6.15-stable review patch. If anyone has any objections, please let me know.
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From: Vinay Belgaumkar vinay.belgaumkar@intel.com
[ Upstream commit 84c0b4a00610afbde650fdb8ad6db0424f7b2cc3 ]
Limit GT max frequency to 2600MHz and wait for frequency to reduce before proceeding with a transient flush. This is really only needed for the transient flush: if L2 flush is needed due to 16023588340 then there's no need to do this additional wait since we are already using the bigger hammer.
v2: Use generic names, ensure user set max frequency requests wait for flush to complete (Rodrigo) v3: - User requests wait via wait_var_event_timeout (Lucas) - Close races on flush + user requests (Lucas) - Fix xe_guc_pc_remove_flush_freq_limit() being called on last gt rather than root gt (Lucas) v4: - Only apply the freq reducing part if a TDF is needed: L2 flush trumps the need for waiting a lower frequency
Fixes: aaa08078e725 ("drm/xe/bmg: Apply Wa_22019338487") Reviewed-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Vinay Belgaumkar vinay.belgaumkar@intel.com Link: https://lore.kernel.org/r/20250618-wa-22019338487-v5-4-b888388477f2@intel.co... Signed-off-by: Lucas De Marchi lucas.demarchi@intel.com (cherry picked from commit deea6a7d6d803d6bb874a3e6f1b312e560e6c6df) Signed-off-by: Lucas De Marchi lucas.demarchi@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/xe/xe_device.c | 8 +- drivers/gpu/drm/xe/xe_guc_pc.c | 125 +++++++++++++++++++++++++++ drivers/gpu/drm/xe/xe_guc_pc.h | 2 + drivers/gpu/drm/xe/xe_guc_pc_types.h | 2 + 4 files changed, 135 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c index 38fdddd7262aa..f3123914b1abf 100644 --- a/drivers/gpu/drm/xe/xe_device.c +++ b/drivers/gpu/drm/xe/xe_device.c @@ -38,6 +38,7 @@ #include "xe_gt_printk.h" #include "xe_gt_sriov_vf.h" #include "xe_guc.h" +#include "xe_guc_pc.h" #include "xe_hw_engine_group.h" #include "xe_hwmon.h" #include "xe_irq.h" @@ -1057,11 +1058,14 @@ void xe_device_td_flush(struct xe_device *xe) return;
root_gt = xe_root_mmio_gt(xe); - if (XE_WA(root_gt, 16023588340)) + if (XE_WA(root_gt, 16023588340)) { /* A transient flush is not sufficient: flush the L2 */ xe_device_l2_flush(xe); - else + } else { + xe_guc_pc_apply_flush_freq_limit(&root_gt->uc.guc.pc); tdf_request_sync(xe); + xe_guc_pc_remove_flush_freq_limit(&root_gt->uc.guc.pc); + } }
u32 xe_device_ccs_bytes(struct xe_device *xe, u64 size) diff --git a/drivers/gpu/drm/xe/xe_guc_pc.c b/drivers/gpu/drm/xe/xe_guc_pc.c index 28b97a2c14e3b..1c7b044413f26 100644 --- a/drivers/gpu/drm/xe/xe_guc_pc.c +++ b/drivers/gpu/drm/xe/xe_guc_pc.c @@ -7,7 +7,9 @@
#include <linux/cleanup.h> #include <linux/delay.h> +#include <linux/jiffies.h> #include <linux/ktime.h> +#include <linux/wait_bit.h>
#include <drm/drm_managed.h> #include <drm/drm_print.h> @@ -53,9 +55,11 @@ #define LNL_MERT_FREQ_CAP 800 #define BMG_MERT_FREQ_CAP 2133 #define BMG_MIN_FREQ 1200 +#define BMG_MERT_FLUSH_FREQ_CAP 2600
#define SLPC_RESET_TIMEOUT_MS 5 /* roughly 5ms, but no need for precision */ #define SLPC_RESET_EXTENDED_TIMEOUT_MS 1000 /* To be used only at pc_start */ +#define SLPC_ACT_FREQ_TIMEOUT_MS 100
/** * DOC: GuC Power Conservation (PC) @@ -143,6 +147,36 @@ static int wait_for_pc_state(struct xe_guc_pc *pc, return -ETIMEDOUT; }
+static int wait_for_flush_complete(struct xe_guc_pc *pc) +{ + const unsigned long timeout = msecs_to_jiffies(30); + + if (!wait_var_event_timeout(&pc->flush_freq_limit, + !atomic_read(&pc->flush_freq_limit), + timeout)) + return -ETIMEDOUT; + + return 0; +} + +static int wait_for_act_freq_limit(struct xe_guc_pc *pc, u32 freq) +{ + int timeout_us = SLPC_ACT_FREQ_TIMEOUT_MS * USEC_PER_MSEC; + int slept, wait = 10; + + for (slept = 0; slept < timeout_us;) { + if (xe_guc_pc_get_act_freq(pc) <= freq) + return 0; + + usleep_range(wait, wait << 1); + slept += wait; + wait <<= 1; + if (slept + wait > timeout_us) + wait = timeout_us - slept; + } + + return -ETIMEDOUT; +} static int pc_action_reset(struct xe_guc_pc *pc) { struct xe_guc_ct *ct = pc_to_ct(pc); @@ -673,6 +707,11 @@ static int xe_guc_pc_set_max_freq_locked(struct xe_guc_pc *pc, u32 freq) */ int xe_guc_pc_set_max_freq(struct xe_guc_pc *pc, u32 freq) { + if (XE_WA(pc_to_gt(pc), 22019338487)) { + if (wait_for_flush_complete(pc) != 0) + return -EAGAIN; + } + guard(mutex)(&pc->freq_lock);
return xe_guc_pc_set_max_freq_locked(pc, freq); @@ -873,6 +912,92 @@ static int pc_adjust_requested_freq(struct xe_guc_pc *pc) return ret; }
+static bool needs_flush_freq_limit(struct xe_guc_pc *pc) +{ + struct xe_gt *gt = pc_to_gt(pc); + + return XE_WA(gt, 22019338487) && + pc->rp0_freq > BMG_MERT_FLUSH_FREQ_CAP; +} + +/** + * xe_guc_pc_apply_flush_freq_limit() - Limit max GT freq during L2 flush + * @pc: the xe_guc_pc object + * + * As per the WA, reduce max GT frequency during L2 cache flush + */ +void xe_guc_pc_apply_flush_freq_limit(struct xe_guc_pc *pc) +{ + struct xe_gt *gt = pc_to_gt(pc); + u32 max_freq; + int ret; + + if (!needs_flush_freq_limit(pc)) + return; + + guard(mutex)(&pc->freq_lock); + + ret = xe_guc_pc_get_max_freq_locked(pc, &max_freq); + if (!ret && max_freq > BMG_MERT_FLUSH_FREQ_CAP) { + ret = pc_set_max_freq(pc, BMG_MERT_FLUSH_FREQ_CAP); + if (ret) { + xe_gt_err_once(gt, "Failed to cap max freq on flush to %u, %pe\n", + BMG_MERT_FLUSH_FREQ_CAP, ERR_PTR(ret)); + return; + } + + atomic_set(&pc->flush_freq_limit, 1); + + /* + * If user has previously changed max freq, stash that value to + * restore later, otherwise use the current max. New user + * requests wait on flush. + */ + if (pc->user_requested_max != 0) + pc->stashed_max_freq = pc->user_requested_max; + else + pc->stashed_max_freq = max_freq; + } + + /* + * Wait for actual freq to go below the flush cap: even if the previous + * max was below cap, the current one might still be above it + */ + ret = wait_for_act_freq_limit(pc, BMG_MERT_FLUSH_FREQ_CAP); + if (ret) + xe_gt_err_once(gt, "Actual freq did not reduce to %u, %pe\n", + BMG_MERT_FLUSH_FREQ_CAP, ERR_PTR(ret)); +} + +/** + * xe_guc_pc_remove_flush_freq_limit() - Remove max GT freq limit after L2 flush completes. + * @pc: the xe_guc_pc object + * + * Retrieve the previous GT max frequency value. + */ +void xe_guc_pc_remove_flush_freq_limit(struct xe_guc_pc *pc) +{ + struct xe_gt *gt = pc_to_gt(pc); + int ret = 0; + + if (!needs_flush_freq_limit(pc)) + return; + + if (!atomic_read(&pc->flush_freq_limit)) + return; + + mutex_lock(&pc->freq_lock); + + ret = pc_set_max_freq(>->uc.guc.pc, pc->stashed_max_freq); + if (ret) + xe_gt_err_once(gt, "Failed to restore max freq %u:%d", + pc->stashed_max_freq, ret); + + atomic_set(&pc->flush_freq_limit, 0); + mutex_unlock(&pc->freq_lock); + wake_up_var(&pc->flush_freq_limit); +} + static int pc_set_mert_freq_cap(struct xe_guc_pc *pc) { int ret = 0; diff --git a/drivers/gpu/drm/xe/xe_guc_pc.h b/drivers/gpu/drm/xe/xe_guc_pc.h index 39102b79602fd..0302c7426ccde 100644 --- a/drivers/gpu/drm/xe/xe_guc_pc.h +++ b/drivers/gpu/drm/xe/xe_guc_pc.h @@ -37,5 +37,7 @@ u64 xe_guc_pc_mc6_residency(struct xe_guc_pc *pc); void xe_guc_pc_init_early(struct xe_guc_pc *pc); int xe_guc_pc_restore_stashed_freq(struct xe_guc_pc *pc); void xe_guc_pc_raise_unslice(struct xe_guc_pc *pc); +void xe_guc_pc_apply_flush_freq_limit(struct xe_guc_pc *pc); +void xe_guc_pc_remove_flush_freq_limit(struct xe_guc_pc *pc);
#endif /* _XE_GUC_PC_H_ */ diff --git a/drivers/gpu/drm/xe/xe_guc_pc_types.h b/drivers/gpu/drm/xe/xe_guc_pc_types.h index 2978ac9a249b5..c02053948a579 100644 --- a/drivers/gpu/drm/xe/xe_guc_pc_types.h +++ b/drivers/gpu/drm/xe/xe_guc_pc_types.h @@ -15,6 +15,8 @@ struct xe_guc_pc { /** @bo: GGTT buffer object that is shared with GuC PC */ struct xe_bo *bo; + /** @flush_freq_limit: 1 when max freq changes are limited by driver */ + atomic_t flush_freq_limit; /** @rp0_freq: HW RP0 frequency - The Maximum one */ u32 rp0_freq; /** @rpa_freq: HW RPa frequency - The Achievable one */