feat(RME): BL31 changes

The following is introduced in the patch
1. Enable GPT translation tables
2. Adds a new context for Realm world and adds realm world awareness in context management
3. Initializes CPU registers in context management for Realm world
Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: I5bc8f3413144fb63d9eb4f5885abdcf5a44b4db1

bl31/aarch64/bl31_entrypoint.S

@@ -172,6 +172,14 @@ func bl31_warm_entrypoint
 		_exception_vectors=runtime_exceptions		\
 		_pie_fixup_size=0
 
+#if ENABLE_RME
+	/*
+	 * Initialise and enable Granule Protection
+	 * before enabling any stage of translation.
+	 */
+	bl	gpt_enable
+#endif
+
 	/*
 	 * We're about to enable MMU and participate in PSCI state coordination.
 	 *

bl31/aarch64/runtime_exceptions.S

@@ -500,6 +500,14 @@ smc_handler64:
 	stp	x16, x17, [x6, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3]
 	str	x18, [x6, #CTX_EL3STATE_OFFSET + CTX_SCR_EL3]
 
+#if ENABLE_RME
+	/* Copy SCR_EL3.NSE bit to the flag to indicate caller's security */
+	ubfx	x7, x18, #SCR_NSE_SHIFT, 1
+
+	/* Shift copied SCR_EL3.NSE bit by 1 to create space for SCR_EL3.NS bit */
+	lsl	x7, x7, #1
+#endif /* ENABLE_RME */
+
 	/* Copy SCR_EL3.NS bit to the flag to indicate caller's security */
 	bfi	x7, x18, #0, #1
 

bl31/bl31.mk

@@ -95,6 +95,13 @@ BL31_SOURCES		+=	lib/cpus/aarch64/wa_cve_2017_5715_bpiall.S	\
 				lib/cpus/aarch64/wa_cve_2017_5715_mmu.S
 endif
 
+ifeq (${ENABLE_RME},1)
+include lib/gpt/gpt.mk
+
+BL31_SOURCES		+=	${GPT_LIB_SRCS}					\
+				${RMMD_SOURCES}
+endif
+
 BL31_LINKERFILE		:=	bl31/bl31.ld.S
 
 # Flag used to indicate if Crash reporting via console should be included

bl31/bl31_context_mgmt.c

@@ -19,7 +19,11 @@
  ******************************************************************************/
 void *cm_get_context(uint32_t security_state)
 {
+#if ENABLE_RME
+	assert(sec_state_is_valid(security_state));
+#else /* ENABLE_RME */
 	assert(security_state <= NON_SECURE);
+#endif
 
 	return get_cpu_data(cpu_context[security_state]);
 }
@@ -30,7 +34,11 @@ void *cm_get_context(uint32_t security_state)
  ******************************************************************************/
 void cm_set_context(void *context, uint32_t security_state)
 {
+#if ENABLE_RME
+	assert(sec_state_is_valid(security_state));
+#else /* ENABLE_RME */
 	assert(security_state <= NON_SECURE);
+#endif
 
 	set_cpu_data(cpu_context[security_state], context);
 }

include/lib/el3_runtime/aarch64/context.h

@@ -406,6 +406,15 @@ DEFINE_REG_STRUCT(pauth, CTX_PAUTH_REGS_ALL);
  * to ensure that SP_EL3 always points to an instance of this
  * structure at exception entry and exit. Each instance will
  * correspond to either the secure or the non-secure state.
+ *
+ * For systems supporting RME:
+ *
+ * Top-level context structure which is used by EL3 firmware to preserve
+ * the state of a core at the next lower EL in a given security state and
+ * save enough EL3 meta data to be able to return to that EL and security
+ * state. The context management library will be used to ensure that
+ * SP_EL3 always points to an instance of this structure at exception
+ * entry and exit.
  */
 typedef struct cpu_context {
 	gp_regs_t gpregs_ctx;

include/lib/el3_runtime/cpu_data.h

@@ -20,14 +20,26 @@
 #define PSCI_CPU_DATA_SIZE_ALIGNED	((PSCI_CPU_DATA_SIZE + 7) & ~7)
 
 /* Offset of cpu_ops_ptr, size 8 bytes */
+#if ENABLE_RME
+#define CPU_DATA_CPU_OPS_PTR		0x18
+#else /* ENABLE_RME */
 #define CPU_DATA_CPU_OPS_PTR		0x10
+#endif /* ENABLE_RME */
 
 #if ENABLE_PAUTH
 /* 8-bytes aligned offset of apiakey[2], size 16 bytes */
+#if ENABLE_RME
+#define	CPU_DATA_APIAKEY_OFFSET		(0x20 + PSCI_CPU_DATA_SIZE_ALIGNED)
+#else /* ENABLE_RME */
 #define CPU_DATA_APIAKEY_OFFSET		(0x18 + PSCI_CPU_DATA_SIZE_ALIGNED)
-#define CPU_DATA_CRASH_BUF_OFFSET	(CPU_DATA_APIAKEY_OFFSET + 0x10)
-#else
+#endif /* ENABLE_RME */
+#define CPU_DATA_CRASH_BUF_OFFSET	(0x10 + CPU_DATA_APIAKEY_OFFSET)
+#else /* ENABLE_PAUTH */
+#if ENABLE_RME
+#define CPU_DATA_CRASH_BUF_OFFSET	(0x20 + PSCI_CPU_DATA_SIZE_ALIGNED)
+#else /* ENABLE_RME */
 #define CPU_DATA_CRASH_BUF_OFFSET	(0x18 + PSCI_CPU_DATA_SIZE_ALIGNED)
+#endif /* ENABLE_RME */
 #endif /* ENABLE_PAUTH */
 
 /* need enough space in crash buffer to save 8 registers */
@@ -86,21 +98,23 @@
 
 /*******************************************************************************
  * Cache of frequently used per-cpu data:
- *   Pointers to non-secure and secure security state contexts
+ *   Pointers to non-secure, realm, and secure security state contexts
  *   Address of the crash stack
  * It is aligned to the cache line boundary to allow efficient concurrent
  * manipulation of these pointers on different cpus
  *
- * TODO: Add other commonly used variables to this (tf_issues#90)
- *
  * The data structure and the _cpu_data accessors should not be used directly
  * by components that have per-cpu members. The member access macros should be
  * used for this.
  ******************************************************************************/
 typedef struct cpu_data {
 #ifdef __aarch64__
+#if ENABLE_RME
+	void *cpu_context[3];
+#else /* ENABLE_RME */
 	void *cpu_context[2];
-#endif
+#endif /* ENABLE_RME */
+#endif /* __aarch64__ */
 	uintptr_t cpu_ops_ptr;
 	struct psci_cpu_data psci_svc_cpu_data;
 #if ENABLE_PAUTH

include/lib/smccc.h

@@ -94,6 +94,8 @@
 /* Various flags passed to SMC handlers */
 #define SMC_FROM_SECURE		(U(0) << 0)
 #define SMC_FROM_NON_SECURE	(U(1) << 0)
+#define SMC_FROM_REALM		(U(3) << 0)
+#define SMC_FROM_MASK		U(3)
 
 #ifndef __ASSEMBLER__
 
@@ -101,8 +103,15 @@
 
 #include <lib/cassert.h>
 
+#if ENABLE_RME
+#define is_caller_non_secure(_f)	(((_f) & SMC_FROM_MASK) == SMC_FROM_NON_SECURE)
+#define is_caller_secure(_f)		(((_f) & SMC_FROM_MASK) == SMC_FROM_SECURE)
+#define is_caller_realm(_f)		(((_f) & SMC_FROM_MASK) == SMC_FROM_REALM)
+#define caller_sec_state(_f)		((_f) & SMC_FROM_MASK)
+#else /* ENABLE_RME */
 #define is_caller_non_secure(_f)	(((_f) & SMC_FROM_NON_SECURE) != U(0))
 #define is_caller_secure(_f)		(!is_caller_non_secure(_f))
+#endif /* ENABLE_RME */
 
 /* The macro below is used to identify a Standard Service SMC call */
 #define is_std_svc_call(_fid)		(GET_SMC_OEN(_fid) == OEN_STD_START)

lib/el3_runtime/aarch64/context_mgmt.c

@@ -23,9 +23,11 @@
 #include <lib/extensions/spe.h>
 #include <lib/extensions/sve.h>
 #include <lib/extensions/twed.h>
+#if ENABLE_RME
+#include <lib/gpt/gpt.h>
+#endif
 #include <lib/utils.h>
 
-
 /*******************************************************************************
  * Context management library initialisation routine. This library is used by
  * runtime services to share pointers to 'cpu_context' structures for the secure
@@ -70,6 +72,10 @@ void cm_setup_context(cpu_context_t *ctx, const entry_point_info_t *ep)
 	gp_regs_t *gp_regs;
 	u_register_t sctlr_elx, actlr_elx;
 
+#if ENABLE_RME
+	u_register_t hcr_el2;
+#endif /* ENABLE_RME */
+
 	assert(ctx != NULL);
 
 	security_state = GET_SECURITY_STATE(ep->h.attr);
@@ -89,24 +95,47 @@ void cm_setup_context(cpu_context_t *ctx, const entry_point_info_t *ep)
 	scr_el3 = read_scr();
 	scr_el3 &= ~(SCR_NS_BIT | SCR_RW_BIT | SCR_FIQ_BIT | SCR_IRQ_BIT |
 			SCR_ST_BIT | SCR_HCE_BIT);
+
+#if ENABLE_RME
+	/* When RME support is enabled, clear the NSE bit as well. */
+	scr_el3 &= ~SCR_NSE_BIT;
+#endif /* ENABLE_RME */
+
 	/*
 	 * SCR_NS: Set the security state of the next EL.
 	 */
-	if (security_state != SECURE)
+	if (security_state == NON_SECURE) {
 		scr_el3 |= SCR_NS_BIT;
+	}
+
+#if ENABLE_RME
+	/* Check for realm state if RME support enabled. */
+	if (security_state == REALM) {
+		scr_el3 |= SCR_NS_BIT | SCR_NSE_BIT;
+
+		/*
+		 * RMM relies on EL3 to setup HCR_EL2 for page table setup.
+		 */
+		hcr_el2 = HCR_TEA_BIT | HCR_E2H_BIT | HCR_TGE_BIT;
+		write_ctx_reg(get_el2_sysregs_ctx(ctx), CTX_HCR_EL2, hcr_el2);
+	}
+#endif /* ENABLE_RME */
+
 	/*
 	 * SCR_EL3.RW: Set the execution state, AArch32 or AArch64, for next
 	 *  Exception level as specified by SPSR.
 	 */
-	if (GET_RW(ep->spsr) == MODE_RW_64)
+	if (GET_RW(ep->spsr) == MODE_RW_64) {
 		scr_el3 |= SCR_RW_BIT;
+	}
 	/*
 	 * SCR_EL3.ST: Traps Secure EL1 accesses to the Counter-timer Physical
 	 *  Secure timer registers to EL3, from AArch64 state only, if specified
 	 *  by the entrypoint attributes.
 	 */
-	if (EP_GET_ST(ep->h.attr) != 0U)
+	if (EP_GET_ST(ep->h.attr) != 0U) {
 		scr_el3 |= SCR_ST_BIT;
+	}
 
 #if RAS_TRAP_LOWER_EL_ERR_ACCESS
 	/*
@@ -140,8 +169,9 @@ void cm_setup_context(cpu_context_t *ctx, const entry_point_info_t *ep)
 	 * If the Secure world wants to use pointer authentication,
 	 * CTX_INCLUDE_PAUTH_REGS must be set to 1.
 	 */
-	if (security_state == NON_SECURE)
+	if (security_state == NON_SECURE) {
 		scr_el3 |= SCR_API_BIT | SCR_APK_BIT;
+	}
 #endif /* !CTX_INCLUDE_PAUTH_REGS */
 
 #if !CTX_INCLUDE_MTE_REGS || ENABLE_ASSERTIONS
@@ -178,7 +208,8 @@ void cm_setup_context(cpu_context_t *ctx, const entry_point_info_t *ep)
 	 *  indicated by the interrupt routing model for BL31.
 	 */
 	scr_el3 |= get_scr_el3_from_routing_model(security_state);
-#endif
+
+#endif /* IMAGE_BL31 */
 
 	/*
 	 * SCR_EL3.HCE: Enable HVC instructions if next execution state is
@@ -206,10 +237,18 @@ void cm_setup_context(cpu_context_t *ctx, const entry_point_info_t *ep)
 		}
 	}
 
+#if ENABLE_RME
+	/*
+	 * RME model uses S-EL2 to emulate R-EL2 so EEL2 bit must be set when
+	 * EL3 ERETs to R-EL2.
+	 */
+	if ((security_state != NON_SECURE) && (GET_EL(ep->spsr) == MODE_EL2)) {
+#else
 	/* Enable S-EL2 if the next EL is EL2 and security state is secure */
 	if ((security_state == SECURE) && (GET_EL(ep->spsr) == MODE_EL2)) {
+#endif /* ENABLE_RME */
 		if (GET_RW(ep->spsr) != MODE_RW_64) {
-			ERROR("S-EL2 can not be used in AArch32.");
+			ERROR("S-EL2 cannot be used in AArch32.");
 			panic();
 		}
 
@@ -238,9 +277,9 @@ void cm_setup_context(cpu_context_t *ctx, const entry_point_info_t *ep)
 	 *  required by PSCI specification)
 	 */
 	sctlr_elx = (EP_GET_EE(ep->h.attr) != 0U) ? SCTLR_EE_BIT : 0U;
-	if (GET_RW(ep->spsr) == MODE_RW_64)
+	if (GET_RW(ep->spsr) == MODE_RW_64) {
 		sctlr_elx |= SCTLR_EL1_RES1;
-	else {
+	} else {
 		/*
 		 * If the target execution state is AArch32 then the following
 		 * fields need to be set.
@@ -370,7 +409,8 @@ void cm_init_my_context(const entry_point_info_t *ep)
 }
 
 /*******************************************************************************
- * Prepare the CPU system registers for first entry into secure or normal world
+ * Prepare the CPU system registers for first entry into realm, secure, or
+ * normal world.
  *
  * If execution is requested to EL2 or hyp mode, SCTLR_EL2 is initialized
  * If execution is requested to non-secure EL1 or svc mode, and the CPU supports
@@ -452,7 +492,7 @@ void cm_prepare_el3_exit(uint32_t security_state)
 			 * architecturally UNKNOWN on reset and are set to zero
 			 * except for field(s) listed below.
 			 *
-			 * CNTHCTL_EL2.EL1PCEN: Set to one to disable traps to
+			 * CNTHCTL_EL2.EL1PTEN: Set to one to disable traps to
 			 *  Hyp mode of Non-secure EL0 and EL1 accesses to the
 			 *  physical timer registers.
 			 *
@@ -461,7 +501,8 @@ void cm_prepare_el3_exit(uint32_t security_state)
 			 *  physical counter registers.
 			 */
 			write_cnthctl_el2(CNTHCTL_RESET_VAL |
-						EL1PCEN_BIT | EL1PCTEN_BIT);
+					CNTHCTL_EL1PTEN_BIT |
+					CNTHCTL_EL1PCTEN_BIT);
 
 			/*
 			 * Initialise CNTVOFF_EL2 to zero as it resets to an
@@ -598,6 +639,9 @@ void cm_el2_sysregs_context_save(uint32_t security_state)
 	 * S-EL2 context if S-EL2 is enabled.
 	 */
 	if ((security_state == NON_SECURE) ||
+#if ENABLE_RME
+	    (security_state == REALM) ||
+#endif /* ENABLE_RME */
 	    ((security_state == SECURE) && ((scr_el3 & SCR_EEL2_BIT) != 0U))) {
 		cpu_context_t *ctx;
 
@@ -620,6 +664,9 @@ void cm_el2_sysregs_context_restore(uint32_t security_state)
 	 * S-EL2 context if S-EL2 is enabled.
 	 */
 	if ((security_state == NON_SECURE) ||
+#if ENABLE_RME
+	    (security_state == REALM) ||
+#endif /* ENABLE_RME */
 	    ((security_state == SECURE) && ((scr_el3 & SCR_EEL2_BIT) != 0U))) {
 		cpu_context_t *ctx;
 
@@ -646,10 +693,18 @@ void cm_el1_sysregs_context_save(uint32_t security_state)
 	el1_sysregs_context_save(get_el1_sysregs_ctx(ctx));
 
 #if IMAGE_BL31
-	if (security_state == SECURE)
+	if (security_state == SECURE) {
 		PUBLISH_EVENT(cm_exited_secure_world);
-	else
+#if ENABLE_RME
+	} else if (security_state == NON_SECURE) {
 		PUBLISH_EVENT(cm_exited_normal_world);
+	}
+#else /* ENABLE_RME */
+	} else {
+		PUBLISH_EVENT(cm_exited_normal_world);
+	}
+#endif /* ENABLE_RME */
+
 #endif
 }
 
@@ -663,10 +718,18 @@ void cm_el1_sysregs_context_restore(uint32_t security_state)
 	el1_sysregs_context_restore(get_el1_sysregs_ctx(ctx));
 
 #if IMAGE_BL31
-	if (security_state == SECURE)
+	if (security_state == SECURE) {
 		PUBLISH_EVENT(cm_entering_secure_world);
-	else
+#if ENABLE_RME
+	} else if (security_state == NON_SECURE) {
 		PUBLISH_EVENT(cm_entering_normal_world);
+	}
+#else /* ENABLE_RME */
+	} else {
+		PUBLISH_EVENT(cm_entering_normal_world);
+	}
+#endif /* ENABLE_RME */
+
 #endif
 }