The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 20d2292754e72e445abe62b7ac453eb945fc626c Mon Sep 17 00:00:00 2001
From: Greentime Hu greentime.hu@sifive.com Date: Wed, 15 Jan 2020 14:54:36 +0800 Subject: [PATCH] riscv: make sure the cores stay looping in .Lsecondary_park
The code in secondary_park is currently placed in the .init section. The kernel reclaims and clears this code when it finishes booting. That causes the cores parked in it to go to somewhere unpredictable, so we move this function out of init to make sure the cores stay looping there.
The instruction bgeu a0, t0, .Lsecondary_park may have "a relocation truncated to fit" issue during linking time. It is because that sections are too far to jump. Let's use tail to jump to the .Lsecondary_park.
Signed-off-by: Greentime Hu greentime.hu@sifive.com Reviewed-by: Anup Patel anup.patel@sifive.com Cc: Andreas Schwab schwab@suse.de Cc: stable@vger.kernel.org Fixes: 76d2a0493a17d ("RISC-V: Init and Halt Code") Signed-off-by: Paul Walmsley paul.walmsley@sifive.com
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 2227db63f895..a4242be66966 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -80,7 +80,9 @@ _start_kernel:
#ifdef CONFIG_SMP li t0, CONFIG_NR_CPUS - bgeu a0, t0, .Lsecondary_park + blt a0, t0, .Lgood_cores + tail .Lsecondary_park +.Lgood_cores: #endif
/* Pick one hart to run the main boot sequence */ @@ -209,11 +211,6 @@ relocate: tail smp_callin #endif
-.align 2 -.Lsecondary_park: - /* We lack SMP support or have too many harts, so park this hart */ - wfi - j .Lsecondary_park END(_start)
#ifdef CONFIG_RISCV_M_MODE @@ -295,6 +292,13 @@ ENTRY(reset_regs) END(reset_regs) #endif /* CONFIG_RISCV_M_MODE */
+.section ".text", "ax",@progbits +.align 2 +.Lsecondary_park: + /* We lack SMP support or have too many harts, so park this hart */ + wfi + j .Lsecondary_park + __PAGE_ALIGNED_BSS /* Empty zero page */ .balign PAGE_SIZE