[PATCH v9 1/3] iommu/io-pgtable-arm-v7s: Add a quirk to allow pgtable PA up to 35bit
Robin Murphy
robin.murphy at arm.com
Wed Jun 15 10:03:21 PDT 2022
On 2022-06-15 17:12, yf.wang at mediatek.com wrote:
> From: Yunfei Wang <yf.wang at mediatek.com>
>
> Single memory zone feature will remove ZONE_DMA32 and ZONE_DMA and
> cause pgtable PA size larger than 32bit.
>
> Since Mediatek IOMMU hardware support at most 35bit PA in pgtable,
> so add a quirk to allow the PA of pgtables support up to bit35.
>
> Signed-off-by: Ning Li <ning.li at mediatek.com>
> Signed-off-by: Yunfei Wang <yf.wang at mediatek.com>
> ---
> drivers/iommu/io-pgtable-arm-v7s.c | 58 +++++++++++++++++++++++-------
> include/linux/io-pgtable.h | 17 +++++----
> 2 files changed, 56 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
> index be066c1503d3..39e5503ac75a 100644
> --- a/drivers/iommu/io-pgtable-arm-v7s.c
> +++ b/drivers/iommu/io-pgtable-arm-v7s.c
> @@ -182,14 +182,8 @@ static bool arm_v7s_is_mtk_enabled(struct io_pgtable_cfg *cfg)
> (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_EXT);
> }
>
> -static arm_v7s_iopte paddr_to_iopte(phys_addr_t paddr, int lvl,
> - struct io_pgtable_cfg *cfg)
> +static arm_v7s_iopte to_mtk_iopte(phys_addr_t paddr, arm_v7s_iopte pte)
> {
> - arm_v7s_iopte pte = paddr & ARM_V7S_LVL_MASK(lvl);
> -
> - if (!arm_v7s_is_mtk_enabled(cfg))
> - return pte;
> -
> if (paddr & BIT_ULL(32))
> pte |= ARM_V7S_ATTR_MTK_PA_BIT32;
> if (paddr & BIT_ULL(33))
> @@ -199,6 +193,17 @@ static arm_v7s_iopte paddr_to_iopte(phys_addr_t paddr, int lvl,
> return pte;
> }
>
> +static arm_v7s_iopte paddr_to_iopte(phys_addr_t paddr, int lvl,
> + struct io_pgtable_cfg *cfg)
> +{
> + arm_v7s_iopte pte = paddr & ARM_V7S_LVL_MASK(lvl);
> +
> + if (arm_v7s_is_mtk_enabled(cfg))
> + return to_mtk_iopte(paddr, pte);
> +
> + return pte;
> +}
> +
> static phys_addr_t iopte_to_paddr(arm_v7s_iopte pte, int lvl,
> struct io_pgtable_cfg *cfg)
> {
> @@ -240,10 +245,17 @@ static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp,
> dma_addr_t dma;
> size_t size = ARM_V7S_TABLE_SIZE(lvl, cfg);
> void *table = NULL;
> + gfp_t gfp_l1;
> +
> + /*
> + * ARM_MTK_TTBR_EXT extend the translation table base support all
> + * memory address.
> + */
> + gfp_l1 = cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT ?
> + GFP_KERNEL : ARM_V7S_TABLE_GFP_DMA;
>
> if (lvl == 1)
> - table = (void *)__get_free_pages(
> - __GFP_ZERO | ARM_V7S_TABLE_GFP_DMA, get_order(size));
> + table = (void *)__get_free_pages(gfp_l1 | __GFP_ZERO, get_order(size));
> else if (lvl == 2)
> table = kmem_cache_zalloc(data->l2_tables, gfp);
>
> @@ -251,7 +263,8 @@ static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp,
> return NULL;
>
> phys = virt_to_phys(table);
> - if (phys != (arm_v7s_iopte)phys) {
> + if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT ?
> + phys >= (1ULL << cfg->oas) : phys != (arm_v7s_iopte)phys) {
Given that the comment above says it supports all of memory, how would
phys >= (1ULL << cfg->oas) ever be true?
> /* Doesn't fit in PTE */
> dev_err(dev, "Page table does not fit in PTE: %pa", &phys);
> goto out_free;
> @@ -457,9 +470,14 @@ static arm_v7s_iopte arm_v7s_install_table(arm_v7s_iopte *table,
> arm_v7s_iopte curr,
> struct io_pgtable_cfg *cfg)
> {
> + phys_addr_t phys = virt_to_phys(table);
> arm_v7s_iopte old, new;
>
> - new = virt_to_phys(table) | ARM_V7S_PTE_TYPE_TABLE;
> + new = phys | ARM_V7S_PTE_TYPE_TABLE;
> +
> + if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT)
> + new = to_mtk_iopte(phys, new);
> +
> if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)
> new |= ARM_V7S_ATTR_NS_TABLE;
>
> @@ -779,6 +797,7 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
> void *cookie)
> {
> struct arm_v7s_io_pgtable *data;
> + slab_flags_t slab_flag;
>
> if (cfg->ias > (arm_v7s_is_mtk_enabled(cfg) ? 34 : ARM_V7S_ADDR_BITS))
> return NULL;
> @@ -788,7 +807,8 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
>
> if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS |
> IO_PGTABLE_QUIRK_NO_PERMS |
> - IO_PGTABLE_QUIRK_ARM_MTK_EXT))
> + IO_PGTABLE_QUIRK_ARM_MTK_EXT |
> + IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT))
> return NULL;
>
> /* If ARM_MTK_4GB is enabled, the NO_PERMS is also expected. */
> @@ -796,15 +816,27 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
> !(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS))
> return NULL;
>
> + if ((cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT) &&
> + !arm_v7s_is_mtk_enabled(cfg))
> + return NULL;
> +
> data = kmalloc(sizeof(*data), GFP_KERNEL);
> if (!data)
> return NULL;
>
> spin_lock_init(&data->split_lock);
> +
> + /*
> + * ARM_MTK_TTBR_EXT extend the translation table base support all
> + * memory address.
> + */
> + slab_flag = cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT ?
> + 0 : ARM_V7S_TABLE_SLAB_FLAGS;
> +
> data->l2_tables = kmem_cache_create("io-pgtable_armv7s_l2",
> ARM_V7S_TABLE_SIZE(2, cfg),
> ARM_V7S_TABLE_SIZE(2, cfg),
> - ARM_V7S_TABLE_SLAB_FLAGS, NULL);
> + slab_flag, NULL);
> if (!data->l2_tables)
> goto out_free_data;
>
> diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
> index 86af6f0a00a2..c9189716f6bd 100644
> --- a/include/linux/io-pgtable.h
> +++ b/include/linux/io-pgtable.h
> @@ -74,17 +74,22 @@ struct io_pgtable_cfg {
> * to support up to 35 bits PA where the bit32, bit33 and bit34 are
> * encoded in the bit9, bit4 and bit5 of the PTE respectively.
> *
> + * IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT: (ARM v7s format) MediaTek IOMMUs
> + * extend the translation table base support up to 35 bits PA, the
> + * encoding format is same with IO_PGTABLE_QUIRK_ARM_MTK_EXT.
> + *
> * IO_PGTABLE_QUIRK_ARM_TTBR1: (ARM LPAE format) Configure the table
> * for use in the upper half of a split address space.
> *
> * IO_PGTABLE_QUIRK_ARM_OUTER_WBWA: Override the outer-cacheability
> * attributes set in the TCR for a non-coherent page-table walker.
> */
> - #define IO_PGTABLE_QUIRK_ARM_NS BIT(0)
> - #define IO_PGTABLE_QUIRK_NO_PERMS BIT(1)
> - #define IO_PGTABLE_QUIRK_ARM_MTK_EXT BIT(3)
> - #define IO_PGTABLE_QUIRK_ARM_TTBR1 BIT(5)
> - #define IO_PGTABLE_QUIRK_ARM_OUTER_WBWA BIT(6)
> + #define IO_PGTABLE_QUIRK_ARM_NS BIT(0)
> + #define IO_PGTABLE_QUIRK_NO_PERMS BIT(1)
> + #define IO_PGTABLE_QUIRK_ARM_MTK_EXT BIT(3)
> + #define IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT BIT(4)
> + #define IO_PGTABLE_QUIRK_ARM_TTBR1 BIT(5)
> + #define IO_PGTABLE_QUIRK_ARM_OUTER_WBWA BIT(6)
> unsigned long quirks;
> unsigned long pgsize_bitmap;
> unsigned int ias;
> @@ -122,7 +127,7 @@ struct io_pgtable_cfg {
> } arm_lpae_s2_cfg;
>
> struct {
> - u32 ttbr;
> + u64 ttbr;
The point of this is to return an encoded TTBR register value, not a raw
base address. I see from the other patches that your register is still
32 bits, so I'd prefer to follow the standard pattern and not need this
change.
Thanks,
Robin.
> u32 tcr;
> u32 nmrr;
> u32 prrr;
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