From: Murali Karicheri <m-karicheri2@ti.com>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Robin Murphy <Robin.Murphy@arm.com>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
Russell King <linux@arm.linux.org.uk>,
Arnd Bergmann <arnd@arndb.de>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
Joerg Roedel <joro@8bytes.org>, Will Deacon <Will.Deacon@arm.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"grant.likely@linaro.org" <grant.likely@linaro.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
Rob Herring <robh+dt@kernel.org>,
"suravee.suthikulpanit@amd.com" <suravee.suthikulpanit@amd.com>,
Bjorn Helgaas <bhelgaas@google.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v4 3/6] of: fix size when dma-range is not used
Date: Mon, 2 Feb 2015 11:10:26 -0500 [thread overview]
Message-ID: <54CFA172.8070408@ti.com> (raw)
In-Reply-To: <20150202121843.GD22661@e104818-lin.cambridge.arm.com>
On 02/02/2015 07:18 AM, Catalin Marinas wrote:
> On Fri, Jan 30, 2015 at 06:06:27PM +0000, Murali Karicheri wrote:
>> On 01/28/2015 12:30 PM, Catalin Marinas wrote:
>>> I think we can remove this check altogether (we leaved without it for a
>>> while) but we need to add 1 when calculating the mask:
>>>
>>> dev->coherent_dma_mask = min(DMA_BIT_MASK(32),
>>> DMA_BIT_MASK(ilog2(size + 1)));
>>>
>> For Keystone, the dma_addr is to be taken care as well to determine the
>> mask. The above will not work.
>
> This was discussed before (not on this thread) and dma_addr should not
> affect the mask, it only affects the pfn offset.
>
>> Based on the discussion so far, this is the function I have come up with
>> incorporating the suggestions. Please review this and see if I have
>> missed out any. This works fine on Keystone.
>>
>> void of_dma_configure(struct device *dev, struct device_node *np)
>> {
>> u64 dma_addr = 0, paddr, size;
>> int ret;
>> bool coherent;
>> unsigned long offset = 0;
>> struct iommu_ops *iommu;
>>
>> /*
>> * Set default size to cover the 32-bit. Drivers are expected to setup
>> * the correct size and dma_mask.
>> */
>> size = 1ULL<< 32;
>>
>> ret = of_dma_get_range(np,&dma_addr,&paddr,&size);
>> if (!ret) {
>> offset = PFN_DOWN(paddr - dma_addr);
>> if (!size) {
>> dev_err(dev, "Invalid size (%llx)\n",
>> size);
>> return;
>> }
>> if (size& 1) {
>> size = size + 1;
>> dev_warn(dev, "Incorrect usage of size (%llx)\n",
>> size);
>> }
>> dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
>> }
>> dev->dma_pfn_offset = offset;
>>
>> /*
>> * Coherent DMA masks larger than 32-bit must be explicitly set by the
>> * driver.
>> */
>> dev->coherent_dma_mask = min(DMA_BIT_MASK(32),
>> DMA_BIT_MASK(ilog2(dma_addr + size)));
>
> That's not correct, coherent_dma_mask should still be calculated solely
> based on size, not dma_addr.
>
> Functions like swiotlb_dma_supported() use phys_to_dma() which on ARM
> (32-bit) subtracts the dma_pfn_offset, so the mask based on size works
> fine.
>
> In the arm64 tree, we haven't taken dma_pfn_offset into account for
> phys_to_dma() yet but if needed for a SoC, we'll add it.
>
I need to hear Arnd's comment on this. I am seeing an issue without this
change. Probably it needs a change else where. I will post the error I
am getting to this list.
Murali
--
Murali Karicheri
Linux Kernel, Texas Instruments
next prev parent reply other threads:[~2015-02-02 16:11 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-23 22:32 [PATCH v4 0/6] PCI: get DMA configuration from parent device Murali Karicheri
2015-01-23 22:32 ` [PATCH v4 1/6] of: iommu: add ptr to OF node arg to of_iommu_configure() Murali Karicheri
2015-01-25 13:32 ` Laurent Pinchart
2015-01-26 18:49 ` Murali Karicheri
2015-01-28 11:33 ` Will Deacon
2015-01-28 12:23 ` Laurent Pinchart
2015-01-28 12:29 ` Will Deacon
2015-01-28 13:15 ` Laurent Pinchart
2015-01-28 13:32 ` Will Deacon
2015-01-28 15:21 ` Murali Karicheri
2015-01-28 23:32 ` Laurent Pinchart
2015-01-29 14:59 ` Murali Karicheri
2015-01-29 16:49 ` Rob Herring
2015-01-30 0:24 ` Laurent Pinchart
2015-01-30 15:23 ` Murali Karicheri
2015-01-23 22:32 ` [PATCH v4 2/6] of: move of_dma_configure() to device.c to help re-use Murali Karicheri
2015-01-23 22:32 ` [PATCH v4 3/6] of: fix size when dma-range is not used Murali Karicheri
2015-01-27 11:27 ` Robin Murphy
2015-01-27 15:44 ` Murali Karicheri
2015-01-27 18:55 ` Murali Karicheri
2015-01-28 11:05 ` Catalin Marinas
2015-01-28 15:45 ` Rob Herring
2015-01-28 17:23 ` Catalin Marinas
2015-01-28 17:34 ` Murali Karicheri
2015-01-28 15:55 ` Robin Murphy
2015-01-28 17:30 ` Catalin Marinas
2015-01-30 18:06 ` Murali Karicheri
2015-02-02 12:18 ` Catalin Marinas
2015-02-02 16:10 ` Murali Karicheri [this message]
2015-02-05 21:42 ` Murali Karicheri
2015-02-05 22:44 ` Catalin Marinas
2015-01-23 22:32 ` [PATCH v4 4/6] of/pci: add of_pci_dma_configure() update dma configuration Murali Karicheri
2015-01-23 23:41 ` Bjorn Helgaas
2015-01-26 23:25 ` Murali Karicheri
2015-01-26 23:59 ` Bjorn Helgaas
2015-01-27 18:14 ` Murali Karicheri
2015-01-27 18:42 ` Bjorn Helgaas
2015-01-27 18:45 ` Murali Karicheri
2015-01-23 22:32 ` [PATCH v4 5/6] PCI: update dma configuration from DT Murali Karicheri
2015-01-23 23:27 ` Bjorn Helgaas
2015-01-26 23:28 ` Murali Karicheri
2015-01-23 22:32 ` [PATCH v4 6/6] arm: dma-mapping: updates to limit dma_mask and iommu mapping size Murali Karicheri
2015-01-27 11:12 ` Robin Murphy
2015-01-27 11:34 ` Catalin Marinas
2015-01-27 15:19 ` Murali Karicheri
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