TF-RMM Release v0.1.0

This is the first external release of TF-RMM and provides a reference
implementation of Realm Management Monitor (RMM) as specified by the
RMM Beta0 specification[1].

The `docs/readme.rst` has more details about the project and
`docs/getting_started/getting-started.rst` has details on how to get
started with TF-RMM.

[1] https://developer.arm.com/documentation/den0137/1-0bet0/?lang=en

Signed-off-by: Soby Mathew <soby.mathew@arm.com>
Change-Id: I205ef14c015e4a37ae9ae1a64e4cd22eb8da746e
diff --git a/runtime/core/handler.c b/runtime/core/handler.c
new file mode 100644
index 0000000..b7f3a55
--- /dev/null
+++ b/runtime/core/handler.c
@@ -0,0 +1,388 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-FileCopyrightText: Copyright TF-RMM Contributors.
+ */
+
+#include <arch.h>
+#include <arch_helpers.h>
+#include <assert.h>
+#include <buffer.h>
+#include <debug.h>
+#include <sizes.h>
+#include <smc-handler.h>
+#include <smc-rmi.h>
+#include <smc.h>
+#include <status.h>
+#include <utils_def.h>
+
+#define STATUS_HANDLER(_id)[_id] = #_id
+
+const char *status_handler[] = {
+	STATUS_HANDLER(RMI_SUCCESS),
+	STATUS_HANDLER(RMI_ERROR_INPUT),
+	STATUS_HANDLER(RMI_ERROR_REALM),
+	STATUS_HANDLER(RMI_ERROR_REC),
+	STATUS_HANDLER(RMI_ERROR_RTT),
+	STATUS_HANDLER(RMI_ERROR_IN_USE)
+};
+COMPILER_ASSERT(ARRAY_LEN(status_handler) == RMI_ERROR_COUNT);
+
+/*
+ * At this level (in handle_ns_smc) we distinguish the RMI calls only on:
+ * - The number of input arguments [0..4], and whether
+ * - The function returns up to three output values in addition
+ *   to the return status code.
+ * Hence, the naming syntax is:
+ * - `*_[0..4]` when no output values are returned, and
+ * - `*_[0..4]_o` when the function returns some output values.
+ */
+
+typedef unsigned long (*handler_0)(void);
+typedef unsigned long (*handler_1)(unsigned long arg0);
+typedef unsigned long (*handler_2)(unsigned long arg0, unsigned long arg1);
+typedef unsigned long (*handler_3)(unsigned long arg0, unsigned long arg1,
+				   unsigned long arg2);
+typedef unsigned long (*handler_4)(unsigned long arg0, unsigned long arg1,
+				   unsigned long arg2, unsigned long arg3);
+typedef unsigned long (*handler_5)(unsigned long arg0, unsigned long arg1,
+				   unsigned long arg2, unsigned long arg3,
+				   unsigned long arg4);
+typedef void (*handler_1_o)(unsigned long arg0, struct smc_result *ret);
+typedef void (*handler_3_o)(unsigned long arg0, unsigned long arg1,
+			    unsigned long arg2, struct smc_result *ret);
+
+enum rmi_type {
+	rmi_type_0,
+	rmi_type_1,
+	rmi_type_2,
+	rmi_type_3,
+	rmi_type_4,
+	rmi_type_5,
+	rmi_type_1_o,
+	rmi_type_3_o
+};
+
+struct smc_handler {
+	const char	*fn_name;
+	enum rmi_type	type;
+	union {
+		handler_0	f0;
+		handler_1	f1;
+		handler_2	f2;
+		handler_3	f3;
+		handler_4	f4;
+		handler_5	f5;
+		handler_1_o	f1_o;
+		handler_3_o	f3_o;
+		void		*fn_dummy;
+	};
+	bool		log_exec;	/* print handler execution */
+	bool		log_error;	/* print in case of error status */
+	unsigned int	out_values;	/* number of output values */
+};
+
+/*
+ * Get handler ID from FID
+ * Precondition: FID is an RMI call
+ */
+#define SMC_RMI_HANDLER_ID(_fid) SMC64_FID_OFFSET_FROM_RANGE_MIN(RMI, _fid)
+
+#define HANDLER_0(_id, _fn, _exec, _error)[SMC_RMI_HANDLER_ID(_id)] = { \
+	.fn_name = #_id, \
+	.type = rmi_type_0, .f0 = _fn, .log_exec = _exec, .log_error = _error,	   \
+	.out_values = 0U }
+#define HANDLER_1(_id, _fn, _exec, _error)[SMC_RMI_HANDLER_ID(_id)] = { \
+	.fn_name = #_id, \
+	.type = rmi_type_1, .f1 = _fn, .log_exec = _exec, .log_error = _error,	   \
+	.out_values = 0U }
+#define HANDLER_2(_id, _fn, _exec, _error)[SMC_RMI_HANDLER_ID(_id)] = { \
+	.fn_name = #_id, \
+	.type = rmi_type_2, .f2 = _fn, .log_exec = _exec, .log_error = _error,     \
+	.out_values = 0U }
+#define HANDLER_3(_id, _fn, _exec, _error)[SMC_RMI_HANDLER_ID(_id)] = { \
+	.fn_name = #_id, \
+	.type = rmi_type_3, .f3 = _fn, .log_exec = _exec, .log_error = _error,	   \
+	.out_values = 0U }
+#define HANDLER_4(_id, _fn, _exec, _error)[SMC_RMI_HANDLER_ID(_id)] = { \
+	.fn_name = #_id, \
+	.type = rmi_type_4, .f4 = _fn, .log_exec = _exec, .log_error = _error,	   \
+	.out_values = 0U }
+#define HANDLER_5(_id, _fn, _exec, _error)[SMC_RMI_HANDLER_ID(_id)] = { \
+	.fn_name = #_id, \
+	.type = rmi_type_5, .f5 = _fn, .log_exec = _exec, .log_error = _error,	   \
+	.out_values = 0U }
+#define HANDLER_1_O(_id, _fn, _exec, _error, _values)[SMC_RMI_HANDLER_ID(_id)] = { \
+	.fn_name = #_id, \
+	.type = rmi_type_1_o, .f1_o = _fn, .log_exec = _exec, .log_error = _error, \
+	.out_values = _values }
+#define HANDLER_3_O(_id, _fn, _exec, _error, _values)[SMC_RMI_HANDLER_ID(_id)] = { \
+	.fn_name = #_id, \
+	.type = rmi_type_3_o, .f3_o = _fn, .log_exec = _exec, .log_error = _error, \
+	.out_values = _values }
+
+/*
+ * The 3rd value enables the execution log.
+ * The 4th value enables the error log.
+ */
+static const struct smc_handler smc_handlers[] = {
+	HANDLER_0(SMC_RMM_VERSION,		 smc_version,			true,  true),
+	HANDLER_1_O(SMC_RMM_FEATURES,		 smc_read_feature_register,	true,  true, 1U),
+	HANDLER_1(SMC_RMM_GRANULE_DELEGATE,	 smc_granule_delegate,		false, true),
+	HANDLER_1(SMC_RMM_GRANULE_UNDELEGATE,	 smc_granule_undelegate,	false, true),
+	HANDLER_2(SMC_RMM_REALM_CREATE,		 smc_realm_create,		true,  true),
+	HANDLER_1(SMC_RMM_REALM_DESTROY,	 smc_realm_destroy,		true,  true),
+	HANDLER_1(SMC_RMM_REALM_ACTIVATE,	 smc_realm_activate,		true,  true),
+	HANDLER_3(SMC_RMM_REC_CREATE,		 smc_rec_create,		true,  true),
+	HANDLER_1(SMC_RMM_REC_DESTROY,		 smc_rec_destroy,		true,  true),
+	HANDLER_2(SMC_RMM_REC_ENTER,		 smc_rec_enter,			false, true),
+	HANDLER_5(SMC_RMM_DATA_CREATE,		 smc_data_create,		false, false),
+	HANDLER_3(SMC_RMM_DATA_CREATE_UNKNOWN,	 smc_data_create_unknown,	false, false),
+	HANDLER_2(SMC_RMM_DATA_DESTROY,		 smc_data_destroy,		false, true),
+	HANDLER_4(SMC_RMM_RTT_CREATE,		 smc_rtt_create,		false, true),
+	HANDLER_4(SMC_RMM_RTT_DESTROY,		 smc_rtt_destroy,		false, true),
+	HANDLER_4(SMC_RMM_RTT_FOLD,		 smc_rtt_fold,			false, true),
+	HANDLER_4(SMC_RMM_RTT_MAP_UNPROTECTED,	 smc_rtt_map_unprotected,	false, false),
+	HANDLER_3(SMC_RMM_RTT_UNMAP_UNPROTECTED, smc_rtt_unmap_unprotected,	false, false),
+	HANDLER_3_O(SMC_RMM_RTT_READ_ENTRY,	 smc_rtt_read_entry,		false, true, 4U),
+	HANDLER_2(SMC_RMM_PSCI_COMPLETE,	 smc_psci_complete,		true,  true),
+	HANDLER_1_O(SMC_RMM_REC_AUX_COUNT,	 smc_rec_aux_count,		true,  true, 1U),
+	HANDLER_3(SMC_RMM_RTT_INIT_RIPAS,	 smc_rtt_init_ripas,		false, true),
+	HANDLER_5(SMC_RMM_RTT_SET_RIPAS,	 smc_rtt_set_ripas,		false, true)
+};
+
+COMPILER_ASSERT(ARRAY_LEN(smc_handlers) == SMC64_NUM_FIDS_IN_RANGE(RMI));
+
+static bool rmi_call_log_enabled = true;
+
+static void rmi_log_on_exit(unsigned long handler_id,
+			    unsigned long arg0,
+			    unsigned long arg1,
+			    unsigned long arg2,
+			    unsigned long arg3,
+			    unsigned long arg4,
+			    struct smc_result *ret)
+{
+	const struct smc_handler *handler = &smc_handlers[handler_id];
+	unsigned long function_id = SMC64_RMI_FID(handler_id);
+	unsigned int i;
+	return_code_t rc;
+
+	if (!handler->log_exec && !handler->log_error) {
+		return;
+	}
+
+	if (function_id == SMC_RMM_VERSION) {
+		/*
+		 * RMM_VERSION is special because it returns the
+		 * version number, not the error code.
+		 */
+		INFO("%-29s %8lx %8lx %8lx %8lx %8lx > %lx\n",
+		     handler->fn_name, arg0, arg1, arg2, arg3, arg4,
+		     ret->x[0]);
+		return;
+	}
+
+	rc = unpack_return_code(ret->x[0]);
+
+	if ((handler->log_exec) ||
+	    (handler->log_error && (rc.status != RMI_SUCCESS))) {
+		INFO("%-29s %8lx %8lx %8lx %8lx %8lx > ",
+			handler->fn_name, arg0, arg1, arg2, arg3, arg4);
+		if (rc.status >= RMI_ERROR_COUNT) {
+			INFO("%lx", ret->x[0]);
+		} else {
+			INFO("%s", status_handler[rc.status]);
+		}
+
+		/* Check for index */
+		if (((function_id == SMC_RMM_REC_ENTER) &&
+		     (rc.status == RMI_ERROR_REALM)) ||
+		     (rc.status == RMI_ERROR_RTT)) {
+			INFO(" %x", rc.index);
+		}
+
+		/* Print output values */
+		for (i = 1U; i <= handler->out_values; i++) {
+			INFO(" %8lx", ret->x[i]);
+		}
+
+		INFO("\n");
+	}
+}
+
+void handle_ns_smc(unsigned long function_id,
+		   unsigned long arg0,
+		   unsigned long arg1,
+		   unsigned long arg2,
+		   unsigned long arg3,
+		   unsigned long arg4,
+		   unsigned long arg5,
+		   struct smc_result *ret)
+{
+	unsigned long handler_id;
+	const struct smc_handler *handler = NULL;
+
+	if (IS_SMC64_RMI_FID(function_id)) {
+		handler_id = SMC_RMI_HANDLER_ID(function_id);
+		if (handler_id < ARRAY_LEN(smc_handlers)) {
+			handler = &smc_handlers[handler_id];
+		}
+	}
+
+	/*
+	 * Check if handler exists and 'fn_dummy' is not NULL
+	 * for not implemented 'function_id' calls in SMC RMI range.
+	 */
+	if ((handler == NULL) || (handler->fn_dummy == NULL)) {
+		VERBOSE("[%s] unknown function_id: %lx\n",
+			__func__, function_id);
+		ret->x[0] = SMC_UNKNOWN;
+		return;
+	}
+
+	assert_cpu_slots_empty();
+
+	switch (handler->type) {
+	case rmi_type_0:
+		ret->x[0] = handler->f0();
+		break;
+	case rmi_type_1:
+		ret->x[0] = handler->f1(arg0);
+		break;
+	case rmi_type_2:
+		ret->x[0] = handler->f2(arg0, arg1);
+		break;
+	case rmi_type_3:
+		ret->x[0] = handler->f3(arg0, arg1, arg2);
+		break;
+	case rmi_type_4:
+		ret->x[0] = handler->f4(arg0, arg1, arg2, arg3);
+		break;
+	case rmi_type_5:
+		ret->x[0] = handler->f5(arg0, arg1, arg2, arg3, arg4);
+		break;
+	case rmi_type_1_o:
+		handler->f1_o(arg0, ret);
+		break;
+	case rmi_type_3_o:
+		handler->f3_o(arg0, arg1, arg2, ret);
+		break;
+	default:
+		assert(false);
+	}
+
+	if (rmi_call_log_enabled) {
+		rmi_log_on_exit(handler_id, arg0, arg1, arg2, arg3, arg4, ret);
+	}
+
+	assert_cpu_slots_empty();
+}
+
+static void report_unexpected(void)
+{
+	unsigned long spsr = read_spsr_el2();
+	unsigned long esr = read_esr_el2();
+	unsigned long elr = read_elr_el2();
+	unsigned long far = read_far_el2();
+
+	INFO("----\n");
+	INFO("Unexpected exception:\n");
+	INFO("SPSR_EL2: 0x%016lx\n", spsr);
+	INFO("ESR_EL2:  0x%016lx\n", esr);
+	INFO("ELR_EL2:  0x%016lx\n", elr);
+	INFO("FAR_EL2:  0x%016lx\n", far);
+	INFO("----\n");
+
+}
+
+unsigned long handle_realm_trap(unsigned long *regs)
+{
+	report_unexpected();
+
+	while (1) {
+		wfe();
+	}
+}
+
+/*
+ * Identifies an abort that the RMM may recover from.
+ */
+struct rmm_trap_element {
+	/*
+	 * The PC at the time of abort.
+	 */
+	unsigned long aborted_pc;
+	/*
+	 * New value of the PC.
+	 */
+	unsigned long new_pc;
+};
+
+#define RMM_TRAP_HANDLER(_aborted_pc, _new_pc) \
+	{ .aborted_pc = (unsigned long)(&_aborted_pc), \
+	  .new_pc = (unsigned long)(&_new_pc) }
+
+/*
+ * The registered locations of load/store instructions that access NS memory.
+ */
+extern void *ns_read;
+extern void *ns_write;
+
+/*
+ * The new value of the PC when the GPF occurs on a registered location.
+ */
+extern void *ns_access_ret_0;
+
+struct rmm_trap_element rmm_trap_list[] = {
+	RMM_TRAP_HANDLER(ns_read, ns_access_ret_0),
+	RMM_TRAP_HANDLER(ns_write, ns_access_ret_0),
+};
+#define RMM_TRAP_LIST_SIZE (sizeof(rmm_trap_list)/sizeof(struct rmm_trap_element))
+
+static void fatal_abort(void)
+{
+	report_unexpected();
+
+	while (1) {
+		wfe();
+	}
+}
+
+static bool is_el2_data_abort_gpf(unsigned long esr)
+{
+	if (((esr & ESR_EL2_EC_MASK) == ESR_EL2_EC_DATA_ABORT_SEL) &&
+	    ((esr & ESR_EL2_ABORT_FSC_MASK) == ESR_EL2_ABORT_FSC_GPF))
+		return true;
+	return false;
+}
+
+/*
+ * Handles the RMM's aborts.
+ * It compares the PC at the time of the abort with the registered addresses.
+ * If it finds a match, it returns the new value of the PC that the RMM should
+ * continue from. Other register values are preserved.
+ * If no match is found, it aborts the RMM.
+ */
+unsigned long handle_rmm_trap(void)
+{
+	int i;
+
+	unsigned long esr = read_esr_el2();
+	unsigned long elr = read_elr_el2();
+
+	/*
+	 * Only the GPF data aborts are recoverable.
+	 */
+	if (!is_el2_data_abort_gpf(esr)) {
+		fatal_abort();
+	}
+
+	for (i = 0; i < RMM_TRAP_LIST_SIZE; i++) {
+		if (rmm_trap_list[i].aborted_pc == elr) {
+			return rmm_trap_list[i].new_pc;
+		}
+	}
+
+	fatal_abort();
+	return 0;
+}