Author: jkim
Date: Wed Feb 25 20:26:48 2009
New Revision: 189055
URL: http://svn.freebsd.org/changeset/base/189055
Log:
Enable support for PAT_WRITE_PROTECTED and PAT_UNCACHED cache modes
unconditionally on amd64. On i386, we assume PAT is usable if the CPU
vendor is not Intel or CPU model is newer than Pentium IV.
Reviewed by: alc, jhb
Modified:
head/sys/amd64/amd64/pmap.c
head/sys/i386/i386/pmap.c
Modified: head/sys/amd64/amd64/pmap.c
==============================================================================
--- head/sys/amd64/amd64/pmap.c Wed Feb 25 20:24:13 2009 (r189054)
+++ head/sys/amd64/amd64/pmap.c Wed Feb 25 20:26:48 2009 (r189055)
@@ -594,7 +594,6 @@ pmap_init_pat(void)
if (!(cpu_feature & CPUID_PAT))
panic("no PAT??");
-#ifdef PAT_WORKS
/*
* Leave the indices 0-3 at the default of WB, WT, UC, and UC-.
* Program 4 and 5 as WP and WC.
@@ -604,23 +603,6 @@ pmap_init_pat(void)
pat_msr &= ~(PAT_MASK(4) | PAT_MASK(5));
pat_msr |= PAT_VALUE(4, PAT_WRITE_PROTECTED) |
PAT_VALUE(5, PAT_WRITE_COMBINING);
-#else
- /*
- * Due to some Intel errata, we can only safely use the lower 4
- * PAT entries. Thus, just replace PAT Index 2 with WC instead
- * of UC-.
- *
- * Intel Pentium III Processor Specification Update
- * Errata E.27 (Upper Four PAT Entries Not Usable With Mode B
- * or Mode C Paging)
- *
- * Intel Pentium IV Processor Specification Update
- * Errata N46 (PAT Index MSB May Be Calculated Incorrectly)
- */
- pat_msr = rdmsr(MSR_PAT);
- pat_msr &= ~PAT_MASK(2);
- pat_msr |= PAT_VALUE(2, PAT_WRITE_COMBINING);
-#endif
wrmsr(MSR_PAT, pat_msr);
}
@@ -783,10 +765,9 @@ pmap_cache_bits(int mode, boolean_t is_p
break;
}
}
-
+
/* Map the caching mode to a PAT index. */
switch (mode) {
-#ifdef PAT_WORKS
case PAT_UNCACHEABLE:
pat_index = 3;
break;
@@ -805,25 +786,9 @@ pmap_cache_bits(int mode, boolean_t is_p
case PAT_WRITE_PROTECTED:
pat_index = 4;
break;
-#else
- case PAT_UNCACHED:
- case PAT_UNCACHEABLE:
- case PAT_WRITE_PROTECTED:
- pat_index = 3;
- break;
- case PAT_WRITE_THROUGH:
- pat_index = 1;
- break;
- case PAT_WRITE_BACK:
- pat_index = 0;
- break;
- case PAT_WRITE_COMBINING:
- pat_index = 2;
- break;
-#endif
default:
panic("Unknown caching mode %d\n", mode);
- }
+ }
/* Map the 3-bit index value into the PAT, PCD, and PWT bits. */
cache_bits = 0;
Modified: head/sys/i386/i386/pmap.c
==============================================================================
--- head/sys/i386/i386/pmap.c Wed Feb 25 20:24:13 2009 (r189054)
+++ head/sys/i386/i386/pmap.c Wed Feb 25 20:26:48 2009 (r189055)
@@ -211,6 +211,8 @@ pt_entry_t pg_nx;
static uma_zone_t pdptzone;
#endif
+static int pat_works; /* Is page attribute table sane? */
+
SYSCTL_NODE(_vm, OID_AUTO, pmap, CTLFLAG_RD, 0, "VM/pmap parameters");
static int pg_ps_enabled;
@@ -477,33 +479,36 @@ pmap_init_pat(void)
if (!(cpu_feature & CPUID_PAT))
return;
-#ifdef PAT_WORKS
- /*
- * Leave the indices 0-3 at the default of WB, WT, UC, and UC-.
- * Program 4 and 5 as WP and WC.
- * Leave 6 and 7 as UC and UC-.
- */
- pat_msr = rdmsr(MSR_PAT);
- pat_msr &= ~(PAT_MASK(4) | PAT_MASK(5));
- pat_msr |= PAT_VALUE(4, PAT_WRITE_PROTECTED) |
- PAT_VALUE(5, PAT_WRITE_COMBINING);
-#else
- /*
- * Due to some Intel errata, we can only safely use the lower 4
- * PAT entries. Thus, just replace PAT Index 2 with WC instead
- * of UC-.
- *
- * Intel Pentium III Processor Specification Update
- * Errata E.27 (Upper Four PAT Entries Not Usable With Mode B
- * or Mode C Paging)
- *
- * Intel Pentium IV Processor Specification Update
- * Errata N46 (PAT Index MSB May Be Calculated Incorrectly)
- */
- pat_msr = rdmsr(MSR_PAT);
- pat_msr &= ~PAT_MASK(2);
- pat_msr |= PAT_VALUE(2, PAT_WRITE_COMBINING);
-#endif
+ if (cpu_vendor_id != CPU_VENDOR_INTEL ||
+ (I386_CPU_FAMILY(cpu_id) == 6 && I386_CPU_MODEL(cpu_id) >= 0xe)) {
+ /*
+ * Leave the indices 0-3 at the default of WB, WT, UC, and UC-.
+ * Program 4 and 5 as WP and WC.
+ * Leave 6 and 7 as UC and UC-.
+ */
+ pat_msr = rdmsr(MSR_PAT);
+ pat_msr &= ~(PAT_MASK(4) | PAT_MASK(5));
+ pat_msr |= PAT_VALUE(4, PAT_WRITE_PROTECTED) |
+ PAT_VALUE(5, PAT_WRITE_COMBINING);
+ pat_works = 1;
+ } else {
+ /*
+ * Due to some Intel errata, we can only safely use the lower 4
+ * PAT entries. Thus, just replace PAT Index 2 with WC instead
+ * of UC-.
+ *
+ * Intel Pentium III Processor Specification Update
+ * Errata E.27 (Upper Four PAT Entries Not Usable With Mode B
+ * or Mode C Paging)
+ *
+ * Intel Pentium IV Processor Specification Update
+ * Errata N46 (PAT Index MSB May Be Calculated Incorrectly)
+ */
+ pat_msr = rdmsr(MSR_PAT);
+ pat_msr &= ~PAT_MASK(2);
+ pat_msr |= PAT_VALUE(2, PAT_WRITE_COMBINING);
+ pat_works = 0;
+ }
wrmsr(MSR_PAT, pat_msr);
}
@@ -753,45 +758,49 @@ pmap_cache_bits(int mode, boolean_t is_p
}
/* Map the caching mode to a PAT index. */
- switch (mode) {
-#ifdef PAT_WORKS
- case PAT_UNCACHEABLE:
- pat_index = 3;
- break;
- case PAT_WRITE_THROUGH:
- pat_index = 1;
- break;
- case PAT_WRITE_BACK:
- pat_index = 0;
- break;
- case PAT_UNCACHED:
- pat_index = 2;
- break;
- case PAT_WRITE_COMBINING:
- pat_index = 5;
- break;
- case PAT_WRITE_PROTECTED:
- pat_index = 4;
- break;
-#else
- case PAT_UNCACHED:
- case PAT_UNCACHEABLE:
- case PAT_WRITE_PROTECTED:
- pat_index = 3;
- break;
- case PAT_WRITE_THROUGH:
- pat_index = 1;
- break;
- case PAT_WRITE_BACK:
- pat_index = 0;
- break;
- case PAT_WRITE_COMBINING:
- pat_index = 2;
- break;
-#endif
- default:
- panic("Unknown caching mode %d\n", mode);
- }
+ if (pat_works) {
+ switch (mode) {
+ case PAT_UNCACHEABLE:
+ pat_index = 3;
+ break;
+ case PAT_WRITE_THROUGH:
+ pat_index = 1;
+ break;
+ case PAT_WRITE_BACK:
+ pat_index = 0;
+ break;
+ case PAT_UNCACHED:
+ pat_index = 2;
+ break;
+ case PAT_WRITE_COMBINING:
+ pat_index = 5;
+ break;
+ case PAT_WRITE_PROTECTED:
+ pat_index = 4;
+ break;
+ default:
+ panic("Unknown caching mode %d\n", mode);
+ }
+ } else {
+ switch (mode) {
+ case PAT_UNCACHED:
+ case PAT_UNCACHEABLE:
+ case PAT_WRITE_PROTECTED:
+ pat_index = 3;
+ break;
+ case PAT_WRITE_THROUGH:
+ pat_index = 1;
+ break;
+ case PAT_WRITE_BACK:
+ pat_index = 0;
+ break;
+ case PAT_WRITE_COMBINING:
+ pat_index = 2;
+ break;
+ default:
+ panic("Unknown caching mode %d\n", mode);
+ }
+ }
/* Map the 3-bit index value into the PAT, PCD, and PWT bits. */
cache_bits = 0;
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