lib: sbi: Introduce register_extensions extension callback

Rather than registering all extensions on their behalf in
sbi_ecall_init(), introduce another extension callback and
invoke that instead. For now, implement each callback by
simply registering the extension, which means this patch
has no intended functional change. In later patches, extension
callbacks will be modified to choose when to register and to
possibly narrow the extension ID range prior to registering.
When an extension range needs to remove IDs, leaving gaps, then
multiple invocations of sbi_ecall_register_extension() may be
used. In summary, later patches for current extensions and the
introductions of future extensions will use the new callback to
ensure that only valid extension IDs from the initial range,
which are also available, will be registered.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

include/sbi/sbi_ecall.h

@@ -24,6 +24,7 @@ struct sbi_ecall_extension {
 	struct sbi_dlist head;
 	unsigned long extid_start;
 	unsigned long extid_end;
+	int (* register_extensions)(void);
 	int (* probe)(unsigned long extid, unsigned long *out_val);
 	int (* handle)(unsigned long extid, unsigned long funcid,
 		       const struct sbi_trap_regs *regs,

lib/sbi/sbi_ecall.c

@@ -154,7 +154,10 @@ int sbi_ecall_init(void)
 
 	for (i = 0; i < sbi_ecall_exts_size; i++) {
 		ext = sbi_ecall_exts[i];
-		ret = sbi_ecall_register_extension(ext);
+		ret = SBI_ENODEV;
+
+		if (ext->register_extensions)
+			ret = ext->register_extensions();
 		if (ret)
 			return ret;
 	}

lib/sbi/sbi_ecall_base.c

@@ -72,8 +72,16 @@ static int sbi_ecall_base_handler(unsigned long extid, unsigned long funcid,
 	return ret;
 }
 
+struct sbi_ecall_extension ecall_base;
+
+static int sbi_ecall_base_register_extensions(void)
+{
+	return sbi_ecall_register_extension(&ecall_base);
+}
+
 struct sbi_ecall_extension ecall_base = {
-	.extid_start = SBI_EXT_BASE,
-	.extid_end = SBI_EXT_BASE,
-	.handle = sbi_ecall_base_handler,
+	.extid_start		= SBI_EXT_BASE,
+	.extid_end		= SBI_EXT_BASE,
+	.register_extensions	= sbi_ecall_base_register_extensions,
+	.handle			= sbi_ecall_base_handler,
 };

lib/sbi/sbi_ecall_cppc.c

@@ -55,9 +55,17 @@ static int sbi_ecall_cppc_probe(unsigned long extid, unsigned long *out_val)
 	return 0;
 }
 
+struct sbi_ecall_extension ecall_cppc;
+
+static int sbi_ecall_cppc_register_extensions(void)
+{
+	return sbi_ecall_register_extension(&ecall_cppc);
+}
+
 struct sbi_ecall_extension ecall_cppc = {
-	.extid_start	= SBI_EXT_CPPC,
-	.extid_end	= SBI_EXT_CPPC,
-	.handle		= sbi_ecall_cppc_handler,
-	.probe		= sbi_ecall_cppc_probe,
+	.extid_start		= SBI_EXT_CPPC,
+	.extid_end		= SBI_EXT_CPPC,
+	.register_extensions	= sbi_ecall_cppc_register_extensions,
+	.probe			= sbi_ecall_cppc_probe,
+	.handle			= sbi_ecall_cppc_handler,
 };

lib/sbi/sbi_ecall_dbcn.c

@@ -64,9 +64,17 @@ static int sbi_ecall_dbcn_probe(unsigned long extid, unsigned long *out_val)
 	return 0;
 }
 
+struct sbi_ecall_extension ecall_dbcn;
+
+static int sbi_ecall_dbcn_register_extensions(void)
+{
+	return sbi_ecall_register_extension(&ecall_dbcn);
+}
+
 struct sbi_ecall_extension ecall_dbcn = {
-	.extid_start = SBI_EXT_DBCN,
-	.extid_end = SBI_EXT_DBCN,
-	.handle = sbi_ecall_dbcn_handler,
-	.probe = sbi_ecall_dbcn_probe,
+	.extid_start		= SBI_EXT_DBCN,
+	.extid_end		= SBI_EXT_DBCN,
+	.register_extensions	= sbi_ecall_dbcn_register_extensions,
+	.probe			= sbi_ecall_dbcn_probe,
+	.handle			= sbi_ecall_dbcn_handler,
 };

lib/sbi/sbi_ecall_hsm.c

@@ -54,8 +54,16 @@ static int sbi_ecall_hsm_handler(unsigned long extid, unsigned long funcid,
 	return ret;
 }
 
+struct sbi_ecall_extension ecall_hsm;
+
+static int sbi_ecall_hsm_register_extensions(void)
+{
+	return sbi_ecall_register_extension(&ecall_hsm);
+}
+
 struct sbi_ecall_extension ecall_hsm = {
-	.extid_start = SBI_EXT_HSM,
-	.extid_end = SBI_EXT_HSM,
-	.handle = sbi_ecall_hsm_handler,
+	.extid_start		= SBI_EXT_HSM,
+	.extid_end		= SBI_EXT_HSM,
+	.register_extensions	= sbi_ecall_hsm_register_extensions,
+	.handle			= sbi_ecall_hsm_handler,
 };

lib/sbi/sbi_ecall_ipi.c

@@ -29,8 +29,16 @@ static int sbi_ecall_ipi_handler(unsigned long extid, unsigned long funcid,
 	return ret;
 }
 
+struct sbi_ecall_extension ecall_ipi;
+
+static int sbi_ecall_ipi_register_extensions(void)
+{
+	return sbi_ecall_register_extension(&ecall_ipi);
+}
+
 struct sbi_ecall_extension ecall_ipi = {
-	.extid_start = SBI_EXT_IPI,
-	.extid_end = SBI_EXT_IPI,
-	.handle = sbi_ecall_ipi_handler,
+	.extid_start		= SBI_EXT_IPI,
+	.extid_end		= SBI_EXT_IPI,
+	.register_extensions	= sbi_ecall_ipi_register_extensions,
+	.handle			= sbi_ecall_ipi_handler,
 };

lib/sbi/sbi_ecall_legacy.c

@@ -117,8 +117,16 @@ static int sbi_ecall_legacy_handler(unsigned long extid, unsigned long funcid,
 	return ret;
 }
 
+struct sbi_ecall_extension ecall_legacy;
+
+static int sbi_ecall_legacy_register_extensions(void)
+{
+	return sbi_ecall_register_extension(&ecall_legacy);
+}
+
 struct sbi_ecall_extension ecall_legacy = {
-	.extid_start = SBI_EXT_0_1_SET_TIMER,
-	.extid_end = SBI_EXT_0_1_SHUTDOWN,
-	.handle = sbi_ecall_legacy_handler,
+	.extid_start		= SBI_EXT_0_1_SET_TIMER,
+	.extid_end		= SBI_EXT_0_1_SHUTDOWN,
+	.register_extensions	= sbi_ecall_legacy_register_extensions,
+	.handle			= sbi_ecall_legacy_handler,
 };

lib/sbi/sbi_ecall_pmu.c

@@ -88,9 +88,17 @@ static int sbi_ecall_pmu_probe(unsigned long extid, unsigned long *out_val)
 	return 0;
 }
 
+struct sbi_ecall_extension ecall_pmu;
+
+static int sbi_ecall_pmu_register_extensions(void)
+{
+	return sbi_ecall_register_extension(&ecall_pmu);
+}
+
 struct sbi_ecall_extension ecall_pmu = {
-	.extid_start = SBI_EXT_PMU,
-	.extid_end = SBI_EXT_PMU,
-	.handle = sbi_ecall_pmu_handler,
-	.probe = sbi_ecall_pmu_probe,
+	.extid_start		= SBI_EXT_PMU,
+	.extid_end		= SBI_EXT_PMU,
+	.register_extensions	= sbi_ecall_pmu_register_extensions,
+	.probe			= sbi_ecall_pmu_probe,
+	.handle			= sbi_ecall_pmu_handler,
 };

lib/sbi/sbi_ecall_rfence.c

@@ -79,8 +79,16 @@ static int sbi_ecall_rfence_handler(unsigned long extid, unsigned long funcid,
 	return ret;
 }
 
+struct sbi_ecall_extension ecall_rfence;
+
+static int sbi_ecall_rfence_register_extensions(void)
+{
+	return sbi_ecall_register_extension(&ecall_rfence);
+}
+
 struct sbi_ecall_extension ecall_rfence = {
-	.extid_start = SBI_EXT_RFENCE,
-	.extid_end = SBI_EXT_RFENCE,
-	.handle = sbi_ecall_rfence_handler,
+	.extid_start		= SBI_EXT_RFENCE,
+	.extid_end		= SBI_EXT_RFENCE,
+	.register_extensions	= sbi_ecall_rfence_register_extensions,
+	.handle			= sbi_ecall_rfence_handler,
 };

lib/sbi/sbi_ecall_srst.c

@@ -67,9 +67,17 @@ static int sbi_ecall_srst_probe(unsigned long extid, unsigned long *out_val)
 	return 0;
 }
 
+struct sbi_ecall_extension ecall_srst;
+
+static int sbi_ecall_srst_register_extensions(void)
+{
+	return sbi_ecall_register_extension(&ecall_srst);
+}
+
 struct sbi_ecall_extension ecall_srst = {
-	.extid_start = SBI_EXT_SRST,
-	.extid_end = SBI_EXT_SRST,
-	.handle = sbi_ecall_srst_handler,
-	.probe = sbi_ecall_srst_probe,
+	.extid_start		= SBI_EXT_SRST,
+	.extid_end		= SBI_EXT_SRST,
+	.register_extensions	= sbi_ecall_srst_register_extensions,
+	.probe			= sbi_ecall_srst_probe,
+	.handle			= sbi_ecall_srst_handler,
 };

lib/sbi/sbi_ecall_susp.c

@@ -40,9 +40,17 @@ static int sbi_ecall_susp_probe(unsigned long extid, unsigned long *out_val)
 	return 0;
 }
 
+struct sbi_ecall_extension ecall_susp;
+
+static int sbi_ecall_susp_register_extensions(void)
+{
+	return sbi_ecall_register_extension(&ecall_susp);
+}
+
 struct sbi_ecall_extension ecall_susp = {
-	.extid_start = SBI_EXT_SUSP,
-	.extid_end = SBI_EXT_SUSP,
-	.handle = sbi_ecall_susp_handler,
-	.probe = sbi_ecall_susp_probe,
+	.extid_start		= SBI_EXT_SUSP,
+	.extid_end		= SBI_EXT_SUSP,
+	.register_extensions	= sbi_ecall_susp_register_extensions,
+	.probe			= sbi_ecall_susp_probe,
+	.handle			= sbi_ecall_susp_handler,
 };

lib/sbi/sbi_ecall_time.c

@@ -33,8 +33,16 @@ static int sbi_ecall_time_handler(unsigned long extid, unsigned long funcid,
 	return ret;
 }
 
+struct sbi_ecall_extension ecall_time;
+
+static int sbi_ecall_time_register_extensions(void)
+{
+	return sbi_ecall_register_extension(&ecall_time);
+}
+
 struct sbi_ecall_extension ecall_time = {
-	.extid_start = SBI_EXT_TIME,
-	.extid_end = SBI_EXT_TIME,
-	.handle = sbi_ecall_time_handler,
+	.extid_start		= SBI_EXT_TIME,
+	.extid_end		= SBI_EXT_TIME,
+	.register_extensions	= sbi_ecall_time_register_extensions,
+	.handle			= sbi_ecall_time_handler,
 };

lib/sbi/sbi_ecall_vendor.c

@@ -47,9 +47,17 @@ static int sbi_ecall_vendor_handler(unsigned long extid, unsigned long funcid,
 						out_val, out_trap);
 }
 
+struct sbi_ecall_extension ecall_vendor;
+
+static int sbi_ecall_vendor_register_extensions(void)
+{
+	return sbi_ecall_register_extension(&ecall_vendor);
+}
+
 struct sbi_ecall_extension ecall_vendor = {
-	.extid_start = SBI_EXT_VENDOR_START,
-	.extid_end = SBI_EXT_VENDOR_END,
-	.probe = sbi_ecall_vendor_probe,
-	.handle = sbi_ecall_vendor_handler,
+	.extid_start		= SBI_EXT_VENDOR_START,
+	.extid_end		= SBI_EXT_VENDOR_END,
+	.register_extensions	= sbi_ecall_vendor_register_extensions,
+	.probe			= sbi_ecall_vendor_probe,
+	.handle			= sbi_ecall_vendor_handler,
 };