWAKE_ALL = BIT(XE_FW_DOMAIN_ID_COUNT)
> };
>
> /**
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