[PATCH v4 1/3] iommu: io-pgtable: add DART pagetable format
From: Sven Peter <hidden>
Date: 2021-06-27 14:37:31
Also in:
linux-devicetree, linux-iommu, lkml
Subsystem:
arm smmu drivers, iommu subsystem, the rest · Maintainers:
Will Deacon, Joerg Roedel, Linus Torvalds
Apple's DART iommu uses a pagetable format that shares some similarities with the ones already implemented by io-pgtable.c. Add a new format variant to support the required differences so that we don't have to duplicate the pagetable handling code. Signed-off-by: Sven Peter <redacted> --- drivers/iommu/io-pgtable-arm.c | 62 ++++++++++++++++++++++++++++++++++ drivers/iommu/io-pgtable.c | 1 + include/linux/io-pgtable.h | 7 ++++ 3 files changed, 70 insertions(+)
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 87def58e79b5..1dd5c45b4b5b 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c@@ -127,6 +127,9 @@ #define ARM_MALI_LPAE_MEMATTR_IMP_DEF 0x88ULL #define ARM_MALI_LPAE_MEMATTR_WRITE_ALLOC 0x8DULL +#define APPLE_DART_PTE_PROT_NO_WRITE (1<<7) +#define APPLE_DART_PTE_PROT_NO_READ (1<<8) + /* IOPTE accessors */ #define iopte_deref(pte,d) __va(iopte_to_paddr(pte, d))
@@ -381,6 +384,15 @@ static arm_lpae_iopte arm_lpae_prot_to_pte(struct arm_lpae_io_pgtable *data, { arm_lpae_iopte pte; + if (data->iop.fmt == ARM_APPLE_DART) { + pte = 0; + if (!(prot & IOMMU_WRITE)) + pte |= APPLE_DART_PTE_PROT_NO_WRITE; + if (!(prot & IOMMU_READ)) + pte |= APPLE_DART_PTE_PROT_NO_READ; + return pte; + } + if (data->iop.fmt == ARM_64_LPAE_S1 || data->iop.fmt == ARM_32_LPAE_S1) { pte = ARM_LPAE_PTE_nG;
@@ -1043,6 +1055,51 @@ arm_mali_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie) return NULL; } +static struct io_pgtable * +apple_dart_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie) +{ + struct arm_lpae_io_pgtable *data; + int i; + + if (cfg->oas > 36) + return NULL; + + data = arm_lpae_alloc_pgtable(cfg); + if (!data) + return NULL; + + /* + * Apple's DART always requires three levels with the first level being + * stored in four MMIO registers. We always concatenate the first and + * second level so that we only have to setup the MMIO registers once. + * This results in an effective two level pagetable. + */ + if (data->start_level < 1) + return NULL; + if (data->start_level == 1 && data->pgd_bits > 2) + return NULL; + if (data->start_level > 1) + data->pgd_bits = 0; + data->start_level = 2; + cfg->apple_dart_cfg.n_ttbrs = 1 << data->pgd_bits; + data->pgd_bits += data->bits_per_level; + + data->pgd = __arm_lpae_alloc_pages(ARM_LPAE_PGD_SIZE(data), GFP_KERNEL, + cfg); + if (!data->pgd) + goto out_free_data; + + for (i = 0; i < cfg->apple_dart_cfg.n_ttbrs; ++i) + cfg->apple_dart_cfg.ttbr[i] = + virt_to_phys(data->pgd + i * ARM_LPAE_GRANULE(data)); + + return &data->iop; + +out_free_data: + kfree(data); + return NULL; +} + struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns = { .alloc = arm_64_lpae_alloc_pgtable_s1, .free = arm_lpae_free_pgtable,
@@ -1068,6 +1125,11 @@ struct io_pgtable_init_fns io_pgtable_arm_mali_lpae_init_fns = { .free = arm_lpae_free_pgtable, }; +struct io_pgtable_init_fns io_pgtable_apple_dart_init_fns = { + .alloc = apple_dart_alloc_pgtable, + .free = arm_lpae_free_pgtable, +}; + #ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE_SELFTEST static struct io_pgtable_cfg *cfg_cookie __initdata;
diff --git a/drivers/iommu/io-pgtable.c b/drivers/iommu/io-pgtable.c
index 6e9917ce980f..fd8e6bd6caf9 100644
--- a/drivers/iommu/io-pgtable.c
+++ b/drivers/iommu/io-pgtable.c@@ -20,6 +20,7 @@ io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] = { [ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns, [ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns, [ARM_MALI_LPAE] = &io_pgtable_arm_mali_lpae_init_fns, + [ARM_APPLE_DART] = &io_pgtable_apple_dart_init_fns, #endif #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S [ARM_V7S] = &io_pgtable_arm_v7s_init_fns,
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index 4d40dfa75b55..a4bfac7f85f7 100644
--- a/include/linux/io-pgtable.h
+++ b/include/linux/io-pgtable.h@@ -16,6 +16,7 @@ enum io_pgtable_fmt { ARM_V7S, ARM_MALI_LPAE, AMD_IOMMU_V1, + ARM_APPLE_DART, IO_PGTABLE_NUM_FMTS, };
@@ -136,6 +137,11 @@ struct io_pgtable_cfg { u64 transtab; u64 memattr; } arm_mali_lpae_cfg; + + struct { + u64 ttbr[4]; + u32 n_ttbrs; + } apple_dart_cfg; }; };
@@ -246,5 +252,6 @@ extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns; extern struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns; extern struct io_pgtable_init_fns io_pgtable_arm_mali_lpae_init_fns; extern struct io_pgtable_init_fns io_pgtable_amd_iommu_v1_init_fns; +extern struct io_pgtable_init_fns io_pgtable_apple_dart_init_fns; #endif /* __IO_PGTABLE_H */
--
2.25.1
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