Merge remote-tracking branch 'remotes/jnsnow/tags/ide-pull-request' into staging

# gpg: Signature made Fri 18 Sep 2015 15:59:02 BST using RSA key ID AAFC390E
# gpg: Good signature from "John Snow (John Huston) <jsnow@redhat.com>"

* remotes/jnsnow/tags/ide-pull-request:
  ahci: clean up initial d2h semantics
  ahci: remove cmd_fis argument from write_fis_d2h
  ahci: fix signature generation
  ahci: remove dead reset code
  atapi: abort transfers with 0 byte limits
  ide: fix ATAPI command permissions
  ide-test: add cdrom dma test
  ide-test: add cdrom pio test
  qtest/ahci: export generate_pattern
  qtest/ahci: use generate_pattern everywhere
  ide: unify io_buffer_offset increments

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 26 insertions, 0 deletions

diff --git a/tests/libqos/libqos.c b/tests/libqos/libqos.c
index fce625b18a..8d7c5a9db8 100644
--- a/tests/libqos/libqos.c
+++ b/tests/libqos/libqos.c
@@ -212,3 +212,29 @@ void prepare_blkdebug_script(const char *debug_fn, const char *event)
     ret = fclose(debug_file);
     g_assert(ret == 0);
 }
+
+void generate_pattern(void *buffer, size_t len, size_t cycle_len)
+{
+    int i, j;
+    unsigned char *tx = (unsigned char *)buffer;
+    unsigned char p;
+    size_t *sx;
+
+    /* Write an indicative pattern that varies and is unique per-cycle */
+    p = rand() % 256;
+    for (i = 0; i < len; i++) {
+        tx[i] = p++ % 256;
+        if (i % cycle_len == 0) {
+            p = rand() % 256;
+        }
+    }
+
+    /* force uniqueness by writing an id per-cycle */
+    for (i = 0; i < len / cycle_len; i++) {
+        j = i * cycle_len;
+        if (j + sizeof(*sx) <= len) {
+            sx = (size_t *)&tx[j];
+            *sx = i;
+        }
+    }
+}