libqos/ahci: Add port_check_nonbusy helper

A simple helper that asserts a given port is not busy processing any
commands via the TFD, Command Issue and SACT registers.
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 1423158090-25580-8-git-send-email-jsnow@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

tests/ahci-test.c

@@ -751,6 +751,7 @@ static void ahci_test_identify(AHCIQState *ahci)
     ahci_port_check_error(ahci, i);
     /* BUG: we expect AHCI_PX_IS_DPS to be set. */
     ahci_port_check_interrupts(ahci, i, AHCI_PX_IS_DHRS | AHCI_PX_IS_PSS);
+    ahci_port_check_nonbusy(ahci, i, cx);
 
     /* Investigate the CMD, assert that we read 512 bytes */
     ahci_get_command_header(ahci, i, cx, &cmd);

tests/libqos/ahci.c

@@ -347,6 +347,24 @@ void ahci_port_check_interrupts(AHCIQState *ahci, uint8_t port,
     g_assert_cmphex(ahci_px_rreg(ahci, port, AHCI_PX_IS), ==, 0);
 }
 
+void ahci_port_check_nonbusy(AHCIQState *ahci, uint8_t port, uint8_t slot)
+{
+    uint32_t reg;
+
+    /* Assert that the command slot is no longer busy (NCQ) */
+    reg = ahci_px_rreg(ahci, port, AHCI_PX_SACT);
+    ASSERT_BIT_CLEAR(reg, (1 << slot));
+
+    /* Non-NCQ */
+    reg = ahci_px_rreg(ahci, port, AHCI_PX_CI);
+    ASSERT_BIT_CLEAR(reg, (1 << slot));
+
+    /* And assert that we are generally not busy. */
+    reg = ahci_px_rreg(ahci, port, AHCI_PX_TFD);
+    ASSERT_BIT_CLEAR(reg, AHCI_PX_TFD_STS_BSY);
+    ASSERT_BIT_CLEAR(reg, AHCI_PX_TFD_STS_DRQ);
+}
+
 /* Get the command in #slot of port #port. */
 void ahci_get_command_header(AHCIQState *ahci, uint8_t port,
                              uint8_t slot, AHCICommandHeader *cmd)

tests/libqos/ahci.h

@@ -436,6 +436,7 @@ void ahci_port_clear(AHCIQState *ahci, uint8_t port);
 void ahci_port_check_error(AHCIQState *ahci, uint8_t port);
 void ahci_port_check_interrupts(AHCIQState *ahci, uint8_t port,
                                 uint32_t intr_mask);
+void ahci_port_check_nonbusy(AHCIQState *ahci, uint8_t port, uint8_t slot);
 void ahci_get_command_header(AHCIQState *ahci, uint8_t port,
                              uint8_t slot, AHCICommandHeader *cmd);
 void ahci_set_command_header(AHCIQState *ahci, uint8_t port,