From: Heiko Carstens <hca@linux.ibm.com>
Date: Tue, 22 Oct 2024 12:05:59 +0000 (+0200)
Subject: s390/mm: Simplify get_fault_type()
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f76901d16008862035265037905fd84364c3d0ac;p=users%2Fwilly%2Fxarray.git

s390/mm: Simplify get_fault_type()

With the gmap code gone get_fault_type() can be simplified:

- every fault with user_mode(regs) == true must be a fault in user address
  space

- every fault with user_mode(regs) == false is only a fault in user
  address space if the used address space is the secondary address space

- every other fault is within the kernel address space

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/r/20241022120601.167009-10-imbrenda@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---

diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index e48910b0b816..6e96fc7905fc 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -68,17 +68,10 @@ static enum fault_type get_fault_type(struct pt_regs *regs)
 {
 	union teid teid = { .val = regs->int_parm_long };
 
-	if (likely(teid.as == PSW_BITS_AS_PRIMARY)) {
-		if (user_mode(regs))
-			return USER_FAULT;
-		return KERNEL_FAULT;
-	}
-	if (teid.as == PSW_BITS_AS_SECONDARY)
+	if (user_mode(regs))
 		return USER_FAULT;
-	/* Access register mode, not used in the kernel */
-	if (teid.as == PSW_BITS_AS_ACCREG)
+	if (teid.as == PSW_BITS_AS_SECONDARY)
 		return USER_FAULT;
-	/* Home space -> access via kernel ASCE */
 	return KERNEL_FAULT;
 }