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Message-ID: <788428ef-28b8-e5f2-b519-44b206179b89@arm.com>
Date: Thu, 9 Aug 2018 11:54:40 +0100
From: Robin Murphy <robin.murphy@....com>
To: Zhen Lei <thunder.leizhen@...wei.com>,
Will Deacon <will.deacon@....com>,
Joerg Roedel <joro@...tes.org>,
linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>,
iommu <iommu@...ts.linux-foundation.org>,
linux-kernel <linux-kernel@...r.kernel.org>
Cc: LinuxArm <linuxarm@...wei.com>, Hanjun Guo <guohanjun@...wei.com>,
Libin <huawei.libin@...wei.com>
Subject: Re: [PATCH v4 3/5] iommu/io-pgtable-arm: add support for non-strict
mode
On 06/08/18 13:27, Zhen Lei wrote:
> To support the non-strict mode, now we only tlbi and sync for the strict
> mode. But for the non-leaf case, always follow strict mode.
>
> Signed-off-by: Zhen Lei <thunder.leizhen@...wei.com>
> ---
> drivers/iommu/io-pgtable-arm.c | 27 ++++++++++++++++++---------
> drivers/iommu/io-pgtable.h | 3 +++
> 2 files changed, 21 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
> index 010a254..bb61bef 100644
> --- a/drivers/iommu/io-pgtable-arm.c
> +++ b/drivers/iommu/io-pgtable-arm.c
> @@ -292,7 +292,7 @@ static void __arm_lpae_set_pte(arm_lpae_iopte *ptep, arm_lpae_iopte pte,
>
> static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
> unsigned long iova, size_t size, int lvl,
> - arm_lpae_iopte *ptep);
> + arm_lpae_iopte *ptep, bool strict);
>
> static void __arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
> phys_addr_t paddr, arm_lpae_iopte prot,
> @@ -319,6 +319,7 @@ static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
> arm_lpae_iopte prot, int lvl,
> arm_lpae_iopte *ptep)
> {
> + size_t unmapped;
> arm_lpae_iopte pte = *ptep;
>
> if (iopte_leaf(pte, lvl)) {
> @@ -334,7 +335,8 @@ static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
> size_t sz = ARM_LPAE_BLOCK_SIZE(lvl, data);
>
> tblp = ptep - ARM_LPAE_LVL_IDX(iova, lvl, data);
> - if (WARN_ON(__arm_lpae_unmap(data, iova, sz, lvl, tblp) != sz))
> + unmapped = __arm_lpae_unmap(data, iova, sz, lvl, tblp, true);
> + if (WARN_ON(unmapped != sz))
What's the extra local variable for?
> return -EINVAL;
> }
>
> @@ -576,15 +578,17 @@ static size_t arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
> }
>
> if (unmap_idx < 0)
> - return __arm_lpae_unmap(data, iova, size, lvl, tablep);
> + return __arm_lpae_unmap(data, iova, size, lvl, tablep, true);
>
> io_pgtable_tlb_add_flush(&data->iop, iova, size, size, true);
> + io_pgtable_tlb_sync(&data->iop);
> +
> return size;
> }
>
> static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
> unsigned long iova, size_t size, int lvl,
> - arm_lpae_iopte *ptep)
> + arm_lpae_iopte *ptep, bool strict)
> {
> arm_lpae_iopte pte;
> struct io_pgtable *iop = &data->iop;
> @@ -609,7 +613,7 @@ static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
> io_pgtable_tlb_sync(iop);
> ptep = iopte_deref(pte, data);
> __arm_lpae_free_pgtable(data, lvl + 1, ptep);
> - } else {
> + } else if (strict) {
Since this is the only place we ever actually evaluate "strict", can't
we just test iop->cfg.quirks directly at this point instead of playing
pass-the-parcel with the extra argument?
Robin.
> io_pgtable_tlb_add_flush(iop, iova, size, size, true);
> }
>
> @@ -625,12 +629,13 @@ static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
>
> /* Keep on walkin' */
> ptep = iopte_deref(pte, data);
> - return __arm_lpae_unmap(data, iova, size, lvl + 1, ptep);
> + return __arm_lpae_unmap(data, iova, size, lvl + 1, ptep, strict);
> }
>
> static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova,
> size_t size)
> {
> + bool strict;
> struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
> arm_lpae_iopte *ptep = data->pgd;
> int lvl = ARM_LPAE_START_LVL(data);
> @@ -638,7 +643,9 @@ static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova,
> if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias)))
> return 0;
>
> - return __arm_lpae_unmap(data, iova, size, lvl, ptep);
> + strict = !(data->iop.cfg.quirks & IO_PGTABLE_QUIRK_NON_STRICT);
> +
> + return __arm_lpae_unmap(data, iova, size, lvl, ptep, strict);
> }
>
> static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
> @@ -771,7 +778,8 @@ static void arm_lpae_restrict_pgsizes(struct io_pgtable_cfg *cfg)
> u64 reg;
> struct arm_lpae_io_pgtable *data;
>
> - if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS | IO_PGTABLE_QUIRK_NO_DMA))
> + if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS | IO_PGTABLE_QUIRK_NO_DMA |
> + IO_PGTABLE_QUIRK_NON_STRICT))
> return NULL;
>
> data = arm_lpae_alloc_pgtable(cfg);
> @@ -863,7 +871,8 @@ static void arm_lpae_restrict_pgsizes(struct io_pgtable_cfg *cfg)
> struct arm_lpae_io_pgtable *data;
>
> /* The NS quirk doesn't apply at stage 2 */
> - if (cfg->quirks & ~IO_PGTABLE_QUIRK_NO_DMA)
> + if (cfg->quirks & ~(IO_PGTABLE_QUIRK_NO_DMA |
> + IO_PGTABLE_QUIRK_NON_STRICT))
> return NULL;
>
> data = arm_lpae_alloc_pgtable(cfg);
> diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h
> index 2df7909..beb14a3 100644
> --- a/drivers/iommu/io-pgtable.h
> +++ b/drivers/iommu/io-pgtable.h
> @@ -71,12 +71,15 @@ struct io_pgtable_cfg {
> * be accessed by a fully cache-coherent IOMMU or CPU (e.g. for a
> * software-emulated IOMMU), such that pagetable updates need not
> * be treated as explicit DMA data.
> + * IO_PGTABLE_QUIRK_NON_STRICT: Put off TLBs invalidation and release
> + * memory first.
> */
> #define IO_PGTABLE_QUIRK_ARM_NS BIT(0)
> #define IO_PGTABLE_QUIRK_NO_PERMS BIT(1)
> #define IO_PGTABLE_QUIRK_TLBI_ON_MAP BIT(2)
> #define IO_PGTABLE_QUIRK_ARM_MTK_4GB BIT(3)
> #define IO_PGTABLE_QUIRK_NO_DMA BIT(4)
> + #define IO_PGTABLE_QUIRK_NON_STRICT BIT(5)
> unsigned long quirks;
> unsigned long pgsize_bitmap;
> unsigned int ias;
> --
> 1.8.3
>
>
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