Messages in this thread |  | | Subject | Re: [PATCH 11/12] platform-msi: Add platform check for subdevice irq domain | From | Lu Baolu <> | Date | Tue, 9 Feb 2021 08:36:08 +0800 |
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Hi Leon,
On 2/8/21 4:21 PM, Leon Romanovsky wrote: > On Wed, Feb 03, 2021 at 12:56:44PM -0800, Megha Dey wrote: >> From: Lu Baolu <baolu.lu@linux.intel.com> >> >> The pci_subdevice_msi_create_irq_domain() should fail if the underlying >> platform is not able to support IMS (Interrupt Message Storage). Otherwise, >> the isolation of interrupt is not guaranteed. >> >> For x86, IMS is only supported on bare metal for now. We could enable it >> in the virtualization environments in the future if interrupt HYPERCALL >> domain is supported or the hardware has the capability of interrupt >> isolation for subdevices. >> >> Cc: David Woodhouse <dwmw@amazon.co.uk> >> Cc: Leon Romanovsky <leon@kernel.org> >> Cc: Kevin Tian <kevin.tian@intel.com> >> Suggested-by: Thomas Gleixner <tglx@linutronix.de> >> Link: https://lore.kernel.org/linux-pci/87pn4nk7nn.fsf@nanos.tec.linutronix.de/ >> Link: https://lore.kernel.org/linux-pci/877dqrnzr3.fsf@nanos.tec.linutronix.de/ >> Link: https://lore.kernel.org/linux-pci/877dqqmc2h.fsf@nanos.tec.linutronix.de/ >> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> >> Signed-off-by: Megha Dey <megha.dey@intel.com> >> --- >> arch/x86/pci/common.c | 74 +++++++++++++++++++++++++++++++++++++++++++++ >> drivers/base/platform-msi.c | 8 +++++ >> include/linux/msi.h | 1 + >> 3 files changed, 83 insertions(+) >> >> diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c >> index 3507f45..263ccf6 100644 >> --- a/arch/x86/pci/common.c >> +++ b/arch/x86/pci/common.c >> @@ -12,6 +12,8 @@ >> #include <linux/init.h> >> #include <linux/dmi.h> >> #include <linux/slab.h> >> +#include <linux/iommu.h> >> +#include <linux/msi.h> >> >> #include <asm/acpi.h> >> #include <asm/segment.h> >> @@ -724,3 +726,75 @@ struct pci_dev *pci_real_dma_dev(struct pci_dev *dev) >> return dev; >> } >> #endif >> + >> +#ifdef CONFIG_DEVICE_MSI > > Sorry for my naive question, but I see it in all your patches in this series > and wonder why did you wrap everything with ifdefs?.
The added code is only called when DEVICE_MSI is configured.
> > All *.c code is wrapped with those ifdefs, which is hard to navigate and > unlikely to give any code/size optimization benefit if kernel is compiled > without CONFIG_DEVICE_MSI. The more common approach is to put those > ifdef in the public header files and leave to the compiler to drop not > called functions.
Yes. This looks better.
> > Thanks >
Best regards, baolu
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