The Tor Browser: security/nss/lib/freebl/mpi/mpcpucache.c@b8a032363ba2 (annotated)

security/nss/lib/freebl/mpi/mpcpucache.c@b8a032363ba2 (annotated)

security/nss/lib/freebl/mpi/mpcpucache.c

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "mpi.h"
 /*
  * This file implements a single function: s_mpi_getProcessorLineSize();
  * s_mpi_getProcessorLineSize() returns the size in bytes of the cache line
  * if a cache exists, or zero if there is no cache. If more than one
  * cache line exists, it should return the smallest line size (which is
  * usually the L1 cache).
  *
  * mp_modexp uses this information to make sure that private key information
  * isn't being leaked through the cache.
  *
  * Currently the file returns good data for most modern x86 processors, and
  * reasonable data on 64-bit ppc processors. All other processors are assumed
  * to have a cache line size of 32 bytes unless modified by target.mk.
  *
  */
 #if defined(i386) || defined(__i386) || defined(__X86__) || defined (_M_IX86) || defined(__x86_64__) || defined(__x86_64) || defined(_M_AMD64)
 /* X86 processors have special instructions that tell us about the cache */
 #include "string.h"
 #if defined(__x86_64__) || defined(__x86_64) || defined(_M_AMD64)
 #define AMD_64 1
 #endif
 /* Generic CPUID function */
 #if defined(AMD_64)
 #if defined(__GNUC__)
 void freebl_cpuid(unsigned long op, unsigned long *eax,
 	                 unsigned long *ebx, unsigned long *ecx,
                          unsigned long *edx)
 {
 	__asm__("cpuid\n\t"
 		: "=a" (*eax),
 		  "=b" (*ebx),
 		  "=c" (*ecx),
 		  "=d" (*edx)
 		: "0" (op));
 }
 #elif defined(_MSC_VER)
 #include <intrin.h>
 void freebl_cpuid(unsigned long op, unsigned long *eax,
            unsigned long *ebx, unsigned long *ecx,
            unsigned long *edx)
 {
     int intrinsic_out[4];
     __cpuid(intrinsic_out, op);
     *eax = intrinsic_out[0];
     *ebx = intrinsic_out[1];
     *ecx = intrinsic_out[2];
     *edx = intrinsic_out[3];
 }
 #endif
 #else /* !defined(AMD_64) */
 /* x86 */
 #if defined(__GNUC__)
 void freebl_cpuid(unsigned long op, unsigned long *eax,
 	                 unsigned long *ebx, unsigned long *ecx,
                          unsigned long *edx)
 {
 /* sigh GCC isn't smart enough to save the ebx PIC register on it's own
  * in this case, so do it by hand. Use edi to store ebx and pass the
  * value returned in ebx from cpuid through edi. */
 	__asm__("mov %%ebx,%%edi\n\t"
 		  "cpuid\n\t"
 		  "xchgl %%ebx,%%edi\n\t"
 		: "=a" (*eax),
 		  "=D" (*ebx),
 		  "=c" (*ecx),
 		  "=d" (*edx)
 		: "0" (op));
 }
 /*
  * try flipping a processor flag to determine CPU type
  */
 static unsigned long changeFlag(unsigned long flag)
 {
 	unsigned long changedFlags, originalFlags;
 	__asm__("pushfl\n\t"            /* get the flags */
 	        "popl %0\n\t"
 	        "movl %0,%1\n\t"	/* save the original flags */
 	        "xorl %2,%0\n\t" 	/* flip the bit */
 		"pushl %0\n\t"  	/* set the flags */
 	        "popfl\n\t"
 		"pushfl\n\t"		/* get the flags again (for return) */
 		"popl %0\n\t"
 		"pushl %1\n\t"		/* restore the original flags */
 		 "popfl\n\t"
 		: "=r" (changedFlags),
 		  "=r" (originalFlags),
 		  "=r" (flag)
 		: "2" (flag));
 	return changedFlags ^ originalFlags;
 }
 #elif defined(_MSC_VER)
 /*
  * windows versions of the above assembler
  */
 #define wcpuid __asm __emit 0fh __asm __emit 0a2h
 void freebl_cpuid(unsigned long op,    unsigned long *Reax,
     unsigned long *Rebx, unsigned long *Recx, unsigned long *Redx)
 {
         unsigned long  Leax, Lebx, Lecx, Ledx;
         __asm {
         pushad
         mov     eax,op
         wcpuid
         mov     Leax,eax
         mov     Lebx,ebx
         mov     Lecx,ecx
         mov     Ledx,edx
         popad
         }
         *Reax = Leax;
         *Rebx = Lebx;
         *Recx = Lecx;
         *Redx = Ledx;
 }
 static unsigned long changeFlag(unsigned long flag)
 {
 	unsigned long changedFlags, originalFlags;
 	__asm {
 		push eax
 		push ebx
 		pushfd 	                /* get the flags */
 	        pop  eax
 		push eax		/* save the flags on the stack */
 	        mov  originalFlags,eax  /* save the original flags */
 		mov  ebx,flag
 	        xor  eax,ebx            /* flip the bit */
 		push eax                /* set the flags */
 	        popfd
 		pushfd                  /* get the flags again (for return) */
 		pop  eax
 		popfd                   /* restore the original flags */
 		mov changedFlags,eax
 		pop ebx
 		pop eax
 	}
 	return changedFlags ^ originalFlags;
 }
 #endif
 #endif
 #if !defined(AMD_64)
 #define AC_FLAG 0x40000
 #define ID_FLAG 0x200000
 /* 386 processors can't flip the AC_FLAG, intel AP Note AP-485 */
 static int is386()
 {
     return changeFlag(AC_FLAG) == 0;
 }
 /* 486 processors can't flip the ID_FLAG, intel AP Note AP-485 */
 static int is486()
 {
     return changeFlag(ID_FLAG) == 0;
 }
 #endif
 /*
  * table for Intel Cache.
  * See Intel Application Note AP-485 for more information
  */
 typedef unsigned char CacheTypeEntry;
 typedef enum {
     Cache_NONE    = 0,
     Cache_UNKNOWN = 1,
     Cache_TLB     = 2,
     Cache_TLBi    = 3,
     Cache_TLBd    = 4,
     Cache_Trace   = 5,
     Cache_L1      = 6,
     Cache_L1i     = 7,
     Cache_L1d     = 8,
     Cache_L2      = 9 ,
     Cache_L2i     = 10 ,
     Cache_L2d     = 11 ,
     Cache_L3      = 12 ,
     Cache_L3i     = 13,
     Cache_L3d     = 14
 } CacheType;
 struct _cache {
     CacheTypeEntry type;
     unsigned char lineSize;
 };
 static const struct _cache CacheMap[256] = {
 /* 00 */ {Cache_NONE,    0   },
 /* 01 */ {Cache_TLBi,    0   },
 /* 02 */ {Cache_TLBi,    0   },
 /* 03 */ {Cache_TLBd,    0   },
 /* 04 */ {Cache_TLBd,        },
 /* 05 */ {Cache_UNKNOWN, 0   },
 /* 06 */ {Cache_L1i,     32  },
 /* 07 */ {Cache_UNKNOWN, 0   },
 /* 08 */ {Cache_L1i,     32  },
 /* 09 */ {Cache_UNKNOWN, 0   },
 /* 0a */ {Cache_L1d,     32  },
 /* 0b */ {Cache_UNKNOWN, 0   },
 /* 0c */ {Cache_L1d,     32  },
 /* 0d */ {Cache_UNKNOWN, 0   },
 /* 0e */ {Cache_UNKNOWN, 0   },
 /* 0f */ {Cache_UNKNOWN, 0   },
 /* 10 */ {Cache_UNKNOWN, 0   },
 /* 11 */ {Cache_UNKNOWN, 0   },
 /* 12 */ {Cache_UNKNOWN, 0   },
 /* 13 */ {Cache_UNKNOWN, 0   },
 /* 14 */ {Cache_UNKNOWN, 0   },
 /* 15 */ {Cache_UNKNOWN, 0   },
 /* 16 */ {Cache_UNKNOWN, 0   },
 /* 17 */ {Cache_UNKNOWN, 0   },
 /* 18 */ {Cache_UNKNOWN, 0   },
 /* 19 */ {Cache_UNKNOWN, 0   },
 /* 1a */ {Cache_UNKNOWN, 0   },
 /* 1b */ {Cache_UNKNOWN, 0   },
 /* 1c */ {Cache_UNKNOWN, 0   },
 /* 1d */ {Cache_UNKNOWN, 0   },
 /* 1e */ {Cache_UNKNOWN, 0   },
 /* 1f */ {Cache_UNKNOWN, 0   },
 /* 20 */ {Cache_UNKNOWN, 0   },
 /* 21 */ {Cache_UNKNOWN, 0   },
 /* 22 */ {Cache_L3,      64  },
 /* 23 */ {Cache_L3,      64  },
 /* 24 */ {Cache_UNKNOWN, 0   },
 /* 25 */ {Cache_L3,      64  },
 /* 26 */ {Cache_UNKNOWN, 0   },
 /* 27 */ {Cache_UNKNOWN, 0   },
 /* 28 */ {Cache_UNKNOWN, 0   },
 /* 29 */ {Cache_L3,      64  },
 /* 2a */ {Cache_UNKNOWN, 0   },
 /* 2b */ {Cache_UNKNOWN, 0   },
 /* 2c */ {Cache_L1d,     64  },
 /* 2d */ {Cache_UNKNOWN, 0   },
 /* 2e */ {Cache_UNKNOWN, 0   },
 /* 2f */ {Cache_UNKNOWN, 0   },
 /* 30 */ {Cache_L1i,     64  },
 /* 31 */ {Cache_UNKNOWN, 0   },
 /* 32 */ {Cache_UNKNOWN, 0   },
 /* 33 */ {Cache_UNKNOWN, 0   },
 /* 34 */ {Cache_UNKNOWN, 0   },
 /* 35 */ {Cache_UNKNOWN, 0   },
 /* 36 */ {Cache_UNKNOWN, 0   },
 /* 37 */ {Cache_UNKNOWN, 0   },
 /* 38 */ {Cache_UNKNOWN, 0   },
 /* 39 */ {Cache_L2,      64  },
 /* 3a */ {Cache_UNKNOWN, 0   },
 /* 3b */ {Cache_L2,      64  },
 /* 3c */ {Cache_L2,      64  },
 /* 3d */ {Cache_UNKNOWN, 0   },
 /* 3e */ {Cache_UNKNOWN, 0   },
 /* 3f */ {Cache_UNKNOWN, 0   },
 /* 40 */ {Cache_L2,      0   },
 /* 41 */ {Cache_L2,      32  },
 /* 42 */ {Cache_L2,      32  },
 /* 43 */ {Cache_L2,      32  },
 /* 44 */ {Cache_L2,      32  },
 /* 45 */ {Cache_L2,      32  },
 /* 46 */ {Cache_UNKNOWN, 0   },
 /* 47 */ {Cache_UNKNOWN, 0   },
 /* 48 */ {Cache_UNKNOWN, 0   },
 /* 49 */ {Cache_UNKNOWN, 0   },
 /* 4a */ {Cache_UNKNOWN, 0   },
 /* 4b */ {Cache_UNKNOWN, 0   },
 /* 4c */ {Cache_UNKNOWN, 0   },
 /* 4d */ {Cache_UNKNOWN, 0   },
 /* 4e */ {Cache_UNKNOWN, 0   },
 /* 4f */ {Cache_UNKNOWN, 0   },
 /* 50 */ {Cache_TLBi,    0   },
 /* 51 */ {Cache_TLBi,    0   },
 /* 52 */ {Cache_TLBi,    0   },
 /* 53 */ {Cache_UNKNOWN, 0   },
 /* 54 */ {Cache_UNKNOWN, 0   },
 /* 55 */ {Cache_UNKNOWN, 0   },
 /* 56 */ {Cache_UNKNOWN, 0   },
 /* 57 */ {Cache_UNKNOWN, 0   },
 /* 58 */ {Cache_UNKNOWN, 0   },
 /* 59 */ {Cache_UNKNOWN, 0   },
 /* 5a */ {Cache_UNKNOWN, 0   },
 /* 5b */ {Cache_TLBd,    0   },
 /* 5c */ {Cache_TLBd,    0   },
 /* 5d */ {Cache_TLBd,    0   },
 /* 5e */ {Cache_UNKNOWN, 0   },
 /* 5f */ {Cache_UNKNOWN, 0   },
 /* 60 */ {Cache_UNKNOWN, 0   },
 /* 61 */ {Cache_UNKNOWN, 0   },
 /* 62 */ {Cache_UNKNOWN, 0   },
 /* 63 */ {Cache_UNKNOWN, 0   },
 /* 64 */ {Cache_UNKNOWN, 0   },
 /* 65 */ {Cache_UNKNOWN, 0   },
 /* 66 */ {Cache_L1d,     64  },
 /* 67 */ {Cache_L1d,     64  },
 /* 68 */ {Cache_L1d,     64  },
 /* 69 */ {Cache_UNKNOWN, 0   },
 /* 6a */ {Cache_UNKNOWN, 0   },
 /* 6b */ {Cache_UNKNOWN, 0   },
 /* 6c */ {Cache_UNKNOWN, 0   },
 /* 6d */ {Cache_UNKNOWN, 0   },
 /* 6e */ {Cache_UNKNOWN, 0   },
 /* 6f */ {Cache_UNKNOWN, 0   },
 /* 70 */ {Cache_Trace,   1   },
 /* 71 */ {Cache_Trace,   1   },
 /* 72 */ {Cache_Trace,   1   },
 /* 73 */ {Cache_UNKNOWN, 0   },
 /* 74 */ {Cache_UNKNOWN, 0   },
 /* 75 */ {Cache_UNKNOWN, 0   },
 /* 76 */ {Cache_UNKNOWN, 0   },
 /* 77 */ {Cache_UNKNOWN, 0   },
 /* 78 */ {Cache_UNKNOWN, 0   },
 /* 79 */ {Cache_L2,      64  },
 /* 7a */ {Cache_L2,      64  },
 /* 7b */ {Cache_L2,      64  },
 /* 7c */ {Cache_L2,      64  },
 /* 7d */ {Cache_UNKNOWN, 0   },
 /* 7e */ {Cache_UNKNOWN, 0   },
 /* 7f */ {Cache_UNKNOWN, 0   },
 /* 80 */ {Cache_UNKNOWN, 0   },
 /* 81 */ {Cache_UNKNOWN, 0   },
 /* 82 */ {Cache_L2,      32  },
 /* 83 */ {Cache_L2,      32  },
 /* 84 */ {Cache_L2,      32  },
 /* 85 */ {Cache_L2,      32  },
 /* 86 */ {Cache_L2,      64  },
 /* 87 */ {Cache_L2,      64  },
 /* 88 */ {Cache_UNKNOWN, 0   },
 /* 89 */ {Cache_UNKNOWN, 0   },
 /* 8a */ {Cache_UNKNOWN, 0   },
 /* 8b */ {Cache_UNKNOWN, 0   },
 /* 8c */ {Cache_UNKNOWN, 0   },
 /* 8d */ {Cache_UNKNOWN, 0   },
 /* 8e */ {Cache_UNKNOWN, 0   },
 /* 8f */ {Cache_UNKNOWN, 0   },
 /* 90 */ {Cache_UNKNOWN, 0   },
 /* 91 */ {Cache_UNKNOWN, 0   },
 /* 92 */ {Cache_UNKNOWN, 0   },
 /* 93 */ {Cache_UNKNOWN, 0   },
 /* 94 */ {Cache_UNKNOWN, 0   },
 /* 95 */ {Cache_UNKNOWN, 0   },
 /* 96 */ {Cache_UNKNOWN, 0   },
 /* 97 */ {Cache_UNKNOWN, 0   },
 /* 98 */ {Cache_UNKNOWN, 0   },
 /* 99 */ {Cache_UNKNOWN, 0   },
 /* 9a */ {Cache_UNKNOWN, 0   },
 /* 9b */ {Cache_UNKNOWN, 0   },
 /* 9c */ {Cache_UNKNOWN, 0   },
 /* 9d */ {Cache_UNKNOWN, 0   },
 /* 9e */ {Cache_UNKNOWN, 0   },
 /* 9f */ {Cache_UNKNOWN, 0   },
 /* a0 */ {Cache_UNKNOWN, 0   },
 /* a1 */ {Cache_UNKNOWN, 0   },
 /* a2 */ {Cache_UNKNOWN, 0   },
 /* a3 */ {Cache_UNKNOWN, 0   },
 /* a4 */ {Cache_UNKNOWN, 0   },
 /* a5 */ {Cache_UNKNOWN, 0   },
 /* a6 */ {Cache_UNKNOWN, 0   },
 /* a7 */ {Cache_UNKNOWN, 0   },
 /* a8 */ {Cache_UNKNOWN, 0   },
 /* a9 */ {Cache_UNKNOWN, 0   },
 /* aa */ {Cache_UNKNOWN, 0   },
 /* ab */ {Cache_UNKNOWN, 0   },
 /* ac */ {Cache_UNKNOWN, 0   },
 /* ad */ {Cache_UNKNOWN, 0   },
 /* ae */ {Cache_UNKNOWN, 0   },
 /* af */ {Cache_UNKNOWN, 0   },
 /* b0 */ {Cache_TLBi,    0   },
 /* b1 */ {Cache_UNKNOWN, 0   },
 /* b2 */ {Cache_UNKNOWN, 0   },
 /* b3 */ {Cache_TLBd,    0   },
 /* b4 */ {Cache_UNKNOWN, 0   },
 /* b5 */ {Cache_UNKNOWN, 0   },
 /* b6 */ {Cache_UNKNOWN, 0   },
 /* b7 */ {Cache_UNKNOWN, 0   },
 /* b8 */ {Cache_UNKNOWN, 0   },
 /* b9 */ {Cache_UNKNOWN, 0   },
 /* ba */ {Cache_UNKNOWN, 0   },
 /* bb */ {Cache_UNKNOWN, 0   },
 /* bc */ {Cache_UNKNOWN, 0   },
 /* bd */ {Cache_UNKNOWN, 0   },
 /* be */ {Cache_UNKNOWN, 0   },
 /* bf */ {Cache_UNKNOWN, 0   },
 /* c0 */ {Cache_UNKNOWN, 0   },
 /* c1 */ {Cache_UNKNOWN, 0   },
 /* c2 */ {Cache_UNKNOWN, 0   },
 /* c3 */ {Cache_UNKNOWN, 0   },
 /* c4 */ {Cache_UNKNOWN, 0   },
 /* c5 */ {Cache_UNKNOWN, 0   },
 /* c6 */ {Cache_UNKNOWN, 0   },
 /* c7 */ {Cache_UNKNOWN, 0   },
 /* c8 */ {Cache_UNKNOWN, 0   },
 /* c9 */ {Cache_UNKNOWN, 0   },
 /* ca */ {Cache_UNKNOWN, 0   },
 /* cb */ {Cache_UNKNOWN, 0   },
 /* cc */ {Cache_UNKNOWN, 0   },
 /* cd */ {Cache_UNKNOWN, 0   },
 /* ce */ {Cache_UNKNOWN, 0   },
 /* cf */ {Cache_UNKNOWN, 0   },
 /* d0 */ {Cache_UNKNOWN, 0   },
 /* d1 */ {Cache_UNKNOWN, 0   },
 /* d2 */ {Cache_UNKNOWN, 0   },
 /* d3 */ {Cache_UNKNOWN, 0   },
 /* d4 */ {Cache_UNKNOWN, 0   },
 /* d5 */ {Cache_UNKNOWN, 0   },
 /* d6 */ {Cache_UNKNOWN, 0   },
 /* d7 */ {Cache_UNKNOWN, 0   },
 /* d8 */ {Cache_UNKNOWN, 0   },
 /* d9 */ {Cache_UNKNOWN, 0   },
 /* da */ {Cache_UNKNOWN, 0   },
 /* db */ {Cache_UNKNOWN, 0   },
 /* dc */ {Cache_UNKNOWN, 0   },
 /* dd */ {Cache_UNKNOWN, 0   },
 /* de */ {Cache_UNKNOWN, 0   },
 /* df */ {Cache_UNKNOWN, 0   },
 /* e0 */ {Cache_UNKNOWN, 0   },
 /* e1 */ {Cache_UNKNOWN, 0   },
 /* e2 */ {Cache_UNKNOWN, 0   },
 /* e3 */ {Cache_UNKNOWN, 0   },
 /* e4 */ {Cache_UNKNOWN, 0   },
 /* e5 */ {Cache_UNKNOWN, 0   },
 /* e6 */ {Cache_UNKNOWN, 0   },
 /* e7 */ {Cache_UNKNOWN, 0   },
 /* e8 */ {Cache_UNKNOWN, 0   },
 /* e9 */ {Cache_UNKNOWN, 0   },
 /* ea */ {Cache_UNKNOWN, 0   },
 /* eb */ {Cache_UNKNOWN, 0   },
 /* ec */ {Cache_UNKNOWN, 0   },
 /* ed */ {Cache_UNKNOWN, 0   },
 /* ee */ {Cache_UNKNOWN, 0   },
 /* ef */ {Cache_UNKNOWN, 0   },
 /* f0 */ {Cache_UNKNOWN, 0   },
 /* f1 */ {Cache_UNKNOWN, 0   },
 /* f2 */ {Cache_UNKNOWN, 0   },
 /* f3 */ {Cache_UNKNOWN, 0   },
 /* f4 */ {Cache_UNKNOWN, 0   },
 /* f5 */ {Cache_UNKNOWN, 0   },
 /* f6 */ {Cache_UNKNOWN, 0   },
 /* f7 */ {Cache_UNKNOWN, 0   },
 /* f8 */ {Cache_UNKNOWN, 0   },
 /* f9 */ {Cache_UNKNOWN, 0   },
 /* fa */ {Cache_UNKNOWN, 0   },
 /* fb */ {Cache_UNKNOWN, 0   },
 /* fc */ {Cache_UNKNOWN, 0   },
 /* fd */ {Cache_UNKNOWN, 0   },
 /* fe */ {Cache_UNKNOWN, 0   },
 /* ff */ {Cache_UNKNOWN, 0   }
 };
 /*
  * use the above table to determine the CacheEntryLineSize.
  */
 static void
 getIntelCacheEntryLineSize(unsigned long val, int *level,
 						unsigned long *lineSize)
 {
     CacheType type;
     type = CacheMap[val].type;
     /* only interested in data caches */
     /* NOTE val = 0x40 is a special value that means no L2 or L3 cache.
      * this data check has the side effect of rejecting that entry. If
      * that wasn't the case, we could have to reject it explicitly */
     if (CacheMap[val].lineSize == 0) {
 	return;
     }
     /* look at the caches, skip types we aren't interested in.
      * if we already have a value for a lower level cache, skip the
      * current entry */
     if ((type == Cache_L1)|| (type == Cache_L1d)) {
 	*level = 1;
 	*lineSize = CacheMap[val].lineSize;
     } else if ((*level >= 2) && ((type == Cache_L2) || (type == Cache_L2d))) {
 	*level = 2;
 	*lineSize = CacheMap[val].lineSize;
     } else if ((*level >= 3) && ((type == Cache_L3) || (type == Cache_L3d))) {
 	*level = 3;
 	*lineSize = CacheMap[val].lineSize;
     }
     return;
 }
 static void
 getIntelRegisterCacheLineSize(unsigned long val,
 			int *level, unsigned long *lineSize)
 {
     getIntelCacheEntryLineSize(val >> 24 & 0xff, level, lineSize);
     getIntelCacheEntryLineSize(val >> 16 & 0xff, level, lineSize);
     getIntelCacheEntryLineSize(val >> 8 & 0xff, level, lineSize);
     getIntelCacheEntryLineSize(val & 0xff, level, lineSize);
 }
 /*
  * returns '0' if no recognized cache is found, or if the cache
  * information is supported by this processor
  */
 static unsigned long
 getIntelCacheLineSize(int cpuidLevel)
 {
     int level = 4;
     unsigned long lineSize = 0;
     unsigned long eax, ebx, ecx, edx;
     int repeat, count;
     if (cpuidLevel < 2) {
 	return 0;
     }
     /* command '2' of the cpuid is intel's cache info call. Each byte of the
      * 4 registers contain a potential descriptor for the cache. The CacheMap
      * table maps the cache entry with the processor cache. Register 'al'
      * contains a count value that cpuid '2' needs to be called in order to
      * find all the cache descriptors. Only registers with the high bit set
      * to 'zero' have valid descriptors. This code loops through all the
      * required calls to cpuid '2' and passes any valid descriptors it finds
      * to the getIntelRegisterCacheLineSize code, which breaks the registers
      * down into their component descriptors. In the end the lineSize of the
      * lowest level cache data cache is returned. */
     freebl_cpuid(2, &eax, &ebx, &ecx, &edx);
     repeat = eax & 0xf;
     for (count = 0; count < repeat; count++) {
 	if ((eax & 0x80000000) == 0) {
 	    getIntelRegisterCacheLineSize(eax & 0xffffff00, &level, &lineSize);
 	}
 	if ((ebx & 0x80000000) == 0) {
 	    getIntelRegisterCacheLineSize(ebx, &level, &lineSize);
 	}
 	if ((ecx & 0x80000000) == 0) {
 	    getIntelRegisterCacheLineSize(ecx, &level, &lineSize);
 	}
 	if ((edx & 0x80000000) == 0) {
 	    getIntelRegisterCacheLineSize(edx, &level, &lineSize);
 	}
 	if (count+1 != repeat) {
 	    freebl_cpuid(2, &eax, &ebx, &ecx, &edx);
 	}
     }
     return lineSize;
 }
 /*
  * returns '0' if the cache info is not supported by this processor.
  * This is based on the AMD extended cache commands for cpuid.
  * (see "AMD Processor Recognition Application Note" Publication 20734).
  * Some other processors use the identical scheme.
  * (see "Processor Recognition, Transmeta Corporation").
  */
 static unsigned long
 getOtherCacheLineSize(unsigned long cpuidLevel)
 {
     unsigned long lineSize = 0;
     unsigned long eax, ebx, ecx, edx;
     /* get the Extended CPUID level */
     freebl_cpuid(0x80000000, &eax, &ebx, &ecx, &edx);
     cpuidLevel = eax;
     if (cpuidLevel >= 0x80000005) {
 	freebl_cpuid(0x80000005, &eax, &ebx, &ecx, &edx);
 	lineSize = ecx & 0xff; /* line Size, L1 Data Cache */
     }
     return lineSize;
 }
 static const char * const manMap[] = {
 #define INTEL     0
     "GenuineIntel",
 #define AMD       1
     "AuthenticAMD",
 #define CYRIX     2
     "CyrixInstead",
 #define CENTAUR   2
     "CentaurHauls",
 #define NEXGEN    3
     "NexGenDriven",
 #define TRANSMETA 4
     "GenuineTMx86",
 #define RISE      5
     "RiseRiseRise",
 #define UMC       6
     "UMC UMC UMC ",
 #define SIS       7
     "Sis Sis Sis ",
 #define NATIONAL  8
     "Geode by NSC",
 };
 static const int n_manufacturers = sizeof(manMap)/sizeof(manMap[0]);
 #define MAN_UNKNOWN 9
 #if !defined(AMD_64)
 #define SSE2_FLAG (1<<26)
 unsigned long
 s_mpi_is_sse2()
 {
     unsigned long eax, ebx, ecx, edx;
     int manufacturer = MAN_UNKNOWN;
     int i;
     char string[13];
     if (is386() || is486()) {
 	return 0;
     }
     freebl_cpuid(0, &eax, &ebx, &ecx, &edx);
     /* string holds the CPU's manufacturer ID string - a twelve
      * character ASCII string stored in ebx, edx, ecx, and
      * the 32-bit extended feature flags are in edx, ecx.
      */
     *(int *)string = ebx;
     *(int *)&string[4] = (int)edx;
     *(int *)&string[8] = (int)ecx;
     string[12] = 0;
     /* has no SSE2 extensions */
     if (eax == 0) {
 	return 0;
     }
     for (i=0; i < n_manufacturers; i++) {
 	if ( strcmp(manMap[i],string) == 0) {
 	    manufacturer = i;
 	    break;
 	}
     }
     freebl_cpuid(1,&eax,&ebx,&ecx,&edx);
     return (edx & SSE2_FLAG) == SSE2_FLAG;
 }
 #endif
 unsigned long
 s_mpi_getProcessorLineSize()
 {
     unsigned long eax, ebx, ecx, edx;
     unsigned long cpuidLevel;
     unsigned long cacheLineSize = 0;
     int manufacturer = MAN_UNKNOWN;
     int i;
     char string[65];
 #if !defined(AMD_64)
     if (is386()) {
 	return 0; /* 386 had no cache */
     } if (is486()) {
 	return 32; /* really? need more info */
     }
 #endif
     /* Pentium, cpuid command is available */
     freebl_cpuid(0, &eax, &ebx, &ecx, &edx);
     cpuidLevel = eax;
     /* string holds the CPU's manufacturer ID string - a twelve
      * character ASCII string stored in ebx, edx, ecx, and
      * the 32-bit extended feature flags are in edx, ecx.
      */
     *(int *)string = ebx;
     *(int *)&string[4] = (int)edx;
     *(int *)&string[8] = (int)ecx;
     string[12] = 0;
     manufacturer = MAN_UNKNOWN;
     for (i=0; i < n_manufacturers; i++) {
 	if ( strcmp(manMap[i],string) == 0) {
 	    manufacturer = i;
 	}
     }
     if (manufacturer == INTEL) {
 	cacheLineSize = getIntelCacheLineSize(cpuidLevel);
     } else {
 	cacheLineSize = getOtherCacheLineSize(cpuidLevel);
     }
     /* doesn't support cache info based on cpuid. This means
      * an old pentium class processor, which have cache lines of
      * 32. If we learn differently, we can use a switch based on
      * the Manufacturer id  */
     if (cacheLineSize == 0) {
 	cacheLineSize = 32;
     }
     return cacheLineSize;
 }
 #define MPI_GET_PROCESSOR_LINE_SIZE_DEFINED 1
 #endif
 #if defined(__ppc64__)
 /*
  *  Sigh, The PPC has some really nice features to help us determine cache
  *  size, since it had lots of direct control functions to do so. The POWER
  *  processor even has an instruction to do this, but it was dropped in
  *  PowerPC. Unfortunately most of them are not available in user mode.
  *
  *  The dcbz function would be a great way to determine cache line size except
  *  1) it only works on write-back memory (it throws an exception otherwise),
  *  and 2) because so many mac programs 'knew' the processor cache size was
  *  32 bytes, they used this instruction as a fast 'zero 32 bytes'. Now the new
  *  G5 processor has 128 byte cache, but dcbz only clears 32 bytes to keep
  *  these programs happy. dcbzl work if 64 bit instructions are supported.
  *  If you know 64 bit instructions are supported, and that stack is
  *  write-back, you can use this code.
  */
 #include "memory.h"
 /* clear the cache line that contains 'array' */
 static inline void dcbzl(char *array)
 {
 	register char *a asm("r2") = array;
 	__asm__ __volatile__( "dcbzl %0,r0" : "=r" (a): "0"(a) );
 }
 #define PPC_DO_ALIGN(x,y) ((char *)\
 			((((long long) (x))+((y)-1))&~((y)-1)))
 #define PPC_MAX_LINE_SIZE 256
 unsigned long
 s_mpi_getProcessorLineSize()
 {
     char testArray[2*PPC_MAX_LINE_SIZE+1];
     char *test;
     int i;
     /* align the array on a maximum line size boundary, so we
      * know we are starting to clear from the first address */
     test = PPC_DO_ALIGN(testArray, PPC_MAX_LINE_SIZE);
     /* set all the values to 1's */
     memset(test, 0xff, PPC_MAX_LINE_SIZE);
     /* clear one cache block starting at 'test' */
     dcbzl(test);
     /* find the size of the cleared area, that's our block size */
     for (i=PPC_MAX_LINE_SIZE; i != 0; i = i/2) {
 	if (test[i-1] == 0) {
 	    return i;
 	}
     }
     return 0;
 }
 #define MPI_GET_PROCESSOR_LINE_SIZE_DEFINED 1
 #endif
 /*
  * put other processor and platform specific cache code here
  * return the smallest cache line size in bytes on the processor
  * (usually the L1 cache). If the OS has a call, this would be
  * a greate place to put it.
  *
  * If there is no cache, return 0;
  *
  * define MPI_GET_PROCESSOR_LINE_SIZE_DEFINED so the generic functions
  * below aren't compiled.
  *
  */
 /* target.mk can define MPI_CACHE_LINE_SIZE if it's common for the family or
  * OS */
 #if defined(MPI_CACHE_LINE_SIZE) && !defined(MPI_GET_PROCESSOR_LINE_SIZE_DEFINED)
 unsigned long
 s_mpi_getProcessorLineSize()
 {
    return MPI_CACHE_LINE_SIZE;
 }
 #define MPI_GET_PROCESSOR_LINE_SIZE_DEFINED 1
 #endif
 /* If no way to get the processor cache line size has been defined, assume
  * it's 32 bytes (most common value, does not significantly impact performance)
  */
 #ifndef MPI_GET_PROCESSOR_LINE_SIZE_DEFINED
 unsigned long
 s_mpi_getProcessorLineSize()
 {
    return 32;
 }
 #endif
 #ifdef TEST_IT
 #include <stdio.h>
 main()
 {
     printf("line size = %d\n", s_mpi_getProcessorLineSize());
 }
 #endif

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security/nss/lib/freebl/mpi/mpcpucache.c@b8a032363ba2 (annotated)

security/nss/lib/freebl/mpi/mpcpucache.c