feat(arm): add stubs for PCI SVC functions

After putting the management of SMC_PCI_SUPPORT in Makefile, there is a
link error when compiling fvp platform with SMC_PCI_SUPPORT=1 in build
command line.
The issue was hidden by the fact that with the previous behavior, the
SMC_PCI_SUPPORT was only enabled in makefiles, and not in C files. And
then pci_smc_handler() was compiled but never used, and then dropped
during the link.
When putting SMC_PCI_SUPPORT flag management in Makefile with eval call
add_defines, this is no more the case. The functions called in the file
services/std_svc/pci_svc.c should then exist.
Create a new file plat/arm/common/arm_pci_svc.c that just stub the
required interfaces.

Change-Id: I68e7d32c80a17bb32486163f2dee59394c9877a1
Signed-off-by: Yann Gautier <yann.gautier@st.com>

2 files changed, 52 insertions, 0 deletions

diff --git a/plat/arm/common/arm_common.mk b/plat/arm/common/arm_common.mk
index c5ea6b0bc..ba171015a 100644
--- a/plat/arm/common/arm_common.mk
+++ b/plat/arm/common/arm_common.mk
@@ -359,10 +359,18 @@ BL31_SOURCES		+=	plat/arm/common/aarch64/execution_state_switch.c\
 				plat/arm/common/arm_sip_svc_validation.c	\
 				plat/arm/common/plat_arm_sip_svc.c		\
 				${ARM_SVC_HANDLER_SRCS}
+
+ifeq ($(SMC_PCI_SUPPORT), 1)
+BL31_SOURCES		+=	plat/arm/common/arm_pci_svc.c
+endif
 else
 BL32_SOURCES		+=	plat/arm/common/arm_sip_svc.c			\
 				plat/arm/common/plat_arm_sip_svc.c		\
 				${ARM_SVC_HANDLER_SRCS}
+
+ifeq ($(SMC_PCI_SUPPORT), 1)
+BL32_SOURCES		+=	plat/arm/common/arm_pci_svc.c
+endif
 endif
 endif
 
diff --git a/plat/arm/common/arm_pci_svc.c b/plat/arm/common/arm_pci_svc.c
new file mode 100644
index 000000000..879910b28
--- /dev/null
+++ b/plat/arm/common/arm_pci_svc.c
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2026, Arm Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdint.h>
+
+#include <services/pci_svc.h>
+
+uint32_t pci_read_config(uint32_t addr, uint32_t off, uint32_t sz, uint32_t *val)
+{
+	uint32_t ret = SMC_PCI_CALL_SUCCESS;
+
+	(void)addr;
+	(void)off;
+	(void)sz;
+	(void)val;
+
+	return ret;
+}
+
+uint32_t pci_write_config(uint32_t addr, uint32_t off, uint32_t sz, uint32_t val)
+{
+	uint32_t ret = SMC_PCI_CALL_SUCCESS;
+
+	(void)addr;
+	(void)off;
+	(void)sz;
+	(void)val;
+
+	return ret;
+}
+
+uint32_t pci_get_bus_for_seg(uint32_t seg, uint32_t *bus_range, uint32_t *nseg)
+{
+	uint32_t ret = SMC_PCI_CALL_SUCCESS;
+
+	(void)seg;
+	(void)bus_range;
+	(void)nseg;
+
+	return ret;
+}