ARM: stm32: Factor out save_boot_params

The STM32MP15xx platform currently comes with two incompatible
implementations of save_boot_params() weak function override.
Factor the save_boot_params() implementation into common cpu.c
code and provide accessors to read out both ROM API table address
and DT address from any place in the code instead.

Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Signed-off-by: Marek Vasut <marex@denx.de>

arch/arm/mach-stm32mp/boot_params.c

@@ -8,33 +8,18 @@
 #include <common.h>
 #include <log.h>
 #include <linux/libfdt.h>
+#include <asm/arch/sys_proto.h>
 #include <asm/sections.h>
 #include <asm/system.h>
 
-/*
- * Force data-section, as .bss will not be valid
- * when save_boot_params is invoked.
- */
-static unsigned long nt_fw_dtb __section(".data");
-
-/*
- * Save the FDT address provided by TF-A in r2 at boot time
- * This function is called from start.S
- */
-void save_boot_params(unsigned long r0, unsigned long r1, unsigned long r2,
-		      unsigned long r3)
-{
-	nt_fw_dtb = r2;
-
-	save_boot_params_ret();
-}
-
 /*
  * Use the saved FDT address provided by TF-A at boot time (NT_FW_CONFIG =
  * Non Trusted Firmware configuration file) when the pointer is valid
  */
 void *board_fdt_blob_setup(int *err)
 {
+	unsigned long nt_fw_dtb = get_stm32mp_bl2_dtb();
+
 	log_debug("%s: nt_fw_dtb=%lx\n", __func__, nt_fw_dtb);
 
 	*err = 0;

arch/arm/mach-stm32mp/cpu.c

@@ -378,3 +378,38 @@ int arch_misc_init(void)
 
 	return 0;
 }
+
+/*
+ * Without forcing the ".data" section, this would get saved in ".bss". BSS
+ * will be cleared soon after, so it's not suitable.
+ */
+static uintptr_t rom_api_table __section(".data");
+static uintptr_t nt_fw_dtb __section(".data");
+
+/*
+ * The ROM gives us the API location in r0 when starting. This is only available
+ * during SPL, as there isn't (yet) a mechanism to pass this on to u-boot. Save
+ * the FDT address provided by TF-A in r2 at boot time. This function is called
+ * from start.S
+ */
+void save_boot_params(unsigned long r0, unsigned long r1, unsigned long r2,
+		      unsigned long r3)
+{
+	if (IS_ENABLED(CONFIG_STM32_ECDSA_VERIFY))
+		rom_api_table = r0;
+
+	if (IS_ENABLED(CONFIG_TFABOOT))
+		nt_fw_dtb = r2;
+
+	save_boot_params_ret();
+}
+
+uintptr_t get_stm32mp_rom_api_table(void)
+{
+	return rom_api_table;
+}
+
+uintptr_t get_stm32mp_bl2_dtb(void)
+{
+	return nt_fw_dtb;
+}

arch/arm/mach-stm32mp/ecdsa_romapi.c

@@ -24,26 +24,10 @@ struct ecdsa_rom_api {
 					   uint32_t ecc_algo);
 };
 
-/*
- * Without forcing the ".data" section, this would get saved in ".bss". BSS
- * will be cleared soon after, so it's not suitable.
- */
-static uintptr_t rom_api_loc __section(".data");
-
-/*
- * The ROM gives us the API location in r0 when starting. This is only available
- * during SPL, as there isn't (yet) a mechanism to pass this on to u-boot.
- */
-void save_boot_params(unsigned long r0, unsigned long r1, unsigned long r2,
-		      unsigned long r3)
-{
-	rom_api_loc = r0;
-	save_boot_params_ret();
-}
-
 static void stm32mp_rom_get_ecdsa_functions(struct ecdsa_rom_api *rom)
 {
-	uintptr_t verify_ptr = rom_api_loc + ROM_API_OFFSET_ECDSA_VERIFY;
+	uintptr_t verify_ptr = get_stm32mp_rom_api_table() +
+			       ROM_API_OFFSET_ECDSA_VERIFY;
 
 	rom->ecdsa_verify_signature = *(void **)verify_ptr;
 }

arch/arm/mach-stm32mp/include/mach/sys_proto.h

@@ -77,3 +77,6 @@ void stm32mp_misc_init(void);
 
 /* helper function: read data from OTP */
 u32 get_otp(int index, int shift, int mask);
+
+uintptr_t get_stm32mp_rom_api_table(void);
+uintptr_t get_stm32mp_bl2_dtb(void);