crypto: ccp - add timeout support in the SEV command

crypto: ccp - add timeout support in the SEV command

commit 3702a0585e64d70d5bf73bf3e943b8d6005b72c1 upstream.

Currently, the CCP driver assumes that the SEV command issued to the PSP
will always return (i.e. it will never hang).  But recently, firmware bugs
have shown that a command can hang.  Since of the SEV commands are used
in probe routines, this can cause boot hangs and/or loss of virtualization
capabilities.

To protect against firmware bugs, add a timeout in the SEV command
execution flow.  If a command does not complete within the specified
timeout then return -ETIMEOUT and stop the driver from executing any
further commands since the state of the SEV firmware is unknown.

Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gary Hook <Gary.Hook@amd.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
[Brijesh: Backported to 4.18..4.19 - offset change in few hunks]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>