1 /*******************************************************************************
2  * Derived from the test case for the "dcbzl" instruction support by
3  * Dave Goodell * <goodell@mcs.anl.gov>
4  * (see: Bug 135264 - dcbzl instruction missing)
5  * and: coregrind/m_machine.c/find_ppc_dcbz_sz()
6  ******************************************************************************/
7 
8 /* ensure we have posix_memalign */
9 #define _POSIX_C_SOURCE 200112L
10 
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <string.h>
14 #include <assert.h>
15 
query_block_size(void)16 static int query_block_size(void)
17 {
18 #define MAX_DCBZL_SZB (128) /* largest known effect of dcbzl */
19   char *test_block = NULL;
20   register char *rb asm ("r14");
21   int block_size, test_block_size = 4 * MAX_DCBZL_SZB, err;
22   char *p;
23 
24   err = posix_memalign ((void **)&test_block, MAX_DCBZL_SZB, test_block_size);
25   if (err) {
26     fprintf(stderr, "posix_memalign() failed (err = %d [%s])\n", err, strerror(err));
27     return err;
28   }
29 
30   rb = test_block;
31 
32   memset(rb, 0xff, test_block_size);
33   asm volatile ("dcbzl 0, %[RB]" : : [RB] "r" (rb));
34   for (block_size = 0, p = rb; (p - rb) < test_block_size; p++)
35     if (!*p)
36       block_size++;
37   assert(block_size == 16 || block_size == 32 || block_size == 64 || block_size == 128);
38 
39   free(test_block);
40   return block_size;
41 }
42 
43 /* Test dcbzl at addr in buffer given dcbzl_block_size */
test_dcbzl_at(char * addr,char * buffer,int block_size)44 static void test_dcbzl_at(char *addr, char *buffer, int block_size)
45 {
46   int i;
47 
48   /* Note: Assumption is that the length of buffer is three times the block_size. */
49   memset(buffer, 0xff, 3 * block_size);
50   asm volatile ("dcbzl %[RA], %[RB]" : : [RA] "r" (0), [RB] "r" (addr));
51   for (i = 0; i < block_size; i++) {
52     assert(buffer[i] == 0xff);
53     assert(buffer[block_size + i] == 0x00);
54     assert(buffer[2 * block_size + i] == 0xff);
55   }
56 }
57 
58 /* Test for insn: dcbzl */
test_dcbzl(void)59 static int test_dcbzl(void)
60 {
61   int err;
62   char *buffer = NULL;
63   int buffer_size;
64   int block_size;
65 
66   block_size = query_block_size();
67   assert(block_size == 16 || block_size == 32 || block_size == 64 || block_size == 128);
68   buffer_size = 3 * block_size;
69   err = posix_memalign((void **) &buffer, block_size, buffer_size);
70   if (err) {
71     fprintf(stderr, "posix_memalign() failed (err = %d [%s])\n", err, strerror(err));
72     return err;
73   }
74 
75   /* check at aligned address within the test block */
76   test_dcbzl_at(&buffer[block_size], buffer, block_size);
77   fprintf(stdout, "Passed dcbzl test at aligned address within the test block.\n");
78 
79   /* check at un-aligned (1 modulo block_size) address within the test block */
80   test_dcbzl_at(&buffer[block_size+1], buffer, block_size);
81   fprintf(stdout, "Passed dcbzl test at un-aligned (1 modulo block_size) address within the test block.\n");
82 
83   /* check at un-aligned ((block_size - 1) modulo block_size) address within the test block */
84   test_dcbzl_at(&buffer[2 * block_size - 1], buffer, block_size);
85   fprintf(stdout, "Passed dcbzl test at un-aligned ((block_size - 1) modulo block_size) address within the test block.\n");
86 
87   free(buffer);
88   return 0;
89 }
90 
main(int argc,char ** argv)91 int main(int argc, char **argv)
92 {
93   int status;
94   status = test_dcbzl ();
95   return status;
96 }
97