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| author |   Thomas Gleixner <tglx@linutronix.de> | 2019-08-21 15:16:31 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2019-08-26 12:11:23 +0200 |
| commit | 3e5bedc2c258341702ddffbd7688c5e6eb01eafa (patch) | |
| tree | 1bcb7f6a1a72c2fc5d4b90e4908d1c24da361827 /arch | |
| parent | x86/retpoline: Don't clobber RFLAGS during CALL_NOSPEC on i386 (diff) | |
| download | linux-dev-3e5bedc2c258341702ddffbd7688c5e6eb01eafa.tar.xz linux-dev-3e5bedc2c258341702ddffbd7688c5e6eb01eafa.zip | |
x86/apic: Fix arch_dynirq_lower_bound() bug for DT enabled machines
Rahul Tanwar reported the following bug on DT systems:
> 'ioapic_dynirq_base' contains the virtual IRQ base number. Presently, it is
> updated to the end of hardware IRQ numbers but this is done only when IOAPIC
> configuration type is IOAPIC_DOMAIN_LEGACY or IOAPIC_DOMAIN_STRICT. There is
> a third type IOAPIC_DOMAIN_DYNAMIC which applies when IOAPIC configuration
> comes from devicetree.
>
> See dtb_add_ioapic() in arch/x86/kernel/devicetree.c
>
> In case of IOAPIC_DOMAIN_DYNAMIC (DT/OF based system), 'ioapic_dynirq_base'
> remains to zero initialized value. This means that for OF based systems,
> virtual IRQ base will get set to zero.
Such systems will very likely not even boot.
For DT enabled machines ioapic_dynirq_base is irrelevant and not
updated, so simply map the IRQ base 1:1 instead.
Reported-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Tested-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: alan@linux.intel.com
Cc: bp@alien8.de
Cc: cheol.yong.kim@intel.com
Cc: qi-ming.wu@intel.com
Cc: rahul.tanwar@intel.com
Cc: rppt@linux.ibm.com
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/20190821081330.1187-1-rahul.tanwar@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/apic/io_apic.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index c7bb6c69f21c..d6af97fd170a 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -2438,7 +2438,13 @@ unsigned int arch_dynirq_lower_bound(unsigned int from) * dmar_alloc_hwirq() may be called before setup_IO_APIC(), so use * gsi_top if ioapic_dynirq_base hasn't been initialized yet. */ - return ioapic_initialized ? ioapic_dynirq_base : gsi_top; + if (!ioapic_initialized) + return gsi_top; + /* + * For DT enabled machines ioapic_dynirq_base is irrelevant and not + * updated. So simply return @from if ioapic_dynirq_base == 0. + */ + return ioapic_dynirq_base ? : from; } #ifdef CONFIG_X86_32 |