s390x/pci: enforce zPCI state checking

Current code uses some fields combinatorially to indicate the state of
a s390 pci device. This patch introduces device states in order to make
the code more readable and more logical.

Signed-off-by: Yi Min Zhao <zyimin@linux.vnet.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

4 files changed, 229 insertions, 82 deletions

diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
index 1b8377241a..0f6fcefe96 100644
--- a/hw/s390x/s390-pci-bus.c
+++ b/hw/s390x/s390-pci-bus.c
@@ -116,16 +116,22 @@ void s390_pci_sclp_configure(SCCB *sccb)
         goto out;
     }
 
-    if (pbdev) {
-        if (pbdev->configured) {
-            rc = SCLP_RC_NO_ACTION_REQUIRED;
-        } else {
-            pbdev->configured = true;
-            rc = SCLP_RC_NORMAL_COMPLETION;
-        }
-    } else {
+    if (!pbdev) {
         DPRINTF("sclp config no dev found\n");
         rc = SCLP_RC_ADAPTER_ID_NOT_RECOGNIZED;
+        goto out;
+    }
+
+    switch (pbdev->state) {
+    case ZPCI_FS_RESERVED:
+        rc = SCLP_RC_ADAPTER_IN_RESERVED_STATE;
+        break;
+    case ZPCI_FS_STANDBY:
+        pbdev->state = ZPCI_FS_DISABLED;
+        rc = SCLP_RC_NORMAL_COMPLETION;
+        break;
+    default:
+        rc = SCLP_RC_NO_ACTION_REQUIRED;
     }
 out:
     psccb->header.response_code = cpu_to_be16(rc);
@@ -142,22 +148,28 @@ void s390_pci_sclp_deconfigure(SCCB *sccb)
         goto out;
     }
 
-    if (pbdev) {
-        if (!pbdev->configured) {
-            rc = SCLP_RC_NO_ACTION_REQUIRED;
-        } else {
-            if (pbdev->summary_ind) {
-                pci_dereg_irqs(pbdev);
-            }
-            if (pbdev->iommu_enabled) {
-                pci_dereg_ioat(pbdev);
-            }
-            pbdev->configured = false;
-            rc = SCLP_RC_NORMAL_COMPLETION;
-        }
-    } else {
+    if (!pbdev) {
         DPRINTF("sclp deconfig no dev found\n");
         rc = SCLP_RC_ADAPTER_ID_NOT_RECOGNIZED;
+        goto out;
+    }
+
+    switch (pbdev->state) {
+    case ZPCI_FS_RESERVED:
+        rc = SCLP_RC_ADAPTER_IN_RESERVED_STATE;
+        break;
+    case ZPCI_FS_STANDBY:
+        rc = SCLP_RC_NO_ACTION_REQUIRED;
+        break;
+    default:
+        if (pbdev->summary_ind) {
+            pci_dereg_irqs(pbdev);
+        }
+        if (pbdev->iommu_enabled) {
+            pci_dereg_ioat(pbdev);
+        }
+        pbdev->state = ZPCI_FS_STANDBY;
+        rc = SCLP_RC_NORMAL_COMPLETION;
     }
 out:
     psccb->header.response_code = cpu_to_be16(rc);
@@ -183,7 +195,7 @@ S390PCIBusDevice *s390_pci_find_dev_by_idx(uint32_t idx)
     for (i = 0; i < PCI_SLOT_MAX; i++) {
         pbdev = &s->pbdev[i];
 
-        if (pbdev->fh == 0) {
+        if (pbdev->state == ZPCI_FS_RESERVED) {
             continue;
         }
 
@@ -233,9 +245,8 @@ static void s390_pci_generate_plug_event(uint16_t pec, uint32_t fh,
     s390_pci_generate_event(2, pec, fh, fid, 0, 0);
 }
 
-static void s390_pci_generate_error_event(uint16_t pec, uint32_t fh,
-                                          uint32_t fid, uint64_t faddr,
-                                          uint32_t e)
+void s390_pci_generate_error_event(uint16_t pec, uint32_t fh, uint32_t fid,
+                                   uint64_t faddr, uint32_t e)
 {
     s390_pci_generate_event(1, pec, fh, fid, faddr, e);
 }
@@ -337,8 +348,14 @@ static IOMMUTLBEntry s390_translate_iommu(MemoryRegion *iommu, hwaddr addr,
         .perm = IOMMU_NONE,
     };
 
-    if (!pbdev->configured || !pbdev->pdev ||
-        !(pbdev->fh & FH_MASK_ENABLE) || !pbdev->iommu_enabled) {
+    switch (pbdev->state) {
+    case ZPCI_FS_ENABLED:
+    case ZPCI_FS_BLOCKED:
+        if (!pbdev->iommu_enabled) {
+            return ret;
+        }
+        break;
+    default:
         return ret;
     }
 
@@ -357,30 +374,13 @@ static IOMMUTLBEntry s390_translate_iommu(MemoryRegion *iommu, hwaddr addr,
         return ret;
     }
 
-    if (!pbdev->g_iota) {
-        pbdev->error_state = true;
-        pbdev->lgstg_blocked = true;
-        s390_pci_generate_error_event(ERR_EVENT_INVALAS, pbdev->fh, pbdev->fid,
-                                      addr, 0);
-        return ret;
-    }
-
     if (addr < pbdev->pba || addr > pbdev->pal) {
-        pbdev->error_state = true;
-        pbdev->lgstg_blocked = true;
-        s390_pci_generate_error_event(ERR_EVENT_OORANGE, pbdev->fh, pbdev->fid,
-                                      addr, 0);
         return ret;
     }
 
     pte = s390_guest_io_table_walk(s390_pci_get_table_origin(pbdev->g_iota),
                                    addr);
-
     if (!pte) {
-        pbdev->error_state = true;
-        pbdev->lgstg_blocked = true;
-        s390_pci_generate_error_event(ERR_EVENT_SERR, pbdev->fh, pbdev->fid,
-                                      addr, ERR_EVENT_Q_BIT);
         return ret;
     }
 
@@ -449,7 +449,7 @@ static void s390_msi_ctrl_write(void *opaque, hwaddr addr, uint64_t data,
         return;
     }
 
-    if (!(pbdev->fh & FH_MASK_ENABLE)) {
+    if (pbdev->state != ZPCI_FS_ENABLED) {
         return;
     }
 
@@ -571,7 +571,7 @@ static void s390_pcihost_hot_plug(HotplugHandler *hotplug_dev,
 
     pbdev->fid = s390_pci_get_pfid(pci_dev);
     pbdev->pdev = pci_dev;
-    pbdev->configured = true;
+    pbdev->state = ZPCI_FS_DISABLED;
     pbdev->fh = s390_pci_get_pfh(pci_dev);
 
     s390_pcihost_setup_msix(pbdev);
@@ -592,8 +592,12 @@ static void s390_pcihost_hot_unplug(HotplugHandler *hotplug_dev,
                                            ->qbus.parent);
     S390PCIBusDevice *pbdev = &s->pbdev[PCI_SLOT(pci_dev->devfn)];
 
-    if (pbdev->configured) {
-        pbdev->configured = false;
+    switch (pbdev->state) {
+    case ZPCI_FS_RESERVED:
+        goto out;
+    case ZPCI_FS_STANDBY:
+        break;
+    default:
         s390_pci_generate_plug_event(HP_EVENT_CONFIGURED_TO_STBRES,
                                      pbdev->fh, pbdev->fid);
     }
@@ -603,6 +607,8 @@ static void s390_pcihost_hot_unplug(HotplugHandler *hotplug_dev,
     pbdev->fh = 0;
     pbdev->fid = 0;
     pbdev->pdev = NULL;
+    pbdev->state = ZPCI_FS_RESERVED;
+out:
     object_unparent(OBJECT(pci_dev));
 }
 
diff --git a/hw/s390x/s390-pci-bus.h b/hw/s390x/s390-pci-bus.h
index 5cf7926135..e332f6a212 100644
--- a/hw/s390x/s390-pci-bus.h
+++ b/hw/s390x/s390-pci-bus.h
@@ -153,6 +153,34 @@ enum ZpciIoatDtype {
 #define ZPCI_TABLE_VALID_MASK           0x20
 #define ZPCI_TABLE_PROT_MASK            0x200
 
+/* PCI Function States
+ *
+ * reserved: default; device has just been plugged or is in progress of being
+ *           unplugged
+ * standby: device is present but not configured; transition from any
+ *          configured state/to this state via sclp configure/deconfigure
+ *
+ * The following states make up the "configured" meta-state:
+ * disabled: device is configured but not enabled; transition between this
+ *           state and enabled via clp enable/disable
+ * enbaled: device is ready for use; transition to disabled via clp disable;
+ *          may enter an error state
+ * blocked: ignore all DMA and interrupts; transition back to enabled or from
+ *          error state via mpcifc
+ * error: an error occured; transition back to enabled via mpcifc
+ * permanent error: an unrecoverable error occured; transition to standby via
+ *                  sclp deconfigure
+ */
+typedef enum {
+    ZPCI_FS_RESERVED,
+    ZPCI_FS_STANDBY,
+    ZPCI_FS_DISABLED,
+    ZPCI_FS_ENABLED,
+    ZPCI_FS_BLOCKED,
+    ZPCI_FS_ERROR,
+    ZPCI_FS_PERMANENT_ERROR,
+} ZpciState;
+
 typedef struct SeiContainer {
     QTAILQ_ENTRY(SeiContainer) link;
     uint32_t fid;
@@ -219,9 +247,7 @@ typedef struct S390MsixInfo {
 
 typedef struct S390PCIBusDevice {
     PCIDevice *pdev;
-    bool configured;
-    bool error_state;
-    bool lgstg_blocked;
+    ZpciState state;
     bool iommu_enabled;
     uint32_t fh;
     uint32_t fid;
@@ -255,6 +281,8 @@ void s390_pci_sclp_configure(SCCB *sccb);
 void s390_pci_sclp_deconfigure(SCCB *sccb);
 void s390_pci_iommu_enable(S390PCIBusDevice *pbdev);
 void s390_pci_iommu_disable(S390PCIBusDevice *pbdev);
+void s390_pci_generate_error_event(uint16_t pec, uint32_t fh, uint32_t fid,
+                                   uint64_t faddr, uint32_t e);
 S390PCIBusDevice *s390_pci_find_dev_by_idx(uint32_t idx);
 S390PCIBusDevice *s390_pci_find_dev_by_fh(uint32_t fh);
 S390PCIBusDevice *s390_pci_find_dev_by_fid(uint32_t fid);
diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c
index 8b6882497b..744f43587c 100644
--- a/hw/s390x/s390-pci-inst.c
+++ b/hw/s390x/s390-pci-inst.c
@@ -108,8 +108,9 @@ static int list_pci(ClpReqRspListPci *rrb, uint8_t *cc)
             pci_get_word(pbdev->pdev->config + PCI_DEVICE_ID));
         stw_p(&rrb->response.fh_list[idx - resume_token].vendor_id,
             pci_get_word(pbdev->pdev->config + PCI_VENDOR_ID));
+        /* Ignore RESERVED devices. */
         stl_p(&rrb->response.fh_list[idx - resume_token].config,
-            pbdev->configured << 31);
+            pbdev->state == ZPCI_FS_STANDBY ? 0 : 1 << 31);
         stl_p(&rrb->response.fh_list[idx - resume_token].fid, pbdev->fid);
         stl_p(&rrb->response.fh_list[idx - resume_token].fh, pbdev->fh);
 
@@ -213,13 +214,13 @@ int clp_service_call(S390CPU *cpu, uint8_t r2)
         switch (reqsetpci->oc) {
         case CLP_SET_ENABLE_PCI_FN:
             pbdev->fh |= FH_MASK_ENABLE;
+            pbdev->state = ZPCI_FS_ENABLED;
             stl_p(&ressetpci->fh, pbdev->fh);
             stw_p(&ressetpci->hdr.rsp, CLP_RC_OK);
             break;
         case CLP_SET_DISABLE_PCI_FN:
             pbdev->fh &= ~FH_MASK_ENABLE;
-            pbdev->error_state = false;
-            pbdev->lgstg_blocked = false;
+            pbdev->state = ZPCI_FS_DISABLED;
             stl_p(&ressetpci->fh, pbdev->fh);
             stw_p(&ressetpci->hdr.rsp, CLP_RC_OK);
             break;
@@ -318,16 +319,25 @@ int pcilg_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2)
     offset = env->regs[r2 + 1];
 
     pbdev = s390_pci_find_dev_by_fh(fh);
-    if (!pbdev || !(pbdev->fh & FH_MASK_ENABLE)) {
+    if (!pbdev) {
         DPRINTF("pcilg no pci dev\n");
         setcc(cpu, ZPCI_PCI_LS_INVAL_HANDLE);
         return 0;
     }
 
-    if (pbdev->lgstg_blocked) {
+    switch (pbdev->state) {
+    case ZPCI_FS_RESERVED:
+    case ZPCI_FS_STANDBY:
+    case ZPCI_FS_DISABLED:
+    case ZPCI_FS_PERMANENT_ERROR:
+        setcc(cpu, ZPCI_PCI_LS_INVAL_HANDLE);
+        return 0;
+    case ZPCI_FS_ERROR:
         setcc(cpu, ZPCI_PCI_LS_ERR);
         s390_set_status_code(env, r2, ZPCI_PCI_ST_BLOCKED);
         return 0;
+    default:
+        break;
     }
 
     if (pcias < 6) {
@@ -435,16 +445,25 @@ int pcistg_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2)
     offset = env->regs[r2 + 1];
 
     pbdev = s390_pci_find_dev_by_fh(fh);
-    if (!pbdev || !(pbdev->fh & FH_MASK_ENABLE)) {
+    if (!pbdev) {
         DPRINTF("pcistg no pci dev\n");
         setcc(cpu, ZPCI_PCI_LS_INVAL_HANDLE);
         return 0;
     }
 
-    if (pbdev->lgstg_blocked) {
+    switch (pbdev->state) {
+    case ZPCI_FS_RESERVED:
+    case ZPCI_FS_STANDBY:
+    case ZPCI_FS_DISABLED:
+    case ZPCI_FS_PERMANENT_ERROR:
+        setcc(cpu, ZPCI_PCI_LS_INVAL_HANDLE);
+        return 0;
+    case ZPCI_FS_ERROR:
         setcc(cpu, ZPCI_PCI_LS_ERR);
         s390_set_status_code(env, r2, ZPCI_PCI_ST_BLOCKED);
         return 0;
+    default:
+        break;
     }
 
     data = env->regs[r1];
@@ -526,18 +545,55 @@ int rpcit_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2)
     end = start + env->regs[r2 + 1];
 
     pbdev = s390_pci_find_dev_by_fh(fh);
-    if (!pbdev || !(pbdev->fh & FH_MASK_ENABLE)) {
+    if (!pbdev) {
         DPRINTF("rpcit no pci dev\n");
         setcc(cpu, ZPCI_PCI_LS_INVAL_HANDLE);
         goto out;
     }
 
+    switch (pbdev->state) {
+    case ZPCI_FS_RESERVED:
+    case ZPCI_FS_STANDBY:
+    case ZPCI_FS_DISABLED:
+    case ZPCI_FS_PERMANENT_ERROR:
+        setcc(cpu, ZPCI_PCI_LS_INVAL_HANDLE);
+        return 0;
+    case ZPCI_FS_ERROR:
+        setcc(cpu, ZPCI_PCI_LS_ERR);
+        s390_set_status_code(env, r1, ZPCI_MOD_ST_ERROR_RECOVER);
+        return 0;
+    default:
+        break;
+    }
+
+    if (!pbdev->g_iota) {
+        pbdev->state = ZPCI_FS_ERROR;
+        setcc(cpu, ZPCI_PCI_LS_ERR);
+        s390_set_status_code(env, r1, ZPCI_PCI_ST_INSUF_RES);
+        s390_pci_generate_error_event(ERR_EVENT_INVALAS, pbdev->fh, pbdev->fid,
+                                      start, 0);
+        goto out;
+    }
+
+    if (end < pbdev->pba || start > pbdev->pal) {
+        pbdev->state = ZPCI_FS_ERROR;
+        setcc(cpu, ZPCI_PCI_LS_ERR);
+        s390_set_status_code(env, r1, ZPCI_PCI_ST_INSUF_RES);
+        s390_pci_generate_error_event(ERR_EVENT_OORANGE, pbdev->fh, pbdev->fid,
+                                      start, 0);
+        goto out;
+    }
+
     mr = &pbdev->iommu_mr;
     while (start < end) {
         entry = mr->iommu_ops->translate(mr, start, 0);
 
         if (!entry.translated_addr) {
+            pbdev->state = ZPCI_FS_ERROR;
             setcc(cpu, ZPCI_PCI_LS_ERR);
+            s390_set_status_code(env, r1, ZPCI_PCI_ST_INSUF_RES);
+            s390_pci_generate_error_event(ERR_EVENT_SERR, pbdev->fh, pbdev->fid,
+                                          start, ERR_EVENT_Q_BIT);
             goto out;
         }
 
@@ -590,16 +646,25 @@ int pcistb_service_call(S390CPU *cpu, uint8_t r1, uint8_t r3, uint64_t gaddr,
     }
 
     pbdev = s390_pci_find_dev_by_fh(fh);
-    if (!pbdev || !(pbdev->fh & FH_MASK_ENABLE)) {
+    if (!pbdev) {
         DPRINTF("pcistb no pci dev fh 0x%x\n", fh);
         setcc(cpu, ZPCI_PCI_LS_INVAL_HANDLE);
         return 0;
     }
 
-    if (pbdev->lgstg_blocked) {
+    switch (pbdev->state) {
+    case ZPCI_FS_RESERVED:
+    case ZPCI_FS_STANDBY:
+    case ZPCI_FS_DISABLED:
+    case ZPCI_FS_PERMANENT_ERROR:
+        setcc(cpu, ZPCI_PCI_LS_INVAL_HANDLE);
+        return 0;
+    case ZPCI_FS_ERROR:
         setcc(cpu, ZPCI_PCI_LS_ERR);
         s390_set_status_code(env, r1, ZPCI_PCI_ST_BLOCKED);
         return 0;
+    default:
+        break;
     }
 
     mr = pbdev->pdev->io_regions[pcias].memory;
@@ -743,12 +808,23 @@ int mpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar)
     }
 
     pbdev = s390_pci_find_dev_by_fh(fh);
-    if (!pbdev || !(pbdev->fh & FH_MASK_ENABLE)) {
+    if (!pbdev) {
         DPRINTF("mpcifc no pci dev fh 0x%x\n", fh);
         setcc(cpu, ZPCI_PCI_LS_INVAL_HANDLE);
         return 0;
     }
 
+    switch (pbdev->state) {
+    case ZPCI_FS_RESERVED:
+    case ZPCI_FS_STANDBY:
+    case ZPCI_FS_DISABLED:
+    case ZPCI_FS_PERMANENT_ERROR:
+        setcc(cpu, ZPCI_PCI_LS_INVAL_HANDLE);
+        return 0;
+    default:
+        break;
+    }
+
     if (s390_cpu_virt_mem_read(cpu, fiba, ar, (uint8_t *)&fib, sizeof(fib))) {
         return 0;
     }
@@ -815,11 +891,25 @@ int mpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar)
         }
         break;
     case ZPCI_MOD_FC_RESET_ERROR:
-        pbdev->error_state = false;
-        pbdev->lgstg_blocked = false;
+        switch (pbdev->state) {
+        case ZPCI_FS_BLOCKED:
+        case ZPCI_FS_ERROR:
+            pbdev->state = ZPCI_FS_ENABLED;
+            break;
+        default:
+            cc = ZPCI_PCI_LS_ERR;
+            s390_set_status_code(env, r1, ZPCI_MOD_ST_SEQUENCE);
+        }
         break;
     case ZPCI_MOD_FC_RESET_BLOCK:
-        pbdev->lgstg_blocked = false;
+        switch (pbdev->state) {
+        case ZPCI_FS_ERROR:
+            pbdev->state = ZPCI_FS_BLOCKED;
+            break;
+        default:
+            cc = ZPCI_PCI_LS_ERR;
+            s390_set_status_code(env, r1, ZPCI_MOD_ST_SEQUENCE);
+        }
         break;
     case ZPCI_MOD_FC_SET_MEASURE:
         pbdev->fmb_addr = ldq_p(&fib.fmb_addr);
@@ -861,6 +951,39 @@ int stpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar)
     }
 
     memset(&fib, 0, sizeof(fib));
+
+    switch (pbdev->state) {
+    case ZPCI_FS_RESERVED:
+    case ZPCI_FS_STANDBY:
+        setcc(cpu, ZPCI_PCI_LS_INVAL_HANDLE);
+        return 0;
+    case ZPCI_FS_DISABLED:
+        if (fh & FH_MASK_ENABLE) {
+            setcc(cpu, ZPCI_PCI_LS_INVAL_HANDLE);
+            return 0;
+        }
+        goto out;
+    /* BLOCKED bit is set to one coincident with the setting of ERROR bit.
+     * FH Enabled bit is set to one in states of ENABLED, BLOCKED or ERROR. */
+    case ZPCI_FS_ERROR:
+        fib.fc |= 0x20;
+    case ZPCI_FS_BLOCKED:
+        fib.fc |= 0x40;
+    case ZPCI_FS_ENABLED:
+        fib.fc |= 0x80;
+        if (pbdev->iommu_enabled) {
+            fib.fc |= 0x10;
+        }
+        if (!(fh & FH_MASK_ENABLE)) {
+            env->regs[r1] |= 1ULL << 63;
+        }
+        break;
+    case ZPCI_FS_PERMANENT_ERROR:
+        setcc(cpu, ZPCI_PCI_LS_ERR);
+        s390_set_status_code(env, r1, ZPCI_STPCIFC_ST_PERM_ERROR);
+        return 0;
+    }
+
     stq_p(&fib.pba, pbdev->pba);
     stq_p(&fib.pal, pbdev->pal);
     stq_p(&fib.iota, pbdev->g_iota);
@@ -873,22 +996,7 @@ int stpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar)
            ((uint32_t)pbdev->sum << 7) | pbdev->routes.adapter.summary_offset;
     stl_p(&fib.data, data);
 
-    if (pbdev->fh & FH_MASK_ENABLE) {
-        fib.fc |= 0x80;
-    }
-
-    if (pbdev->error_state) {
-        fib.fc |= 0x40;
-    }
-
-    if (pbdev->lgstg_blocked) {
-        fib.fc |= 0x20;
-    }
-
-    if (pbdev->g_iota) {
-        fib.fc |= 0x10;
-    }
-
+out:
     if (s390_cpu_virt_mem_write(cpu, fiba, ar, (uint8_t *)&fib, sizeof(fib))) {
         return 0;
     }
diff --git a/hw/s390x/s390-pci-inst.h b/hw/s390x/s390-pci-inst.h
index b084f2346b..c35f3371f4 100644
--- a/hw/s390x/s390-pci-inst.h
+++ b/hw/s390x/s390-pci-inst.h
@@ -249,6 +249,11 @@ typedef struct ClpReqRspQueryPciGrp {
 #define ZPCI_MOD_FC_RESET_BLOCK 9
 #define ZPCI_MOD_FC_SET_MEASURE 10
 
+/* Store PCI Function Controls status codes */
+#define ZPCI_STPCIFC_ST_PERM_ERROR    8
+#define ZPCI_STPCIFC_ST_INVAL_DMAAS   28
+#define ZPCI_STPCIFC_ST_ERROR_RECOVER 40
+
 /* FIB function controls */
 #define ZPCI_FIB_FC_ENABLED     0x80
 #define ZPCI_FIB_FC_ERROR       0x40