From 3318f7b5cefbff96b1bb49584ac38d2c9997a830 Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Mon, 19 May 2025 10:51:28 -0700 Subject: iommu/io-pgtable-arm: Add quirk to quiet WARN_ON() In situations where mapping/unmapping sequence can be controlled by userspace, attempting to map over a region that has not yet been unmapped is an error. But not something that should spam dmesg. Now that there is a quirk, we can also drop the selftest_running flag, and use the quirk instead for selftests. Acked-by: Robin Murphy Signed-off-by: Rob Clark Link: https://lore.kernel.org/r/20250519175348.11924-6-robdclark@gmail.com [will: Rename quirk to IO_PGTABLE_QUIRK_NO_WARN per Robin's suggestion] Signed-off-by: Will Deacon --- include/linux/io-pgtable.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux') diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h index bba2a51c87d2..138fbd89b1e6 100644 --- a/include/linux/io-pgtable.h +++ b/include/linux/io-pgtable.h @@ -88,6 +88,13 @@ struct io_pgtable_cfg { * * IO_PGTABLE_QUIRK_ARM_HD: Enables dirty tracking in stage 1 pagetable. * IO_PGTABLE_QUIRK_ARM_S2FWB: Use the FWB format for the MemAttrs bits + * + * IO_PGTABLE_QUIRK_NO_WARN: Do not WARN_ON() on conflicting + * mappings, but silently return -EEXISTS. Normally an attempt + * to map over an existing mapping would indicate some sort of + * kernel bug, which would justify the WARN_ON(). But for GPU + * drivers, this could be under control of userspace. Which + * deserves an error return, but not to spam dmesg. */ #define IO_PGTABLE_QUIRK_ARM_NS BIT(0) #define IO_PGTABLE_QUIRK_NO_PERMS BIT(1) @@ -97,6 +104,7 @@ struct io_pgtable_cfg { #define IO_PGTABLE_QUIRK_ARM_OUTER_WBWA BIT(6) #define IO_PGTABLE_QUIRK_ARM_HD BIT(7) #define IO_PGTABLE_QUIRK_ARM_S2FWB BIT(8) + #define IO_PGTABLE_QUIRK_NO_WARN BIT(9) unsigned long quirks; unsigned long pgsize_bitmap; unsigned int ias; -- cgit v1.2.3