scm_call_atomic*() can return a negative 32 bit value indicating
an error. Change the function signature to indicate that this is
possible.
Change-Id: I633bb521410f9a07495ec5e73e3a8b0e9adb7af1
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
The atomic SCM APIs are useful for commands that are guaranteed
by the secure side to be uninterruptable, atomic and SMP safe.
The calling convention use registers for passing parameters and
return values between the secure and non-secure side. Support
this interface with scm_call_atomic[1-2]() functions
corresponding to the number of arguments passed.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
When we're interrupted on the secure side, we should just issue
another smc instruction again instead of replaying the arguments
to smc. Fix it.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>
Assign the registers used in the inline assembly immediately
before the inline assembly block. This ensures the compiler
doesn't optimize away dead register assignments when it
shouldn't.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: David Brown <davidb@codeaurora.org>
We don't want the compiler to remove these asm statements or
reorder them in any way. Mark them as volatile to be sure.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: David Brown <davidb@codeaurora.org>
SCM is the protocol used to communicate between the secure and
non-secure code executing on the applications processor. The
non-secure side uses a physically contiguous buffer to pass
information to the secure side; where the buffer conforms to a
format that is agreed upon by both sides. The use of a buffer
allows multiple pending requests to be in flight on the secure
side. It also benefits use cases where the command or response
buffer contains large chunks of data.
Reviewed-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>
