From 2dc0bc1138eecc88b2c376ccb0b0acb215c25a5c Mon Sep 17 00:00:00 2001
From: Michael Ellerman <mpe@ellerman.id.au>
Date: Tue, 1 Aug 2023 20:26:50 +1000
Subject: [PATCH] powerpc/64e: Fix secondary thread bringup for ELFv2 kernels
When booting on e6500 with an ELF v2 ABI kernel, the secondary threads do
not start correctly:
[ 0.051118] smp: Bringing up secondary CPUs ...
[ 5.072700] Processor 1 is stuck.
This occurs because the startup code is written to use function
descriptors when loading the entry point for the secondary threads. When
building with ELF v2 ABI there are no function descriptors, and the code
loads junk values for the entry point address.
Fix it by using ppc_function_entry() in C, and DOTSYM() in asm, both of
which work correctly for ELF v2 ABI as well as ELF v1 ABI kernels.
Fixes: 8c5fa3b5c4df ("powerpc/64: Make ELFv2 the default for big-endian builds")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230801102650.48705-1-mpe@ellerman.id.au
---
arch/powerpc/kernel/head_64.S | 3 +--
arch/powerpc/platforms/85xx/smp.c | 2 +-
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index f132d8704263c..6440b1bb332ac 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -375,8 +375,7 @@ _GLOBAL(generic_secondary_smp_init)
beq 20f
/* start the specified thread */
- LOAD_REG_ADDR(r5, fsl_secondary_thread_init)
- ld r4, 0(r5)
+ LOAD_REG_ADDR(r5, DOTSYM(fsl_secondary_thread_init))
bl book3e_start_thread
/* stop the current thread */
diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c
index 9c43cf32f4c9f..40aa582068883 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -180,7 +180,7 @@ static void wake_hw_thread(void *info)
unsigned long inia;
int cpu = *(const int *)info;
- inia = *(unsigned long *)fsl_secondary_thread_init;
+ inia = ppc_function_entry(fsl_secondary_thread_init);
book3e_start_thread(cpu_thread_in_core(cpu), inia);
}
#endif
--
GitLab