From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47965) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wn2BM-0005J4-BN for qemu-devel@nongnu.org; Wed, 21 May 2014 04:47:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Wn2BF-0000Y3-C6 for qemu-devel@nongnu.org; Wed, 21 May 2014 04:47:28 -0400 Message-ID: <537C6818.7010302@suse.de> Date: Wed, 21 May 2014 10:47:20 +0200 From: Alexander Graf MIME-Version: 1.0 References: <1400147999-4793-1-git-send-email-aik@ozlabs.ru> <1400147999-4793-5-git-send-email-aik@ozlabs.ru> <537C6511.6080403@suse.de> <537C67E7.2020606@ozlabs.ru> In-Reply-To: <537C67E7.2020606@ozlabs.ru> Content-Type: text/plain; charset=KOI8-R; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 4/8] spapr: Move interrupt allocator to xics List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy , qemu-devel@nongnu.org Cc: qemu-ppc@nongnu.org On 21.05.14 10:46, Alexey Kardashevskiy wrote: > On 05/21/2014 06:34 PM, Alexander Graf wrote: >> On 15.05.14 11:59, Alexey Kardashevskiy wrote: >>> The current allocator returns IRQ numbers from a pool and does not >>> support IRQs reuse in any form as it did not keep track of what it >>> previously returned, it only keeps the last returned IRQ. Some use >>> cases such as PCI hot(un)plug may require IRQ release and reallocation. >>> >>> This moves an allocator from SPAPR to XICS. >>> >>> This switches IRQ users to use new API. >>> >>> This uses LSI/MSI flags to know if interrupt is allocated. >>> >>> The interrupt release function will be posted as a separate patch. >>> >>> Signed-off-by: Alexey Kardashevskiy >>> --- >>> hw/intc/xics.c | 88 >>> ++++++++++++++++++++++++++++++++++++++++++++++++++ >>> hw/ppc/spapr.c | 67 -------------------------------------- >>> hw/ppc/spapr_events.c | 2 +- >>> hw/ppc/spapr_pci.c | 6 ++-- >>> hw/ppc/spapr_vio.c | 2 +- >>> include/hw/ppc/spapr.h | 10 ------ >>> include/hw/ppc/xics.h | 2 ++ >>> trace-events | 4 +++ >>> 8 files changed, 99 insertions(+), 82 deletions(-) >>> >>> diff --git a/hw/intc/xics.c b/hw/intc/xics.c >>> index 83a809e..fdcbb3a 100644 >>> --- a/hw/intc/xics.c >>> +++ b/hw/intc/xics.c >>> @@ -689,6 +689,94 @@ void xics_set_irq_type(XICSState *icp, int irq, bool >>> lsi) >>> ics_set_irq_type(ics, irq - ics->offset, lsi); >>> } >>> +#define ICS_IRQ_FREE(ics, srcno) \ >>> + (!((ics)->irqs[(srcno)].flags & (XICS_FLAGS_IRQ_MASK))) >>> + >>> +static int ics_find_free_block(ICSState *ics, int num, int alignnum) >>> +{ >>> + int first, i; >>> + >>> + for (first = 0; first < ics->nr_irqs; first += alignnum) { >>> + if (num > (ics->nr_irqs - first)) { >>> + return -1; >>> + } >>> + for (i = first; i < first + num; ++i) { >>> + if (!ICS_IRQ_FREE(ics, i)) { >>> + break; >>> + } >>> + } >>> + if (i == (first + num)) { >>> + return first; >>> + } >>> + } >>> + >>> + return -1; >>> +} >>> + >>> +int xics_alloc(XICSState *icp, int src, int irq_hint, bool lsi) >>> +{ >>> + ICSState *ics = &icp->ics[src]; >>> + int irq; >>> + >>> + if (irq_hint) { >>> + assert(src == xics_find_source(icp, irq_hint)); >> Could this ever get triggered by a guest? Why don't we just fail as if the >> IRQ wasn't available? > The @irq_hist is only used when the user specified IRQ in the command line, > this is why it is assert. And the guest never gets to choose IRQ number, it > receives numbers either via device tree (and QEMU puts those numbers there, > not SLOF) or ibm,change-msi (QEMU returns numbers). Ok, it's safe then :). Alex