Unverified Commit 3c469798 authored by Guo Ren's avatar Guo Ren Committed by Palmer Dabbelt
Browse files

riscv: Enable LOCKDEP_SUPPORT & fixup TRACE_IRQFLAGS_SUPPORT 



Lockdep is needed by proving the spinlocks and rwlocks. To suupport
it, we need fixup TRACE_IRQFLAGS_SUPPORT in kernel/entry.S. This
patch follow Documentation/irqflags-tracing.txt.

Signed-off-by: default avatarGuo Ren <guoren@linux.alibaba.com>
Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent c1595992

arch/riscv/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -179,6 +179,9 @@ config PGTABLE_LEVELS 
	default 3 if 64BIT

	default 2



config LOCKDEP_SUPPORT

	def_bool y



source "arch/riscv/Kconfig.socs"



menu "Platform type"

arch/riscv/kernel/entry.S

+33 −1
Original line number Diff line number Diff line
@@ -97,19 +97,26 @@ _save_context: 
	la gp, __global_pointer$

.option pop



	la ra, ret_from_exception

#ifdef CONFIG_TRACE_IRQFLAGS

	call trace_hardirqs_off

#endif

	/*

	 * MSB of cause differentiates between

	 * interrupts and exceptions

	 */

	bge s4, zero, 1f



	la ra, ret_from_exception



	/* Handle interrupts */

	move a0, sp /* pt_regs */

	la a1, handle_arch_irq

	REG_L a1, (a1)

	jr a1

1:

#ifdef CONFIG_TRACE_IRQFLAGS

	call trace_hardirqs_on

#endif

	/*

	 * Exceptions run with interrupts enabled or disabled depending on the

	 * state of SR_PIE in m/sstatus.
@@ -119,6 +126,7 @@ _save_context: 
	csrs CSR_STATUS, SR_IE



1:

	la ra, ret_from_exception

	/* Handle syscalls */

	li t0, EXC_SYSCALL

	beq s4, t0, handle_syscall
@@ -137,6 +145,17 @@ _save_context: 
	tail do_trap_unknown



handle_syscall:

#ifdef CONFIG_TRACE_IRQFLAGS

	/* Recover a0 - a7 for system calls */

	REG_L a0, PT_A0(sp)

	REG_L a1, PT_A1(sp)

	REG_L a2, PT_A2(sp)

	REG_L a3, PT_A3(sp)

	REG_L a4, PT_A4(sp)

	REG_L a5, PT_A5(sp)

	REG_L a6, PT_A6(sp)

	REG_L a7, PT_A7(sp)

#endif

	 /* save the initial A0 value (needed in signal handlers) */

	REG_S a0, PT_ORIG_A0(sp)

	/*
@@ -190,6 +209,9 @@ ret_from_syscall_rejected: 
ret_from_exception:

	REG_L s0, PT_STATUS(sp)

	csrc CSR_STATUS, SR_IE

#ifdef CONFIG_TRACE_IRQFLAGS

	call trace_hardirqs_off

#endif

#ifdef CONFIG_RISCV_M_MODE

	/* the MPP value is too large to be used as an immediate arg for addi */

	li t0, SR_MPP
@@ -216,6 +238,16 @@ resume_userspace: 
	csrw CSR_SCRATCH, tp



restore_all:

#ifdef CONFIG_TRACE_IRQFLAGS

	REG_L s1, PT_STATUS(sp)

	andi t0, s1, SR_PIE

	beqz t0, 1f

	call trace_hardirqs_on

	j 2f

1:

	call trace_hardirqs_off

2:

#endif

	REG_L a0, PT_STATUS(sp)

	/*

	 * The current load reservation is effectively part of the processor's

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