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authorThomas Gleixner <tglx@linutronix.de>2017-09-13 23:29:14 +0200
committerThomas Gleixner <tglx@linutronix.de>2017-09-25 20:38:26 +0200
commit2f75d9e1c90511bff6d1ce4de94503cc28fec032 (patch)
treeeb17ed8cb0cbd6c10cc3119267e790d8a4a1bb8c /kernel/irq/Kconfig
parent22d0b12f3560d3b3264ee79faa1c05a5060fb916 (diff)
downloadlinux-stericsson-2f75d9e1c90511bff6d1ce4de94503cc28fec032.tar.gz
genirq: Implement bitmap matrix allocator
Implement the infrastructure for a simple bitmap based allocator, which will replace the x86 vector allocator. It's in the core code as other architectures might be able to reuse/extend it. For now it only implements allocations for single CPUs, but it's simple to add multi CPU allocation support if required. The concept is rather simple: Global information: system_vector bitmap global accounting PerCPU information: allocation bitmap managed allocation bitmap local accounting The system vector bitmap is used to exclude vectors system wide from the allocation space. The allocation bitmap is used to keep track of per cpu used vectors. The managed allocation bitmap is used to reserve vectors for managed interrupts. When a regular (non managed) interrupt allocation happens then the following rule applies: tmpmap = system_map | alloc_map | managed_map find_zero_bit(tmpmap) Oring the bitmaps together gives the real available space. The same rule applies for reserving a managed interrupt vector. But contrary to the regular interrupts the reservation only marks the bit in the managed map and therefor excludes it from the regular allocations. The managed map is only cleaned out when the a managed interrupt is completely released and it stays alive accross CPU offline/online operations. For managed interrupt allocations the rule is: tmpmap = managed_map & ~alloc_map find_first_bit(tmpmap) This returns the first bit which is in the managed map, but not yet allocated in the allocation map. The allocation marks it in the allocation map and hands it back to the caller for use. The rest of the code are helper functions to handle the various requirements and the accounting which are necessary to replace the x86 vector allocation code. The result is a single patch as the evolution of this infrastructure cannot be represented in bits and pieces. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Yu Chen <yu.c.chen@intel.com> Acked-by: Juergen Gross <jgross@suse.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Alok Kataria <akataria@vmware.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rui Zhang <rui.zhang@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Len Brown <lenb@kernel.org> Link: https://lkml.kernel.org/r/20170913213153.185437174@linutronix.de
Diffstat (limited to 'kernel/irq/Kconfig')
-rw-r--r--kernel/irq/Kconfig3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index a117adf7084b..ac1a3e29d3b9 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -97,6 +97,9 @@ config HANDLE_DOMAIN_IRQ
config IRQ_TIMINGS
bool
+config GENERIC_IRQ_MATRIX_ALLOCATOR
+ bool
+
config IRQ_DOMAIN_DEBUG
bool "Expose hardware/virtual IRQ mapping via debugfs"
depends on IRQ_DOMAIN && DEBUG_FS