src/hwinfo/src/smp/smp.c

   1 /*
   2 [_Anarchy_(alan@lightning.swansea.uk.linux.org)] you should do one check
   3    though - if the board seems to be SMP and the CPU in /proc/cpuinfo is non
   4    intel dont install an SMP kernel - thats a dual pentium board with a cyrix
   5    or similar single cpu in it
   6 */
   7
   8
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <unistd.h>
  12 #include <fcntl.h>
  13 #include <sys/mman.h>
  14 #include <string.h>
  15 #include <errno.h>
  16
  17 #ifdef __i386__
  18 #define SMP_MAGIC_IDENT (('_'<<24)|('P'<<16)|('M'<<8)|'_')
  19
  20 struct intel_mp_floating
  21 {
  22         char mpf_signature[4];          /* "_MP_"                       */
  23         unsigned long mpf_physptr;      /* Configuration table address  */
  24         unsigned char mpf_length;       /* Our length (paragraphs)      */
  25         unsigned char mpf_specification;/* Specification version        */
  26         unsigned char mpf_checksum;     /* Checksum (makes sum 0)       */
  27         unsigned char mpf_feature1;     /* Standard or configuration ?  */
  28         unsigned char mpf_feature2;     /* Bit7 set for IMCR|PIC        */
  29         unsigned char mpf_feature3;     /* Unused (0)                   */
  30         unsigned char mpf_feature4;     /* Unused (0)                   */
  31         unsigned char mpf_feature5;     /* Unused (0)                   */
  32 };
  33
  34 struct mp_config_table
  35 {
  36         char mpc_signature[4];
  37 #define MPC_SIGNATURE "PCMP"
  38         unsigned short mpc_length;      /* Size of table */
  39         char  mpc_spec;                 /* 0x01 */
  40         char  mpc_checksum;
  41         char  mpc_oem[8];
  42         char  mpc_productid[12];
  43         unsigned long mpc_oemptr;       /* 0 if not present */
  44         unsigned short mpc_oemsize;     /* 0 if not present */
  45         unsigned short mpc_oemcount;
  46         unsigned long mpc_lapic;        /* APIC address */
  47         unsigned long reserved;
  48 };
  49
  50 /* Followed by entries */
  51
  52 #define MP_PROCESSOR    0
  53 #define MP_BUS          1
  54 #define MP_IOAPIC       2
  55 #define MP_INTSRC       3
  56 #define MP_LINTSRC      4
  57
  58 struct mpc_config_processor
  59 {
  60         unsigned char mpc_type;
  61         unsigned char mpc_apicid;       /* Local APIC number */
  62         unsigned char mpc_apicver;      /* Its versions */
  63         unsigned char mpc_cpuflag;
  64 #define CPU_ENABLED             1       /* Processor is available */
  65 #define CPU_BOOTPROCESSOR       2       /* Processor is the BP */
  66         unsigned long mpc_cpufeature;
  67 #define CPU_STEPPING_MASK 0x0F
  68 #define CPU_MODEL_MASK  0xF0
  69 #define CPU_FAMILY_MASK 0xF00
  70         unsigned long mpc_featureflag;  /* CPUID feature value */
  71         unsigned long mpc_reserved[2];
  72 };
  73
  74 struct mpc_config_bus
  75 {
  76         unsigned char mpc_type;
  77         unsigned char mpc_busid;
  78         unsigned char mpc_bustype[6] __attribute((packed));
  79 };
  80
  81 #define BUSTYPE_EISA    "EISA"
  82 #define BUSTYPE_ISA     "ISA"
  83 #define BUSTYPE_INTERN  "INTERN"        /* Internal BUS */
  84 #define BUSTYPE_MCA     "MCA"
  85 #define BUSTYPE_VL      "VL"            /* Local bus */
  86 #define BUSTYPE_PCI     "PCI"
  87 #define BUSTYPE_PCMCIA  "PCMCIA"
  88
  89 /* We don't understand the others */
  90
  91 struct mpc_config_ioapic
  92 {
  93         unsigned char mpc_type;
  94         unsigned char mpc_apicid;
  95         unsigned char mpc_apicver;
  96         unsigned char mpc_flags;
  97 #define MPC_APIC_USABLE         0x01
  98         unsigned long mpc_apicaddr;
  99 };
 100
 101 struct mpc_config_intsrc
 102 {
 103         unsigned char mpc_type;
 104         unsigned char mpc_irqtype;
 105         unsigned short mpc_irqflag;
 106         unsigned char mpc_srcbus;
 107         unsigned char mpc_srcbusirq;
 108         unsigned char mpc_dstapic;
 109         unsigned char mpc_dstirq;
 110 };
 111
 112 #define MP_INT_VECTORED         0
 113 #define MP_INT_NMI              1
 114 #define MP_INT_SMI              2
 115 #define MP_INT_EXTINT           3
 116
 117 #define MP_IRQDIR_DEFAULT       0
 118 #define MP_IRQDIR_HIGH          1
 119 #define MP_IRQDIR_LOW           3
 120
 121
 122 struct mpc_config_intlocal
 123 {
 124         unsigned char mpc_type;
 125         unsigned char mpc_irqtype;
 126         unsigned short mpc_irqflag;
 127         unsigned char mpc_srcbusid;
 128         unsigned char mpc_srcbusirq;
 129         unsigned char mpc_destapic;
 130 #define MP_APIC_ALL     0xFF
 131         unsigned char mpc_destapiclint;
 132 };
 133
 134
 135 /*
 136  *      Default configurations
 137  *
 138  *      1       2 CPU ISA 82489DX
 139  *      2       2 CPU EISA 82489DX no IRQ 8 or timer chaining
 140  *      3       2 CPU EISA 82489DX
 141  *      4       2 CPU MCA 82489DX
 142  *      5       2 CPU ISA+PCI
 143  *      6       2 CPU EISA+PCI
 144  *      7       2 CPU MCA+PCI
 145  */
 146
 147
 148 static int smp_found_config=0;
 149
 150 /*
 151  *      Checksum an MP configuration block.
 152  */
 153
 154 static int mpf_checksum(unsigned char *mp, int len)
 155 {
 156         int sum=0;
 157         while(len--)
 158                 sum+=*mp++;
 159         return sum&0xFF;
 160 }
 161
 162 static int do_smp_scan_config(unsigned long *bp, unsigned long length)
 163 {
 164         struct intel_mp_floating *mpf;
 165
 166 /*
 167         if (sizeof(*mpf)!=16)
 168                 logMessage("Error: MPF size\n");
 169 */
 170
 171         while (length>0)
 172         {
 173                 if (*bp==SMP_MAGIC_IDENT)
 174                 {
 175                         mpf=(struct intel_mp_floating *)bp;
 176                         if (mpf->mpf_length==1 &&
 177                                 !mpf_checksum((unsigned char *)bp,16) &&
 178                                 (mpf->mpf_specification == 1
 179                                  || mpf->mpf_specification == 4) )
 180                         {
 181                                 /*logMessage("Intel MultiProcessor Specification v1.%d\n", mpf->mpf_specification);
 182                                 if (mpf->mpf_feature2&(1<<7))
 183                                         logMessage("    IMCR and PIC compatibility mode.\n");
 184                                 else
 185                                         logMessage("    Virtual Wire compatibility mode.\n");
 186 */
 187                                 smp_found_config=1;
 188                                 return 1;
 189                         }
 190                 }
 191                 bp+=4;
 192                 length-=16;
 193         }
 194
 195         return 0;
 196 }
 197
 198 static int smp_scan_config(int mem_fd, unsigned long base,
 199                            unsigned long length)
 200 {
 201         void *p;
 202         int o;
 203
 204         o=base&0xFFF;
 205         base-=o;
 206         length+=o;
 207
 208         p=mmap(0, (length+4095)&0xFFFFF000,  PROT_READ, MAP_SHARED,
 209                 mem_fd, (base&0xFFFF0000));
 210         if(p==MAP_FAILED)
 211         {
 212                 /*logMessage("SMP Probe error: mmap: %s", strerror(errno));*/
 213                 return 1;
 214         }
 215         do_smp_scan_config(p+o, length-o);
 216         munmap(p, (length+4095)&0xFFFFF000);
 217         return 0;
 218 }
 219
 220 static int intelDetectSMP(void)
 221 {
 222         int mem_fd;
 223
 224         mem_fd=open("/dev/mem", O_RDONLY);
 225
 226         if(mem_fd==-1)
 227         {
 228                 /*logMessage("Error detecting SMP: /dev/mem: %s", strerror(errno));*/
 229         }
 230
 231         /*
 232          * FIXME: Linux assumes you have 640K of base ram..
 233          * this continues the error...
 234          *
 235          * 1) Scan the bottom 1K for a signature
 236          * 2) Scan the top 1K of base RAM
 237          * 3) Scan the 64K of bios
 238          */
 239         if (!smp_scan_config(mem_fd, 0x0, 0x400) &&
 240             !smp_scan_config(mem_fd, 639*0x400,0x400) &&
 241             !smp_scan_config(mem_fd, 0xF0000,0x10000)) {
 242 #if 0
 243
 244                 /*
 245                  * If it is an SMP machine we should know now, unless the
 246                  * configuration is in an EISA/MCA bus machine with an
 247                  * extended bios data area.
 248                  *
 249                  * there is a real-mode segmented pointer pointing to the
 250                  * 4K EBDA area at 0x40E, calculate and scan it here.
 251                  *
 252                  * NOTE! There are Linux loaders that will corrupt the EBDA
 253                  * area, and as such this kind of SMP config may be less
 254                  * trustworthy, simply because the SMP table may have been
 255                  * stomped on during early boot. These loaders are buggy and
 256                  * should be fixed.
 257                  */
 258                 unsigned int address;
 259
 260                 address = *(unsigned short *)phys_to_virt(0x40E);
 261                 address<<=4;
 262                 smp_scan_config(mem_fd, address, 0x1000);
 263                 if (smp_found_config)
 264                         /*logMessage("WARNING: MP table in the EBDA can be UNSAFE, contact linux-smp@vger.rutgers.edu if you experience SMP problems!\n");*/
 265 #endif
 266         }
 267 /*
 268         if(smp_found_config)
 269                 logMessage("Detected SMP capable motherboard\n");
 270         else
 271                 logMessage("Detected non SMP capable motherboard\n");
 272 */
 273         return smp_found_config;
 274 }
 275
 276 int detectSMP(void)
 277 {
 278     static int isSMP = -1;
 279
 280     if (isSMP != -1)
 281         return isSMP;
 282
 283     return isSMP = intelDetectSMP();
 284 }
 285
 286 #endif /* __i386__ */