kern/55926: aarch64: pci_intr_alloc() return msi/msi-x count, but struct msi is not initialized.

[hashikaw%mail.ru@localhost]

>Number:         55926
>Category:       kern
>Synopsis:       aarch64: pci_intr_alloc() return msi/msi-x count, but struct msi is not initialized.
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jan 14 04:30:00 +0000 2021
>Originator:     Kouichi Hashikawa
>Release:        NetBSD-9.99.77
>Organization:
>Environment:
>Description:
Like RPi4, on system that gic_v2m_init() is not called
(struct msi is not initialized), 
pci_intr_alloc() returns msi/msi-x count (---> Patch 1).

I have a question, if a system has msi/msi-x capability,
and pci_intr_alloc() returns only intx count,
then turn off PCI_MSI_CTL_MSI_ENABLE or PCI_MSIX_CTL_ENABLE flag on
pci_msi_machdep.c? or each driver?


>How-To-Repeat:

>Fix:
(Patch 1)
--------
--- src/sys/arch/arm/pci/pci_msi_machdep.c-dist 2020-02-13 15:28:25.000000000 +0900
+++ src/sys/arch/arm/pci/pci_msi_machdep.c      2021-01-14 13:07:53.053314571 +0900
@@ -142,7 +142,7 @@
        struct arm_pci_msi *msi;
 
        msi = arm_pci_msi_find_frame(pih);
-       if (msi == NULL)
+       if (msi == NULL || msi->msi_intr_establish == NULL)
                return NULL;
 
        return msi->msi_intr_establish(msi, pih, ipl, func, arg, xname);
@@ -204,6 +204,7 @@
 pci_intr_alloc(const struct pci_attach_args *pa, pci_intr_handle_t **ihps, int *counts, pci_intr_type_t max_type)
 {
        int intx_count, msi_count, msix_count, error;
+       struct arm_pci_msi *msi;
 
        error = EINVAL;
 
@@ -230,20 +231,32 @@
                intx_count = msi_count = msix_count = 1;
        }
 
-       if (msix_count == -1)
-               msix_count = pci_msix_count(pa->pa_pc, pa->pa_tag);
-       if (msix_count > 0 && (error = pci_msix_alloc_exact(pa, ihps, msix_count)) == 0) {
-               if (counts != NULL)
-                       counts[PCI_INTR_TYPE_MSIX] = msix_count;
-               return 0;
-       }
+       msi = arm_pci_msi_lookup(pa);
 
-       if (msi_count == -1)
-               msi_count = pci_msi_count(pa->pa_pc, pa->pa_tag);
-       if (msi_count > 0 && (error = pci_msi_alloc_exact(pa, ihps, msi_count)) == 0) {
-               if (counts != NULL)
-                       counts[PCI_INTR_TYPE_MSI] = msi_count;
-               return 0;
+       if (msi != NULL) {
+               if (msi->msix_alloc != NULL) {
+                       if (msix_count == -1)
+                               msix_count = pci_msix_count(pa->pa_pc, 
+                                   pa->pa_tag);
+                       if (msix_count > 0 && (error = pci_msix_alloc_exact(pa, 
+                           ihps, msix_count)) == 0) {
+                               if (counts != NULL)
+                                       counts[PCI_INTR_TYPE_MSIX] = msix_count;
+                               return 0;
+                       }
+               }
+
+               if (msi->msi_alloc != NULL) {
+                       if (msi_count == -1)
+                               msi_count = pci_msi_count(pa->pa_pc, 
+                                   pa->pa_tag);
+                       if (msi_count > 0 && (error = pci_msi_alloc_exact(pa, 
+                           ihps, msi_count)) == 0) {
+                               if (counts != NULL)
+                                       counts[PCI_INTR_TYPE_MSI] = msi_count;
+                               return 0;
+                       }
+               }
        }
 
        if (intx_count > 0 && (error = pci_intx_alloc(pa, ihps)) == 0) {
@@ -266,6 +279,8 @@
        if ((pih[0] & (ARM_PCI_INTR_MSIX|ARM_PCI_INTR_MSI)) != 0) {
                msi = arm_pci_msi_find_frame(pih[0]);
                KASSERT(msi != NULL);
+               if (msi->msi_intr_release == NULL)
+                       return;
                msi->msi_intr_release(msi, pih, count);
        }