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Message-ID: <36caefde-066b-1e37-2251-d932a6a15a9a@arm.com>
Date: Thu, 20 Sep 2018 12:54:46 +0100
From: Robin Murphy <robin.murphy@....com>
To: Yong Wu <yong.wu@...iatek.com>
Cc: Joerg Roedel <joro@...tes.org>, Rob Herring <robh+dt@...nel.org>,
Matthias Brugger <matthias.bgg@...il.com>,
Tomasz Figa <tfiga@...gle.com>,
Will Deacon <will.deacon@....com>,
Daniel Kurtz <djkurtz@...gle.com>,
linux-mediatek@...ts.infradead.org, srv_heupstream@...iatek.com,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org,
iommu@...ts.linux-foundation.org, arnd@...db.de,
yingjoe.chen@...iatek.com
Subject: Re: [PATCH 04/13] iommu/io-pgtable-arm-v7s: Extend MediaTek 4GB mode
On 20/09/18 06:54, Yong Wu wrote:
> Hi Robin,
>
> Could you help take a look at this patch since I changed the v7s
> here?
> Thanks.
Sorry, I did have a very quick skim through this series when it landed
in my inbox but I've not yet found the chance to go through it properly.
Since I am actually back doing io-pgtable stuff right now, I'll take a
look shortly.
Thanks,
Robin.
> 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@...iatek.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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