From 157ad4ccff0754d9eb57d3a4fa31264ee6e9716b Mon Sep 17 00:00:00 2001 From: AngeloGioacchino Del Regno Date: Mon, 4 Dec 2023 12:42:15 +0100 Subject: drm/panfrost: Synchronize and disable interrupts before powering off To make sure that we don't unintentionally perform any unclocked and/or unpowered R/W operation on GPU registers, before turning off clocks and regulators we must make sure that no GPU, JOB or MMU ISR execution is pending: doing that requires to add a mechanism to synchronize the interrupts on suspend. Add functions panfrost_{gpu,job,mmu}_suspend_irq() which will perform interrupts masking and ISR execution synchronization, and then call those in the panfrost_device_runtime_suspend() handler in the exact sequence of job (may require mmu!) -> mmu -> gpu. As a side note, JOB and MMU suspend_irq functions needed some special treatment: as their interrupt handlers will unmask interrupts, it was necessary to add an `is_suspended` bitmap which is used to address the possible corner case of unintentional IRQ unmasking because of ISR execution after a call to synchronize_irq(). At resume, clear each is_suspended bit in the reset path of JOB/MMU to allow unmasking the interrupts. Signed-off-by: AngeloGioacchino Del Regno Reviewed-by: Boris Brezillon Tested-by: Marek Szyprowski Reviewed-by: Steven Price Signed-off-by: Boris Brezillon Link: https://patchwork.freedesktop.org/patch/msgid/20231204114215.54575-4-angelogioacchino.delregno@collabora.com --- drivers/gpu/drm/panfrost/panfrost_device.c | 3 +++ drivers/gpu/drm/panfrost/panfrost_device.h | 8 ++++++++ drivers/gpu/drm/panfrost/panfrost_gpu.c | 18 ++++++++++++++++-- drivers/gpu/drm/panfrost/panfrost_gpu.h | 1 + drivers/gpu/drm/panfrost/panfrost_job.c | 26 ++++++++++++++++++++++---- drivers/gpu/drm/panfrost/panfrost_job.h | 1 + drivers/gpu/drm/panfrost/panfrost_mmu.c | 22 +++++++++++++++++++--- drivers/gpu/drm/panfrost/panfrost_mmu.h | 1 + 8 files changed, 71 insertions(+), 9 deletions(-) (limited to 'drivers/gpu') diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c index c90ad5ee34e7..a45e4addcc19 100644 --- a/drivers/gpu/drm/panfrost/panfrost_device.c +++ b/drivers/gpu/drm/panfrost/panfrost_device.c @@ -421,6 +421,9 @@ static int panfrost_device_runtime_suspend(struct device *dev) return -EBUSY; panfrost_devfreq_suspend(pfdev); + panfrost_job_suspend_irq(pfdev); + panfrost_mmu_suspend_irq(pfdev); + panfrost_gpu_suspend_irq(pfdev); panfrost_gpu_power_off(pfdev); return 0; diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h index 54a8aad54259..62f7e3527385 100644 --- a/drivers/gpu/drm/panfrost/panfrost_device.h +++ b/drivers/gpu/drm/panfrost/panfrost_device.h @@ -25,6 +25,13 @@ struct panfrost_perfcnt; #define NUM_JOB_SLOTS 3 #define MAX_PM_DOMAINS 5 +enum panfrost_drv_comp_bits { + PANFROST_COMP_BIT_GPU, + PANFROST_COMP_BIT_JOB, + PANFROST_COMP_BIT_MMU, + PANFROST_COMP_BIT_MAX +}; + /** * enum panfrost_gpu_pm - Supported kernel power management features * @GPU_PM_CLK_DIS: Allow disabling clocks during system suspend @@ -109,6 +116,7 @@ struct panfrost_device { struct panfrost_features features; const struct panfrost_compatible *comp; + DECLARE_BITMAP(is_suspended, PANFROST_COMP_BIT_MAX); spinlock_t as_lock; unsigned long as_in_use_mask; diff --git a/drivers/gpu/drm/panfrost/panfrost_gpu.c b/drivers/gpu/drm/panfrost/panfrost_gpu.c index 7adc4441fa14..9063ce254642 100644 --- a/drivers/gpu/drm/panfrost/panfrost_gpu.c +++ b/drivers/gpu/drm/panfrost/panfrost_gpu.c @@ -22,9 +22,13 @@ static irqreturn_t panfrost_gpu_irq_handler(int irq, void *data) { struct panfrost_device *pfdev = data; - u32 state = gpu_read(pfdev, GPU_INT_STAT); - u32 fault_status = gpu_read(pfdev, GPU_FAULT_STATUS); + u32 fault_status, state; + if (test_bit(PANFROST_COMP_BIT_GPU, pfdev->is_suspended)) + return IRQ_NONE; + + fault_status = gpu_read(pfdev, GPU_FAULT_STATUS); + state = gpu_read(pfdev, GPU_INT_STAT); if (!state) return IRQ_NONE; @@ -61,6 +65,8 @@ int panfrost_gpu_soft_reset(struct panfrost_device *pfdev) gpu_write(pfdev, GPU_INT_MASK, 0); gpu_write(pfdev, GPU_INT_CLEAR, GPU_IRQ_RESET_COMPLETED); + clear_bit(PANFROST_COMP_BIT_GPU, pfdev->is_suspended); + gpu_write(pfdev, GPU_CMD, GPU_CMD_SOFT_RESET); ret = readl_relaxed_poll_timeout(pfdev->iomem + GPU_INT_RAWSTAT, val, val & GPU_IRQ_RESET_COMPLETED, 10, 10000); @@ -452,6 +458,14 @@ void panfrost_gpu_power_off(struct panfrost_device *pfdev) dev_err(pfdev->dev, "l2 power transition timeout"); } +void panfrost_gpu_suspend_irq(struct panfrost_device *pfdev) +{ + set_bit(PANFROST_COMP_BIT_GPU, pfdev->is_suspended); + + gpu_write(pfdev, GPU_INT_MASK, 0); + synchronize_irq(pfdev->gpu_irq); +} + int panfrost_gpu_init(struct panfrost_device *pfdev) { int err; diff --git a/drivers/gpu/drm/panfrost/panfrost_gpu.h b/drivers/gpu/drm/panfrost/panfrost_gpu.h index 876fdad9f721..d841b86504ea 100644 --- a/drivers/gpu/drm/panfrost/panfrost_gpu.h +++ b/drivers/gpu/drm/panfrost/panfrost_gpu.h @@ -15,6 +15,7 @@ u32 panfrost_gpu_get_latest_flush_id(struct panfrost_device *pfdev); int panfrost_gpu_soft_reset(struct panfrost_device *pfdev); void panfrost_gpu_power_on(struct panfrost_device *pfdev); void panfrost_gpu_power_off(struct panfrost_device *pfdev); +void panfrost_gpu_suspend_irq(struct panfrost_device *pfdev); void panfrost_cycle_counter_get(struct panfrost_device *pfdev); void panfrost_cycle_counter_put(struct panfrost_device *pfdev); diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c index f9446e197428..0c2dbf6ef2a5 100644 --- a/drivers/gpu/drm/panfrost/panfrost_job.c +++ b/drivers/gpu/drm/panfrost/panfrost_job.c @@ -405,6 +405,8 @@ void panfrost_job_enable_interrupts(struct panfrost_device *pfdev) int j; u32 irq_mask = 0; + clear_bit(PANFROST_COMP_BIT_JOB, pfdev->is_suspended); + for (j = 0; j < NUM_JOB_SLOTS; j++) { irq_mask |= MK_JS_MASK(j); } @@ -413,6 +415,14 @@ void panfrost_job_enable_interrupts(struct panfrost_device *pfdev) job_write(pfdev, JOB_INT_MASK, irq_mask); } +void panfrost_job_suspend_irq(struct panfrost_device *pfdev) +{ + set_bit(PANFROST_COMP_BIT_JOB, pfdev->is_suspended); + + job_write(pfdev, JOB_INT_MASK, 0); + synchronize_irq(pfdev->js->irq); +} + static void panfrost_job_handle_err(struct panfrost_device *pfdev, struct panfrost_job *job, unsigned int js) @@ -792,17 +802,25 @@ static irqreturn_t panfrost_job_irq_handler_thread(int irq, void *data) struct panfrost_device *pfdev = data; panfrost_job_handle_irqs(pfdev); - job_write(pfdev, JOB_INT_MASK, - GENMASK(16 + NUM_JOB_SLOTS - 1, 16) | - GENMASK(NUM_JOB_SLOTS - 1, 0)); + + /* Enable interrupts only if we're not about to get suspended */ + if (!test_bit(PANFROST_COMP_BIT_JOB, pfdev->is_suspended)) + job_write(pfdev, JOB_INT_MASK, + GENMASK(16 + NUM_JOB_SLOTS - 1, 16) | + GENMASK(NUM_JOB_SLOTS - 1, 0)); + return IRQ_HANDLED; } static irqreturn_t panfrost_job_irq_handler(int irq, void *data) { struct panfrost_device *pfdev = data; - u32 status = job_read(pfdev, JOB_INT_STAT); + u32 status; + + if (test_bit(PANFROST_COMP_BIT_JOB, pfdev->is_suspended)) + return IRQ_NONE; + status = job_read(pfdev, JOB_INT_STAT); if (!status) return IRQ_NONE; diff --git a/drivers/gpu/drm/panfrost/panfrost_job.h b/drivers/gpu/drm/panfrost/panfrost_job.h index 17ff808dba07..ec581b97852b 100644 --- a/drivers/gpu/drm/panfrost/panfrost_job.h +++ b/drivers/gpu/drm/panfrost/panfrost_job.h @@ -47,6 +47,7 @@ int panfrost_job_get_slot(struct panfrost_job *job); int panfrost_job_push(struct panfrost_job *job); void panfrost_job_put(struct panfrost_job *job); void panfrost_job_enable_interrupts(struct panfrost_device *pfdev); +void panfrost_job_suspend_irq(struct panfrost_device *pfdev); int panfrost_job_is_idle(struct panfrost_device *pfdev); #endif diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c index ac4296c1e54b..f38385fe76bb 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -231,6 +231,8 @@ void panfrost_mmu_reset(struct panfrost_device *pfdev) { struct panfrost_mmu *mmu, *mmu_tmp; + clear_bit(PANFROST_COMP_BIT_MMU, pfdev->is_suspended); + spin_lock(&pfdev->as_lock); pfdev->as_alloc_mask = 0; @@ -670,6 +672,9 @@ static irqreturn_t panfrost_mmu_irq_handler(int irq, void *data) { struct panfrost_device *pfdev = data; + if (test_bit(PANFROST_COMP_BIT_MMU, pfdev->is_suspended)) + return IRQ_NONE; + if (!mmu_read(pfdev, MMU_INT_STAT)) return IRQ_NONE; @@ -744,9 +749,12 @@ static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data) status = mmu_read(pfdev, MMU_INT_RAWSTAT) & ~pfdev->as_faulty_mask; } - spin_lock(&pfdev->as_lock); - mmu_write(pfdev, MMU_INT_MASK, ~pfdev->as_faulty_mask); - spin_unlock(&pfdev->as_lock); + /* Enable interrupts only if we're not about to get suspended */ + if (!test_bit(PANFROST_COMP_BIT_MMU, pfdev->is_suspended)) { + spin_lock(&pfdev->as_lock); + mmu_write(pfdev, MMU_INT_MASK, ~pfdev->as_faulty_mask); + spin_unlock(&pfdev->as_lock); + } return IRQ_HANDLED; }; @@ -777,3 +785,11 @@ void panfrost_mmu_fini(struct panfrost_device *pfdev) { mmu_write(pfdev, MMU_INT_MASK, 0); } + +void panfrost_mmu_suspend_irq(struct panfrost_device *pfdev) +{ + set_bit(PANFROST_COMP_BIT_MMU, pfdev->is_suspended); + + mmu_write(pfdev, MMU_INT_MASK, 0); + synchronize_irq(pfdev->mmu_irq); +} diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.h b/drivers/gpu/drm/panfrost/panfrost_mmu.h index cc2a0d307feb..022a9a74a114 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.h +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.h @@ -14,6 +14,7 @@ void panfrost_mmu_unmap(struct panfrost_gem_mapping *mapping); int panfrost_mmu_init(struct panfrost_device *pfdev); void panfrost_mmu_fini(struct panfrost_device *pfdev); void panfrost_mmu_reset(struct panfrost_device *pfdev); +void panfrost_mmu_suspend_irq(struct panfrost_device *pfdev); u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu); void panfrost_mmu_as_put(struct panfrost_device *pfdev, struct panfrost_mmu *mmu); -- cgit