Merge changes from topic "bk/context_refactor" into integration

* changes:
  fix(gicv3): restore scr_el3 after changing it
  refactor(cm): make SVE and SME build dependencies logical

Makefile

@@ -916,11 +916,20 @@ ifeq (${ENABLE_RME},1)
     endif
 endif
 
+ifneq (${ENABLE_SME_FOR_NS},0)
+    ifeq (${ENABLE_SVE_FOR_NS},0)
+        $(error "ENABLE_SME_FOR_NS requires ENABLE_SVE_FOR_NS")
+    endif
+endif
+
 # Secure SME/SVE requires the non-secure component as well
 ifeq (${ENABLE_SME_FOR_SWD},1)
     ifeq (${ENABLE_SME_FOR_NS},0)
         $(error "ENABLE_SME_FOR_SWD requires ENABLE_SME_FOR_NS")
     endif
+    ifeq (${ENABLE_SVE_FOR_SWD},0)
+        $(error "ENABLE_SME_FOR_SWD requires ENABLE_SVE_FOR_SWD")
+    endif
 endif
 ifeq (${ENABLE_SVE_FOR_SWD},1)
     ifeq (${ENABLE_SVE_FOR_NS},0)

bl31/bl31.mk

@@ -101,12 +101,10 @@ endif
 
 ifneq (${ENABLE_SME_FOR_NS},0)
 BL31_SOURCES		+=	lib/extensions/sme/sme.c
-BL31_SOURCES		+=	lib/extensions/sve/sve.c
-else
+endif
 ifneq (${ENABLE_SVE_FOR_NS},0)
 BL31_SOURCES		+=	lib/extensions/sve/sve.c
 endif
-endif
 
 ifneq (${ENABLE_MPAM_FOR_LOWER_ELS},0)
 BL31_SOURCES		+=	lib/extensions/mpam/mpam.c

docs/getting_started/build-options.rst

@@ -436,7 +436,8 @@ Common build options
    (SME), SVE, and FPU/SIMD for the non-secure world only. These features share
    registers so are enabled together. Using this option without
    ENABLE_SME_FOR_SWD=1 will cause SME, SVE, and FPU/SIMD instructions in secure
-   world to trap to EL3. SME is an optional architectural feature for AArch64
+   world to trap to EL3. Requires ``ENABLE_SVE_FOR_NS`` to be set as SME is a
+   superset of SVE. SME is an optional architectural feature for AArch64
    and TF-A support is experimental. At this time, this build option cannot be
    used on systems that have SPD=spmd/SPM_MM or ENABLE_RME, and attempting to
    build with these options will fail. This flag can take the values 0 to 2, to
@@ -450,10 +451,9 @@ Common build options
    align with the ``FEATURE_DETECTION`` mechanism. Default is 0.
 
 -  ``ENABLE_SME_FOR_SWD``: Boolean option to enable the Scalable Matrix
-   Extension for secure world use along with SVE and FPU/SIMD, ENABLE_SME_FOR_NS
-   must also be set to use this. If enabling this, the secure world MUST
-   handle context switching for SME, SVE, and FPU/SIMD registers to ensure that
-   no data is leaked to non-secure world. This is experimental. Default is 0.
+   Extension for secure world. Used along with SVE and FPU/SIMD.
+   ENABLE_SME_FOR_NS and ENABLE_SVE_FOR_SWD must also be set to use this.
+   This is experimental. Default is 0.
 
 -  ``ENABLE_SPE_FOR_NS`` : Numeric value to enable Statistical Profiling
    extensions. This is an optional architectural feature for AArch64.
@@ -469,17 +469,15 @@ Common build options
    This is to avoid corruption of the Non-secure world data in the Z-registers
    which are aliased by the SIMD and FP registers. The build option is not
    compatible with the ``CTX_INCLUDE_FPREGS`` build option, and will raise an
-   assert on platforms where SVE is implemented and ``ENABLE_SVE_FOR_NS`` enabled.
-   This flag can take the values 0 to 2, to align with the ``FEATURE_DETECTION``
-   mechanism. The default is 2 but is automatically disabled when
-   ENABLE_SME_FOR_NS is enabled ( set to 1 or 2) since SME encompasses SVE.
-   At this time, this build option cannot be used on systems that have SPM_MM
-   enabled.
+   assert on platforms where SVE is implemented and ``ENABLE_SVE_FOR_NS``
+   enabled.  This flag can take the values 0 to 2, to align with the
+   ``FEATURE_DETECTION`` mechanism. At this time, this build option cannot be
+   used on systems that have SPM_MM enabled. The default is 1.
 
 -  ``ENABLE_SVE_FOR_SWD``: Boolean option to enable SVE for the Secure world.
    SVE is an optional architectural feature for AArch64. Note that this option
-   requires ENABLE_SVE_FOR_NS to be enabled. The default is 0 and it
-   is automatically disabled when the target architecture is AArch32.
+   requires ENABLE_SVE_FOR_NS to be enabled. The default is 0 and it is
+   automatically disabled when the target architecture is AArch32.
 
 -  ``ENABLE_STACK_PROTECTOR``: String option to enable the stack protection
    checks in GCC. Allowed values are "all", "strong", "default" and "none". The

drivers/arm/gic/v3/gicv3_main.c

@@ -330,6 +330,8 @@ void gicv3_cpuif_enable(unsigned int proc_num)
 	/* Enable Group1 Secure interrupts */
 	write_icc_igrpen1_el3(read_icc_igrpen1_el3() |
 				IGRPEN1_EL3_ENABLE_G1S_BIT);
+	/* and restore the original */
+	write_scr_el3(scr_el3);
 	isb();
 	/* Add DSB to ensure visibility of System register writes */
 	dsb();

lib/el3_runtime/aarch64/context_mgmt.c

@@ -517,12 +517,13 @@ static void manage_extensions_nonsecure(bool el2_unused, cpu_context_t *ctx)
 		amu_enable(el2_unused, ctx);
 	}
 
-	/* Enable SME, SVE, and FPU/SIMD for non-secure world. */
+	/* Enable SVE and FPU/SIMD */
+	if (is_feat_sve_supported()) {
+		sve_enable(ctx);
+	}
+
 	if (is_feat_sme_supported()) {
 		sme_enable(ctx);
-	} else if (is_feat_sve_supported()) {
-		/* Enable SVE and FPU/SIMD for non-secure world. */
-		sve_enable(ctx);
 	}
 
 	if (is_feat_mpam_supported()) {
@@ -553,22 +554,7 @@ static void manage_extensions_nonsecure(bool el2_unused, cpu_context_t *ctx)
 static void manage_extensions_secure(cpu_context_t *ctx)
 {
 #if IMAGE_BL31
-
-	if (is_feat_sme_supported()) {
-		if (ENABLE_SME_FOR_SWD) {
-		/*
-		 * Enable SME, SVE, FPU/SIMD in secure context, secure manager
-		 * must ensure SME, SVE, and FPU/SIMD context properly managed.
-		 */
-			sme_enable(ctx);
-		} else {
-		/*
-		 * Disable SME, SVE, FPU/SIMD in secure context so non-secure
-		 * world can safely use the associated registers.
-		 */
-			sme_disable(ctx);
-		}
-	} else if (is_feat_sve_supported()) {
+	if (is_feat_sve_supported()) {
 		if (ENABLE_SVE_FOR_SWD) {
 		/*
 		 * Enable SVE and FPU in secure context, secure manager must
@@ -585,6 +571,21 @@ static void manage_extensions_secure(cpu_context_t *ctx)
 		}
 	}
 
+	if (is_feat_sme_supported()) {
+		if (ENABLE_SME_FOR_SWD) {
+		/*
+		 * Enable SME, SVE, FPU/SIMD in secure context, secure manager
+		 * must ensure SME, SVE, and FPU/SIMD context properly managed.
+		 */
+			sme_enable(ctx);
+		} else {
+		/*
+		 * Disable SME, SVE, FPU/SIMD in secure context so non-secure
+		 * world can safely use the associated registers.
+		 */
+			sme_disable(ctx);
+		}
+	}
 #endif /* IMAGE_BL31 */
 }
 

lib/extensions/sme/sme.c

@@ -65,9 +65,6 @@ void sme_enable(cpu_context_t *context)
 	/* Reset CPTR_EL3 value. */
 	write_cptr_el3(cptr_el3);
 	isb();
-
-	/* Enable SVE/FPU in addition to SME. */
-	sve_enable(context);
 }
 
 void sme_disable(cpu_context_t *context)

make_helpers/defaults.mk

@@ -401,14 +401,6 @@ SVE_VECTOR_LEN			:= 2048
 # SME defaults to disabled
 ENABLE_SME_FOR_NS		:= 0
 ENABLE_SME_FOR_SWD		:= 0
-
-# If SME is enabled then force SVE off
-ifneq (${ENABLE_SME_FOR_NS},0)
-	override ENABLE_SVE_FOR_NS	:= 0
-	override ENABLE_SVE_FOR_SWD	:= 0
-endif
-
-# SME2 defaults to disabled
 ENABLE_SME2_FOR_NS		:= 0
 
 SANITIZE_UB := off