As reported in [1], the hisi-lpc driver has certain issues in handling logical PIO regions, specifically unregistering regions.
This series add a method to unregister a logical PIO region, and fixes up the driver to use them.
RCU usage in logical PIO code looks to always have been broken, so that is fixed also. This is not a major fix as the list which RCU protects would be rarely modified.
At this point, there are still separate ongoing discussions about how to stop the logical PIO and PCI host bridge code leaking ranges, as in [2], which I haven't had a chance to look at recently.
Hopefully this series can go through the arm soc tree and the maintainers have no issue with that. I'm talking specifically about the logical PIO code, which went through PCI tree on only previous upstreaming.
[1] https://lore.kernel.org/lkml/1560770148-57960-1-git-send-email-john.garry@hu... [2] https://lore.kernel.org/lkml/4b24fd36-e716-7c5e-31cc-13da727802e7@huawei.com...
Changes since v3: https://lore.kernel.org/lkml/1561566418-22714-1-git-send-email-john.garry@hu... - drop optimisation patch (lib: logic_pio: Enforce LOGIC_PIO_INDIRECT region ops are set at registration) Not a fix - rebase to v5.3-rc2 - cc stable
Change since v2: - Add hisi_lpc_acpi_remove() stub to fix build for !CONFIG_ACPI
Changes since v1: - Add more reasoning in RCU fix patch - Create separate patch to change LOGIC_PIO_CPU_MMIO registration to accomodate unregistration
John Garry (5): lib: logic_pio: Fix RCU usage lib: logic_pio: Avoid possible overlap for unregistering regions lib: logic_pio: Add logic_pio_unregister_range() bus: hisi_lpc: Unregister logical PIO range to avoid potential use-after-free bus: hisi_lpc: Add .remove method to avoid driver unbind crash
drivers/bus/hisi_lpc.c | 47 +++++++++++++++++++++---- include/linux/logic_pio.h | 1 + lib/logic_pio.c | 73 +++++++++++++++++++++++++++++---------- 3 files changed, 96 insertions(+), 25 deletions(-)