x86/platform/amd: replace down_timeout() with down_interruptible()

JIRA: https://issues.redhat.com/browse/RHEL-102859

commit 784e48a
Author: Jake Hillion <jake@hillion.co.uk>
Date:   Thu Jun 5 19:09:27 2025 +0100

    x86/platform/amd: replace down_timeout() with down_interruptible()

    Currently hsmp_send_message() uses down_timeout() with a 100ms timeout
    to take the semaphore. However __hsmp_send_message(), the content of the
    critical section, has a sleep in it. On systems with significantly
    delayed scheduling behaviour this may take over 100ms.

    Convert this method to down_interruptible(). Leave the error handling
    the same as the documentation currently is not specific about what error
    is returned.

    Previous behaviour: a caller who competes with another caller stuck in
    the critical section due to scheduler delays would receive -ETIME.

    New behaviour: a caller who competes with another caller stuck in the
    critical section due to scheduler delays will complete successfully.

    Reviewed-by: Suma Hegde <suma.hegde@amd.com>
    Tested-by: Suma Hegde <suma.hegde@amd.com>
    Signed-off-by: Jake Hillion <jake@hillion.co.uk>
    Link: https://lore.kernel.org/r/20250605-amd-hsmp-v2-2-a811bc3dd74a@hillion.co.uk
    Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
    Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

Signed-off-by: David Arcari <darcari@redhat.com>

Author: darcari

drivers/platform/x86/amd/hsmp/hsmp.c

@@ -214,13 +214,7 @@ int hsmp_send_message(struct hsmp_message *msg)
 		return -ENODEV;
 	sock = &hsmp_pdev.sock[msg->sock_ind];
 
-	/*
-	 * The time taken by smu operation to complete is between
-	 * 10us to 1ms. Sometime it may take more time.
-	 * In SMP system timeout of 100 millisecs should
-	 * be enough for the previous thread to finish the operation
-	 */
-	ret = down_timeout(&sock->hsmp_sem, msecs_to_jiffies(HSMP_MSG_TIMEOUT));
+	ret = down_interruptible(&sock->hsmp_sem);
 	if (ret < 0)
 		return ret;