[U-Boot] [PATCH 11/13] ARM: UniPhier: optimize kicking secondary CPUs code
Masahiro Yamada
yamada.masahiro at socionext.com
Sun Mar 22 16:07:31 CET 2015
Currently, the secondary CPU(s) are kicked three times:
Boot ROM ---(kick)--> SPL ---(kick)--> U-boot ---(kick)--> Linux.
It makes the boot sequence very complicated.
This commit merges the first and the second kicks, so the secondary
CPU(s) can directly jump from SPL to Linux.
arch/arm/mach-uniphier/smp.S is no longer necessary.
Linux boot test passed.
Signed-off-by: Masahiro Yamada <yamada.masahiro at socionext.com>
---
arch/arm/mach-uniphier/Makefile | 1 -
arch/arm/mach-uniphier/cache_uniphier.c | 13 ++------
arch/arm/mach-uniphier/lowlevel_init.S | 42 +++++++++++++++++++++----
arch/arm/mach-uniphier/smp.S | 54 ---------------------------------
4 files changed, 38 insertions(+), 72 deletions(-)
delete mode 100644 arch/arm/mach-uniphier/smp.S
diff --git a/arch/arm/mach-uniphier/Makefile b/arch/arm/mach-uniphier/Makefile
index f191aa3..24591d6 100644
--- a/arch/arm/mach-uniphier/Makefile
+++ b/arch/arm/mach-uniphier/Makefile
@@ -22,7 +22,6 @@ obj-$(CONFIG_BOARD_EARLY_INIT_R) += board_early_init_r.o
obj-$(CONFIG_BOARD_LATE_INIT) += board_late_init.o
obj-y += reset.o
obj-y += cache_uniphier.o
-obj-$(CONFIG_UNIPHIER_SMP) += smp.o
obj-$(CONFIG_CMD_PINMON) += cmd_pinmon.o
obj-$(CONFIG_CMD_DDRPHY_DUMP) += cmd_ddrphy.o
diff --git a/arch/arm/mach-uniphier/cache_uniphier.c b/arch/arm/mach-uniphier/cache_uniphier.c
index 52f3c7c..4bf01bc 100644
--- a/arch/arm/mach-uniphier/cache_uniphier.c
+++ b/arch/arm/mach-uniphier/cache_uniphier.c
@@ -1,6 +1,7 @@
/*
* Copyright (C) 2012-2014 Panasonic Corporation
- * Author: Masahiro Yamada <yamada.m at jp.panasonic.com>
+ * Copyright (C) 2015 Socionext Inc.
+ * Author: Masahiro Yamada <yamada.masahiro at socionext.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
@@ -119,20 +120,10 @@ void v7_outer_cache_disable(void)
writel(tmp, SSCC);
}
-void wakeup_secondary(void);
-
void enable_caches(void)
{
uint32_t reg;
-#ifdef CONFIG_UNIPHIER_SMP
- /*
- * The secondary CPU must move to DDR,
- * before L2 disable.
- * On SPL, the Page Table is located on the L2.
- */
- wakeup_secondary();
-#endif
/*
* UniPhier SoCs must use L2 cache for init stack pointer.
* We disable L2 and L1 in this order.
diff --git a/arch/arm/mach-uniphier/lowlevel_init.S b/arch/arm/mach-uniphier/lowlevel_init.S
index 4a23ea4..825b160 100644
--- a/arch/arm/mach-uniphier/lowlevel_init.S
+++ b/arch/arm/mach-uniphier/lowlevel_init.S
@@ -48,6 +48,25 @@ ENTRY(lowlevel_init)
bl enable_mmu
#ifdef CONFIG_UNIPHIER_SMP
+secondary_startup:
+ /*
+ * Entry point for secondary CPUs
+ *
+ * The Boot ROM has already enabled MMU for the secondary CPUs as well
+ * as for the primary one. The MMU table embedded in the Boot ROM
+ * prohibits the DRAM access, so it is impossible to bring the
+ * secondary CPUs into DRAM directly. They must jump here into SPL,
+ * which is run on L2 cache.
+ *
+ * Boot Sequence
+ * [primary CPU] [secondary CPUs]
+ * start from Boot ROM start from Boot ROM
+ * jump to SPL sleep in Boot ROM
+ * kick secondaries ---(sev)---> jump to SPL
+ * jump to U-Boot main sleep in SPL
+ * jump to Linux
+ * kick secondaries ---(sev)---> jump to Linux
+ */
/*
* ACTLR (Auxiliary Control Register) for Cortex-A9
* bit[9] Parity on
@@ -68,17 +87,28 @@ ENTRY(lowlevel_init)
and r0, r0, #0x3
cmp r0, #0x0
beq primary_cpu
- ldr r1, =ROM_BOOT_ROMRSV2
+ /* only for secondary CPUs */
+ ldr r1, =ROM_BOOT_ROMRSV2 @ The last data access to L2 cache
+ mrc p15, 0, r0, c1, c0, 0 @ SCTLR (System Control Register)
+ orr r0, r0, #CR_I @ Enable ICache
+ bic r0, r0, #(CR_C | CR_M) @ MMU and Dcache must be disabled
+ mcr p15, 0, r0, c1, c0, 0 @ before jumping to Linux
mov r0, #0
str r0, [r1]
-0: wfe
- ldr r0, [r1]
+ b 1f
+ /*
+ * L2 cache is shared among all the CPUs and it might be disabled by
+ * the primary one. Before that, the following 5 lines must be cached
+ * on the Icaches of the secondary CPUs.
+ */
+0: wfe @ kicked by Linux
+1: ldr r0, [r1]
cmp r0, #0
- beq 0b
- bx r0 @ r0: entry point of U-Boot main for the secondary CPU
+ bxne r0 @ r0: Linux entry for secondary CPUs
+ b 0b
primary_cpu:
ldr r1, =ROM_BOOT_ROMRSV2
- ldr r0, =_start @ entry for the secondary CPU
+ ldr r0, =secondary_startup
str r0, [r1]
ldr r0, [r1] @ make sure str is complete before sev
sev @ kick the secondary CPU
diff --git a/arch/arm/mach-uniphier/smp.S b/arch/arm/mach-uniphier/smp.S
deleted file mode 100644
index 18e3a9d..0000000
--- a/arch/arm/mach-uniphier/smp.S
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Copyright (C) 2013 Panasonic Corporation
- * Author: Masahiro Yamada <yamada.m at jp.panasonic.com>
- *
- * SPDX-License-Identifier: GPL-2.0+
- */
-
-#include <config.h>
-#include <linux/linkage.h>
-#include <asm/system.h>
-#include <mach/led.h>
-#include <mach/sbc-regs.h>
-
-/* Entry point of U-Boot main program for the secondary CPU */
-LENTRY(secondary_entry)
- mrc p15, 0, r0, c1, c0, 0 @ SCTLR (System Contrl Register)
- bic r0, r0, #(CR_C | CR_M) @ MMU and Dcache disable
- mcr p15, 0, r0, c1, c0, 0
- mcr p15, 0, r0, c8, c7, 0 @ invalidate TLBs
- mcr p15, 0, r0, c7, c5, 0 @ invalidate icache
- dsb
- led_write(C,0,,)
- ldr r1, =ROM_BOOT_ROMRSV2
- mov r0, #0
- str r0, [r1]
-0: wfe
- ldr r4, [r1] @ r4: entry point for secondary CPUs
- cmp r4, #0
- beq 0b
- led_write(C, P, U, 1)
- bx r4 @ secondary CPUs jump to linux
-ENDPROC(secondary_entry)
-
-ENTRY(wakeup_secondary)
- ldr r1, =ROM_BOOT_ROMRSV2
-0: ldr r0, [r1]
- cmp r0, #0
- bne 0b
-
- /* set entry address and send event to the secondary CPU */
- ldr r0, =secondary_entry
- str r0, [r1]
- ldr r0, [r1] @ make sure store is complete
- mov r0, #0x100
-0: subs r0, r0, #1 @ I don't know the reason, but without this wait
- bne 0b @ fails to wake up the secondary CPU
- sev
-
- /* wait until the secondary CPU reach to secondary_entry */
-0: ldr r0, [r1]
- cmp r0, #0
- bne 0b
- bx lr
-ENDPROC(wakeup_secondary)
--
1.9.1
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