svn commit: r357594 - head/sys/riscv/riscv

[John Baldwin]

Author: jhb
Date: Wed Feb  5 20:32:37 2020
New Revision: 357594
URL: https://svnweb.freebsd.org/changeset/base/357594

Log:
  Use csr_read() to read sstatus instead of inline assembly.
  
  While here, remove a local variable to avoid the CSR read in non-debug
  kernels.
  
  Reviewed by:	mhorne
  MFC after:	1 week
  Sponsored by:	DARPA
  Differential Revision:	https://reviews.freebsd.org/D23511

Modified:
  head/sys/riscv/riscv/trap.c

Modified: head/sys/riscv/riscv/trap.c
==============================================================================
--- head/sys/riscv/riscv/trap.c	Wed Feb  5 20:11:08 2020	(r357593)
+++ head/sys/riscv/riscv/trap.c	Wed Feb  5 20:32:37 2020	(r357594)
@@ -245,12 +245,10 @@ void
 do_trap_supervisor(struct trapframe *frame)
 {
 	uint64_t exception;
-	uint64_t sstatus;
 
 	/* Ensure we came from supervisor mode, interrupts disabled */
-	__asm __volatile("csrr %0, sstatus" : "=&r" (sstatus));
-	KASSERT((sstatus & (SSTATUS_SPP | SSTATUS_SIE)) == SSTATUS_SPP,
-			("We must came from S mode with interrupts disabled"));
+	KASSERT((csr_read(sstatus) & (SSTATUS_SPP | SSTATUS_SIE)) ==
+	    SSTATUS_SPP, ("Came from S mode with interrupts enabled"));
 
 	exception = (frame->tf_scause & EXCP_MASK);
 	if (frame->tf_scause & EXCP_INTR) {
@@ -305,7 +303,6 @@ do_trap_user(struct trapframe *frame)
 {
 	uint64_t exception;
 	struct thread *td;
-	uint64_t sstatus;
 	struct pcb *pcb;
 
 	td = curthread;
@@ -313,9 +310,8 @@ do_trap_user(struct trapframe *frame)
 	pcb = td->td_pcb;
 
 	/* Ensure we came from usermode, interrupts disabled */
-	__asm __volatile("csrr %0, sstatus" : "=&r" (sstatus));
-	KASSERT((sstatus & (SSTATUS_SPP | SSTATUS_SIE)) == 0,
-			("We must came from U mode with interrupts disabled"));
+	KASSERT((csr_read(sstatus) & (SSTATUS_SPP | SSTATUS_SIE)) == 0,
+	    ("Came from U mode with interrupts enabled"));
 
 	exception = (frame->tf_scause & EXCP_MASK);
 	if (frame->tf_scause & EXCP_INTR) {