From: Christoph Hellwig <hch@lst.de>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Christoph Hellwig <hch@lst.de>, Jonas Bonn <jonas@southpole.se>,
Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
Stafford Horne <shorne@gmail.com>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
openrisc@lists.librecores.org, iommu@lists.linux-foundation.org,
linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] dma-mapping: support setting memory uncached in place
Date: Fri, 21 Feb 2020 15:16:56 +0100 [thread overview]
Message-ID: <20200221141656.GF6968@lst.de> (raw)
In-Reply-To: <502fa745-ddad-f91b-52bc-52edecf8fdbc@arm.com>
On Thu, Feb 20, 2020 at 05:21:35PM +0000, Robin Murphy wrote:
>> @@ -196,10 +192,15 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size,
>> memset(ret, 0, size);
>> - if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) &&
>> - dma_alloc_need_uncached(dev, attrs)) {
>> + if (dma_alloc_need_uncached(dev, attrs)) {
>> arch_dma_prep_coherent(page, size);
>> - ret = uncached_kernel_address(ret);
>> +
>> + if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED)) {
>> + if (!arch_dma_set_uncached(ret, size))
>> + goto out_free_pages;
>> + } else if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT)) {
>> + ret = uncached_kernel_address(ret);
>
> Hmm, would we actually need to keep ARCH_HAS_UNCACHED_SEGMENT? If
> arch_dma_set_uncached() returned void*/ERR_PTR instead, then it could work
> for both cases (with arch_dma_clear_uncached() being a no-op for segments).
Yes, I think so. I was a little worried about what to do with
cached_kernel_address() in that scheme, but it turns out with the recent
round of dma-direct cleanup that is actually entirely unused now.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Jonas Bonn <jonas@southpole.se>,
Mark Rutland <mark.rutland@arm.com>,
linux-kernel@vger.kernel.org,
Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
iommu@lists.linux-foundation.org, openrisc@lists.librecores.org,
linux-arch@vger.kernel.org, Stafford Horne <shorne@gmail.com>,
Will Deacon <will@kernel.org>, Christoph Hellwig <hch@lst.de>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 1/2] dma-mapping: support setting memory uncached in place
Date: Fri, 21 Feb 2020 15:16:56 +0100 [thread overview]
Message-ID: <20200221141656.GF6968@lst.de> (raw)
In-Reply-To: <502fa745-ddad-f91b-52bc-52edecf8fdbc@arm.com>
On Thu, Feb 20, 2020 at 05:21:35PM +0000, Robin Murphy wrote:
>> @@ -196,10 +192,15 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size,
>> memset(ret, 0, size);
>> - if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) &&
>> - dma_alloc_need_uncached(dev, attrs)) {
>> + if (dma_alloc_need_uncached(dev, attrs)) {
>> arch_dma_prep_coherent(page, size);
>> - ret = uncached_kernel_address(ret);
>> +
>> + if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED)) {
>> + if (!arch_dma_set_uncached(ret, size))
>> + goto out_free_pages;
>> + } else if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT)) {
>> + ret = uncached_kernel_address(ret);
>
> Hmm, would we actually need to keep ARCH_HAS_UNCACHED_SEGMENT? If
> arch_dma_set_uncached() returned void*/ERR_PTR instead, then it could work
> for both cases (with arch_dma_clear_uncached() being a no-op for segments).
Yes, I think so. I was a little worried about what to do with
cached_kernel_address() in that scheme, but it turns out with the recent
round of dma-direct cleanup that is actually entirely unused now.
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Jonas Bonn <jonas@southpole.se>,
Mark Rutland <mark.rutland@arm.com>,
linux-kernel@vger.kernel.org,
Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
iommu@lists.linux-foundation.org, openrisc@lists.librecores.org,
linux-arch@vger.kernel.org, Stafford Horne <shorne@gmail.com>,
Will Deacon <will@kernel.org>, Christoph Hellwig <hch@lst.de>,
linux-arm-kernel@lists.infradead.org,
Marek Szyprowski <m.szyprowski@samsung.com>
Subject: Re: [PATCH 1/2] dma-mapping: support setting memory uncached in place
Date: Fri, 21 Feb 2020 15:16:56 +0100 [thread overview]
Message-ID: <20200221141656.GF6968@lst.de> (raw)
In-Reply-To: <502fa745-ddad-f91b-52bc-52edecf8fdbc@arm.com>
On Thu, Feb 20, 2020 at 05:21:35PM +0000, Robin Murphy wrote:
>> @@ -196,10 +192,15 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size,
>> memset(ret, 0, size);
>> - if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) &&
>> - dma_alloc_need_uncached(dev, attrs)) {
>> + if (dma_alloc_need_uncached(dev, attrs)) {
>> arch_dma_prep_coherent(page, size);
>> - ret = uncached_kernel_address(ret);
>> +
>> + if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED)) {
>> + if (!arch_dma_set_uncached(ret, size))
>> + goto out_free_pages;
>> + } else if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT)) {
>> + ret = uncached_kernel_address(ret);
>
> Hmm, would we actually need to keep ARCH_HAS_UNCACHED_SEGMENT? If
> arch_dma_set_uncached() returned void*/ERR_PTR instead, then it could work
> for both cases (with arch_dma_clear_uncached() being a no-op for segments).
Yes, I think so. I was a little worried about what to do with
cached_kernel_address() in that scheme, but it turns out with the recent
round of dma-direct cleanup that is actually entirely unused now.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: openrisc@lists.librecores.org
Subject: [OpenRISC] [PATCH 1/2] dma-mapping: support setting memory uncached in place
Date: Fri, 21 Feb 2020 15:16:56 +0100 [thread overview]
Message-ID: <20200221141656.GF6968@lst.de> (raw)
In-Reply-To: <502fa745-ddad-f91b-52bc-52edecf8fdbc@arm.com>
On Thu, Feb 20, 2020 at 05:21:35PM +0000, Robin Murphy wrote:
>> @@ -196,10 +192,15 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size,
>> memset(ret, 0, size);
>> - if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) &&
>> - dma_alloc_need_uncached(dev, attrs)) {
>> + if (dma_alloc_need_uncached(dev, attrs)) {
>> arch_dma_prep_coherent(page, size);
>> - ret = uncached_kernel_address(ret);
>> +
>> + if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED)) {
>> + if (!arch_dma_set_uncached(ret, size))
>> + goto out_free_pages;
>> + } else if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT)) {
>> + ret = uncached_kernel_address(ret);
>
> Hmm, would we actually need to keep ARCH_HAS_UNCACHED_SEGMENT? If
> arch_dma_set_uncached() returned void*/ERR_PTR instead, then it could work
> for both cases (with arch_dma_clear_uncached() being a no-op for segments).
Yes, I think so. I was a little worried about what to do with
cached_kernel_address() in that scheme, but it turns out with the recent
round of dma-direct cleanup that is actually entirely unused now.
next prev parent reply other threads:[~2020-02-21 14:17 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-20 17:01 provide in-place uncached remapping for dma-direct (resend) Christoph Hellwig
2020-02-20 17:01 ` [OpenRISC] " Christoph Hellwig
2020-02-20 17:01 ` Christoph Hellwig
2020-02-20 17:01 ` Christoph Hellwig
2020-02-20 17:01 ` [PATCH 1/2] dma-mapping: support setting memory uncached in place Christoph Hellwig
2020-02-20 17:01 ` [OpenRISC] " Christoph Hellwig
2020-02-20 17:01 ` Christoph Hellwig
2020-02-20 17:01 ` Christoph Hellwig
2020-02-20 17:01 ` Christoph Hellwig
2020-02-20 17:21 ` Robin Murphy
2020-02-20 17:21 ` [OpenRISC] " Robin Murphy
2020-02-20 17:21 ` Robin Murphy
2020-02-20 17:21 ` Robin Murphy
2020-02-21 14:16 ` Christoph Hellwig [this message]
2020-02-21 14:16 ` [OpenRISC] " Christoph Hellwig
2020-02-21 14:16 ` Christoph Hellwig
2020-02-21 14:16 ` Christoph Hellwig
2020-02-20 17:01 ` [PATCH 2/2] openrisc: use the generic in-place uncached DMA allocator Christoph Hellwig
2020-02-20 17:01 ` [OpenRISC] " Christoph Hellwig
2020-02-20 17:01 ` Christoph Hellwig
2020-02-20 17:01 ` Christoph Hellwig
2020-02-20 17:01 ` Christoph Hellwig
2020-02-21 22:14 ` Stafford Horne
2020-02-21 22:14 ` [OpenRISC] " Stafford Horne
2020-02-21 22:14 ` Stafford Horne
2020-02-21 22:14 ` Stafford Horne
2020-02-24 19:45 ` Christoph Hellwig
2020-02-24 19:45 ` [OpenRISC] " Christoph Hellwig
2020-02-24 19:45 ` Christoph Hellwig
2020-02-24 19:45 ` Christoph Hellwig
2020-02-25 10:10 ` Stafford Horne
2020-02-25 10:10 ` [OpenRISC] " Stafford Horne
2020-02-25 10:10 ` Stafford Horne
2020-02-25 10:10 ` Stafford Horne
-- strict thread matches above, loose matches on Subject: below --
2019-11-07 17:40 provide in-place uncached remapping for dma-direct Christoph Hellwig
2019-11-07 17:40 ` [PATCH 1/2] dma-mapping: support setting memory uncached in place Christoph Hellwig
2019-11-07 17:40 ` Christoph Hellwig
2019-11-07 17:40 ` Christoph Hellwig
2019-11-07 17:40 ` Christoph Hellwig
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