lib: sbi: Only register available extensions

When an extension implements a probe function it means there's a
chance that the extension is not available. Use this function in the
register_extensions callback to determine if the extension should be
registered at all. Where the probe implementation is simple, just
open code the check.

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

lib/sbi/sbi_ecall_cppc.c

@@ -59,6 +59,9 @@ struct sbi_ecall_extension ecall_cppc;
 
 static int sbi_ecall_cppc_register_extensions(void)
 {
+	if (!sbi_cppc_get_device())
+		return 0;
+
 	return sbi_ecall_register_extension(&ecall_cppc);
 }
 

lib/sbi/sbi_ecall_dbcn.c

@@ -68,6 +68,9 @@ struct sbi_ecall_extension ecall_dbcn;
 
 static int sbi_ecall_dbcn_register_extensions(void)
 {
+	if (!sbi_console_get_device())
+		return 0;
+
 	return sbi_ecall_register_extension(&ecall_dbcn);
 }
 

lib/sbi/sbi_ecall_srst.c

@@ -71,6 +71,12 @@ struct sbi_ecall_extension ecall_srst;
 
 static int sbi_ecall_srst_register_extensions(void)
 {
+	unsigned long out_val;
+
+	sbi_ecall_srst_probe(SBI_EXT_SRST, &out_val);
+	if (!out_val)
+		return 0;
+
 	return sbi_ecall_register_extension(&ecall_srst);
 }
 

lib/sbi/sbi_ecall_susp.c

@@ -44,6 +44,12 @@ struct sbi_ecall_extension ecall_susp;
 
 static int sbi_ecall_susp_register_extensions(void)
 {
+	unsigned long out_val;
+
+	sbi_ecall_susp_probe(SBI_EXT_SUSP, &out_val);
+	if (!out_val)
+		return 0;
+
 	return sbi_ecall_register_extension(&ecall_susp);
 }
 

lib/sbi/sbi_ecall_vendor.c

@@ -22,24 +22,11 @@ static inline unsigned long sbi_ecall_vendor_id(void)
 		 (SBI_EXT_VENDOR_END - SBI_EXT_VENDOR_START));
 }
 
-static int sbi_ecall_vendor_probe(unsigned long extid,
-				  unsigned long *out_val)
-{
-	if (!sbi_platform_vendor_ext_check(sbi_platform_thishart_ptr()))
-		*out_val = 0;
-	else
-		*out_val = 1;
-	return 0;
-}
-
 static int sbi_ecall_vendor_handler(unsigned long extid, unsigned long funcid,
 				    const struct sbi_trap_regs *regs,
 				    unsigned long *out_val,
 				    struct sbi_trap_info *out_trap)
 {
-	if (!sbi_platform_vendor_ext_check(sbi_platform_thishart_ptr()))
-		return SBI_ERR_NOT_SUPPORTED;
-
 	return sbi_platform_vendor_ext_provider(sbi_platform_thishart_ptr(),
 						funcid, regs,
 						out_val, out_trap);
@@ -51,6 +38,9 @@ static int sbi_ecall_vendor_register_extensions(void)
 {
 	unsigned long extid = sbi_ecall_vendor_id();
 
+	if (!sbi_platform_vendor_ext_check(sbi_platform_thishart_ptr()))
+		return 0;
+
 	ecall_vendor.extid_start = extid;
 	ecall_vendor.extid_end = extid;
 
@@ -61,6 +51,5 @@ struct sbi_ecall_extension ecall_vendor = {
 	.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,
 };

lib/sbi/sbi_init.c

@@ -323,12 +323,6 @@ static void __noreturn init_coldboot(struct sbi_scratch *scratch, u32 hartid)
 		sbi_hart_hang();
 	}
 
-	rc = sbi_ecall_init();
-	if (rc) {
-		sbi_printf("%s: ecall init failed (error %d)\n", __func__, rc);
-		sbi_hart_hang();
-	}
-
 	/*
 	 * Note: Finalize domains after HSM initialization so that we
 	 * can startup non-root domains.
@@ -350,8 +344,9 @@ static void __noreturn init_coldboot(struct sbi_scratch *scratch, u32 hartid)
 	}
 
 	/*
-	 * Note: Platform final initialization should be last so that
+	 * Note: Platform final initialization should be after finalizing
-	 * it sees correct domain assignment and PMP configuration.
+	 * domains so that it sees correct domain assignment and PMP
+	 * configuration for FDT fixups.
 	 */
 	rc = sbi_platform_final_init(plat, true);
 	if (rc) {
@@ -360,6 +355,17 @@ static void __noreturn init_coldboot(struct sbi_scratch *scratch, u32 hartid)
 		sbi_hart_hang();
 	}
 
+	/*
+	 * Note: Ecall initialization should be after platform final
+	 * initialization so that all available platform devices are
+	 * already registered.
+	 */
+	rc = sbi_ecall_init();
+	if (rc) {
+		sbi_printf("%s: ecall init failed (error %d)\n", __func__, rc);
+		sbi_hart_hang();
+	}
+
 	sbi_boot_print_general(scratch);
 
 	sbi_boot_print_domains(scratch);