[PATCH v2 4/5] MIPS: cavium-octeon: Execute the smp handle after jumping to kernel linked address

From: Jinyang He
Date: Mon Apr 12 2021 - 08:28:43 EST


Once relocation is required, some fixed addresses in `smp handle` will be
affected. For example, octeon_processor_relocated_kernel_entry may cause
the problem of loading wrong memory at old address.

This patch makes smp cpu do two more things, one is to set ST0_KX, another
is to jump to the kernel linked address. They will not destroy the
cavium-octeon platform. This patch adds two platform-related macros,
SMP_IN_KERNEL_ENTRY and smp_in_kernel_handle, which can be used on other
platforms to deal with the SMP CPU in the kernel_entry, if the smp CPU
entered the kernel entry.

Signed-off-by: Jinyang He <hejinyang@xxxxxxxxxxx>
---
arch/mips/include/asm/mach-cavium-octeon/kernel-entry-init.h | 7 +++++++
arch/mips/kernel/head.S | 4 ++++
2 files changed, 11 insertions(+)

diff --git a/arch/mips/include/asm/mach-cavium-octeon/kernel-entry-init.h b/arch/mips/include/asm/mach-cavium-octeon/kernel-entry-init.h
index e66767d..21b9854 100644
--- a/arch/mips/include/asm/mach-cavium-octeon/kernel-entry-init.h
+++ b/arch/mips/include/asm/mach-cavium-octeon/kernel-entry-init.h
@@ -86,6 +86,13 @@
dli v0, 0x27
dmtc0 v0, CP0_DCACHE_ERR_REG
1:
+ .set pop
+.endm
+
+#define SMP_IN_KERNEL_ENTRY
+.macro smp_in_kernel_entry_handle
+ .set push
+ .set arch=octeon
# Get my core id
rdhwr v0, $0
# Jump the master to kernel_entry
diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
index 0186285..6cfe23e 100644
--- a/arch/mips/kernel/head.S
+++ b/arch/mips/kernel/head.S
@@ -104,6 +104,10 @@ NESTED(kernel_entry, 16, sp) # kernel entry point
jr t0
2:

+#ifdef SMP_IN_KERNEL_ENTRY
+ smp_in_kernel_entry_handle
+#endif
+
PTR_LA t0, __bss_start # clear .bss
LONG_S zero, (t0)
PTR_LA t1, __bss_stop - LONGSIZE
--
2.1.0