Is the limit going to be increased at some point? Is there a true limit somewhere?
On Wed, Apr 18, 2018 at 11:45 AM, John Baldwin <j...@freebsd.org> wrote: > Author: jhb > Date: Wed Apr 18 18:45:34 2018 > New Revision: 332735 > URL: https://svnweb.freebsd.org/changeset/base/332735 > > Log: > Fix two off-by-one errors when allocating MSI and MSI-X interrupts. > > x86 enforces an (arbitray) limit on the number of available MSI and > MSI-X interrupts to simplify code (in particular, interrupt_source[] > is statically sized). This means that an attempt to allocate an MSI > vector needs to fail if it would go beyond the limit, but the checks > for exceeding the limit had an off-by-one error. In the case of MSI-X > which allocates interrupts one at a time this meant that IRQ 768 kept > getting handed out multiple times for msix_alloc() instead of failing > because all MSI IRQs were in use. > > Tested by: lidl > MFC after: 1 week > > Modified: > head/sys/x86/x86/msi.c > > Modified: head/sys/x86/x86/msi.c > ============================================================ > ================== > --- head/sys/x86/x86/msi.c Wed Apr 18 18:45:04 2018 (r332734) > +++ head/sys/x86/x86/msi.c Wed Apr 18 18:45:34 2018 (r332735) > @@ -404,7 +404,7 @@ again: > /* Do we need to create some new sources? */ > if (cnt < count) { > /* If we would exceed the max, give up. */ > - if (i + (count - cnt) > FIRST_MSI_INT + NUM_MSI_INTS) { > + if (i + (count - cnt) >= FIRST_MSI_INT + NUM_MSI_INTS) { > mtx_unlock(&msi_lock); > free(mirqs, M_MSI); > return (ENXIO); > @@ -645,7 +645,7 @@ again: > /* Do we need to create a new source? */ > if (msi == NULL) { > /* If we would exceed the max, give up. */ > - if (i + 1 > FIRST_MSI_INT + NUM_MSI_INTS) { > + if (i + 1 >= FIRST_MSI_INT + NUM_MSI_INTS) { > mtx_unlock(&msi_lock); > return (ENXIO); > } > > _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
