[PATCH v5 04/27] iommu/io-pgtable-arm: Factor kernel specific code out
From: Mostafa Saleh <smostafa@google.com>
Date: 2025-11-17 18:48:31
Also in:
kvmarm, linux-iommu, lkml
Subsystem:
arm smmu drivers, iommu subsystem, the rest · Maintainers:
Will Deacon, Joerg Roedel, Linus Torvalds
Some of the used APIs are only part of the kernel and are not available in the hypervisor, factor those out: - alloc/free memory - CMOs - virt/phys conversions Which are implemented by the kernel in io-pgtable-arm-kernel.c and similarly for the hypervisor later in this series. va/pa conversion kept as macros. Signed-off-by: Mostafa Saleh <smostafa@google.com> --- drivers/iommu/Makefile | 2 +- drivers/iommu/io-pgtable-arm-kernel.c | 103 ++++++++++++++++++++++++++ drivers/iommu/io-pgtable-arm.c | 101 +++---------------------- drivers/iommu/io-pgtable-arm.h | 19 +++++ 4 files changed, 133 insertions(+), 92 deletions(-) create mode 100644 drivers/iommu/io-pgtable-arm-kernel.c
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 8e8843316c4b..439431fd4bc5 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile@@ -12,7 +12,7 @@ obj-$(CONFIG_IOMMU_DEBUGFS) += iommu-debugfs.o obj-$(CONFIG_IOMMU_DMA) += dma-iommu.o obj-$(CONFIG_IOMMU_IO_PGTABLE) += io-pgtable.o obj-$(CONFIG_IOMMU_IO_PGTABLE_ARMV7S) += io-pgtable-arm-v7s.o -obj-$(CONFIG_IOMMU_IO_PGTABLE_LPAE) += io-pgtable-arm.o +obj-$(CONFIG_IOMMU_IO_PGTABLE_LPAE) += io-pgtable-arm.o io-pgtable-arm-kernel.o obj-$(CONFIG_IOMMU_IO_PGTABLE_LPAE_KUNIT_TEST) += io-pgtable-arm-selftests.o obj-$(CONFIG_IOMMU_IO_PGTABLE_DART) += io-pgtable-dart.o obj-$(CONFIG_IOMMU_IOVA) += iova.o
diff --git a/drivers/iommu/io-pgtable-arm-kernel.c b/drivers/iommu/io-pgtable-arm-kernel.c
new file mode 100644
index 000000000000..d025f7c180f9
--- /dev/null
+++ b/drivers/iommu/io-pgtable-arm-kernel.c@@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * CPU-agnostic ARM page table allocator. + * + * Copyright (C) 2014 ARM Limited + * + * Author: Will Deacon <will.deacon@arm.com> + */ +#include <linux/dma-mapping.h> + +#include <linux/io-pgtable.h> +#include <linux/kernel.h> +#include <linux/slab.h> + +#include "io-pgtable-arm.h" +#include "iommu-pages.h" + +static dma_addr_t __arm_lpae_dma_addr(void *pages) +{ + return (dma_addr_t)virt_to_phys(pages); +} + +void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp, + struct io_pgtable_cfg *cfg, + void *cookie) +{ + struct device *dev = cfg->iommu_dev; + size_t alloc_size; + dma_addr_t dma; + void *pages; + + /* + * For very small starting-level translation tables the HW requires a + * minimum alignment of at least 64 to cover all cases. + */ + alloc_size = max(size, 64); + if (cfg->alloc) + pages = cfg->alloc(cookie, alloc_size, gfp); + else + pages = iommu_alloc_pages_node_sz(dev_to_node(dev), gfp, + alloc_size); + + if (!pages) + return NULL; + + if (!cfg->coherent_walk) { + dma = dma_map_single(dev, pages, size, DMA_TO_DEVICE); + if (dma_mapping_error(dev, dma)) + goto out_free; + /* + * We depend on the IOMMU being able to work with any physical + * address directly, so if the DMA layer suggests otherwise by + * translating or truncating them, that bodes very badly... + */ + if (dma != virt_to_phys(pages)) + goto out_unmap; + } + + return pages; + +out_unmap: + dev_err(dev, "Cannot accommodate DMA translation for IOMMU page tables\n"); + dma_unmap_single(dev, dma, size, DMA_TO_DEVICE); + +out_free: + if (cfg->free) + cfg->free(cookie, pages, size); + else + iommu_free_pages(pages); + + return NULL; +} + +void __arm_lpae_free_pages(void *pages, size_t size, + struct io_pgtable_cfg *cfg, + void *cookie) +{ + if (!cfg->coherent_walk) + dma_unmap_single(cfg->iommu_dev, __arm_lpae_dma_addr(pages), + size, DMA_TO_DEVICE); + + if (cfg->free) + cfg->free(cookie, pages, size); + else + iommu_free_pages(pages); +} + +void __arm_lpae_sync_pte(arm_lpae_iopte *ptep, int num_entries, + struct io_pgtable_cfg *cfg) +{ + dma_sync_single_for_device(cfg->iommu_dev, __arm_lpae_dma_addr(ptep), + sizeof(*ptep) * num_entries, DMA_TO_DEVICE); +} + +void *__arm_lpae_alloc_data(size_t size, gfp_t gfp) +{ + return kmalloc(size, gfp); +} + +void __arm_lpae_free_data(void *p) +{ + return kfree(p); +}
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index e6626004b323..377c15bc8350 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c@@ -15,12 +15,10 @@ #include <linux/sizes.h> #include <linux/slab.h> #include <linux/types.h> -#include <linux/dma-mapping.h> #include <asm/barrier.h> #include "io-pgtable-arm.h" -#include "iommu-pages.h" #define ARM_LPAE_MAX_ADDR_BITS 52 #define ARM_LPAE_S2_MAX_CONCAT_PAGES 16
@@ -143,7 +141,7 @@ #define ARM_MALI_LPAE_MEMATTR_WRITE_ALLOC 0x8DULL /* IOPTE accessors */ -#define iopte_deref(pte,d) __va(iopte_to_paddr(pte, d)) +#define iopte_deref(pte,d) __arm_lpae_phys_to_virt(iopte_to_paddr(pte, d)) #define iopte_type(pte) \ (((pte) >> ARM_LPAE_PTE_TYPE_SHIFT) & ARM_LPAE_PTE_TYPE_MASK)
@@ -164,8 +162,6 @@ struct arm_lpae_io_pgtable { void *pgd; }; -typedef u64 arm_lpae_iopte; - static inline bool iopte_leaf(arm_lpae_iopte pte, int lvl, enum io_pgtable_fmt fmt) {
@@ -243,83 +239,6 @@ static inline bool arm_lpae_concat_mandatory(struct io_pgtable_cfg *cfg, (data->start_level == 1) && (oas == 40); } -static dma_addr_t __arm_lpae_dma_addr(void *pages) -{ - return (dma_addr_t)virt_to_phys(pages); -} - -static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp, - struct io_pgtable_cfg *cfg, - void *cookie) -{ - struct device *dev = cfg->iommu_dev; - size_t alloc_size; - dma_addr_t dma; - void *pages; - - /* - * For very small starting-level translation tables the HW requires a - * minimum alignment of at least 64 to cover all cases. - */ - alloc_size = max(size, 64); - if (cfg->alloc) - pages = cfg->alloc(cookie, alloc_size, gfp); - else - pages = iommu_alloc_pages_node_sz(dev_to_node(dev), gfp, - alloc_size); - - if (!pages) - return NULL; - - if (!cfg->coherent_walk) { - dma = dma_map_single(dev, pages, size, DMA_TO_DEVICE); - if (dma_mapping_error(dev, dma)) - goto out_free; - /* - * We depend on the IOMMU being able to work with any physical - * address directly, so if the DMA layer suggests otherwise by - * translating or truncating them, that bodes very badly... - */ - if (dma != virt_to_phys(pages)) - goto out_unmap; - } - - return pages; - -out_unmap: - dev_err(dev, "Cannot accommodate DMA translation for IOMMU page tables\n"); - dma_unmap_single(dev, dma, size, DMA_TO_DEVICE); - -out_free: - if (cfg->free) - cfg->free(cookie, pages, size); - else - iommu_free_pages(pages); - - return NULL; -} - -static void __arm_lpae_free_pages(void *pages, size_t size, - struct io_pgtable_cfg *cfg, - void *cookie) -{ - if (!cfg->coherent_walk) - dma_unmap_single(cfg->iommu_dev, __arm_lpae_dma_addr(pages), - size, DMA_TO_DEVICE); - - if (cfg->free) - cfg->free(cookie, pages, size); - else - iommu_free_pages(pages); -} - -static void __arm_lpae_sync_pte(arm_lpae_iopte *ptep, int num_entries, - struct io_pgtable_cfg *cfg) -{ - dma_sync_single_for_device(cfg->iommu_dev, __arm_lpae_dma_addr(ptep), - sizeof(*ptep) * num_entries, DMA_TO_DEVICE); -} - static void __arm_lpae_clear_pte(arm_lpae_iopte *ptep, struct io_pgtable_cfg *cfg, int num_entries) { for (int i = 0; i < num_entries; i++)
@@ -395,7 +314,7 @@ static arm_lpae_iopte arm_lpae_install_table(arm_lpae_iopte *table, arm_lpae_iopte old, new; struct io_pgtable_cfg *cfg = &data->iop.cfg; - new = paddr_to_iopte(__pa(table), data) | ARM_LPAE_PTE_TYPE_TABLE; + new = paddr_to_iopte(__arm_lpae_virt_to_phys(table), data) | ARM_LPAE_PTE_TYPE_TABLE; if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS) new |= ARM_LPAE_PTE_NSTABLE;
@@ -616,7 +535,7 @@ static void arm_lpae_free_pgtable(struct io_pgtable *iop) struct arm_lpae_io_pgtable *data = io_pgtable_to_data(iop); __arm_lpae_free_pgtable(data, data->start_level, data->pgd); - kfree(data); + __arm_lpae_free_data(data); } static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
@@ -930,7 +849,7 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg) if (cfg->oas > ARM_LPAE_MAX_ADDR_BITS) return NULL; - data = kmalloc(sizeof(*data), GFP_KERNEL); + data = __arm_lpae_alloc_data(sizeof(*data), GFP_KERNEL); if (!data) return NULL;
@@ -1053,11 +972,11 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie) wmb(); /* TTBR */ - cfg->arm_lpae_s1_cfg.ttbr = virt_to_phys(data->pgd); + cfg->arm_lpae_s1_cfg.ttbr = __arm_lpae_virt_to_phys(data->pgd); return &data->iop; out_free_data: - kfree(data); + __arm_lpae_free_data(data); return NULL; }
@@ -1149,11 +1068,11 @@ arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie) wmb(); /* VTTBR */ - cfg->arm_lpae_s2_cfg.vttbr = virt_to_phys(data->pgd); + cfg->arm_lpae_s2_cfg.vttbr = __arm_lpae_virt_to_phys(data->pgd); return &data->iop; out_free_data: - kfree(data); + __arm_lpae_free_data(data); return NULL; }
@@ -1223,7 +1142,7 @@ arm_mali_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie) /* Ensure the empty pgd is visible before TRANSTAB can be written */ wmb(); - cfg->arm_mali_lpae_cfg.transtab = virt_to_phys(data->pgd) | + cfg->arm_mali_lpae_cfg.transtab = __arm_lpae_virt_to_phys(data->pgd) | ARM_MALI_LPAE_TTBR_READ_INNER | ARM_MALI_LPAE_TTBR_ADRMODE_TABLE; if (cfg->coherent_walk)
@@ -1232,7 +1151,7 @@ arm_mali_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie) return &data->iop; out_free_data: - kfree(data); + __arm_lpae_free_data(data); return NULL; }
diff --git a/drivers/iommu/io-pgtable-arm.h b/drivers/iommu/io-pgtable-arm.h
index ba7cfdf7afa0..62d127dae1c2 100644
--- a/drivers/iommu/io-pgtable-arm.h
+++ b/drivers/iommu/io-pgtable-arm.h@@ -2,6 +2,8 @@ #ifndef IO_PGTABLE_ARM_H_ #define IO_PGTABLE_ARM_H_ +#include <linux/io-pgtable.h> + #define ARM_LPAE_TCR_TG0_4K 0 #define ARM_LPAE_TCR_TG0_64K 1 #define ARM_LPAE_TCR_TG0_16K 2
@@ -27,4 +29,21 @@ #define ARM_LPAE_TCR_PS_48_BIT 0x5ULL #define ARM_LPAE_TCR_PS_52_BIT 0x6ULL +typedef u64 arm_lpae_iopte; + +void __arm_lpae_sync_pte(arm_lpae_iopte *ptep, int num_entries, + struct io_pgtable_cfg *cfg); +void __arm_lpae_free_pages(void *pages, size_t size, + struct io_pgtable_cfg *cfg, + void *cookie); +void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp, + struct io_pgtable_cfg *cfg, + void *cookie); +void *__arm_lpae_alloc_data(size_t size, gfp_t gfp); +void __arm_lpae_free_data(void *p); +#ifndef __KVM_NVHE_HYPERVISOR__ +#define __arm_lpae_virt_to_phys __pa +#define __arm_lpae_phys_to_virt __va +#endif /* !__KVM_NVHE_HYPERVISOR__ */ + #endif /* IO_PGTABLE_ARM_H_ */
--
2.52.0.rc1.455.g30608eb744-goog