tools/testing/selftests/powerpc/tm/tm-vmxcopy.c

   1 /*
   2  * Copyright 2015, Michael Neuling, IBM Corp.
   3  * Licensed under GPLv2.
   4  *
   5  * Original: Michael Neuling 4/12/2013
   6  * Edited: Rashmica Gupta 4/12/2015
   7  *
   8  * See if the altivec state is leaked out of an aborted transaction due to
   9  * kernel vmx copy loops.
  10  *
  11  * When the transaction aborts, VSR values should rollback to the values
  12  * they held before the transaction commenced. Using VSRs while transaction
  13  * is suspended should not affect the checkpointed values.
  14  *
  15  * (1) write A to a VSR
  16  * (2) start transaction
  17  * (3) suspend transaction
  18  * (4) change the VSR to B
  19  * (5) trigger kernel vmx copy loop
  20  * (6) abort transaction
  21  * (7) check that the VSR value is A
  22  */
  23
  24 #include <inttypes.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <unistd.h>
  28 #include <sys/mman.h>
  29 #include <string.h>
  30 #include <assert.h>
  31
  32 #include "tm.h"
  33 #include "utils.h"
  34
  35 int test_vmxcopy()
  36 {
  37         long double vecin = 1.3;
  38         long double vecout;
  39         unsigned long pgsize = getpagesize();
  40         int i;
  41         int fd;
  42         int size = pgsize*16;
  43         char tmpfile[] = "/tmp/page_faultXXXXXX";
  44         char buf[pgsize];
  45         char *a;
  46         uint64_t aborted = 0;
  47
  48         SKIP_IF(!have_htm());
  49         SKIP_IF(!is_ppc64le());
  50
  51         fd = mkstemp(tmpfile);
  52         assert(fd >= 0);
  53
  54         memset(buf, 0, pgsize);
  55         for (i = 0; i < size; i += pgsize)
  56                 assert(write(fd, buf, pgsize) == pgsize);
  57
  58         unlink(tmpfile);
  59
  60         a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
  61         assert(a != MAP_FAILED);
  62
  63         asm __volatile__(
  64                 "lxvd2x 40,0,%[vecinptr];"      /* set 40 to initial value*/
  65                 "tbegin.;"
  66                 "beq    3f;"
  67                 "tsuspend.;"
  68                 "xxlxor 40,40,40;"              /* set 40 to 0 */
  69                 "std    5, 0(%[map]);"          /* cause kernel vmx copy page */
  70                 "tabort. 0;"
  71                 "tresume.;"
  72                 "tend.;"
  73                 "li     %[res], 0;"
  74                 "b      5f;"
  75
  76                 /* Abort handler */
  77                 "3:;"
  78                 "li     %[res], 1;"
  79
  80                 "5:;"
  81                 "stxvd2x 40,0,%[vecoutptr];"
  82                 : [res]"=r"(aborted)
  83                 : [vecinptr]"r"(&vecin),
  84                   [vecoutptr]"r"(&vecout),
  85                   [map]"r"(a)
  86                 : "memory", "r0", "r3", "r4", "r5", "r6", "r7");
  87
  88         if (aborted && (vecin != vecout)){
  89                 printf("FAILED: vector state leaked on abort %f != %f\n",
  90                        (double)vecin, (double)vecout);
  91                 return 1;
  92         }
  93
  94         munmap(a, size);
  95
  96         close(fd);
  97
  98         return 0;
  99 }
 100
 101 int main(void)
 102 {
 103         return test_harness(test_vmxcopy, "tm_vmxcopy");
 104 }