diff options
| author | Kaustabh Chakraborty <kauschluss@disroot.org> | 2025-07-12 17:19:30 +0530 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2025-07-14 12:32:47 +0100 |
| commit | 2d70fdd9b5c9a10c5a4b15179b425ff554b60c6d (patch) | |
| tree | 0ffdff3e60e56c32874e78117b009c95a90dc5f6 | |
| parent | 86731a2a651e58953fc949573895f2fa6d456841 (diff) | |
iommu/exynos: add support for reserved regions
The bootloader configures a reserved memory region for framebuffer,
which is protected by the IOMMU. The kernel-side driver is oblivious as
of which memory region is set up by the bootloader. In such case, the
IOMMU tries to reference the reserved region - which is not reserved in
the kernel anymore - and it results in an unrecoverable page fault. More
information about it is provided in [1].
Add support for reserved regions using iommu_dma_get_resv_regions().
For OF supported boards, this requires defining the region in the
iommu-addresses property of the IOMMU owner's node.
Link: https://lore.kernel.org/r/544ad69cba52a9b87447e3ac1c7fa8c3@disroot.org [1]
Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
Link: https://lore.kernel.org/r/20250712-exynos-sysmmu-resv-regions-v1-1-e79681fcab1a@disroot.org
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | drivers/iommu/exynos-iommu.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c index fcb6a0f7c082..f499861da1b1 100644 --- a/drivers/iommu/exynos-iommu.c +++ b/drivers/iommu/exynos-iommu.c @@ -22,6 +22,7 @@ #include <linux/pm_runtime.h> #include <linux/slab.h> +#include "dma-iommu.h" #include "iommu-pages.h" typedef u32 sysmmu_iova_t; @@ -1478,6 +1479,7 @@ static const struct iommu_ops exynos_iommu_ops = { .probe_device = exynos_iommu_probe_device, .release_device = exynos_iommu_release_device, .pgsize_bitmap = SECT_SIZE | LPAGE_SIZE | SPAGE_SIZE, + .get_resv_regions = iommu_dma_get_resv_regions, .of_xlate = exynos_iommu_of_xlate, .default_domain_ops = &(const struct iommu_domain_ops) { .attach_dev = exynos_iommu_attach_device, |