x86/ioapic/32: Decrapify phys_id_present_map operation
authorThomas Gleixner <tglx@linutronix.de>
Tue, 8 Aug 2023 22:03:59 +0000 (15:03 -0700)
committerDave Hansen <dave.hansen@linux.intel.com>
Wed, 9 Aug 2023 18:58:26 +0000 (11:58 -0700)
commit9faee3ecbfedebc6cdd0d96bfb2788ad8d62ef7e
tree6bd59860f9b9709bcb3410ad723113a2be88bf1c
parent9a2a637af06621e69893e5d5cde3c0eba5aeba0f
x86/ioapic/32: Decrapify phys_id_present_map operation

The operation to set the IOAPIC ID in phys_id_present_map is as convoluted
as it can be.

  1) Allocate a bitmap of 32byte size on the stack
  2) Zero the bitmap and set the IOAPIC ID bit
  3) Or the temporary bitmap over phys_id_present_map

The same functionality can be achieved by setting the IOAPIC ID bit
directly in the phys_id_present_map.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)
arch/x86/kernel/apic/io_apic.c