Re: [PATCH 2/4] firmware: xilinx: Release all peripheral devices from firmware

["Pandey, Radhey Shyam" <radheys@amd.com>]

On 7/23/2026 6:18 PM, Jay Buddhabhatti wrote:
> During a kexec restart, only the kernel is reloaded while devices
> allocated in firmware persist, causing state mismatches between the
> kernel and firmware.
> 
> Introduce PM_DEV_ALL_PERIPH node ID (0x18224FFFU) to release all
> peripheral devices during kexec. On graceful restarts, this happens in
> zynqmp_firmware_shutdown(). On crash kernel restarts, it happens in
> zynqmp_firmware_probe() of the reloaded kernel.
> 
> Releasing all peripherals depends on firmware support for the
> PM_DEV_ALL_PERIPH node ID. On firmware that does not implement it (the
> feature check reports a version below PM_API_VERSION_3) the release is
> skipped and a warning such as "Bulk device release is not supported by
> firmware" is logged, e.g. on Versal NET firmware that predates this API.
> 
> Signed-off-by: Jay Buddhabhatti <jay.buddhabhatti@amd.com>

Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Thanks!
> ---
>   drivers/firmware/xilinx/zynqmp.c     | 15 ++++++++++++++-
>   include/linux/firmware/xlnx-zynqmp.h |  4 ++++
>   2 files changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/firmware/xilinx/zynqmp.c b/drivers/firmware/xilinx/zynqmp.c
> index 95ffd8f33ce9..64d2109eefd2 100644
> --- a/drivers/firmware/xilinx/zynqmp.c
> +++ b/drivers/firmware/xilinx/zynqmp.c
> @@ -2070,7 +2070,7 @@ ATTRIBUTE_GROUPS(zynqmp_firmware);
>    * zynqmp_clear_pm_state() - Clear subsystem state
>    * @dev: Device pointer used for logging
>    *
> - * Clears PM specific data in TF-A.
> + * Clears PM specific data in TF-A and firmware.
>    *
>    * Return: Returns status, either success or error
>    */
> @@ -2097,6 +2097,19 @@ static int zynqmp_clear_pm_state(struct device *dev)
>   			dev_warn(dev, "TF_A_CLEAR_PM_STATE is not supported in TF-A: %d\n", ret);
>   			ret = 0;
>   		}
> +
> +		/* Check if the firmware supports the PM_DEV_ALL_PERIPH node ID */
> +		ret = do_feature_check_call(PM_RELEASE_NODE);
> +		if (ret >= 0 && ((ret & FIRMWARE_VERSION_MASK) >= PM_API_VERSION_3)) {
> +			/* Attempt to release all peripheral devices via firmware */
> +			ret = zynqmp_pm_release_node(PM_DEV_ALL_PERIPH);
> +			if (ret)
> +				dev_err(dev, "Failed to release all peripheral devices: %d\n", ret);
> +		} else {
> +			dev_warn(dev,
> +				 "Bulk device release is not supported by firmware: %d\n", ret);
> +			ret = 0;
> +		}
>   	}
>   
>   	return ret;
> diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h
> index baaa88b0b197..ac39e5492961 100644
> --- a/include/linux/firmware/xlnx-zynqmp.h
> +++ b/include/linux/firmware/xlnx-zynqmp.h
> @@ -50,6 +50,7 @@
>   /* PM API versions */
>   #define PM_API_VERSION_1	1
>   #define PM_API_VERSION_2	2
> +#define PM_API_VERSION_3	3
>   
>   #define PM_PINCTRL_PARAM_SET_VERSION	2
>   
> @@ -145,6 +146,9 @@
>   #define XPM_EVENT_ERROR_MASK_NOC_NCR		BIT(13)
>   #define XPM_EVENT_ERROR_MASK_NOC_CR		BIT(12)
>   
> +/* Node ID for all peripheral devices */
> +#define PM_DEV_ALL_PERIPH	0x18224FFFU
> +
>   enum pm_module_id {
>   	PM_MODULE_ID = 0x0,
>   	XPM_MODULE_ID = 0x2,