Messages in this thread Patch in this message | | | Date | Fri, 18 Feb 2011 09:07:29 -0500 | From | Konrad Rzeszutek Wilk <> | Subject | Re: [Xen-devel] [PATCH 1/3] pci/xen: Use xen_allocate_pirq_msi |
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On Thu, Feb 17, 2011 at 09:30:03AM -0500, Konrad Rzeszutek Wilk wrote: > On Thu, Feb 17, 2011 at 08:41:31AM +0000, Ian Campbell wrote: > > On Wed, 2011-02-16 at 22:17 +0000, Konrad Rzeszutek Wilk wrote: > > > There is no need to use the old interface. > > > > xen_allocate_pirq -> xen_map_pirq_gsi -> PHYSDEVOP_alloc_irq_vector IFF > > xen_initial_domain() in addition to the kernel side book-keeping side of > > things (set chip and handler, update irq_info etc) whereas > > xen_allocate_pirq_msi just does the kernel book keeping. > > > > Also xen_allocate_pirq allocates an IRQ in the 1-1 GSI space whereas > > xen_allocate_pirq_msi allocates a dynamic one in the >GSI IRQ space. > > Which is OK. These are MSIs. > > > > So this change is actually a semantic change and not just a switch to a > > new interface. I think the change is OK (because the caller is domU > > Right. > > > only?) but a comment explaining this would be appreciated. > > Correct: "domU side". > > Will fix it up.
How does this look to you?
From eb832bece3131ecbdb509f7f2a9bc53f6692177c Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Date: Wed, 16 Feb 2011 13:43:04 -0500 Subject: [PATCH 3/5] pci/xen: Use xen_allocate_pirq_msi instead of xen_allocate_pirq
xen_allocate_pirq -> xen_map_pirq_gsi -> PHYSDEVOP_alloc_irq_vector IFF xen_initial_domain() in addition to the kernel side book-keeping side of things (set chip and handler, update irq_info etc) whereas xen_allocate_pirq_msi just does the kernel book keeping.
Also xen_allocate_pirq allocates an IRQ in the 1-1 GSI space whereas xen_allocate_pirq_msi allocates a dynamic one in the >GSI IRQ space.
All of this is uneccessary as this code path is only executed when we run as a domU PV guest with an MSI/MSI-X PCI card passed in. Hence we can jump straight to allocating an dynamic IRQ (and binding it to the proper PIRQ) and skip the rest.
In short: this change is a cosmetic one.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- arch/x86/pci/xen.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c index 25cd4a0..6432f75 100644 --- a/arch/x86/pci/xen.c +++ b/arch/x86/pci/xen.c @@ -157,14 +157,14 @@ static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) goto error; i = 0; list_for_each_entry(msidesc, &dev->msi_list, list) { - irq = xen_allocate_pirq(v[i], 0, /* not sharable */ + xen_allocate_pirq_msi( (type == PCI_CAP_ID_MSIX) ? - "pcifront-msi-x" : "pcifront-msi"); + "pcifront-msi-x" : "pcifront-msi", + &irq, &v[i], XEN_ALLOC_IRQ); if (irq < 0) { ret = -1; goto free; } - ret = set_irq_msi(irq, msidesc); if (ret) goto error_while; -- 1.7.1
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