LXR linux/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
  35int 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
  50        fd = mkstemp(tmpfile);
  51        assert(fd >= 0);
  52
  53        memset(buf, 0, pgsize);
  54        for (i = 0; i < size; i += pgsize)
  55                assert(write(fd, buf, pgsize) == pgsize);
  56
  57        unlink(tmpfile);
  58
  59        a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
  60        assert(a != MAP_FAILED);
  61
  62        asm __volatile__(
  63                "lxvd2x 40,0,%[vecinptr];"      /* set 40 to initial value*/
  64                "tbegin.;"
  65                "beq    3f;"
  66                "tsuspend.;"
  67                "xxlxor 40,40,40;"              /* set 40 to 0 */
  68                "std    5, 0(%[map]);"          /* cause kernel vmx copy page */
  69                "tabort. 0;"
  70                "tresume.;"
  71                "tend.;"
  72                "li     %[res], 0;"
  73                "b      5f;"
  74
  75                /* Abort handler */
  76                "3:;"
  77                "li     %[res], 1;"
  78
  79                "5:;"
  80                "stxvd2x 40,0,%[vecoutptr];"
  81                : [res]"=r"(aborted)
  82                : [vecinptr]"r"(&vecin),
  83                  [vecoutptr]"r"(&vecout),
  84                  [map]"r"(a)
  85                : "memory", "r0", "r3", "r4", "r5", "r6", "r7");
  86
  87        if (aborted && (vecin != vecout)){
  88                printf("FAILED: vector state leaked on abort %f != %f\n",
  89                       (double)vecin, (double)vecout);
  90                return 1;
  91        }
  92
  93        munmap(a, size);
  94
  95        close(fd);
  96
  97        return 0;
  98}
  99
 100int main(void)
 101{
 102        return test_harness(test_vmxcopy, "tm_vmxcopy");
 103}
 104