Re: [PATCH v3 4/8] drm/panthor: Store IRQ register base iomem pointer in panthor_irq

Steven Price
2026-04-30T09:21:31Z

On 27/04/2026 16:59, Karunika Choo wrote:
> Update common IRQ handling code to work from an IRQ-local iomem base
> instead of referencing block-specific interrupt register offsets.
>
> Store the interrupt base address iomem pointer in struct panthor_irq and
> switch the shared IRQ helpers to use generic INT_* offsets from that
> local base. This removes the need for each caller to expose absolute IRQ
> register addresses while keeping the common IRQ flow unchanged.
>
> No functional change intended.
>
> v3:
> - Clean up definition of pwr->irq.iomem.
> v2:
> - Change IRQ request function to accept an iomem pointer instead of
> computing it from an offset argument.
>
> Signed-off-by: Karunika Choo <karunika.choo@arm.com>

Reviewed-by: Steven Price <steven.price@arm.com>

> ---
> drivers/gpu/drm/panthor/panthor_device.h | 32 ++++++++++++++--------
> drivers/gpu/drm/panthor/panthor_fw.c | 5 ++--
> drivers/gpu/drm/panthor/panthor_fw_regs.h | 2 ++
> drivers/gpu/drm/panthor/panthor_gpu.c | 6 ++--
> drivers/gpu/drm/panthor/panthor_gpu_regs.h | 3 ++
> drivers/gpu/drm/panthor/panthor_mmu.c | 5 ++--
> drivers/gpu/drm/panthor/panthor_mmu_regs.h | 3 ++
> drivers/gpu/drm/panthor/panthor_pwr.c | 6 ++--
> 8 files changed, 42 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
> index 285bf7e4439e..4e4607bca7cc 100644
> --- a/drivers/gpu/drm/panthor/panthor_device.h
> +++ b/drivers/gpu/drm/panthor/panthor_device.h
> @@ -82,6 +82,9 @@ struct panthor_irq {
> /** @ptdev: Panthor device */
> struct panthor_device *ptdev;
>
> + /** @iomem: CPU mapping of IRQ base address */
> + void __iomem *iomem;
> +
> /** @irq: IRQ number. */
> int irq;
>
> @@ -488,6 +491,11 @@ panthor_exception_is_fault(u32 exception_code)
> const char *panthor_exception_name(struct panthor_device *ptdev,
> u32 exception_code);
>
> +#define INT_RAWSTAT 0x0
> +#define INT_CLEAR 0x4
> +#define INT_MASK 0x8
> +#define INT_STAT 0xc
> +
> /**
> * PANTHOR_IRQ_HANDLER() - Define interrupt handlers and the interrupt
> * registration function.
> @@ -498,14 +506,13 @@ const char *panthor_exception_name(struct panthor_device *ptdev,
> *
> * void (*handler)(struct panthor_device *, u32 status);
> */
> -#define PANTHOR_IRQ_HANDLER(__name, __reg_prefix, __handler) \
> +#define PANTHOR_IRQ_HANDLER(__name, __handler) \
> static irqreturn_t panthor_ ## __name ## _irq_raw_handler(int irq, void *data) \
> { \
> struct panthor_irq *pirq = data; \
> - struct panthor_device *ptdev = pirq->ptdev; \
> enum panthor_irq_state old_state; \
> \
> - if (!gpu_read(ptdev->iomem, __reg_prefix ## _INT_STAT)) \
> + if (!gpu_read(pirq->iomem, INT_STAT)) \
> return IRQ_NONE; \
> \
> guard(spinlock_irqsave)(&pirq->mask_lock); \
> @@ -515,7 +522,7 @@ static irqreturn_t panthor_ ## __name ## _irq_raw_handler(int irq, void *data)
> if (old_state != PANTHOR_IRQ_STATE_ACTIVE) \
> return IRQ_NONE; \
> \
> - gpu_write(ptdev->iomem, __reg_prefix ## _INT_MASK, 0); \
> + gpu_write(pirq->iomem, INT_MASK, 0); \
> return IRQ_WAKE_THREAD; \
> } \
> \
> @@ -534,7 +541,7 @@ static irqreturn_t panthor_ ## __name ## _irq_threaded_handler(int irq, void *da
> * right before the HW event kicks in. TLDR; it's all expected races we're \
> * covered for. \
> */ \
> - u32 status = gpu_read(ptdev->iomem, __reg_prefix ## _INT_RAWSTAT) & pirq->mask; \
> + u32 status = gpu_read(pirq->iomem, INT_RAWSTAT) & pirq->mask; \
> \
> if (!status) \
> break; \
> @@ -550,7 +557,7 @@ static irqreturn_t panthor_ ## __name ## _irq_threaded_handler(int irq, void *da
> PANTHOR_IRQ_STATE_PROCESSING, \
> PANTHOR_IRQ_STATE_ACTIVE); \
> if (old_state == PANTHOR_IRQ_STATE_PROCESSING) \
> - gpu_write(ptdev->iomem, __reg_prefix ## _INT_MASK, pirq->mask); \
> + gpu_write(pirq->iomem, INT_MASK, pirq->mask); \
> } \
> \
> return ret; \
> @@ -560,7 +567,7 @@ static inline void panthor_ ## __name ## _irq_suspend(struct panthor_irq *pirq)
> { \
> scoped_guard(spinlock_irqsave, &pirq->mask_lock) { \
> atomic_set(&pirq->state, PANTHOR_IRQ_STATE_SUSPENDING); \
> - gpu_write(pirq->ptdev->iomem, __reg_prefix ## _INT_MASK, 0); \
> + gpu_write(pirq->iomem, INT_MASK, 0); \
> } \
> synchronize_irq(pirq->irq); \
> atomic_set(&pirq->state, PANTHOR_IRQ_STATE_SUSPENDED); \
> @@ -571,17 +578,18 @@ static inline void panthor_ ## __name ## _irq_resume(struct panthor_irq *pirq)
> guard(spinlock_irqsave)(&pirq->mask_lock); \
> \
> atomic_set(&pirq->state, PANTHOR_IRQ_STATE_ACTIVE); \
> - gpu_write(pirq->ptdev->iomem, __reg_prefix ## _INT_CLEAR, pirq->mask); \
> - gpu_write(pirq->ptdev->iomem, __reg_prefix ## _INT_MASK, pirq->mask); \
> + gpu_write(pirq->iomem, INT_CLEAR, pirq->mask); \
> + gpu_write(pirq->iomem, INT_MASK, pirq->mask); \
> } \
> \
> static int panthor_request_ ## __name ## _irq(struct panthor_device *ptdev, \
> struct panthor_irq *pirq, \
> - int irq, u32 mask) \
> + int irq, u32 mask, void __iomem *iomem) \
> { \
> pirq->ptdev = ptdev; \
> pirq->irq = irq; \
> pirq->mask = mask; \
> + pirq->iomem = iomem; \
> spin_lock_init(&pirq->mask_lock); \
> panthor_ ## __name ## _irq_resume(pirq); \
> \
> @@ -603,7 +611,7 @@ static inline void panthor_ ## __name ## _irq_enable_events(struct panthor_irq *
> * If the IRQ is suspended/suspending, the mask is restored at resume time. \
> */ \
> if (atomic_read(&pirq->state) == PANTHOR_IRQ_STATE_ACTIVE) \
> - gpu_write(pirq->ptdev->iomem, __reg_prefix ## _INT_MASK, pirq->mask); \
> + gpu_write(pirq->iomem, INT_MASK, pirq->mask); \
> } \
> \
> static inline void panthor_ ## __name ## _irq_disable_events(struct panthor_irq *pirq, u32 mask)\
> @@ -617,7 +625,7 @@ static inline void panthor_ ## __name ## _irq_disable_events(struct panthor_irq
> * If the IRQ is suspended/suspending, the mask is restored at resume time. \
> */ \
> if (atomic_read(&pirq->state) == PANTHOR_IRQ_STATE_ACTIVE) \
> - gpu_write(pirq->ptdev->iomem, __reg_prefix ## _INT_MASK, pirq->mask); \
> + gpu_write(pirq->iomem, INT_MASK, pirq->mask); \
> }
>
> extern struct workqueue_struct *panthor_cleanup_wq;
> diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
> index 4a0c23e987b6..73ef07a37e22 100644
> --- a/drivers/gpu/drm/panthor/panthor_fw.c
> +++ b/drivers/gpu/drm/panthor/panthor_fw.c
> @@ -1088,7 +1088,7 @@ static void panthor_job_irq_handler(struct panthor_device *ptdev, u32 status)
> trace_gpu_job_irq(ptdev->base.dev, status, duration);
> }
> }
> -PANTHOR_IRQ_HANDLER(job, JOB, panthor_job_irq_handler);
> +PANTHOR_IRQ_HANDLER(job, panthor_job_irq_handler);
>
> static int panthor_fw_start(struct panthor_device *ptdev)
> {
> @@ -1470,7 +1470,8 @@ int panthor_fw_init(struct panthor_device *ptdev)
> if (irq <= 0)
> return -ENODEV;
>
> - ret = panthor_request_job_irq(ptdev, &fw->irq, irq, 0);
> + ret = panthor_request_job_irq(ptdev, &fw->irq, irq, 0,
> + ptdev->iomem + JOB_INT_BASE);
> if (ret) {
> drm_err(&ptdev->base, "failed to request job irq");
> return ret;
> diff --git a/drivers/gpu/drm/panthor/panthor_fw_regs.h b/drivers/gpu/drm/panthor/panthor_fw_regs.h
> index d523d41e18dd..eeb41aff249b 100644
> --- a/drivers/gpu/drm/panthor/panthor_fw_regs.h
> +++ b/drivers/gpu/drm/panthor/panthor_fw_regs.h
> @@ -15,6 +15,8 @@
> #define MCU_STATUS_HALT 2
> #define MCU_STATUS_FATAL 3
>
> +#define JOB_INT_BASE 0x1000
> +
> #define JOB_INT_RAWSTAT 0x1000
> #define JOB_INT_CLEAR 0x1004
> #define JOB_INT_MASK 0x1008
> diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c b/drivers/gpu/drm/panthor/panthor_gpu.c
> index 747ac332be64..f00f3d9be240 100644
> --- a/drivers/gpu/drm/panthor/panthor_gpu.c
> +++ b/drivers/gpu/drm/panthor/panthor_gpu.c
> @@ -110,7 +110,7 @@ static void panthor_gpu_irq_handler(struct panthor_device *ptdev, u32 status)
> }
> spin_unlock(&ptdev->gpu->reqs_lock);
> }
> -PANTHOR_IRQ_HANDLER(gpu, GPU, panthor_gpu_irq_handler);
> +PANTHOR_IRQ_HANDLER(gpu, panthor_gpu_irq_handler);
>
> /**
> * panthor_gpu_unplug() - Called when the GPU is unplugged.
> @@ -162,7 +162,9 @@ int panthor_gpu_init(struct panthor_device *ptdev)
> if (irq < 0)
> return irq;
>
> - ret = panthor_request_gpu_irq(ptdev, &ptdev->gpu->irq, irq, GPU_INTERRUPTS_MASK);
> + ret = panthor_request_gpu_irq(ptdev, &ptdev->gpu->irq, irq,
> + GPU_INTERRUPTS_MASK,
> + ptdev->iomem + GPU_INT_BASE);
> if (ret)
> return ret;
>
> diff --git a/drivers/gpu/drm/panthor/panthor_gpu_regs.h b/drivers/gpu/drm/panthor/panthor_gpu_regs.h
> index 75474b7d7341..3f60c45985a7 100644
> --- a/drivers/gpu/drm/panthor/panthor_gpu_regs.h
> +++ b/drivers/gpu/drm/panthor/panthor_gpu_regs.h
> @@ -4,6 +4,8 @@
> #ifndef __PANTHOR_GPU_REGS_H__
> #define __PANTHOR_GPU_REGS_H__
>
> +#define GPU_CONTROL_BASE 0x0
> +
> #define GPU_ID 0x0
> #define GPU_ARCH_MAJOR(x) ((x) >> 28)
> #define GPU_ARCH_MINOR(x) (((x) & GENMASK(27, 24)) >> 24)
> @@ -28,6 +30,7 @@
> #define GPU_AS_PRESENT 0x18
> #define GPU_CSF_ID 0x1C
>
> +#define GPU_INT_BASE 0x20
> #define GPU_INT_RAWSTAT 0x20
> #define GPU_INT_CLEAR 0x24
> #define GPU_INT_MASK 0x28
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
> index 853f5ebfe5c6..64d53e7cb763 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -584,7 +584,7 @@ static u32 panthor_mmu_as_fault_mask(struct panthor_device *ptdev, u32 as)
>
> /* Forward declaration to call helpers within as_enable/disable */
> static void panthor_mmu_irq_handler(struct panthor_device *ptdev, u32 status);
> -PANTHOR_IRQ_HANDLER(mmu, MMU, panthor_mmu_irq_handler);
> +PANTHOR_IRQ_HANDLER(mmu, panthor_mmu_irq_handler);
>
> static int panthor_mmu_as_enable(struct panthor_device *ptdev, u32 as_nr,
> u64 transtab, u64 transcfg, u64 memattr)
> @@ -3247,7 +3247,8 @@ int panthor_mmu_init(struct panthor_device *ptdev)
> return -ENODEV;
>
> ret = panthor_request_mmu_irq(ptdev, &mmu->irq, irq,
> - panthor_mmu_fault_mask(ptdev, ~0));
> + panthor_mmu_fault_mask(ptdev, ~0),
> + ptdev->iomem + MMU_INT_BASE);
> if (ret)
> return ret;
>
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu_regs.h b/drivers/gpu/drm/panthor/panthor_mmu_regs.h
> index cc9cf603cec6..de460042651d 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu_regs.h
> +++ b/drivers/gpu/drm/panthor/panthor_mmu_regs.h
> @@ -5,6 +5,9 @@
> #define __PANTHOR_MMU_REGS_H__
>
> /* MMU regs */
> +
> +#define MMU_INT_BASE 0x2000
> +
> #define MMU_INT_RAWSTAT 0x2000
> #define MMU_INT_CLEAR 0x2004
> #define MMU_INT_MASK 0x2008
> diff --git a/drivers/gpu/drm/panthor/panthor_pwr.c b/drivers/gpu/drm/panthor/panthor_pwr.c
> index aafb0c5c7d23..705d998447b5 100644
> --- a/drivers/gpu/drm/panthor/panthor_pwr.c
> +++ b/drivers/gpu/drm/panthor/panthor_pwr.c
> @@ -70,7 +70,7 @@ static void panthor_pwr_irq_handler(struct panthor_device *ptdev, u32 status)
> }
> spin_unlock(&ptdev->pwr->reqs_lock);
> }
> -PANTHOR_IRQ_HANDLER(pwr, PWR, panthor_pwr_irq_handler);
> +PANTHOR_IRQ_HANDLER(pwr, panthor_pwr_irq_handler);
>
> static void panthor_pwr_write_command(struct panthor_device *ptdev, u32 command, u64 args)
> {
> @@ -464,7 +464,9 @@ int panthor_pwr_init(struct panthor_device *ptdev)
> if (irq < 0)
> return irq;
>
> - err = panthor_request_pwr_irq(ptdev, &pwr->irq, irq, PWR_INTERRUPTS_MASK);
> + err = panthor_request_pwr_irq(
> + ptdev, &pwr->irq, irq, PWR_INTERRUPTS_MASK,
> + ptdev->iomem + PWR_CONTROL_BASE);
> if (err)
> return err;
>