svn commit: r340029 - head/sys/riscv/riscv

[John Baldwin]

Author: jhb
Date: Thu Nov  1 22:17:51 2018
New Revision: 340029
URL: https://svnweb.freebsd.org/changeset/base/340029

Log:
  Set PTE_A and PTE_D for user mappings in pmap_enter().
  
  This assumes that an access according to the prot in 'flags' triggered
  a fault and is going to be retried after the fault returns, so the two
  flags are set preemptively to avoid refaulting on the retry.
  
  While here, only bother setting PTE_D for kernel mappings in pmap_enter
  for writable mappings.
  
  Reviewed by:	markj
  Sponsored by:	DARPA
  Differential Revision:	https://reviews.freebsd.org/D17782

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

Modified: head/sys/riscv/riscv/pmap.c
==============================================================================
--- head/sys/riscv/riscv/pmap.c	Thu Nov  1 22:15:25 2018	(r340028)
+++ head/sys/riscv/riscv/pmap.c	Thu Nov  1 22:17:51 2018	(r340029)
@@ -2088,13 +2088,15 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, v
 	pa = VM_PAGE_TO_PHYS(m);
 	pn = (pa / PAGE_SIZE);
 
-	new_l3 = PTE_V | PTE_R | PTE_X;
+	new_l3 = PTE_V | PTE_R | PTE_X | PTE_A;
+	if (flags & VM_PROT_WRITE)
+		new_l3 |= PTE_D;
 	if (prot & VM_PROT_WRITE)
 		new_l3 |= PTE_W;
 	if ((va >> 63) == 0)
 		new_l3 |= PTE_U;
-	else
-		new_l3 |= PTE_A | PTE_D;
+	else if (prot & VM_PROT_WRITE)
+		new_l3 |= PTE_D;
 
 	new_l3 |= (pn << PTE_PPN0_S);
 	if ((flags & PMAP_ENTER_WIRED) != 0)