[PATCH 04/13] iommu/io-pgtable-arm-v7s: Extend MediaTek 4GB mode

Yong Wu yong.wu at mediatek.com
Wed Sep 19 22:54:30 PDT 2018


Hi Robin,

   Could you help take a look at this patch since I changed the v7s
here?
   Thanks.

On Mon, 2018-09-03 at 14:01 +0800, Yong Wu wrote:
> MediaTek extend the arm v7s descriptor to support the dram over 4GB.
> 
> In the mt2712 and mt8173, it's called "4GB mode", the physical address
> is from 0x4000_0000 to 0x1_3fff_ffff, but from EMI point of view, it
> is remapped to high address from 0x1_0000_0000 to 0x1_ffff_ffff, the
> bit32 is always enabled. thus, in the M4U, we always enable the bit9
> for all PTEs which means to enable bit32 of physical address.
> 
> but in mt8183, M4U support the dram from 0x4000_0000 to 0x3_ffff_ffff
> which isn't remaped. We extend the PTEs: the bit9 represent bit32 of
> PA and the bit4 represent bit33 of PA. Meanwhile the iova still is
> 32bits.
> 
> In order to unify code, in the "4GB mode", we add the bit32 for the
> physical address manually in our driver.
> 
> Correspondingly, Adding bit32 and bit33 for the PA in the iova_to_phys
> has to been moved into v7s.
> 
> Signed-off-by: Yong Wu <yong.wu at mediatek.com>
> ---
> In mt8183, the PA is from 0x4000_0000 to 0x3_ffff_ffff while the iova
> still is 32bits. Acturally, our HW extend the v7s pgtable. currently
> the lvl1 pgtable is 16KB, our HW double it. but 32bit iova is enough
> for us currently, thus we don't change it.
> ---
>  drivers/iommu/io-pgtable-arm-v7s.c | 38 ++++++++++++++++++++++++++++++--------
>  drivers/iommu/io-pgtable.h         |  8 ++++----
>  drivers/iommu/mtk_iommu.c          | 15 +++++++++------
>  drivers/iommu/mtk_iommu.h          |  1 +
>  4 files changed, 44 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
> index b5948ba..47538dd 100644
> --- a/drivers/iommu/io-pgtable-arm-v7s.c
> +++ b/drivers/iommu/io-pgtable-arm-v7s.c
> @@ -124,7 +124,9 @@
>  #define ARM_V7S_TEX_MASK		0x7
>  #define ARM_V7S_ATTR_TEX(val)		(((val) & ARM_V7S_TEX_MASK) << ARM_V7S_TEX_SHIFT)
>  
> -#define ARM_V7S_ATTR_MTK_4GB		BIT(9) /* MTK extend it for 4GB mode */
> +/* MTK extend the two bits below for over 4GB mode */
> +#define ARM_V7S_ATTR_MTK_PA_BIT32	BIT(9)
> +#define ARM_V7S_ATTR_MTK_PA_BIT33	BIT(4)
>  
>  /* *well, except for TEX on level 2 large pages, of course :( */
>  #define ARM_V7S_CONT_PAGE_TEX_SHIFT	6
> @@ -268,7 +270,8 @@ static void __arm_v7s_set_pte(arm_v7s_iopte *ptep, arm_v7s_iopte pte,
>  }
>  
>  static arm_v7s_iopte arm_v7s_prot_to_pte(int prot, int lvl,
> -					 struct io_pgtable_cfg *cfg)
> +					 struct io_pgtable_cfg *cfg,
> +					 phys_addr_t paddr) /* Only for MTK */
>  {
>  	bool ap = !(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS);
>  	arm_v7s_iopte pte = ARM_V7S_ATTR_NG | ARM_V7S_ATTR_S;
> @@ -295,8 +298,12 @@ static arm_v7s_iopte arm_v7s_prot_to_pte(int prot, int lvl,
>  	if (lvl == 1 && (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS))
>  		pte |= ARM_V7S_ATTR_NS_SECTION;
>  
> -	if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_4GB)
> -		pte |= ARM_V7S_ATTR_MTK_4GB;
> +	if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_4GB) {
> +		if (paddr & BIT_ULL(32))
> +			pte |= ARM_V7S_ATTR_MTK_PA_BIT32;
> +		if (paddr & BIT_ULL(33))
> +			pte |= ARM_V7S_ATTR_MTK_PA_BIT33;
> +	}
>  
>  	return pte;
>  }
> @@ -392,7 +399,7 @@ static int arm_v7s_init_pte(struct arm_v7s_io_pgtable *data,
>  			return -EEXIST;
>  		}
>  
> -	pte = arm_v7s_prot_to_pte(prot, lvl, cfg);
> +	pte = arm_v7s_prot_to_pte(prot, lvl, cfg, paddr);
>  	if (num_entries > 1)
>  		pte = arm_v7s_pte_to_cont(pte, lvl);
>  
> @@ -484,7 +491,11 @@ static int arm_v7s_map(struct io_pgtable_ops *ops, unsigned long iova,
>  	if (!(prot & (IOMMU_READ | IOMMU_WRITE)))
>  		return 0;
>  
> -	if (WARN_ON(upper_32_bits(iova) || upper_32_bits(paddr)))
> +	if (WARN_ON(upper_32_bits(iova)))
> +		return -ERANGE;
> +
> +	if (WARN_ON(upper_32_bits(paddr) &&
> +		    !(iop->cfg.quirks & IO_PGTABLE_QUIRK_ARM_MTK_4GB)))
>  		return -ERANGE;
>  
>  	ret = __arm_v7s_map(data, iova, paddr, size, prot, 1, data->pgd);
> @@ -563,7 +574,7 @@ static size_t arm_v7s_split_blk_unmap(struct arm_v7s_io_pgtable *data,
>  	num_entries = size >> ARM_V7S_LVL_SHIFT(2);
>  	unmap_idx = ARM_V7S_LVL_IDX(iova, 2);
>  
> -	pte = arm_v7s_prot_to_pte(arm_v7s_pte_to_prot(blk_pte, 1), 2, cfg);
> +	pte = arm_v7s_prot_to_pte(arm_v7s_pte_to_prot(blk_pte, 1), 2, cfg, 0);
>  	if (num_entries > 1)
>  		pte = arm_v7s_pte_to_cont(pte, 2);
>  
> @@ -677,7 +688,9 @@ static phys_addr_t arm_v7s_iova_to_phys(struct io_pgtable_ops *ops,
>  					unsigned long iova)
>  {
>  	struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops);
> +	struct io_pgtable_cfg *cfg = &data->iop.cfg;
>  	arm_v7s_iopte *ptep = data->pgd, pte;
> +	phys_addr_t paddr;
>  	int lvl = 0;
>  	u32 mask;
>  
> @@ -693,7 +706,16 @@ static phys_addr_t arm_v7s_iova_to_phys(struct io_pgtable_ops *ops,
>  	mask = ARM_V7S_LVL_MASK(lvl);
>  	if (arm_v7s_pte_is_cont(pte, lvl))
>  		mask *= ARM_V7S_CONT_PAGES;
> -	return (pte & mask) | (iova & ~mask);
> +	paddr = (pte & mask) | (iova & ~mask);
> +
> +	if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT) &&
> +	    cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_4GB) {
> +		if (pte & ARM_V7S_ATTR_MTK_PA_BIT32)
> +			paddr |= BIT_ULL(32);
> +		if (pte & ARM_V7S_ATTR_MTK_PA_BIT33)
> +			paddr |= BIT_ULL(33);
> +	}
> +	return paddr;
>  }
>  
>  static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
> diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h
> index 2df7909..0eeed94 100644
> --- a/drivers/iommu/io-pgtable.h
> +++ b/drivers/iommu/io-pgtable.h
> @@ -62,10 +62,10 @@ struct io_pgtable_cfg {
>  	 *	(unmapped) entries but the hardware might do so anyway, perform
>  	 *	TLB maintenance when mapping as well as when unmapping.
>  	 *
> -	 * IO_PGTABLE_QUIRK_ARM_MTK_4GB: (ARM v7s format) Set bit 9 in all
> -	 *	PTEs, for Mediatek IOMMUs which treat it as a 33rd address bit
> -	 *	when the SoC is in "4GB mode" and they can only access the high
> -	 *	remap of DRAM (0x1_00000000 to 0x1_ffffffff).
> +	 * IO_PGTABLE_QUIRK_ARM_MTK_4GB: (ARM v7s format) Set bit 4 and 9 in all
> +	 *	PTEs, for Mediatek IOMMUs which treat it as the 33rd and 32rd
> +	 *	address bit when the SoC dram is over 4GB and they can access
> +	 *	the physical address from 0x4000_0000 to 0x3_ffff_ffff.
>  	 *
>  	 * IO_PGTABLE_QUIRK_NO_DMA: Guarantees that the tables will only ever
>  	 *	be accessed by a fully cache-coherent IOMMU or CPU (e.g. for a
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index c0e2da5..86bf647 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -367,12 +367,17 @@ static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova,
>  			 phys_addr_t paddr, size_t size, int prot)
>  {
>  	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
> +	struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();
>  	unsigned long flags;
>  	int ret;
>  
> +	if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT) &&
> +	    data->plat_data->has_4gb_mode &&
> +	    data->enable_4GB)
> +		paddr |= BIT_ULL(32);
> +
>  	spin_lock_irqsave(&dom->pgtlock, flags);
> -	ret = dom->iop->map(dom->iop, iova, paddr & DMA_BIT_MASK(32),
> -			    size, prot);
> +	ret = dom->iop->map(dom->iop, iova, paddr, size, prot);
>  	spin_unlock_irqrestore(&dom->pgtlock, flags);
>  
>  	return ret;
> @@ -401,7 +406,6 @@ static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
>  					  dma_addr_t iova)
>  {
>  	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
> -	struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();
>  	unsigned long flags;
>  	phys_addr_t pa;
>  
> @@ -409,9 +413,6 @@ static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
>  	pa = dom->iop->iova_to_phys(dom->iop, iova);
>  	spin_unlock_irqrestore(&dom->pgtlock, flags);
>  
> -	if (data->enable_4GB)
> -		pa |= BIT_ULL(32);
> -
>  	return pa;
>  }
>  
> @@ -735,10 +736,12 @@ static int __maybe_unused mtk_iommu_resume(struct device *dev)
>  
>  static const struct mtk_iommu_plat_data mt2712_data = {
>  	.m4u_plat = M4U_MT2712,
> +	.has_4gb_mode = true,
>  };
>  
>  static const struct mtk_iommu_plat_data mt8173_data = {
>  	.m4u_plat = M4U_MT8173,
> +	.has_4gb_mode = true,
>  };
>  
>  static const struct of_device_id mtk_iommu_of_ids[] = {
> diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
> index 333a0ef..a243047 100644
> --- a/drivers/iommu/mtk_iommu.h
> +++ b/drivers/iommu/mtk_iommu.h
> @@ -43,6 +43,7 @@ enum mtk_iommu_plat {
>  
>  struct mtk_iommu_plat_data {
>  	enum mtk_iommu_plat m4u_plat;
> +	bool has_4gb_mode;
>  };
>  
>  struct mtk_iommu_domain;





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