[src/trunk]: src/sys/arch/x86/x86 Remap the rodata and data+bss segments with...

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1b8d3e5345e3
branches:  trunk
changeset: 345215:1b8d3e5345e3
user:      maxv <maxv%NetBSD.org@localhost>
date:      Fri May 13 10:24:42 2016 +0000

description:
Remap the rodata and data+bss segments with large pages on x86. There still
is a bug in the way the text segment is mapped, but I'll see later.

diffstat:

 sys/arch/x86/x86/pmap.c |  50 ++++++++++++++++++++++++++++++++++++------------
 1 files changed, 37 insertions(+), 13 deletions(-)

diffs (104 lines):

diff -r e792af54716c -r 1b8d3e5345e3 sys/arch/x86/x86/pmap.c
--- a/sys/arch/x86/x86/pmap.c   Fri May 13 10:18:01 2016 +0000
+++ b/sys/arch/x86/x86/pmap.c   Fri May 13 10:24:42 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.191 2016/05/12 06:45:16 maxv Exp $  */
+/*     $NetBSD: pmap.c,v 1.192 2016/05/13 10:24:42 maxv Exp $  */
 
 /*-
  * Copyright (c) 2008, 2010 The NetBSD Foundation, Inc.
@@ -171,7 +171,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.191 2016/05/12 06:45:16 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.192 2016/05/13 10:24:42 maxv Exp $");
 
 #include "opt_user_ldt.h"
 #include "opt_lockdebug.h"
@@ -1272,7 +1272,6 @@
         * which happens in cpu_init(), which is run on each cpu
         * (and happens later)
         */
-
        if (cpu_feature[0] & CPUID_PGE) {
                pmap_pg_g = PG_G;               /* enable software */
 
@@ -1296,18 +1295,19 @@
        }
 
        /*
-        * enable large pages if they are supported.
+        * Enable large pages if they are supported.
         */
-
        if (cpu_feature[0] & CPUID_PSE) {
                paddr_t pa;
                extern char __rodata_start;
+               extern char __data_start;
+               extern char __kernel_end;
 
                lcr4(rcr4() | CR4_PSE); /* enable hardware (via %cr4) */
                pmap_largepages = 1;    /* enable software */
 
                /*
-                * the TLB must be flushed after enabling large pages
+                * The TLB must be flushed after enabling large pages
                 * on Pentium CPUs, according to section 3.6.2.2 of
                 * "Intel Architecture Software Developer's Manual,
                 * Volume 3: System Programming".
@@ -1315,16 +1315,18 @@
                tlbflushg();
 
                /*
-                * now, remap the kernel text using large pages.  we
-                * assume that the linker has properly aligned the
-                * .rodata segment to a NBPD_L2 boundary.
+                * Now, we remap several kernel segments with large pages. We
+                * cover as many pages as we can.
                 */
+
+               /* Remap the kernel text using large pages. */
+               kva = KERNBASE;
                kva_end = rounddown((vaddr_t)&__rodata_start, NBPD_L1);
-               for (pa = 0, kva = KERNBASE; kva + NBPD_L2 <= kva_end;
-                    kva += NBPD_L2, pa += NBPD_L2) {
+               pa = kva - KERNBASE;
+               for (/* */; kva + NBPD_L2 <= kva_end; kva += NBPD_L2,
+                   pa += NBPD_L2) {
                        pde = &L2_BASE[pl2_i(kva)];
-                       *pde = pa | pmap_pg_g | PG_PS |
-                           PG_KR | PG_V;       /* zap! */
+                       *pde = pa | pmap_pg_g | PG_PS | PG_KR | PG_V;
                        tlbflushg();
                }
 #if defined(DEBUG)
@@ -1333,6 +1335,28 @@
                    howmany(kva - KERNBASE, NBPD_L2),
                    howmany((vaddr_t)&__rodata_start - kva, NBPD_L1));
 #endif /* defined(DEBUG) */
+
+               /* Remap the kernel rodata using large pages. */
+               kva = roundup((vaddr_t)&__rodata_start, NBPD_L2);
+               kva_end = rounddown((vaddr_t)&__data_start, NBPD_L1);
+               pa = kva - KERNBASE;
+               for (/* */; kva + NBPD_L2 <= kva_end; kva += NBPD_L2,
+                   pa += NBPD_L2) {
+                       pde = &L2_BASE[pl2_i(kva)];
+                       *pde = pa | pmap_pg_g | PG_PS | pg_nx | PG_KR | PG_V;
+                       tlbflushg();
+               }
+
+               /* Remap the kernel data+bss using large pages. */
+               kva = roundup((vaddr_t)&__data_start, NBPD_L2);
+               kva_end = rounddown((vaddr_t)&__kernel_end, NBPD_L1);
+               pa = kva - KERNBASE;
+               for (/* */; kva + NBPD_L2 <= kva_end; kva += NBPD_L2,
+                   pa += NBPD_L2) {
+                       pde = &L2_BASE[pl2_i(kva)];
+                       *pde = pa | pmap_pg_g | PG_PS | pg_nx | PG_KW | PG_V;
+                       tlbflushg();
+               }
        }
 #endif /* !XEN */