services/spm_deprecated: permit timer sysreg access at S-EL0

Expose the timer registers that are accessible at EL0 per the
architecture to the SPM payload running in secure EL0. Note
that this requires NS_TIMER_SWITCH to be enable for all users
of this code.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

services/std_svc/spm_deprecated/spm.mk

@@ -21,3 +21,6 @@ SPM_SOURCES	:=	$(addprefix services/std_svc/spm_deprecated/, \
 
 # Let the top-level Makefile know that we intend to include a BL32 image
 NEED_BL32		:=	yes
+
+# required so that SPM code executing at S-EL0 can access the timer registers
+NS_TIMER_SWITCH		:=	1

services/std_svc/spm_deprecated/spm_setup.c

@@ -168,6 +168,9 @@ void spm_sp_setup(sp_context_t *sp_ctx)
 	write_ctx_reg(get_sysregs_ctx(ctx), CTX_VBAR_EL1,
 			SPM_SHIM_EXCEPTIONS_PTR);
 
+	write_ctx_reg(get_sysregs_ctx(ctx), CTX_CNTKCTL_EL1,
+		      EL0PTEN_BIT | EL0VTEN_BIT | EL0PCTEN_BIT | EL0VCTEN_BIT);
+
 	/*
 	 * FPEN: Allow the Secure Partition to access FP/SIMD registers.
 	 * Note that SPM will not do any saving/restoring of these registers on