sergiotarxz/nuttx
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smp: add busy wait flag

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test:
We can use qemu for testing.
compiling
make distclean -j20; ./tools/configure.sh -l qemu-armv8a:nsh_smp ;make -j20
running
qemu-system-aarch64 -cpu cortex-a53 -smp 4 -nographic -machine virt,virtualization=on,gic-version=3 -net none -chardev stdio,id=con,mux=on -serial chardev:con -mon chardev=con,mode=readline -kernel ./nuttx
Signed-off-by: hujun5 <hujun5@xiaomi.com>
This commit is contained in:
hujun5 2024-02-20 11:03:10 +08:00 committed by Xiang Xiao
parent 1bf4198556
commit 600368fbe2
2 changed files with 30 additions and 0 deletions
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11
arch/arm/src/armv7-a/Kconfig
View File

@ -47,6 +47,17 @@ config ARMV7A_HAVE_L2CC
Selected by the configuration tool if the architecture supports any
kind of L2 cache.
config ARMV7A_SMP_BUSY_WAIT
bool "Busy wait when SMP boot"
default n
depends on SMP
---help---
Enables busy wait when SMP boot
config ARMV7A_SMP_BUSY_WAIT_FLAG_ADDR
hex "Busy wait flag address"
depends on ARMV7A_SMP_BUSY_WAIT
config ARMV7A_HAVE_L2CC_PL310
bool
default n

19
arch/arm/src/armv7-a/arm_head.S
View File

@ -183,7 +183,17 @@ __start:
and r0, r0, #0x3
cmp r0, #0
beq __cpu0_start
#ifdef CONFIG_ARMV7A_SMP_BUSY_WAIT
ldr r2, =CONFIG_ARMV7A_SMP_BUSY_WAIT_FLAG_ADDR
1:
ldr r1, [r2, #0]
cmp r1, #0
beq 1b
#else
wfe
#endif
cmp r0, #1
beq __cpu1_start
# if CONFIG_SMP_NCPUS > 2
@ -674,6 +684,15 @@ __cpu0_start:
bl arm_boot
/* finish busy wait */
#ifdef CONFIG_ARMV7A_SMP_BUSY_WAIT
ldr r0, =CONFIG_ARMV7A_SMP_BUSY_WAIT_FLAG_ADDR
mov r1, #1
str r1, [r0]
dsb sy
#endif
/* Finally branch to the OS entry point */
mov lr, #0 /* LR = return address (none) */