libqos/ahci: Add command header helpers

Adds command header helper functions:
-ahci_command_header_set
-ahci_command_header_get,
-ahci_command_destroy, and
-ahci_cmd_pick

These helpers help to quickly manage the command header information in
the AHCI device.

ahci_command_header_set and get will store or retrieve an AHCI command
header, respectively.

ahci_cmd_pick chooses the first available but least recently used
command slot to allow us to cycle through the available command slots.

ahci_command_destroy obliterates all information contained within a
given slot's command header, and frees its associated command table,
but not its DMA buffer!

Lastly, the command table pointer fields (dba and dbau) are merged into
a single 64bit value to make managing 64bit tests simpler.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1423158090-25580-5-git-send-email-jsnow@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

2 files changed, 87 insertions, 5 deletions

diff --git a/tests/libqos/ahci.c b/tests/libqos/ahci.c
index 3b1b9ba..8c3f664 100644
--- a/tests/libqos/ahci.c
+++ b/tests/libqos/ahci.c
@@ -310,3 +310,78 @@ void ahci_port_clear(AHCIQState *ahci, uint8_t port)
     /* Wipe the FIS-Recieve Buffer */
     qmemset(ahci->port[port].fb, 0x00, 0x100);
 }
+
+/* Get the command in #slot of port #port. */
+void ahci_get_command_header(AHCIQState *ahci, uint8_t port,
+                             uint8_t slot, AHCICommandHeader *cmd)
+{
+    uint64_t ba = ahci->port[port].clb;
+    ba += slot * sizeof(AHCICommandHeader);
+    memread(ba, cmd, sizeof(AHCICommandHeader));
+
+    cmd->flags = le16_to_cpu(cmd->flags);
+    cmd->prdtl = le16_to_cpu(cmd->prdtl);
+    cmd->prdbc = le32_to_cpu(cmd->prdbc);
+    cmd->ctba = le64_to_cpu(cmd->ctba);
+}
+
+/* Set the command in #slot of port #port. */
+void ahci_set_command_header(AHCIQState *ahci, uint8_t port,
+                             uint8_t slot, AHCICommandHeader *cmd)
+{
+    AHCICommandHeader tmp;
+    uint64_t ba = ahci->port[port].clb;
+    ba += slot * sizeof(AHCICommandHeader);
+
+    tmp.flags = cpu_to_le16(cmd->flags);
+    tmp.prdtl = cpu_to_le16(cmd->prdtl);
+    tmp.prdbc = cpu_to_le32(cmd->prdbc);
+    tmp.ctba = cpu_to_le64(cmd->ctba);
+
+    memwrite(ba, &tmp, sizeof(AHCICommandHeader));
+}
+
+void ahci_destroy_command(AHCIQState *ahci, uint8_t port, uint8_t slot)
+{
+    AHCICommandHeader cmd;
+
+    /* Obtain the Nth Command Header */
+    ahci_get_command_header(ahci, port, slot, &cmd);
+    if (cmd.ctba == 0) {
+        /* No address in it, so just return -- it's empty. */
+        goto tidy;
+    }
+
+    /* Free the Table */
+    ahci_free(ahci, cmd.ctba);
+
+ tidy:
+    /* NULL the header. */
+    memset(&cmd, 0x00, sizeof(cmd));
+    ahci_set_command_header(ahci, port, slot, &cmd);
+    ahci->port[port].ctba[slot] = 0;
+    ahci->port[port].prdtl[slot] = 0;
+}
+
+unsigned ahci_pick_cmd(AHCIQState *ahci, uint8_t port)
+{
+    unsigned i;
+    unsigned j;
+    uint32_t reg;
+
+    reg = ahci_px_rreg(ahci, port, AHCI_PX_CI);
+
+    /* Pick the least recently used command slot that's available */
+    for (i = 0; i < 32; ++i) {
+        j = ((ahci->port[port].next + i) % 32);
+        if (reg & (1 << j)) {
+            continue;
+        }
+        ahci_destroy_command(ahci, port, i);
+        ahci->port[port].next = (j + 1) % 32;
+        return j;
+    }
+
+    g_test_message("All command slots were busy.");
+    g_assert_not_reached();
+}
diff --git a/tests/libqos/ahci.h b/tests/libqos/ahci.h
index 1fddf33..0835be4 100644
--- a/tests/libqos/ahci.h
+++ b/tests/libqos/ahci.h
@@ -248,6 +248,9 @@
 typedef struct AHCIPortQState {
     uint64_t fb;
     uint64_t clb;
+    uint64_t ctba[32];
+    uint16_t prdtl[32];
+    uint8_t next; /** Next Command Slot to Use **/
 } AHCIPortQState;
 
 typedef struct AHCIQState {
@@ -333,8 +336,7 @@ typedef struct AHCICommandHeader {
     uint16_t flags; /* Cmd-Fis-Len, PMP#, and flags. */
     uint16_t prdtl; /* Phys Region Desc. Table Length */
     uint32_t prdbc; /* Phys Region Desc. Byte Count */
-    uint32_t ctba;  /* Command Table Descriptor Base Address */
-    uint32_t ctbau; /*                                    '' Upper */
+    uint64_t ctba;  /* Command Table Descriptor Base Address */
     uint32_t res[4];
 } __attribute__((__packed__)) AHCICommandHeader;
 
@@ -343,11 +345,10 @@ typedef struct AHCICommandHeader {
  * struct ahci_command.
  */
 typedef struct PRD {
-    uint32_t dba;  /* Data Base Address */
-    uint32_t dbau; /* Data Base Address Upper */
+    uint64_t dba;  /* Data Base Address */
     uint32_t res;  /* Reserved */
     uint32_t dbc;  /* Data Byte Count (0-indexed) & Interrupt Flag (bit 2^31) */
-} PRD;
+} __attribute__((__packed__)) PRD;
 
 /*** Macro Utilities ***/
 #define BITANY(data, mask) (((data) & (mask)) != 0)
@@ -432,5 +433,11 @@ void start_ahci_device(AHCIQState *ahci);
 void ahci_hba_enable(AHCIQState *ahci);
 unsigned ahci_port_select(AHCIQState *ahci);
 void ahci_port_clear(AHCIQState *ahci, uint8_t port);
+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,
+                             uint8_t slot, AHCICommandHeader *cmd);
+void ahci_destroy_command(AHCIQState *ahci, uint8_t port, uint8_t slot);
+unsigned ahci_pick_cmd(AHCIQState *ahci, uint8_t port);
 
 #endif