feat(qemu-sbsa): handle platform version

QEMU provides platform version information via DT. We want to use it
in firmware to handle differences between platform versions.

Signed-off-by: Marcin Juszkiewicz <marcin.juszkiewicz@linaro.org>
Change-Id: I8def66dac9dd5d7ab0e459baa40e27a11b65f0ba

plat/qemu/common/qemu_bl31_setup.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2023, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -55,6 +55,11 @@ void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
 	/* Initialize the console to provide early debug support */
 	qemu_console_init();
 
+/* Platform names have to be lowercase. */
+#ifdef PLAT_qemu_sbsa
+	sip_svc_init();
+#endif
+
 	/*
 	 * Check params passed from BL2
 	 */

plat/qemu/common/qemu_private.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2023, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -18,6 +18,9 @@ unsigned int plat_qemu_calc_core_pos(u_register_t mpidr);
 const mmap_region_t *plat_qemu_get_mmap(void);
 
 void qemu_console_init(void);
+#ifdef PLAT_qemu_sbsa
+void sip_svc_init(void);
+#endif
 
 void plat_qemu_gic_init(void);
 void qemu_pwr_gic_on_finish(void);

plat/qemu/qemu_sbsa/platform.mk

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2019-2021, Linaro Limited and Contributors. All rights reserved.
+# Copyright (c) 2019-2023, Linaro Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -97,6 +97,7 @@ BL31_SOURCES		+=	${QEMU_CPU_LIBS}				\
 				lib/semihosting/${ARCH}/semihosting_call.S	\
 				plat/common/plat_psci_common.c			\
 				${PLAT_QEMU_PATH}/sbsa_pm.c			\
+				${PLAT_QEMU_PATH}/sbsa_sip_svc.c		\
 				${PLAT_QEMU_PATH}/sbsa_topology.c		\
 				${PLAT_QEMU_COMMON_PATH}/aarch64/plat_helpers.S	\
 				${PLAT_QEMU_COMMON_PATH}/qemu_bl31_setup.c	\

plat/qemu/qemu_sbsa/sbsa_sip_svc.c

@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2023, Linaro Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <common/runtime_svc.h>
+#include <libfdt.h>
+#include <smccc_helpers.h>
+
+/* default platform version is 0.0 */
+static int platform_version_major;
+static int platform_version_minor;
+
+#define SMC_FASTCALL       0x80000000
+#define SMC64_FUNCTION     (SMC_FASTCALL   | 0x40000000)
+#define SIP_FUNCTION       (SMC64_FUNCTION | 0x02000000)
+#define SIP_FUNCTION_ID(n) (SIP_FUNCTION   | (n))
+
+/*
+ * We do not use SMCCC_ARCH_SOC_ID here because qemu_sbsa is virtual platform
+ * which uses SoC present in QEMU. And they can change on their own while we
+ * need version of whole 'virtual hardware platform'.
+ */
+#define SIP_SVC_VERSION  SIP_FUNCTION_ID(1)
+
+void read_platform_version(void *dtb)
+{
+	int node;
+
+	node = fdt_path_offset(dtb, "/");
+	if (node >= 0) {
+		platform_version_major = fdt32_ld(fdt_getprop(dtb, node,
+							      "machine-version-major", NULL));
+		platform_version_minor = fdt32_ld(fdt_getprop(dtb, node,
+							      "machine-version-minor", NULL));
+	}
+}
+
+void sip_svc_init(void)
+{
+	/* Read DeviceTree data before MMU is enabled */
+
+	void *dtb = (void *)(uintptr_t)ARM_PRELOADED_DTB_BASE;
+	int err;
+
+	err = fdt_open_into(dtb, dtb, PLAT_QEMU_DT_MAX_SIZE);
+	if (err < 0) {
+		ERROR("Invalid Device Tree at %p: error %d\n", dtb, err);
+		return;
+	}
+
+	err = fdt_check_header(dtb);
+	if (err < 0) {
+		ERROR("Invalid DTB file passed\n");
+		return;
+	}
+
+	read_platform_version(dtb);
+	INFO("Platform version: %d.%d\n", platform_version_major, platform_version_minor);
+}
+
+/*
+ * This function is responsible for handling all SiP calls from the NS world
+ */
+uintptr_t sbsa_sip_smc_handler(uint32_t smc_fid,
+			       u_register_t x1,
+			       u_register_t x2,
+			       u_register_t x3,
+			       u_register_t x4,
+			       void *cookie,
+			       void *handle,
+			       u_register_t flags)
+{
+	uint32_t ns;
+
+	/* Determine which security state this SMC originated from */
+	ns = is_caller_non_secure(flags);
+	if (!ns) {
+		ERROR("%s: wrong world SMC (0x%x)\n", __func__, smc_fid);
+		SMC_RET1(handle, SMC_UNK);
+	}
+
+	switch (smc_fid) {
+	case SIP_SVC_VERSION:
+		INFO("Platform version requested\n");
+		SMC_RET3(handle, NULL, platform_version_major, platform_version_minor);
+
+	default:
+		ERROR("%s: unhandled SMC (0x%x) (function id: %d)\n", __func__, smc_fid,
+		      smc_fid - SIP_FUNCTION);
+		SMC_RET1(handle, SMC_UNK);
+	}
+}
+
+int sbsa_sip_smc_setup(void)
+{
+	return 0;
+}
+
+/* Define a runtime service descriptor for fast SMC calls */
+DECLARE_RT_SVC(
+	sbsa_sip_svc,
+	OEN_SIP_START,
+	OEN_SIP_END,
+	SMC_TYPE_FAST,
+	sbsa_sip_smc_setup,
+	sbsa_sip_smc_handler
+);