[Qemu-devel] [PATCH 08/15] qtest/ahci: Add issue_command helper

[John Snow <jsnow@redhat.com>]

issue_command is a small routine that informs the
AHCI device that we have finalized our command and
we'd wish for the device to begin processing it.

issue_command polls the AHCI device waiting for
the device to finish, in order to achieve a
synchronous effect.

Signed-off-by: John Snow <jsnow@redhat.com>
---
 tests/ahci-test.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/tests/ahci-test.c b/tests/ahci-test.c
index fcf5ffb..4615681 100644
--- a/tests/ahci-test.c
+++ b/tests/ahci-test.c
@@ -1343,6 +1343,26 @@ static void set_command_header(AHCIState *ahci, uint8_t px,
     memwrite(ba, cmd, sizeof(AHCICommand));
 }
 
+/**
+ * Issue Command #cx via PxCI and, if ncq is true, PxSACT
+ */
+static void issue_command(AHCIState *ahci, uint8_t px,
+                          uint8_t cx, bool ncq)
+{
+    if (ncq) {
+        PX_WREG(px, AHCI_PX_SACT, (1 << cx));
+    }
+
+    PX_WREG(px, AHCI_PX_CI, (1 << cx));
+    /* We can't rely on STS_BSY until the command has started processing.
+     * Therefore, we also use the Command Issue bit as indication of
+     * a command in-flight. */
+    while (BITSET(PX_RREG(px, AHCI_PX_TFD), AHCI_PX_TFD_STS_BSY) ||
+           BITSET(PX_RREG(px, AHCI_PX_CI), (1 << cx))) {
+        usleep(50);
+    }
+}
+
 static void destroy_command(AHCIState *ahci, uint8_t px, uint8_t cx)
 {
     AHCICommand cmd;
@@ -1541,10 +1561,7 @@ static void ahci_test_identify(AHCIState *ahci)
     g_assert_cmphex(PX_RREG(i, AHCI_PX_IS), ==, 0);
 
     /* Issue Command #cx via PxCI */
-    PX_WREG(i, AHCI_PX_CI, (1 << cx));
-    while (BITSET(PX_RREG(i, AHCI_PX_TFD), AHCI_PX_TFD_STS_BSY)) {
-        usleep(50);
-    }
+    issue_command(ahci, i, cx, 0);
     port_check_error(ahci, i);
 
     /* Check for expected interrupts */
-- 
1.9.3