refactor(cm): move EL3 registers to global context

Currently, EL3 context registers are duplicated per-world per-cpu.
Some registers have the same value across all CPUs, so this patch
moves these registers out into a per-world context to reduce
memory usage.

Change-Id: I91294e3d5f4af21a58c23599af2bdbd2a747c54a
Signed-off-by: Elizabeth Ho <elizabeth.ho@arm.com>
Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
diff --git a/lib/extensions/sme/sme.c b/lib/extensions/sme/sme.c
index d705b64..b1409b9 100644
--- a/lib/extensions/sme/sme.c
+++ b/lib/extensions/sme/sme.c
@@ -22,17 +22,22 @@
 	/* Get the context state. */
 	state = get_el3state_ctx(context);
 
-	/* Enable SME in CPTR_EL3. */
-	reg = read_ctx_reg(state, CTX_CPTR_EL3);
-	reg |= ESM_BIT;
-	write_ctx_reg(state, CTX_CPTR_EL3, reg);
-
 	/* Set the ENTP2 bit in SCR_EL3 to enable access to TPIDR2_EL0. */
 	reg = read_ctx_reg(state, CTX_SCR_EL3);
 	reg |= SCR_ENTP2_BIT;
 	write_ctx_reg(state, CTX_SCR_EL3, reg);
 }
 
+void sme_enable_per_world(per_world_context_t *per_world_ctx)
+{
+	u_register_t reg;
+
+	/* Enable SME in CPTR_EL3. */
+	reg = per_world_ctx->ctx_cptr_el3;
+	reg |= ESM_BIT;
+	per_world_ctx->ctx_cptr_el3 = reg;
+}
+
 void sme_init_el3(void)
 {
 	u_register_t cptr_el3 = read_cptr_el3();
@@ -43,7 +48,7 @@
 	isb();
 
 	/*
-	 * Set the max LEN value and FA64 bit. This register is set up globally
+	 * Set the max LEN value and FA64 bit. This register is set up per_world
 	 * to be the least restrictive, then lower ELs can restrict as needed
 	 * using SMCR_EL2 and SMCR_EL1.
 	 */
@@ -87,15 +92,20 @@
 	/* Get the context state. */
 	state = get_el3state_ctx(context);
 
-	/* Disable SME, SVE, and FPU since they all share registers. */
-	reg = read_ctx_reg(state, CTX_CPTR_EL3);
-	reg &= ~ESM_BIT;	/* Trap SME */
-	reg &= ~CPTR_EZ_BIT;	/* Trap SVE */
-	reg |= TFP_BIT;		/* Trap FPU/SIMD */
-	write_ctx_reg(state, CTX_CPTR_EL3, reg);
-
 	/* Disable access to TPIDR2_EL0. */
 	reg = read_ctx_reg(state, CTX_SCR_EL3);
 	reg &= ~SCR_ENTP2_BIT;
 	write_ctx_reg(state, CTX_SCR_EL3, reg);
 }
+
+void sme_disable_per_world(per_world_context_t *per_world_ctx)
+{
+	u_register_t reg;
+
+	/* Disable SME, SVE, and FPU since they all share registers. */
+	reg = per_world_ctx->ctx_cptr_el3;
+	reg &= ~ESM_BIT;	/* Trap SME */
+	reg &= ~CPTR_EZ_BIT;	/* Trap SVE */
+	reg |= TFP_BIT;		/* Trap FPU/SIMD */
+	per_world_ctx->ctx_cptr_el3 = reg;
+}