Date: Wed, 15 Nov 2017 23:23:21 +0900 (JST) From: Mori Hiroki <yamori813@yahoo.co.jp> To: Landon J Fuller <landonf@freebsd.org>, "freebsd-mips@freebsd.org" <freebsd-mips@freebsd.org> Subject: Re: MIPS INTRNG changes Message-ID: <742722.83866.qm@web101707.mail.ssk.yahoo.co.jp> In-Reply-To: <1510699808.25350.3@smtp.office.plausible.coop> References: <1510699808.25350.3@smtp.office.plausible.coop>
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Hi sys/mips/atheros/ar531x/ is non-FDT and INTERNG. I will check this patch on real cpu tomorrow. Hiroki Mori ----- Original Message ----- > From: Landon J Fuller <landonf@freebsd.org> > To: freebsd-mips@freebsd.org > Cc: > Date: 2017/11/15, Wed 07:50 > Subject: MIPS INTRNG changes > > Howdy - > > To support nested INTRNG interrupt controllers on non-FDT MIPS targets, I've > implemented a replacement for the cpu_establish_[hard|soft]intr() workaround > introduced in r305527 (D7692); I'll be commiting this in three days unless > anyone objects: > > https://reviews.freebsd.org/D12385 > > Background: > > Since non-FDT INTRNG targets do not have an equivalent to OFW_BUS_MAP_INTR(), > it is necessary for the MIPS nexus driver to implicitly establish INTRNG > interrupt mappings on behalf of child devices. > > The workaround introduced in r305527 implements this as follows, on non-FDT > INTRNG MIPS targets: > > - mips/nexus.c assumes that all bus interrupt requests are for a MIPS > interrupt managed by mips/mips_pic.c > - Call mips_pic's cpu_create_intr_map() from nexus_activate_resource() to > allocate a new interrupt mapping on-demand. > - Call mips_pic's cpu_get_irq_resource() from nexus_setup_intr() to fetch a > shared IRQ struct resource for the MIPS interrupt. > > In addition to assuming that all IRQs are owned by mips_pic, on-demand IRQ > mapping in the BUS_ACTIVATE_RESOURCE() path produces some unexpected behavior: > > - Any child bus that uses bus_generic_rl_alloc_resource() or > resource_list_alloc() > to implement BUS_ALLOC_RESOURCE() will update the child device's resource > list entry to reference the newly mapped IRQ -- but only if the resource is > allocated with the RF_ACTIVE flag, resulting in BUS_ACTIVATE_RESOURCE() being > called from BUS_ALLOC_RESOURCE() before the resource_list_entry update is > performed. > - BUS_ACTIVATE_RESOURCE() is itself not resource_list-aware; if RF_ACTIVE is > not set during allocation, and bus_activate_resource() is instead called > directly, the child's resource list entry will _not_ updated to the newly > mapped IRQ. > > Since the resource_list_entry _may_ be updated to reference the IRQ mapping, > IRQs > mappings implicitly created in nexus_activate_resource() cannot be implicitly > unmapped in nexus_deactivate_resource() and must be leaked, as references to > the mapping may remain in a child's resource_list_entry. > > Rather than performing on-demand mapping during resource activation, my changes > preemptively produce (on non-FDT targets) a set of IRQ mappings for all MIPS > IRQs in nexus_attach(), using a fixed range of INTRNG IRQ assignments (0-7) that > may be statically referenced by child devices. > > With D12385, the mips nexus behavior will now be: > > - On non-FDT MIPS INTRNG targets, produce a set of fixed MIPS IRQ mappings > in nexus_attach() for the MIPS IRQ range. > - On all MIPS INTRNG targets, call mips_pic_activate_intr() from > nexus_activate_resource() to perform activation; this will either perform > mips_pic-specific activation if the IRQ is found in mips_pic' table of > MIPS IRQ mappings, or will call intr_activate_irq() for IRQs not managed by > mips_pic (e.g. IRQs mapped by a child PIC). > - On all MIPS INTRNG targets, call mips_pic_deactivate_intr() from > nexus_deactivate_resource(); this will either perform mips_pic-specific > deactivation, or call intr_deactivate_irq() for IRQs not managed by > mips_pic. > > Cheers, > Landon > > _______________________________________________ > freebsd-mips@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-mips > To unsubscribe, send any mail to > "freebsd-mips-unsubscribe@freebsd.org" >help
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