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PAT support



Hi!

Attached patch adds PAT support to x86.
I implement BUS_SPACE_MAP_PREFETCHABLE with it.

Note, this patch adds MI pmap flags to uvm_pmap.h.
Please review if they fit to the other ports than x86, too.

PMAP_NOCACHE turned into an MI flag, so the following
ports need an update:

hp700, hppa and sgimips.

Please send me the update-patches. I will accumulate
them so all will go into the tree in one go.

When you boot with -x you should see something like this:

$ dmesg | grep PAT
cpu0: PAT enabled
cpu1: PAT enabled
$

Any comments?

Christoph

# HG changeset patch
# User cegger%netbsd.org@localhost
# Date 1274224212 -7200
Implement PAT support

diff -r 73a60e5046f3 -r 673a064554df sys/arch/amd64/include/pte.h
--- a/sys/arch/amd64/include/pte.h
+++ b/sys/arch/amd64/include/pte.h
@@ -105,18 +105,23 @@ typedef uint64_t pt_entry_t;              /* PTE */
 #define        PG_RW           0x0000000000000002      /* read-write */
 #define        PG_u            0x0000000000000004      /* user accessible */
 #define        PG_PROT         0x0000000000000006
-#define        PG_N            0x0000000000000018      /* non-cacheable */
+#define PG_WT          0x0000000000000008      /* write-through */
+#define        PG_N            0x0000000000000010      /* non-cacheable */
 #define        PG_U            0x0000000000000020      /* used */
 #define        PG_M            0x0000000000000040      /* modified */
-#define PG_PS          0x0000000000000080      /* 2MB page size */
+#define PG_PAT         0x0000000000000080      /* PAT (on pte) */
+#define PG_PS          0x0000000000000080      /* 2MB page size (on pde) */
 #define PG_G           0x0000000000000100      /* not flushed */
 #define PG_AVAIL1      0x0000000000000200
 #define PG_AVAIL2      0x0000000000000400
 #define PG_AVAIL3      0x0000000000000800
+#define PG_LGPAT       0x0000000000001000      /* PAT on large pages */
 #define        PG_FRAME        0x000ffffffffff000
 #define        PG_NX           0x8000000000000000
 
-#define        PG_LGFRAME      0x000fffffffe00000      /* large (2M) page 
frame mask */
+#define PG_2MFRAME     0x000fffffffe00000      /* large (2M) page frame mask */
+#define PG_1GFRAME     0x000fffffc0000000      /* large (1G) page frame mask */
+#define        PG_LGFRAME      PG_2MFRAME
 
 /*
  * short forms of protection codes
@@ -125,13 +130,6 @@ typedef uint64_t pt_entry_t;               /* PTE */
 #define        PG_KR           0x0000000000000000      /* kernel read-only */
 #define        PG_KW           0x0000000000000002      /* kernel read-write */
 
-/*
- * page protection exception bits
- */
-
-#define PGEX_P         0x01    /* protection violation (vs. no mapping) */
-#define PGEX_W         0x02    /* exception during a write cycle */
-#define PGEX_U         0x04    /* exception while in user mode (upl) */
-#define PGEX_X         0x10    /* exception during instruction fetch */
+#include <x86/pte.h>
 
 #endif /* _AMD64_PTE_H_ */
diff -r 73a60e5046f3 -r 673a064554df sys/arch/i386/include/pte.h
--- a/sys/arch/i386/include/pte.h
+++ b/sys/arch/i386/include/pte.h
@@ -218,7 +218,9 @@ typedef uint32_t pt_entry_t;                /* PTE */
 /* macros to get real L2 and L3 index, from our "extended" L2 index */
 #define l2tol3(idx)    ((idx) >> (L3_SHIFT - L2_SHIFT))
 #define l2tol2(idx)    ((idx) & (L2_REALMASK >>  L2_SHIFT))
+
 #else /* PAE */
+
 #define        L1_SHIFT        12
 #define        L2_SHIFT        22
 #define        NBPD_L1         (1UL << L1_SHIFT) /* # bytes mapped by L1 ent 
(4K) */
@@ -245,14 +247,17 @@ typedef uint32_t pt_entry_t;              /* PTE */
 #define        PG_RW           0x00000002      /* read-write page */
 #define        PG_u            0x00000004      /* user accessible page */
 #define        PG_PROT         0x00000806      /* all protection bits */
-#define        PG_N            0x00000018      /* non-cacheable */
+#define PG_WT          0x00000008      /* write through */
+#define        PG_N            0x00000010      /* non-cacheable */
 #define        PG_U            0x00000020      /* has been used */
 #define        PG_M            0x00000040      /* has been modified */
+#define PG_PAT         0x00000080      /* PAT (on pte) */
 #define PG_PS          0x00000080      /* 4MB page size */
 #define PG_G           0x00000100      /* global, don't TLB flush */
 #define PG_AVAIL1      0x00000200      /* ignored by hardware */
 #define PG_AVAIL2      0x00000400      /* ignored by hardware */
 #define PG_AVAIL3      0x00000800      /* ignored by hardware */
+#define PG_LGPAT       0x00001000      /* PAT on large pages */
 
 /*
  * various short-hand protection codes
@@ -267,13 +272,6 @@ typedef uint32_t pt_entry_t;               /* PTE */
 #define        PG_NX           0               /* dummy */
 #endif
 
-/*
- * page protection exception bits
- */
-
-#define PGEX_P         0x01    /* protection violation (vs. no mapping) */
-#define PGEX_W         0x02    /* exception during a write cycle */
-#define PGEX_U         0x04    /* exception while in user mode (upl) */
-#define PGEX_X         0x10    /* exception during instruction fetch */
+#include <x86/pte.h>
 
 #endif /* _I386_PTE_H_ */
diff -r 73a60e5046f3 -r 673a064554df sys/arch/x86/conf/files.x86
--- a/sys/arch/x86/conf/files.x86
+++ b/sys/arch/x86/conf/files.x86
@@ -62,6 +62,7 @@ file  arch/x86/x86/nmi.c
 file   arch/x86/x86/idt.c
 file   arch/x86/x86/ipi.c
 file   arch/x86/x86/mtrr_i686.c        mtrr
+file   arch/x86/x86/pat.c
 file   arch/x86/x86/patch.c
 file   arch/x86/x86/platform.c
 file   arch/x86/x86/pmap.c
diff -r 73a60e5046f3 -r 673a064554df sys/arch/x86/include/pat.h
--- /dev/null
+++ b/sys/arch/x86/include/pat.h
@@ -0,0 +1,36 @@
+/*      $NetBSD: $    */
+
+/*
+ * Copyright (c) 2010 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Christoph Egger.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cpu.h>
+
+extern bool cpu_pat_enabled;
+
+void pat_init(struct cpu_info *);
diff -r 73a60e5046f3 -r 673a064554df sys/arch/x86/include/pmap.h
--- a/sys/arch/x86/include/pmap.h
+++ b/sys/arch/x86/include/pmap.h
@@ -178,7 +178,6 @@ struct pmap {
 /*
  * MD flags that we use for pmap_enter and pmap_kenter_pa:
  */
-#define PMAP_NOCACHE   0x01000000      /* set the non-cacheable bit */
 
 /*
  * global kernel variables
diff -r 73a60e5046f3 -r 673a064554df sys/arch/x86/include/pte.h
--- /dev/null
+++ b/sys/arch/x86/include/pte.h
@@ -0,0 +1,21 @@
+/*     $NetBSD: $ */
+
+#ifndef _X86_PTE_H
+#define _X86_PTE_H
+
+/* Cacheability bits when we are using PAT */
+#define PGC_WB          0               /* The default */
+#define PGC_WC          PG_WT           /* WT and CD is WC */
+#define PGC_UCMINUS     PG_N            /* UC but mtrr can override */
+#define PGC_UC          (PG_WT | PG_N)  /* hard UC */
+
+/*
+ * page protection exception bits
+ */
+
+#define PGEX_P         0x01    /* protection violation (vs. no mapping) */
+#define PGEX_W         0x02    /* exception during a write cycle */
+#define PGEX_U         0x04    /* exception while in user mode (upl) */
+#define PGEX_X         0x10    /* exception during instruction fetch */
+
+#endif /* _X86_PTE_H */
diff -r 73a60e5046f3 -r 673a064554df sys/arch/x86/include/specialreg.h
--- a/sys/arch/x86/include/specialreg.h
+++ b/sys/arch/x86/include/specialreg.h
@@ -343,6 +343,7 @@
 #define        MSR_MTRRfix4K_E8000     0x26d
 #define        MSR_MTRRfix4K_F0000     0x26e
 #define        MSR_MTRRfix4K_F8000     0x26f
+#define MSR_CR_PAT             0x277
 #define MSR_MTRRdefType                0x2ff
 #define MSR_MC0_CTL            0x400
 #define MSR_MC0_STATUS         0x401
diff -r 73a60e5046f3 -r 673a064554df sys/arch/x86/x86/bus_space.c
--- a/sys/arch/x86/x86/bus_space.c
+++ b/sys/arch/x86/x86/bus_space.c
@@ -199,8 +199,7 @@ bus_space_map(bus_space_tag_t t, bus_add
         * For memory space, map the bus physical address to
         * a kernel virtual address.
         */
-       error = x86_mem_add_mapping(bpa, size,
-               (flags & BUS_SPACE_MAP_CACHEABLE) != 0, bshp);
+       error = x86_mem_add_mapping(bpa, size, flags, bshp);
        if (error) {
                if (extent_free(ex, bpa, size, EX_NOWAIT |
                    (ioport_malloc_safe ? EX_MALLOCOK : 0))) {
@@ -232,8 +231,7 @@ _x86_memio_map(bus_space_tag_t t, bus_ad
         * For memory space, map the bus physical address to
         * a kernel virtual address.
         */
-       return (x86_mem_add_mapping(bpa, size,
-           (flags & BUS_SPACE_MAP_CACHEABLE) != 0, bshp));
+       return x86_mem_add_mapping(bpa, size, flags, bshp);
 }
 
 int
@@ -286,8 +284,7 @@ bus_space_alloc(bus_space_tag_t t, bus_a
         * For memory space, map the bus physical address to
         * a kernel virtual address.
         */
-       error = x86_mem_add_mapping(bpa, size,
-           (flags & BUS_SPACE_MAP_CACHEABLE) != 0, bshp);
+       error = x86_mem_add_mapping(bpa, size, flags, bshp);
        if (error) {
                if (extent_free(iomem_ex, bpa, size, EX_NOWAIT |
                    (ioport_malloc_safe ? EX_MALLOCOK : 0))) {
@@ -304,17 +301,19 @@ bus_space_alloc(bus_space_tag_t t, bus_a
 
 int
 x86_mem_add_mapping(bus_addr_t bpa, bus_size_t size,
-               int cacheable, bus_space_handle_t *bshp)
+               int flags, bus_space_handle_t *bshp)
 {
        paddr_t pa, endpa;
        vaddr_t va, sva;
-       u_int pmapflags = 0;
+       u_int pmapflags = PMAP_NOCACHE;
 
        pa = x86_trunc_page(bpa);
        endpa = x86_round_page(bpa + size);
 
-       if (!cacheable)
-               pmapflags |= PMAP_NOCACHE;
+       if (flags & BUS_SPACE_MAP_CACHEABLE)
+               pmapflags = 0;
+       else if (flags & BUS_SPACE_MAP_PREFETCHABLE)
+               pmapflags = PMAP_WRITE_COMBINE;
 
 #ifdef DIAGNOSTIC
        if (endpa != 0 && endpa <= pa)
diff -r 73a60e5046f3 -r 673a064554df sys/arch/x86/x86/cpu.c
--- a/sys/arch/x86/x86/cpu.c
+++ b/sys/arch/x86/x86/cpu.c
@@ -111,6 +111,8 @@ __KERNEL_RCSID(0, "$NetBSD: cpu.c,v 1.70
 #include <i386/isa/nvram.h>
 #include <dev/isa/isareg.h>
 
+#include <x86/pat.h>
+
 #include "tsc.h"
 
 #if MAXCPUS > 32
@@ -424,6 +426,7 @@ cpu_attach(device_t parent, device_t sel
                panic("unknown processor type??\n");
        }
 
+       pat_init(ci);
        atomic_or_32(&cpus_attached, ci->ci_cpumask);
 
        if (!pmf_device_register(self, cpu_suspend, cpu_resume))
diff -r 73a60e5046f3 -r 673a064554df sys/arch/x86/x86/pat.c
--- /dev/null
+++ b/sys/arch/x86/x86/pat.c
@@ -0,0 +1,65 @@
+/*     $NetBSD: $ */
+/*
+ * Copyright (c) 2010 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Christoph Egger.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+#include <sys/param.h>
+#include <sys/systm.h>
+
+#include <uvm/uvm_extern.h>
+#include <x86/pat.h>
+#include <machine/specialreg.h>
+
+bool cpu_pat_enabled = false;
+
+void pat_init(struct cpu_info *ci)
+{
+       uint64_t pat;
+
+       if (!(ci->ci_feat_val[0] & CPUID_PAT))
+               return;
+
+#define        PATENTRY(n, type)       (type << ((n) * 8))
+#define        PAT_UC          0x0ULL
+#define        PAT_WC          0x1ULL
+#define        PAT_WT          0x4ULL
+#define        PAT_WP          0x5ULL
+#define        PAT_WB          0x6ULL
+#define        PAT_UCMINUS     0x7ULL
+
+       /* We change WT to WC. Leave all other entries the default values. */
+       pat = PATENTRY(0, PAT_WB) | PATENTRY(1, PAT_WC) |
+             PATENTRY(2, PAT_UCMINUS) | PATENTRY(3, PAT_UC) |
+             PATENTRY(4, PAT_WB) | PATENTRY(5, PAT_WC) |
+             PATENTRY(6, PAT_UCMINUS) | PATENTRY(7, PAT_UC);
+
+       wrmsr(MSR_CR_PAT, pat);
+       cpu_pat_enabled = true;
+       aprint_debug_dev(ci->ci_dev, "PAT enabled\n");
+}
diff -r 73a60e5046f3 -r 673a064554df sys/arch/x86/x86/pmap.c
--- a/sys/arch/x86/x86/pmap.c
+++ b/sys/arch/x86/x86/pmap.c
@@ -178,6 +178,7 @@ __KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.1
 #include <machine/isa_machdep.h>
 #include <machine/cpuvar.h>
 
+#include <x86/pat.h>
 #include <x86/pmap.h>
 #include <x86/pmap_pv.h>
 
@@ -1004,6 +1005,38 @@ pmap_exec_fixup(struct vm_map *map, stru
 }
 #endif /* !defined(__x86_64__) */
 
+static pt_entry_t
+pmap_pat_flags(u_int flags)
+{
+       u_int cacheflags = (flags & PMAP_CACHE_MASK);
+
+       if (!cpu_pat_enabled) {
+               switch (cacheflags) {
+               case PMAP_NOCACHE:
+               case PMAP_NOCACHE_OVR:
+                       /* results in PGC_UCMINUS on cpus which have
+                        * the cpuid PAT but PAT "disabled"
+                        */
+                       return PG_N;
+               default:
+                       return 0;
+               }
+       }
+
+       switch (cacheflags) {
+       case PMAP_NOCACHE:
+               return PGC_UC;
+       case PMAP_WRITE_COMBINE:
+               return PGC_WC;
+       case PMAP_WRITE_BACK:
+               return PGC_WB;
+       case PMAP_NOCACHE_OVR:
+               return PGC_UCMINUS;
+       }
+
+       return 0;
+}
+
 /*
  * p m a p   k e n t e r   f u n c t i o n s
  *
@@ -1041,8 +1074,7 @@ pmap_kenter_pa(vaddr_t va, paddr_t pa, v
 #endif /* DOM0OPS */
                npte = pmap_pa2pte(pa);
        npte |= protection_codes[prot] | PG_k | PG_V | pmap_pg_g;
-       if (flags & PMAP_NOCACHE)
-               npte |= PG_N;
+       npte |= pmap_pat_flags(flags);
        opte = pmap_pte_testset(pte, npte); /* zap! */
 #if defined(DIAGNOSTIC)
        /* XXX For now... */
@@ -3961,10 +3993,9 @@ pmap_enter_ma(struct pmap *pmap, vaddr_t
 #endif /* XEN */
 
        npte = ma | protection_codes[prot] | PG_V;
+       npte |= pmap_pat_flags(flags);
        if (wired)
                npte |= PG_W;
-       if (flags & PMAP_NOCACHE)
-               npte |= PG_N;
        if (va < VM_MAXUSER_ADDRESS)
                npte |= PG_u;
        else if (va < VM_MAX_ADDRESS)
diff -r 73a60e5046f3 -r 673a064554df sys/arch/xen/conf/files.xen
--- a/sys/arch/xen/conf/files.xen
+++ b/sys/arch/xen/conf/files.xen
@@ -145,6 +145,7 @@ file        arch/xen/x86/consinit.c
 file   arch/x86/x86/identcpu.c
 file   arch/xen/x86/intr.c
 file   arch/x86/x86/ipi.c
+file   arch/x86/x86/pat.c
 file   arch/x86/x86/pmap.c
 file   arch/x86/x86/sys_machdep.c
 file   arch/x86/x86/tsc.c
diff -r 73a60e5046f3 -r 673a064554df sys/arch/xen/x86/cpu.c
--- a/sys/arch/xen/x86/cpu.c
+++ b/sys/arch/xen/x86/cpu.c
@@ -111,6 +111,8 @@ __KERNEL_RCSID(0, "$NetBSD: cpu.c,v 1.44
 #include <dev/ic/mc146818reg.h>
 #include <dev/isa/isareg.h>
 
+#include <x86/pat.h>
+
 #if MAXCPUS > 32
 #error cpu_info contains 32bit bitmasks
 #endif
@@ -517,6 +519,7 @@ cpu_attach_common(device_t parent, devic
                panic("unknown processor type??\n");
        }
 
+       pat_init(ci);
        atomic_or_32(&cpus_attached, ci->ci_cpumask);
 
 #if 0
diff -r 73a60e5046f3 -r 673a064554df sys/uvm/uvm_pmap.h
--- a/sys/uvm/uvm_pmap.h
+++ b/sys/uvm/uvm_pmap.h
@@ -109,7 +109,28 @@ typedef struct pmap_statistics     *pmap_sta
 #define        PMAP_KMPAGE     0x00000000
 #endif /* PMAP_ENABLE_PMAP_KMPAGE */
 
-#define        PMAP_MD_MASK    0xff000000      /* Machine-dependent bits */
+#define        PMAP_MD_MASK    0xff000000      /* [BOTH] Machine-dependent 
bits */
+#define PMAP_PROT_MASK 0x0000000f      /* [BOTH] VM_PROT_* bit mask */
+
+/*
+ * Cache Type Encodings
+ */
+#define PMAP_CACHE_MASK                0x00000f00
+
+/* All accesses are uncacheable. No speculative accesses. */
+#define PMAP_NOCACHE           0x00000100      /* [BOTH] */
+
+/* All accesses are uncacheable. No speculative accesses.
+ * Writes are combined. */
+#define PMAP_WRITE_COMBINE     0x00000200      /* [BOTH] */
+
+/* On reads, cachelines become shared or exclusive if allocated on cache miss.
+ * On writes, cachelines become modified on a cache miss.  */
+#define PMAP_WRITE_BACK                0x00000300      /* [BOTH] */
+
+/* = PMAP_NOCACHE but overrideable (e.g. on x86 by MTRRs) */
+#define PMAP_NOCACHE_OVR       0x00000400      /* [BOTH] */
+
 
 #ifndef PMAP_EXCLUDE_DECLS     /* Used in Sparc port to virtualize pmap mod */
 #ifdef _KERNEL


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