Hi Thomas, > -----Original Message----- > From: Thomas Gleixner <[email protected]> > Sent: Wednesday, July 22, 2020 1:45 PM > To: Jiang, Dave <[email protected]>; [email protected]; Dey, Megha > <[email protected]>; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; Pan, Jacob jun <[email protected]>; Raj, > Ashok <[email protected]>; [email protected]; Liu, Yi L > <[email protected]>; > Lu, Baolu <[email protected]>; Tian, Kevin <[email protected]>; Kumar, > Sanjay K <[email protected]>; Luck, Tony <[email protected]>; Lin, > Jing <[email protected]>; Williams, Dan J <[email protected]>; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; Hansen, Dave > <[email protected]>; [email protected]; [email protected]; > [email protected]; [email protected]; Ortiz, Samuel > <[email protected]>; Hossain, Mona <[email protected]> > Cc: [email protected]; [email protected]; > [email protected]; [email protected]; [email protected] > Subject: Re: [PATCH RFC v2 03/18] irq/dev-msi: Create IR-DEV-MSI irq domain > > Dave Jiang <[email protected]> writes: > > From: Megha Dey <[email protected]> > > > > When DEV_MSI is enabled, the dev_msi_default_domain is updated to the > > base DEV-MSI irq domain. If interrupt remapping is enabled, we create > > s/we//
ok > > > a new IR-DEV-MSI irq domain and update the dev_msi_default domain to > > the same. > > > > For X86, introduce a new irq_alloc_type which will be used by the > > interrupt remapping driver. > > > > Reviewed-by: Dan Williams <[email protected]> > > Signed-off-by: Megha Dey <[email protected]> > > Signed-off-by: Dave Jiang <[email protected]> > > --- > > arch/x86/include/asm/hw_irq.h | 1 + > > arch/x86/kernel/apic/msi.c | 12 ++++++ > > drivers/base/dev-msi.c | 66 > > +++++++++++++++++++++++++++++++---- > > drivers/iommu/intel/irq_remapping.c | 11 +++++- > > include/linux/intel-iommu.h | 1 + > > include/linux/irqdomain.h | 11 ++++++ > > include/linux/msi.h | 3 ++ > > Why is this mixing generic code, x86 core code and intel specific driver code? > This is new functionality so: > > 1) Provide the infrastructure > 2) Add support to architecture specific parts > 3) Enable it Ok, I will try to adhere to the layering next time around.. > > > + > > +#ifdef CONFIG_DEV_MSI > > +int dev_msi_prepare(struct irq_domain *domain, struct device *dev, > > + int nvec, msi_alloc_info_t *arg) { > > + memset(arg, 0, sizeof(*arg)); > > + > > + arg->type = X86_IRQ_ALLOC_TYPE_DEV_MSI; > > + > > + return 0; > > +} > > +#endif > > What is this? Tons of new lines for taking up more space and not a single > comment. Hmm, I will add a comment.. > > > -static int dev_msi_prepare(struct irq_domain *domain, struct device > > *dev, > > +int __weak dev_msi_prepare(struct irq_domain *domain, struct device > > +*dev, > > int nvec, msi_alloc_info_t *arg) { > > memset(arg, 0, sizeof(*arg)); > > Oh well. So every architecure which needs to override this and I assume all > which are eventually going to support it need to do the memset() in their > override. > > memset(arg,,,); > arch_dev_msi_prepare(); > > Per you suggestion, I have introduced arch_dev_msi_prepare which returns 0 by default unless overridden by arch code in the next patch set. > > - dev_msi_default_domain = msi_create_irq_domain(fn, > &dev_msi_domain_info, parent); > > + /* > > + * This initcall may come after remap code is initialized. Ensure that > > + * dev_msi_default domain is updated correctly. > > What? No, this is a disgusting hack. Get your ordering straight, that's not > rocket > science. > Hmm yeah, actually I realized we don't really need to have 2 new IRQ domains for dev-msi (with and without interrupt remapping enabled). Hence all this will go away in the next round of patches. > > +#ifdef CONFIG_IRQ_REMAP > > IRQ_REMAP is x86 specific. Is this file x86 only or intended to be for > general use? > If it's x86 only, then this should be clearly documented. If not, then these > x86'isms have no place here. True, I will take care of this in the next patch set. > > > +struct irq_domain *create_remap_dev_msi_irq_domain(struct irq_domain > *parent, > > + const char *name) > > So we have msi_create_irq_domain() and this is about dev_msi, right? So can > you please stick with a consistent naming scheme? sure > > > +{ > > + struct fwnode_handle *fn; > > + struct irq_domain *domain; > > + > > + fn = irq_domain_alloc_named_fwnode(name); > > + if (!fn) > > + return NULL; > > + > > + domain = msi_create_irq_domain(fn, &dev_msi_ir_domain_info, > parent); > > + if (!domain) { > > + pr_warn("failed to initialize irqdomain for IR-DEV-MSI.\n"); > > + return ERR_PTR(-ENXIO); > > + } > > + > > + irq_domain_update_bus_token(domain, > DOMAIN_BUS_PLATFORM_MSI); > > + > > + if (!dev_msi_default_domain) > > + dev_msi_default_domain = domain; > > Can this be called several times? If so, then this lacks a comment. If not, > then > this condition is useless. Hmm this will go way in the next patch set, thank you for your input! > > Thanks, > > tglx
