[ Upstream commit118b918018
] This fixes a concurrency issue addressed in commit34cb275283
("UIO: Fix concurrency issue"): "In a SMP case there was a race condition issue between Uio_pdrv_genirq_irqcontrol() running on one CPU and irq handler on another CPU. Fix it by spin_locking shared resources access inside irq handler." The implementation of "uio_dmem_genirq" was based on "uio_pdrv_genirq" and it is used in a similar manner to the "uio_pdrv_genirq" driver with respect to interrupt configuration and handling. At the time "uio_dmem_genirq" was merged, both had the same implementation of the 'uio_info' handlers irqcontrol() and handler(), thus, both had the same concurrency issue mentioned by the above commit. However, the above patch was only applied to the "uio_pdrv_genirq" driver. Split out from commit34cb275283
("UIO: Fix concurrency issue"). Fixes:0a0c3b5a24
("Add new uio device for dynamic memory allocation") Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com> Link: https://lore.kernel.org/r/20220930224100.816175-3-rafaelmendsr@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>