From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C15241BDEA; Mon, 25 Sep 2023 16:19:10 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9199DDA7; Mon, 25 Sep 2023 09:19:45 -0700 (PDT) Received: from [10.57.0.188] (unknown [10.57.0.188]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0EB443F59C; Mon, 25 Sep 2023 09:19:05 -0700 (PDT) Message-ID: <3b116df9-cdaa-a6f8-6e5d-8865eefc31ce@arm.com> Date: Mon, 25 Sep 2023 17:19:01 +0100 Precedence: bulk X-Mailing-List: linux-sunxi@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Subject: Re: [PATCH] iommu/sun50i: Convert to map_pages/unmap_pages Content-Language: en-GB To: Jernej Skrabec , joro@8bytes.org, will@kernel.org Cc: wens@csie.org, samuel@sholland.org, iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org References: <20230912181941.2971036-1-jernej.skrabec@gmail.com> From: Robin Murphy In-Reply-To: <20230912181941.2971036-1-jernej.skrabec@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2023-09-12 19:19, Jernej Skrabec wrote: > Convert driver to use map_pages and unmap_pages. Since functions operate > on page table, extend them to be able to operate on whole table, not > just one entry. > > Signed-off-by: Jernej Skrabec > --- > Hi! > > I'm not sure if it makes sense to check validity of page table entry when > unmaping pages makes sense. What do you think? > > Best regards, > Jernej > > drivers/iommu/sun50i-iommu.c | 55 +++++++++++++++++++++--------------- > 1 file changed, 33 insertions(+), 22 deletions(-) > > diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c > index 74c5cb93e900..be6102730a56 100644 > --- a/drivers/iommu/sun50i-iommu.c > +++ b/drivers/iommu/sun50i-iommu.c > @@ -589,11 +589,12 @@ static u32 *sun50i_dte_get_page_table(struct sun50i_iommu_domain *sun50i_domain, > } > > static int sun50i_iommu_map(struct iommu_domain *domain, unsigned long iova, > - phys_addr_t paddr, size_t size, int prot, gfp_t gfp) > + phys_addr_t paddr, size_t pgsize, size_t pgcount, > + int prot, gfp_t gfp, size_t *mapped) > { > struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain); > struct sun50i_iommu *iommu = sun50i_domain->iommu; > - u32 pte_index; > + u32 pte_index, count, i; > u32 *page_table, *pte_addr; > int ret = 0; > > @@ -604,45 +605,55 @@ static int sun50i_iommu_map(struct iommu_domain *domain, unsigned long iova, > } > > pte_index = sun50i_iova_get_pte_index(iova); > - pte_addr = &page_table[pte_index]; > - if (unlikely(sun50i_pte_is_page_valid(*pte_addr))) { > - phys_addr_t page_phys = sun50i_pte_get_page_address(*pte_addr); > - dev_err(iommu->dev, > - "iova %pad already mapped to %pa cannot remap to %pa prot: %#x\n", > - &iova, &page_phys, &paddr, prot); > - ret = -EBUSY; > - goto out; > + count = min(pgcount, (size_t)NUM_PT_ENTRIES - pte_index); > + for (i = 0; i < count; i++) { > + pte_addr = &page_table[pte_index + i]; > + if (unlikely(sun50i_pte_is_page_valid(*pte_addr))) { > + phys_addr_t page_phys = sun50i_pte_get_page_address(*pte_addr); > + > + dev_err(iommu->dev, > + "iova %pad already mapped to %pa cannot remap to %pa prot: %#x\n", > + &iova, &page_phys, &paddr, prot); > + ret = -EBUSY; > + goto out; > + } > + *pte_addr = sun50i_mk_pte(paddr, prot); > + paddr += SPAGE_SIZE; > } > > - *pte_addr = sun50i_mk_pte(paddr, prot); > - sun50i_table_flush(sun50i_domain, pte_addr, 1); > + sun50i_table_flush(sun50i_domain, &page_table[pte_index], i); I think you want the "out" label here, so that "mapped" is still updated and the core knows how much to undo on failure. I guess one could argue that the pagetables are already messed up if that happens, but it still doesn't seem like a good reason to deliberately compound the problem by leaving behind even more "unexpected" entries. Thanks, Robin. > + *mapped = i * SPAGE_SIZE; > > out: > return ret; > } > > static size_t sun50i_iommu_unmap(struct iommu_domain *domain, unsigned long iova, > - size_t size, struct iommu_iotlb_gather *gather) > + size_t pgsize, size_t pgcount, > + struct iommu_iotlb_gather *gather) > { > struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain); > + u32 dte, count, i, pte_index; > phys_addr_t pt_phys; > u32 *pte_addr; > - u32 dte; > > dte = sun50i_domain->dt[sun50i_iova_get_dte_index(iova)]; > if (!sun50i_dte_is_pt_valid(dte)) > return 0; > > pt_phys = sun50i_dte_get_pt_address(dte); > - pte_addr = (u32 *)phys_to_virt(pt_phys) + sun50i_iova_get_pte_index(iova); > + pte_index = sun50i_iova_get_pte_index(iova); > + pte_addr = (u32 *)phys_to_virt(pt_phys) + pte_index; > > - if (!sun50i_pte_is_page_valid(*pte_addr)) > - return 0; > + count = min(pgcount, (size_t)NUM_PT_ENTRIES - pte_index); > + for (i = 0; i < count; i++) > + if (!sun50i_pte_is_page_valid(pte_addr[i])) > + break; > > - memset(pte_addr, 0, sizeof(*pte_addr)); > - sun50i_table_flush(sun50i_domain, pte_addr, 1); > + memset(pte_addr, 0, sizeof(*pte_addr) * i); > + sun50i_table_flush(sun50i_domain, pte_addr, i); > > - return SZ_4K; > + return i * SPAGE_SIZE; > } > > static phys_addr_t sun50i_iommu_iova_to_phys(struct iommu_domain *domain, > @@ -838,8 +849,8 @@ static const struct iommu_ops sun50i_iommu_ops = { > .iotlb_sync_map = sun50i_iommu_iotlb_sync_map, > .iotlb_sync = sun50i_iommu_iotlb_sync, > .iova_to_phys = sun50i_iommu_iova_to_phys, > - .map = sun50i_iommu_map, > - .unmap = sun50i_iommu_unmap, > + .map_pages = sun50i_iommu_map, > + .unmap_pages = sun50i_iommu_unmap, > .free = sun50i_iommu_domain_free, > } > };