Re: [PATCH v3 0/8] drm/panthor: Localize register access by component

Liviu Dudau
2026-04-30T16:36:49Z

On Mon, Apr 27, 2026 at 04:59:26PM +0100, Karunika Choo wrote:
> Hi all,
>
> This series refactors the panthor register access paths so that each
> component uses its own local iomem base instead of relying on the
> global device mapping throughout the driver.
>
> Today a number of register definitions and helpers are still expressed
> in terms of the full device register space, which makes it easy for one
> component to reach into another component's registers.
>
> The series prepares the driver for a cleaner per-component layout in 3
> steps:
> - make the low-level GPU register helpers operate on an iomem pointer
> rather than a panthor_device pointer
> - split register definitions and move cross-component accesses behind
> helpers owned by the relevant component
> - convert GPU, PWR, firmware and MMU code to use component-local iomem
> bases, while keeping IRQ handling on a dedicated IRQ-local base.
>
> The end result is that register accesses become more obviously scoped to
> the component that owns them, cross-component register accesses are
> removed from callers, and the common IRQ helpers no longer depend on
> absolute register offsets.
>
> No functional change is intended.
>
> v3:
> - Picked up Acks and Reviewed-bys from Boris, Liviu, and Steve.
> - Cleaned up definition of pwr->iomem and pwr->irq.iomem.
> - Link to v2: https://lore.kernel.org/all/20260412142951.2309135-1-karunika.choo@arm.com/
> v2:
> - Picked up Acks from Boris.
> - Moved GPU_ID definitions into panthor_gpu_regs.h and deleted
> panthor_hw_regs.h
> - Fixed incorrect spelling of timestamp helper functions.
> - Changed IRQ request function to take an iomem pointer instead of an
> offset.
> - Update panthor_gpu_info_init() to use the correct block-local iomem
> pointers for register accesses.
> - Link to v1: https://lore.kernel.org/all/20260410164637.549145-1-karunika.choo@arm.com/
>
> Kind regards,
> Karunika

Pushed to drm-misc-next.

Best regards,
Liviu

>
> Karunika Choo (8):
> drm/panthor: Pass an iomem pointer to GPU register access helpers
> drm/panthor: Split register definitions by components
> drm/panthor: Replace cross-component register accesses with helpers
> drm/panthor: Store IRQ register base iomem pointer in panthor_irq
> drm/panthor: Use a local iomem base for GPU registers
> drm/panthor: Use a local iomem base for PWR registers
> drm/panthor: Use a local iomem base for firmware control registers
> drm/panthor: Use a local iomem base for MMU AS registers
>
> drivers/gpu/drm/panthor/panthor_device.c | 28 +-
> drivers/gpu/drm/panthor/panthor_device.h | 92 ++++---
> drivers/gpu/drm/panthor/panthor_drv.c | 7 +-
> drivers/gpu/drm/panthor/panthor_fw.c | 40 ++-
> drivers/gpu/drm/panthor/panthor_fw.h | 1 +
> drivers/gpu/drm/panthor/panthor_fw_regs.h | 29 ++
> drivers/gpu/drm/panthor/panthor_gpu.c | 101 +++++--
> drivers/gpu/drm/panthor/panthor_gpu.h | 6 +
> drivers/gpu/drm/panthor/panthor_gpu_regs.h | 119 +++++++++
> drivers/gpu/drm/panthor/panthor_heap.c | 2 +-
> drivers/gpu/drm/panthor/panthor_hw.c | 54 ++--
> drivers/gpu/drm/panthor/panthor_hw.h | 2 +-
> drivers/gpu/drm/panthor/panthor_mmu.c | 46 ++--
> drivers/gpu/drm/panthor/panthor_mmu_regs.h | 69 +++++
> drivers/gpu/drm/panthor/panthor_pwr.c | 93 ++++---
> drivers/gpu/drm/panthor/panthor_pwr_regs.h | 79 ++++++
> drivers/gpu/drm/panthor/panthor_regs.h | 291 ---------------------
> drivers/gpu/drm/panthor/panthor_sched.c | 5 +-
> 18 files changed, 584 insertions(+), 480 deletions(-)
> create mode 100644 drivers/gpu/drm/panthor/panthor_fw_regs.h
> create mode 100644 drivers/gpu/drm/panthor/panthor_gpu_regs.h
> create mode 100644 drivers/gpu/drm/panthor/panthor_mmu_regs.h
> create mode 100644 drivers/gpu/drm/panthor/panthor_pwr_regs.h
> delete mode 100644 drivers/gpu/drm/panthor/panthor_regs.h
>
> --
> 2.43.0
>

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