Re: [PATCH v1 02/27] drm/panthor: Move register access helpers out of panthor_device.h

[Liviu Dudau <liviu.dudau@arm.com>]

On Tue, Sep 22, 2026 at 09:44:56PM +0100, Karunika Choo wrote:
> Move register access helpers out of panthor_device.h to allow reuse by
> other panthor drivers that will be added to enable v15 support.
> 
> Signed-off-by: Karunika Choo <karunika.choo@arm.com>

Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>

Best regards,
Liviu

> ---
> v1:
> - Includes "panthor_device_io.h" directly in "panthor_device.h" instead
>   of peppering multiple files with the header.
> 
>  drivers/gpu/drm/panthor/panthor_device.h    | 74 +-----------------
>  drivers/gpu/drm/panthor/panthor_device_io.h | 83 +++++++++++++++++++++
>  2 files changed, 85 insertions(+), 72 deletions(-)
>  create mode 100644 drivers/gpu/drm/panthor/panthor_device_io.h
> 
> diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
> index b55a3f9edd414..54031c5252473 100644
> --- a/drivers/gpu/drm/panthor/panthor_device.h
> +++ b/drivers/gpu/drm/panthor/panthor_device.h
> @@ -6,7 +6,6 @@
>  #ifndef __PANTHOR_DEVICE_H__
>  #define __PANTHOR_DEVICE_H__
> 
> -#include <linux/atomic.h>
>  #include <linux/io-pgtable.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/pm_runtime.h>
> @@ -19,6 +18,8 @@
>  #include <drm/gpu_scheduler.h>
>  #include <drm/panthor_drm.h>
> 
> +#include "panthor_device_io.h"
> +
>  struct panthor_csf;
>  struct panthor_csf_ctx;
>  struct panthor_device;
> @@ -495,77 +496,6 @@ panthor_exception_is_fault(u32 exception_code)
>  const char *panthor_exception_name(struct panthor_device *ptdev,
>  				   u32 exception_code);
> 
> -static inline void gpu_write(void __iomem *iomem, u32 reg, u32 data)
> -{
> -	writel(data, iomem + reg);
> -}
> -
> -static inline u32 gpu_read(void __iomem *iomem, u32 reg)
> -{
> -	return readl(iomem + reg);
> -}
> -
> -static inline u32 gpu_read_relaxed(void __iomem *iomem, u32 reg)
> -{
> -	return readl_relaxed(iomem + reg);
> -}
> -
> -static inline void gpu_write64(void __iomem *iomem, u32 reg, u64 data)
> -{
> -	gpu_write(iomem, reg, lower_32_bits(data));
> -	gpu_write(iomem, reg + 4, upper_32_bits(data));
> -}
> -
> -static inline u64 gpu_read64(void __iomem *iomem, u32 reg)
> -{
> -	return (gpu_read(iomem, reg) | ((u64)gpu_read(iomem, reg + 4) << 32));
> -}
> -
> -static inline u64 gpu_read64_relaxed(void __iomem *iomem, u32 reg)
> -{
> -	return (gpu_read_relaxed(iomem, reg) |
> -		((u64)gpu_read_relaxed(iomem, reg + 4) << 32));
> -}
> -
> -static inline u64 gpu_read64_counter(void __iomem *iomem, u32 reg)
> -{
> -	u32 lo, hi1, hi2;
> -	do {
> -		hi1 = gpu_read(iomem, reg + 4);
> -		lo = gpu_read(iomem, reg);
> -		hi2 = gpu_read(iomem, reg + 4);
> -	} while (hi1 != hi2);
> -	return lo | ((u64)hi2 << 32);
> -}
> -
> -#define gpu_read_poll_timeout(iomem, reg, val, cond, delay_us, timeout_us)	\
> -	read_poll_timeout(gpu_read, val, cond, delay_us, timeout_us, false,	\
> -			  iomem, reg)
> -
> -#define gpu_read_poll_timeout_atomic(iomem, reg, val, cond, delay_us,		\
> -				     timeout_us)				\
> -	read_poll_timeout_atomic(gpu_read, val, cond, delay_us, timeout_us,	\
> -				 false, iomem, reg)
> -
> -#define gpu_read64_poll_timeout(iomem, reg, val, cond, delay_us, timeout_us)	\
> -	read_poll_timeout(gpu_read64, val, cond, delay_us, timeout_us, false,	\
> -			  iomem, reg)
> -
> -#define gpu_read64_poll_timeout_atomic(iomem, reg, val, cond, delay_us,		\
> -				       timeout_us)				\
> -	read_poll_timeout_atomic(gpu_read64, val, cond, delay_us, timeout_us,	\
> -				 false, iomem, reg)
> -
> -#define gpu_read_relaxed_poll_timeout_atomic(iomem, reg, val, cond, delay_us,	\
> -					     timeout_us)			\
> -	read_poll_timeout_atomic(gpu_read_relaxed, val, cond, delay_us,		\
> -				 timeout_us, false, iomem, reg)
> -
> -#define gpu_read64_relaxed_poll_timeout(iomem, reg, val, cond, delay_us,	\
> -					timeout_us)				\
> -	read_poll_timeout(gpu_read64_relaxed, val, cond, delay_us, timeout_us,	\
> -			  false, iomem, reg)
> -
>  #define INT_RAWSTAT 0x0
>  #define INT_CLEAR   0x4
>  #define INT_MASK    0x8
> diff --git a/drivers/gpu/drm/panthor/panthor_device_io.h b/drivers/gpu/drm/panthor/panthor_device_io.h
> new file mode 100644
> index 0000000000000..2287a0d9f86c2
> --- /dev/null
> +++ b/drivers/gpu/drm/panthor/panthor_device_io.h
> @@ -0,0 +1,83 @@
> +/* SPDX-License-Identifier: GPL-2.0 or MIT */
> +/* Copyright 2026 ARM Limited. All rights reserved. */
> +
> +#ifndef __PANTHOR_DEVICE_IO_H__
> +#define __PANTHOR_DEVICE_IO_H__
> +
> +#include <linux/atomic.h>
> +#include <linux/io.h>
> +
> +
> +static inline void gpu_write(void __iomem *iomem, u32 reg, u32 data)
> +{
> +	writel(data, iomem + reg);
> +}
> +
> +static inline u32 gpu_read(void __iomem *iomem, u32 reg)
> +{
> +	return readl(iomem + reg);
> +}
> +
> +static inline u32 gpu_read_relaxed(void __iomem *iomem, u32 reg)
> +{
> +	return readl_relaxed(iomem + reg);
> +}
> +
> +static inline void gpu_write64(void __iomem *iomem, u32 reg, u64 data)
> +{
> +	gpu_write(iomem, reg, lower_32_bits(data));
> +	gpu_write(iomem, reg + 4, upper_32_bits(data));
> +}
> +
> +static inline u64 gpu_read64(void __iomem *iomem, u32 reg)
> +{
> +	return (gpu_read(iomem, reg) | ((u64)gpu_read(iomem, reg + 4) << 32));
> +}
> +
> +static inline u64 gpu_read64_relaxed(void __iomem *iomem, u32 reg)
> +{
> +	return (gpu_read_relaxed(iomem, reg) |
> +		((u64)gpu_read_relaxed(iomem, reg + 4) << 32));
> +}
> +
> +static inline u64 gpu_read64_counter(void __iomem *iomem, u32 reg)
> +{
> +	u32 lo, hi1, hi2;
> +	do {
> +		hi1 = gpu_read(iomem, reg + 4);
> +		lo = gpu_read(iomem, reg);
> +		hi2 = gpu_read(iomem, reg + 4);
> +	} while (hi1 != hi2);
> +	return lo | ((u64)hi2 << 32);
> +}
> +
> +#define gpu_read_poll_timeout(iomem, reg, val, cond, delay_us, timeout_us)	\
> +	read_poll_timeout(gpu_read, val, cond, delay_us, timeout_us, false,	\
> +			  iomem, reg)
> +
> +#define gpu_read_poll_timeout_atomic(iomem, reg, val, cond, delay_us,		\
> +				     timeout_us)				\
> +	read_poll_timeout_atomic(gpu_read, val, cond, delay_us, timeout_us,	\
> +				 false, iomem, reg)
> +
> +#define gpu_read64_poll_timeout(iomem, reg, val, cond, delay_us, timeout_us)	\
> +	read_poll_timeout(gpu_read64, val, cond, delay_us, timeout_us, false,	\
> +			  iomem, reg)
> +
> +#define gpu_read64_poll_timeout_atomic(iomem, reg, val, cond, delay_us,		\
> +				       timeout_us)				\
> +	read_poll_timeout_atomic(gpu_read64, val, cond, delay_us, timeout_us,	\
> +				 false, iomem, reg)
> +
> +#define gpu_read_relaxed_poll_timeout_atomic(iomem, reg, val, cond, delay_us,	\
> +					     timeout_us)			\
> +	read_poll_timeout_atomic(gpu_read_relaxed, val, cond, delay_us,		\
> +				 timeout_us, false, iomem, reg)
> +
> +#define gpu_read64_relaxed_poll_timeout(iomem, reg, val, cond, delay_us,	\
> +					timeout_us)				\
> +	read_poll_timeout(gpu_read64_relaxed, val, cond, delay_us, timeout_us,	\
> +			  false, iomem, reg)
> +
> +
> +#endif /* __PANTHOR_DEVICE_IO_H__ */
> --
> 2.43.0
> 

-- 
====================
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| but they're not |
| giving me the   |
 \ source code!  /
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