From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752568AbeAQJbL (ORCPT + 1 other); Wed, 17 Jan 2018 04:31:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52594 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752311AbeAQJbJ (ORCPT ); Wed, 17 Jan 2018 04:31:09 -0500 Date: Wed, 17 Jan 2018 17:31:05 +0800 From: Baoquan He To: linux-kernel@vger.kernel.org, ebiederm@xmission.com Cc: mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com, x86@kernel.org, douly.fnst@cn.fujitsu.com, rostedt@goodmis.org, jgross@suse.com, peterz@infradead.org, uobergfe@redhat.com, joro@8bytes.org Subject: Re: [RESEND PATCH 3/3] x86/apic: Clean up the names of legacy irq mode setting related functions Message-ID: <20180117093105.GD2321@localhost.localdomain> References: <1515123732-28908-1-git-send-email-bhe@redhat.com> <20180105043929.GL7235@x1> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180105043929.GL7235@x1> User-Agent: Mutt/1.9.1 (2017-09-22) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Wed, 17 Jan 2018 09:31:09 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: CC Eric On 01/05/18 at 12:39pm, Baoquan He wrote: > X86 MP spec defines 3 different interrupt modes: > 1) PIC Mode—bypasses all APIC components and forces the system to > operate in single-processor mode. > 2) Virtual Wire Mode—uses an APIC as a virtual wire, but otherwise > operates the same as PIC Mode. > 3) Symmetric I/O Mode—enables the system to operate with more than > one processor. > > The current disconnect_bsp_APIC includes two parts: one is to set system > as PIC mode if it's available, the other is to change system back to > Virtual Wire mode. Only PIC mode will detach the APIC from the interrupt > system, Virtual Wire mode doesn't. > > Besides Virutal Wire mode has two kinds: one is only setting Local APIC > as Virtual Wire mode and interrupts are delivered from the PIC to the > CPU which Local APIC connected to, the other is both Loca APIC and IO-APIC > need be set as Virtual Wire mode. > > So based on above knowledge, take IO-APIC Virtual Wire mode setting code > out and wrap it inot a new function ioapic_set_virtual_wire_mode. Meanwhile > change the name of disconnect_bsp_APIC as lapic_set_legacy_irq_mode. These > makes the legacy irq mode setting more understandable. > > Signed-off-by: Baoquan He > --- > arch/x86/include/asm/apic.h | 2 +- > arch/x86/include/asm/io_apic.h | 5 ++--- > arch/x86/kernel/apic/apic.c | 11 ++++++----- > arch/x86/kernel/apic/io_apic.c | 17 ++++++++++------- > arch/x86/kernel/x86_init.c | 2 +- > drivers/iommu/irq_remapping.c | 2 +- > 6 files changed, 21 insertions(+), 18 deletions(-) > > diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h > index a9e57f08bfa6..004c48bc8bc8 100644 > --- a/arch/x86/include/asm/apic.h > +++ b/arch/x86/include/asm/apic.h > @@ -132,7 +132,7 @@ extern int get_physical_broadcast(void); > > extern int lapic_get_maxlvt(void); > extern void clear_local_APIC(void); > -extern void disconnect_bsp_APIC(int virt_wire_setup); > +extern void lapic_set_legacy_irq_mode(int virt_wire_setup); > extern void disable_local_APIC(void); > extern void lapic_shutdown(void); > extern void sync_Arb_IDs(void); > diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h > index e38ad3863a2c..6800dcea1d21 100644 > --- a/arch/x86/include/asm/io_apic.h > +++ b/arch/x86/include/asm/io_apic.h > @@ -183,7 +183,7 @@ extern void disable_ioapic_support(void); > > extern void __init io_apic_init_mappings(void); > extern unsigned int native_io_apic_read(unsigned int apic, unsigned int reg); > -extern void native_disable_io_apic(void); > +extern void switch_to_legacy_irq_mode(void); > > static inline unsigned int io_apic_read(unsigned int apic, unsigned int reg) > { > @@ -193,7 +193,6 @@ static inline unsigned int io_apic_read(unsigned int apic, unsigned int reg) > extern void setup_IO_APIC(void); > extern void enable_IO_APIC(void); > extern void clear_IO_APIC (void); > -extern void switch_to_legacy_irq_mode(void); > extern int IO_APIC_get_PCI_irq_vector(int bus, int devfn, int pin); > extern void print_IO_APICs(void); > #else /* !CONFIG_X86_IO_APIC */ > @@ -229,7 +228,7 @@ static inline void mp_save_irq(struct mpc_intsrc *m) { } > static inline void disable_ioapic_support(void) { } > static inline void io_apic_init_mappings(void) { } > #define native_io_apic_read NULL > -#define native_disable_io_apic NULL > +#define switch_to_legacy_irq_mode NULL > > static inline void setup_IO_APIC(void) { } > static inline void enable_IO_APIC(void) { } > diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c > index 7e613fb90630..301d90d4a0c3 100644 > --- a/arch/x86/kernel/apic/apic.c > +++ b/arch/x86/kernel/apic/apic.c > @@ -2050,13 +2050,14 @@ static void __init connect_bsp_APIC(void) > } > > /** > - * disconnect_bsp_APIC - detach the APIC from the interrupt system > - * @virt_wire_setup: indicates, whether virtual wire mode is selected > + * lapic_set_legacy_irq_mode - switch Local APIC back to be legacy irq mode. > + * @virt_wire_setup: indicates, whether virtual wire mode is selected > * > - * Virtual wire mode is necessary to deliver legacy interrupts even when the > - * APIC is disabled. > + * If PIC mode is available, LAPIC need be disconnected with CPU. Otherwise > + * enable LAPIC and set it to be virtual wire mode. However if IO-APIC has > + * been virtual wire mode, LVT0 of LAPIC need be masked. > */ > -void disconnect_bsp_APIC(int virt_wire_setup) > +void lapic_set_legacy_irq_mode(int virt_wire_setup) > { > unsigned int value; > > diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c > index a47aa915d18c..b7fd4236b0e5 100644 > --- a/arch/x86/kernel/apic/io_apic.c > +++ b/arch/x86/kernel/apic/io_apic.c > @@ -1410,7 +1410,7 @@ void __init enable_IO_APIC(void) > clear_IO_APIC(); > } > > -void native_disable_io_apic(void) > +static void ioapic_set_virtual_wire_mode(void) > { > /* > * If the i8259 is routed through an IOAPIC > @@ -1433,21 +1433,24 @@ void native_disable_io_apic(void) > */ > ioapic_write_entry(ioapic_i8259.apic, ioapic_i8259.pin, entry); > } > - > - if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config()) > - disconnect_bsp_APIC(ioapic_i8259.pin != -1); > } > > /* > - * Not an __init, needed by kexec/kdump code. > - * For safety IO-APIC and Local APIC need be cleared before this. > + * In legacy irq mode, full DOS compatibility with the uniprocessor PC/AT is > + * provided by using the APICs in conjunction with standard 8259A-equivalent > + * programmable interrupt controllers (PICs). It's necessary to deliver legacy > + * interrupts even when APIC mode is not enabled. This is required by kexec/ > + * kdump before enter into the 2nd kernel. > */ > void switch_to_legacy_irq_mode(void) > { > if (!nr_legacy_irqs()) > return; > > - x86_io_apic_ops.disable(); > + ioapic_set_virtual_wire_mode(); > + > + if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config()) > + lapic_set_legacy_irq_mode(ioapic_i8259.pin != -1); > } > > #ifdef CONFIG_X86_32 > diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c > index 1151ccd72ce9..c30f0f273dbd 100644 > --- a/arch/x86/kernel/x86_init.c > +++ b/arch/x86/kernel/x86_init.c > @@ -148,5 +148,5 @@ void arch_restore_msi_irqs(struct pci_dev *dev) > > struct x86_io_apic_ops x86_io_apic_ops __ro_after_init = { > .read = native_io_apic_read, > - .disable = native_disable_io_apic, > + .disable = switch_to_legacy_irq_mode, > }; > diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c > index 49721b4e1975..751472ddf536 100644 > --- a/drivers/iommu/irq_remapping.c > +++ b/drivers/iommu/irq_remapping.c > @@ -37,7 +37,7 @@ static void irq_remapping_disable_io_apic(void) > * now. > */ > if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config()) > - disconnect_bsp_APIC(0); > + lapic_set_legacy_irq_mode(0); > } > > static void __init irq_remapping_modify_x86_ops(void) > -- > 2.5.5 >