[Qemu-devel] [PATCH 27/28] ahci: Add test_hba_enable to ahci-test.

[John Snow <jsnow@redhat.com>]

This test engages the HBA functionality and initializes
values to sane defaults to allow for minimal HBA functionality.

Buffers are allocated and pointers are updated to allow minimal
I/O commands to complete as expected. Error registers and responses
are sanity checked for specification adherence.

Signed-off-by: John Snow <jsnow@redhat.com>
---
 tests/ahci-test.c | 150 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 150 insertions(+)

diff --git a/tests/ahci-test.c b/tests/ahci-test.c
index 727c939..f342e2c 100644
--- a/tests/ahci-test.c
+++ b/tests/ahci-test.c
@@ -460,6 +460,140 @@ static QPCIDevice *start_ahci_device(QPCIDevice *ahci, HBA **hba_base)
     return ahci;
 }
 
+/**
+ * Test and initialize the AHCI's HBA memory areas.
+ * Initialize and start any ports with devices attached.
+ * Bring the HBA into the idle state.
+ */
+static void ahci_hba_enable(QPCIDevice *ahci, HBA *hba_base)
+{
+    /* Bits of interest in this section:
+     * GHC.AE     Global Host Control / AHCI Enable
+     * PxCMD.ST   Port Command: Start
+     * PxCMD.SUD  "Spin Up Device"
+     * PxCMD.POD  "Power On Device"
+     * PxCMD.FRE  "FIS Receive Enable"
+     * PxCMD.FR   "FIS Receive Running"
+     * PxCMD.CR   "Command List Running"
+     */
+
+    g_assert(ahci != NULL);
+    g_assert(hba_base != NULL);
+
+    uint32_t reg, ports_impl, clb, fb;
+    uint16_t i;
+    uint8_t num_cmd_slots;
+
+    g_assert(hba_base != 0);
+
+    /* Set GHC.AE to 1 */
+    ahci_set(AHCI_GHC, AHCI_GHC_AE);
+    reg = ahci_rreg(AHCI_GHC);
+    assert_bit_set(reg, AHCI_GHC_AE);
+
+    /* Read CAP.NCS, how many command slots do we have? */
+    reg = ahci_rreg(AHCI_CAP);
+    num_cmd_slots = ((reg & AHCI_CAP_NCS) >> ctzl(AHCI_CAP_NCS)) + 1;
+    g_test_message("Number of Command Slots: %u", num_cmd_slots);
+
+    /* Determine which ports are implemented. */
+    ports_impl = ahci_rreg(AHCI_PI);
+
+    for (i = 0; ports_impl; ports_impl >>= 1, ++i) {
+        if (!(ports_impl & 0x01)) {
+            continue;
+        }
+
+        g_test_message("Initializing port %u", i);
+
+        reg = px_rreg(i, AHCI_PX_CMD);
+        if (bitclr(reg, AHCI_PX_CMD_ST | AHCI_PX_CMD_CR |
+                   AHCI_PX_CMD_FRE | AHCI_PX_CMD_FR)) {
+            g_test_message("port is idle");
+        } else {
+            g_test_message("port needs to be idled");
+            px_clr(i, AHCI_PX_CMD, (AHCI_PX_CMD_ST | AHCI_PX_CMD_FRE));
+            /* The port has 500ms to disengage. */
+            usleep(500000);
+            reg = px_rreg(i, AHCI_PX_CMD);
+            assert_bit_clear(reg, AHCI_PX_CMD_CR);
+            assert_bit_clear(reg, AHCI_PX_CMD_FR);
+            g_test_message("port is now idle");
+            /* The spec does allow for possibly needing a PORT RESET
+             * or HBA reset if we fail to idle the port. */
+        }
+
+        /* Allocate Memory for the Command List Buffer & FIS Buffer */
+        /* PxCLB space ... 0x20 per command, as in 4.2.2 p 36 */
+        clb = guest_alloc(guest_malloc, num_cmd_slots * 0x20);
+        g_test_message("CLB: 0x%08x", clb);
+        px_wreg(i, AHCI_PX_CLB, clb);
+        g_assert_cmphex(clb, ==, px_rreg(i, AHCI_PX_CLB));
+
+        /* PxFB space ... 0x100, as in 4.2.1 p 35 */
+        fb = guest_alloc(guest_malloc, 0x100);
+        g_test_message("FB: 0x%08x", fb);
+        px_wreg(i, AHCI_PX_FB, fb);
+        g_assert_cmphex(fb, ==, px_rreg(i, AHCI_PX_FB));
+
+        /* Clear PxSERR, PxIS, then IS.IPS[x] by writing '1's. */
+        px_wreg(i, AHCI_PX_SERR, 0xFFFFFFFF);
+        px_wreg(i, AHCI_PX_IS, 0xFFFFFFFF);
+        ahci_wreg(AHCI_IS, (1 << i));
+
+        /* Verify Interrupts Cleared */
+        reg = px_rreg(i, AHCI_PX_SERR);
+        g_assert(reg == 0);
+
+        reg = px_rreg(i, AHCI_PX_IS);
+        g_assert(reg == 0);
+
+        reg = ahci_rreg(AHCI_IS);
+        assert_bit_clear(reg, (1 << i));
+
+        /* Enable All Interrupts: */
+        px_wreg(i, AHCI_PX_IE, 0xFFFFFFFF);
+        reg = px_rreg(i, AHCI_PX_IE);
+        g_assert_cmphex(reg, ==, ~((uint32_t)AHCI_PX_IE_RESERVED));
+
+        /* Enable the FIS Receive Engine. */
+        px_set(i, AHCI_PX_CMD, AHCI_PX_CMD_FRE);
+        reg = px_rreg(i, AHCI_PX_CMD);
+        assert_bit_set(reg, AHCI_PX_CMD_FR);
+
+        /* AHCI 1.3 spec: if !STS.BSY, !STS.DRQ and PxSSTS.DET indicates
+         * physical presence, a device is present and may be started. However,
+         * PxSERR.DIAG.X /may/ need to be cleared a priori. */
+        reg = px_rreg(i, AHCI_PX_SERR);
+        if (bitset(reg, AHCI_PX_SERR_DIAG_X)) {
+            px_set(i, AHCI_PX_SERR, AHCI_PX_SERR_DIAG_X);
+        }
+
+        reg = px_rreg(i, AHCI_PX_TFD);
+        if (bitclr(reg, AHCI_PX_TFD_STS_BSY | AHCI_PX_TFD_STS_DRQ)) {
+            reg = px_rreg(i, AHCI_PX_SSTS);
+            if ((reg & AHCI_PX_SSTS_DET) == SSTS_DET_ESTABLISHED) {
+                /* Device Found: set PxCMD.ST := 1 */
+                px_set(i, AHCI_PX_CMD, AHCI_PX_CMD_ST);
+                assert_bit_set(px_rreg(i, AHCI_PX_CMD), AHCI_PX_CMD_CR);
+                g_test_message("Started Device %u", i);
+            } else if ((reg & AHCI_PX_SSTS_DET)) {
+                /* Device present, but in some unknown state. */
+                g_assert_not_reached();
+            }
+        }
+    }
+
+    /* Enable GHC.IE */
+    ahci_set(AHCI_GHC, AHCI_GHC_IE);
+    reg = ahci_rreg(AHCI_GHC);
+    assert_bit_set(reg, AHCI_GHC_IE);
+
+    /* TODO: The device should now be idling and waiting for commands.
+     * In the future, a small test-case to inspect the Register D2H FIS
+     * and clear the initial interrupts might be good. */
+}
+
 /*** Specification Adherence Tests ***/
 
 /**
@@ -1093,6 +1227,21 @@ static void test_hba_spec(void)
     ahci_shutdown(ahci);
 }
 
+/**
+ * Engage the HBA functionality of the AHCI PCI device,
+ * and bring it into a functional idle state.
+ */
+static void test_hba_enable(void)
+{
+    QPCIDevice *ahci;
+    HBA *hba_base;
+
+    ahci_boot(&ahci);
+    ahci_pci_enable(ahci, &hba_base);
+    ahci_hba_enable(ahci, hba_base);
+    ahci_shutdown(ahci);
+}
+
 /******************************************************************************/
 
 int main(int argc, char **argv)
@@ -1123,6 +1272,7 @@ int main(int argc, char **argv)
     qtest_add_func("/ahci/pci_spec",   test_pci_spec);
     qtest_add_func("/ahci/pci_enable", test_pci_enable);
     qtest_add_func("/ahci/hba_spec",   test_hba_spec);
+    qtest_add_func("/ahci/hba_enable", test_hba_enable);
 
     ret = g_test_run();
 
-- 
1.9.3