[U-Boot] [PATCH v2 1/4] riscv: hart_lottery and available harts features can be selectable

[Andes <uboot@andestech.com>]

From: Rick Chen <rick@andestech.com>

In smp flow these two features only can be enabled when U-Boot
booting from ram. It shall be disabled when U-Boot booting from
flash.

Add CONFIG_XIP to NOT select this two features. It's default value
will say NO for booting from ram.

AE350 will encounter the the write failure problem since
hart_lottery and available_harts_lock was not in ram address but
in flash address when booing from flash.

This patch can help to fix the write failure problem when AE350
booting from flash by disabling this two features.

Signed-off-by: Rick Chen <rick@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
---
 arch/riscv/Kconfig                   | 10 ++++++++++
 arch/riscv/cpu/cpu.c                 |  3 ++-
 arch/riscv/cpu/start.S               |  7 ++++++-
 arch/riscv/include/asm/global_data.h |  2 ++
 arch/riscv/lib/asm-offsets.c         |  2 ++
 arch/riscv/lib/smp.c                 |  2 ++
 6 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index ae8ff7b..fb9a8c6 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -162,6 +162,16 @@ config SBI_IPI
 	default y if RISCV_SMODE
 	depends on SMP
 
+config XIP
+	bool "XIP mode"
+	default n
+	help
+	  XIP (eXecute In Place) is a method for executing code directly
+	  from a serial NOR flash memory without copying the code to ram.
+	  This must NOT support hart lottery and available harts features.
+	  These two feature only can be enabled when U-Boot booting from
+	  ram, but shall be disabled when booting from flash.
+
 config STACK_SIZE_SHIFT
 	int
 	default 13
diff --git a/arch/riscv/cpu/cpu.c b/arch/riscv/cpu/cpu.c
index c32de8a..768c44c 100644
--- a/arch/riscv/cpu/cpu.c
+++ b/arch/riscv/cpu/cpu.c
@@ -16,13 +16,14 @@
  * before the bss section is available.
  */
 phys_addr_t prior_stage_fdt_address __attribute__((section(".data")));
+#ifndef CONFIG_XIP
 u32 hart_lottery __attribute__((section(".data"))) = 0;
-
 /*
  * The main hart running U-Boot has acquired available_harts_lock until it has
  * finished initialization of global data.
  */
 u32 available_harts_lock = 1;
+#endif
 
 static inline bool supports_extension(char ext)
 {
diff --git a/arch/riscv/cpu/start.S b/arch/riscv/cpu/start.S
index a4433fb..41d9a32 100644
--- a/arch/riscv/cpu/start.S
+++ b/arch/riscv/cpu/start.S
@@ -98,6 +98,7 @@ call_board_init_f_0:
 	mv	sp, a0
 #endif
 
+#ifndef CONFIG_XIP
 	/*
 	 * Pick hart to initialize global data and run U-Boot. The other harts
 	 * wait for initialization to complete.
@@ -106,6 +107,9 @@ call_board_init_f_0:
 	li	s2, 1
 	amoswap.w s2, t1, 0(t0)
 	bnez	s2, wait_for_gd_init
+#else
+	bnez	tp, secondary_hart_loop
+#endif
 
 	la	t0, prior_stage_fdt_address
 	SREG	s1, 0(t0)
@@ -115,6 +119,7 @@ call_board_init_f_0:
 	/* save the boot hart id to global_data */
 	SREG	tp, GD_BOOT_HART(gp)
 
+#ifndef CONFIG_XIP
 	la	t0, available_harts_lock
 	fence	rw, w
 	amoswap.w zero, zero, 0(t0)
@@ -141,7 +146,7 @@ wait_for_gd_init:
 	 * secondary_hart_loop.
 	 */
 	bnez	s2, secondary_hart_loop
-
+#endif
 	/* Enable cache */
 	jal	icache_enable
 	jal	dcache_enable
diff --git a/arch/riscv/include/asm/global_data.h b/arch/riscv/include/asm/global_data.h
index dffcd45..b74bd7e 100644
--- a/arch/riscv/include/asm/global_data.h
+++ b/arch/riscv/include/asm/global_data.h
@@ -27,7 +27,9 @@ struct arch_global_data {
 #ifdef CONFIG_SMP
 	struct ipi_data ipi[CONFIG_NR_CPUS];
 #endif
+#ifndef CONFIG_XIP
 	ulong available_harts;
+#endif
 };
 
 #include <asm-generic/global_data.h>
diff --git a/arch/riscv/lib/asm-offsets.c b/arch/riscv/lib/asm-offsets.c
index f998402..4fa4fd3 100644
--- a/arch/riscv/lib/asm-offsets.c
+++ b/arch/riscv/lib/asm-offsets.c
@@ -14,7 +14,9 @@
 int main(void)
 {
 	DEFINE(GD_BOOT_HART, offsetof(gd_t, arch.boot_hart));
+#ifndef CONFIG_XIP
 	DEFINE(GD_AVAILABLE_HARTS, offsetof(gd_t, arch.available_harts));
+#endif
 
 	return 0;
 }
diff --git a/arch/riscv/lib/smp.c b/arch/riscv/lib/smp.c
index caa292c..cc66f15 100644
--- a/arch/riscv/lib/smp.c
+++ b/arch/riscv/lib/smp.c
@@ -63,9 +63,11 @@ static int send_ipi_many(struct ipi_data *ipi)
 			continue;
 		}
 
+#ifndef CONFIG_XIP
 		/* skip if hart is not available */
 		if (!(gd->arch.available_harts & (1 << reg)))
 			continue;
+#endif
 
 		gd->arch.ipi[reg].addr = ipi->addr;
 		gd->arch.ipi[reg].arg0 = ipi->arg0;
-- 
2.7.4