Re: [PATCH v7 1/9] sysreset: qemu virt: Use map_sysmem()

[Kuan-Wei Chiu <visitorckw@gmail.com>]

On Sat, May 16, 2026 at 04:39:53PM +0900, Daniel Palmer wrote:
> In the platform data there is a phys_addr_t (an integer) for the address
> of the register and we pass that as-is into writel() which is fine in most
> places because we don't need to do any mapping and the macro for writel()
> does a cast to a pointer.
> 
> If writel() is a static inline function the address argument is a pointer
> so passing it in as an integer without casting it first causes warnings or
> build failure.
> 
> map_sysmem() handles the casting part and if phys_addr_t is 32bits when
> on a 64bit machine.
> 
> Signed-off-by: Daniel Palmer <daniel@thingy.jp>

Acked-by: Kuan-Wei Chiu <visitorckw@gmail.com>

> ---
>  drivers/sysreset/sysreset_qemu_virt_ctrl.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/sysreset/sysreset_qemu_virt_ctrl.c b/drivers/sysreset/sysreset_qemu_virt_ctrl.c
> index e7cacc9b6e98..61b38d507fc5 100644
> --- a/drivers/sysreset/sysreset_qemu_virt_ctrl.c
> +++ b/drivers/sysreset/sysreset_qemu_virt_ctrl.c
> @@ -8,6 +8,7 @@
>  #include <dm.h>
>  #include <qemu_virt_ctrl.h>
>  #include <sysreset.h>
> +#include <mapmem.h>
>  #include <asm/io.h>
>  #include <linux/err.h>
>  
> @@ -24,6 +25,7 @@
>  static int qemu_virt_ctrl_request(struct udevice *dev, enum sysreset_t type)
>  {
>  	struct qemu_virt_ctrl_plat *plat = dev_get_plat(dev);
> +	void __iomem *reg = map_sysmem(plat->reg + VIRT_CTRL_REG_CMD, 0x4);
>  	u32 val;
>  
>  	switch (type) {
> @@ -38,7 +40,7 @@ static int qemu_virt_ctrl_request(struct udevice *dev, enum sysreset_t type)
>  		return -EPROTONOSUPPORT;
>  	}
>  
> -	writel(val, plat->reg + VIRT_CTRL_REG_CMD);
> +	writel(val, reg);
>  
>  	return -EINPROGRESS;
>  }
> -- 
> 2.53.0
>