[PATCH v2 01/11] ARM: at91: sama5: switch to nonnaked entry functions

[Ahmad Fatoum]

Functions were kept naked because they modify the stack pointer.
We can hoist that up and change the board-provided entry point
to be non-naked to be more robust in face of unexpected compiler
optimizations.

Acked-by: Sam Ravnborg <sam at ravnborg.org>
Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 .../boards/microchip-ksz9477-evb/lowlevel.c   |  6 ++----
 .../arm/boards/sama5d27-giantboard/lowlevel.c |  4 ++--
 arch/arm/boards/sama5d27-som1/lowlevel.c      |  4 ++--
 arch/arm/boards/sama5d3_xplained/lowlevel.c   |  6 ++----
 arch/arm/mach-at91/include/mach/barebox-arm.h | 19 +++++++++++++++----
 5 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/arch/arm/boards/microchip-ksz9477-evb/lowlevel.c b/arch/arm/boards/microchip-ksz9477-evb/lowlevel.c
index 93ae4819750c..6290766caa78 100644
--- a/arch/arm/boards/microchip-ksz9477-evb/lowlevel.c
+++ b/arch/arm/boards/microchip-ksz9477-evb/lowlevel.c
@@ -32,7 +32,7 @@ static void dbgu_init(void)
 	putc_ll('>');
 }
 
-SAMA5_ENTRY_FUNCTION(start_sama5d3_xplained_ung8071_xload_mmc, r4)
+SAMA5D3_ENTRY_FUNCTION(start_sama5d3_xplained_ung8071_xload_mmc, r4)
 {
 	sama5d3_lowlevel_init();
 
@@ -49,12 +49,10 @@ SAMA5_ENTRY_FUNCTION(start_sama5d3_xplained_ung8071_xload_mmc, r4)
 
 extern char __dtb_z_at91_microchip_ksz9477_evb_start[];
 
-SAMA5_ENTRY_FUNCTION(start_sama5d3_xplained_ung8071, r4)
+SAMA5D3_ENTRY_FUNCTION(start_sama5d3_xplained_ung8071, r4)
 {
 	void *fdt;
 
-	arm_setup_stack(SAMA5D3_SRAM_BASE + SAMA5D3_SRAM_SIZE);
-
 	if (IS_ENABLED(CONFIG_DEBUG_LL))
 		dbgu_init();
 
diff --git a/arch/arm/boards/sama5d27-giantboard/lowlevel.c b/arch/arm/boards/sama5d27-giantboard/lowlevel.c
index ee8297fa4562..fac39dd066a2 100644
--- a/arch/arm/boards/sama5d27-giantboard/lowlevel.c
+++ b/arch/arm/boards/sama5d27-giantboard/lowlevel.c
@@ -15,7 +15,7 @@
 /* PCK = 492MHz, MCK = 164MHz */
 #define MASTER_CLOCK	164000000
 
-SAMA5_ENTRY_FUNCTION(start_sama5d27_giantboard_xload_mmc, r4)
+SAMA5D2_ENTRY_FUNCTION(start_sama5d27_giantboard_xload_mmc, r4)
 {
 	void __iomem *dbgu_base;
 
@@ -36,7 +36,7 @@ SAMA5_ENTRY_FUNCTION(start_sama5d27_giantboard_xload_mmc, r4)
 
 extern char __dtb_z_at91_sama5d27_giantboard_start[];
 
-SAMA5_ENTRY_FUNCTION(start_sama5d27_giantboard, r4)
+SAMA5D2_ENTRY_FUNCTION(start_sama5d27_giantboard, r4)
 {
 	void *fdt;
 
diff --git a/arch/arm/boards/sama5d27-som1/lowlevel.c b/arch/arm/boards/sama5d27-som1/lowlevel.c
index b0937119184b..24c08d9722b3 100644
--- a/arch/arm/boards/sama5d27-som1/lowlevel.c
+++ b/arch/arm/boards/sama5d27-som1/lowlevel.c
@@ -39,7 +39,7 @@ static void ek_turn_led(unsigned color)
 	}
 }
 
-SAMA5_ENTRY_FUNCTION(start_sama5d27_som1_ek_xload_mmc, r4)
+SAMA5D2_ENTRY_FUNCTION(start_sama5d27_som1_ek_xload_mmc, r4)
 {
 	void __iomem *dbgu_base;
 	sama5d2_lowlevel_init();
@@ -60,7 +60,7 @@ SAMA5_ENTRY_FUNCTION(start_sama5d27_som1_ek_xload_mmc, r4)
 
 extern char __dtb_z_at91_sama5d27_som1_ek_start[];
 
-SAMA5_ENTRY_FUNCTION(start_sama5d27_som1_ek, r4)
+SAMA5D2_ENTRY_FUNCTION(start_sama5d27_som1_ek, r4)
 {
 	void *fdt;
 
diff --git a/arch/arm/boards/sama5d3_xplained/lowlevel.c b/arch/arm/boards/sama5d3_xplained/lowlevel.c
index df561af36d5e..be6b2960d40d 100644
--- a/arch/arm/boards/sama5d3_xplained/lowlevel.c
+++ b/arch/arm/boards/sama5d3_xplained/lowlevel.c
@@ -33,7 +33,7 @@ static void dbgu_init(void)
 	pbl_set_putc(at91_dbgu_putc, IOMEM(AT91_BASE_DBGU1));
 }
 
-SAMA5_ENTRY_FUNCTION(start_sama5d3_xplained_xload_mmc, r4)
+SAMA5D3_ENTRY_FUNCTION(start_sama5d3_xplained_xload_mmc, r4)
 {
 	sama5d3_lowlevel_init();
 
@@ -50,12 +50,10 @@ SAMA5_ENTRY_FUNCTION(start_sama5d3_xplained_xload_mmc, r4)
 
 extern char __dtb_z_at91_sama5d3_xplained_start[];
 
-SAMA5_ENTRY_FUNCTION(start_sama5d3_xplained, r4)
+SAMA5D3_ENTRY_FUNCTION(start_sama5d3_xplained, r4)
 {
 	void *fdt;
 
-	arm_setup_stack(SAMA5D3_SRAM_BASE + SAMA5D3_SRAM_SIZE);
-
 	if (IS_ENABLED(CONFIG_DEBUG_LL))
 		dbgu_init();
 
diff --git a/arch/arm/mach-at91/include/mach/barebox-arm.h b/arch/arm/mach-at91/include/mach/barebox-arm.h
index 4a65c6f8fa55..f6bdd5ab2375 100644
--- a/arch/arm/mach-at91/include/mach/barebox-arm.h
+++ b/arch/arm/mach-at91/include/mach/barebox-arm.h
@@ -3,19 +3,30 @@
 #define AT91_BAREBOX_ARM_H_
 
 #include <asm/barebox-arm.h>
+#include <asm/common.h>
+#include <mach/sama5d3.h>
 
-#define SAMA5_ENTRY_FUNCTION(name, r4)						\
+#define SAMA5_ENTRY_FUNCTION(name, stack_top, r4)				\
 	void name (u32 r0, u32 r1, u32 r2, u32 r3);				\
 										\
 	static void __##name(u32);						\
 										\
-	void NAKED __section(.text_head_entry_##name)	name			\
+	void __naked __section(.text_head_entry_##name)	name			\
 				(u32 r0, u32 r1, u32 r2, u32 r3)		\
 		{								\
 			register u32 r4 asm("r4");				\
 			__barebox_arm_head();					\
+			if (stack_top)						\
+				arm_setup_stack(stack_top);			\
 			__##name(r4);						\
 		}								\
-		static void NAKED noinline __##name				\
-			(u32 r4)
+		static void noinline __##name(u32 r4)
+
+/* BootROM already initialized usable stack top */
+#define SAMA5D2_ENTRY_FUNCTION(name, r4)					\
+	SAMA5_ENTRY_FUNCTION(name, 0, r4)
+
+#define SAMA5D3_ENTRY_FUNCTION(name, r4)					\
+	SAMA5_ENTRY_FUNCTION(name, SAMA5D3_SRAM_BASE + SAMA5D3_SRAM_SIZE, r4)
+
 #endif
-- 
2.30.2