[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <ae050c36-8179-e465-84f0-e46c361bd71e@gmail.com>
Date: Wed, 19 May 2021 11:54:42 -0700
From: Florian Fainelli <f.fainelli@...il.com>
To: Claire Chang <tientzu@...omium.org>,
Rob Herring <robh+dt@...nel.org>, mpe@...erman.id.au,
Joerg Roedel <joro@...tes.org>, Will Deacon <will@...nel.org>,
Frank Rowand <frowand.list@...il.com>,
Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
boris.ostrovsky@...cle.com, jgross@...e.com,
Christoph Hellwig <hch@....de>,
Marek Szyprowski <m.szyprowski@...sung.com>
Cc: benh@...nel.crashing.org, paulus@...ba.org,
"list@....net:IOMMU DRIVERS" <iommu@...ts.linux-foundation.org>,
sstabellini@...nel.org, Robin Murphy <robin.murphy@....com>,
grant.likely@....com, xypron.glpk@....de,
Thierry Reding <treding@...dia.com>, mingo@...nel.org,
bauerman@...ux.ibm.com, peterz@...radead.org,
Greg KH <gregkh@...uxfoundation.org>,
Saravana Kannan <saravanak@...gle.com>,
"Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
heikki.krogerus@...ux.intel.com,
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
Randy Dunlap <rdunlap@...radead.org>,
Dan Williams <dan.j.williams@...el.com>,
Bartosz Golaszewski <bgolaszewski@...libre.com>,
linux-devicetree <devicetree@...r.kernel.org>,
lkml <linux-kernel@...r.kernel.org>,
linuxppc-dev@...ts.ozlabs.org, xen-devel@...ts.xenproject.org,
Nicolas Boichat <drinkcat@...omium.org>,
Jim Quinlan <james.quinlan@...adcom.com>, tfiga@...omium.org,
bskeggs@...hat.com, bhelgaas@...gle.com, chris@...is-wilson.co.uk,
daniel@...ll.ch, airlied@...ux.ie, dri-devel@...ts.freedesktop.org,
intel-gfx@...ts.freedesktop.org, jani.nikula@...ux.intel.com,
jxgao@...gle.com, joonas.lahtinen@...ux.intel.com,
linux-pci@...r.kernel.org, maarten.lankhorst@...ux.intel.com,
matthew.auld@...el.com, rodrigo.vivi@...el.com,
thomas.hellstrom@...ux.intel.com
Subject: Re: [PATCH v7 04/15] swiotlb: Add restricted DMA pool initialization
On 5/17/2021 11:42 PM, Claire Chang wrote:
> Add the initialization function to create restricted DMA pools from
> matching reserved-memory nodes.
>
> Signed-off-by: Claire Chang <tientzu@...omium.org>
> ---
> include/linux/device.h | 4 +++
> include/linux/swiotlb.h | 3 +-
> kernel/dma/swiotlb.c | 76 +++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 82 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 38a2071cf776..4987608ea4ff 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -416,6 +416,7 @@ struct dev_links_info {
> * @dma_pools: Dma pools (if dma'ble device).
> * @dma_mem: Internal for coherent mem override.
> * @cma_area: Contiguous memory area for dma allocations
> + * @dma_io_tlb_mem: Internal for swiotlb io_tlb_mem override.
> * @archdata: For arch-specific additions.
> * @of_node: Associated device tree node.
> * @fwnode: Associated device node supplied by platform firmware.
> @@ -521,6 +522,9 @@ struct device {
> #ifdef CONFIG_DMA_CMA
> struct cma *cma_area; /* contiguous memory area for dma
> allocations */
> +#endif
> +#ifdef CONFIG_DMA_RESTRICTED_POOL
> + struct io_tlb_mem *dma_io_tlb_mem;
> #endif
> /* arch specific additions */
> struct dev_archdata archdata;
> diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
> index 216854a5e513..03ad6e3b4056 100644
> --- a/include/linux/swiotlb.h
> +++ b/include/linux/swiotlb.h
> @@ -72,7 +72,8 @@ extern enum swiotlb_force swiotlb_force;
> * range check to see if the memory was in fact allocated by this
> * API.
> * @nslabs: The number of IO TLB blocks (in groups of 64) between @start and
> - * @end. This is command line adjustable via setup_io_tlb_npages.
> + * @end. For default swiotlb, this is command line adjustable via
> + * setup_io_tlb_npages.
> * @used: The number of used IO TLB block.
> * @list: The free list describing the number of free entries available
> * from each index.
> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
> index b849b01a446f..1d8eb4de0d01 100644
> --- a/kernel/dma/swiotlb.c
> +++ b/kernel/dma/swiotlb.c
> @@ -39,6 +39,13 @@
> #ifdef CONFIG_DEBUG_FS
> #include <linux/debugfs.h>
> #endif
> +#ifdef CONFIG_DMA_RESTRICTED_POOL
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/of_fdt.h>
> +#include <linux/of_reserved_mem.h>
> +#include <linux/slab.h>
> +#endif
>
> #include <asm/io.h>
> #include <asm/dma.h>
> @@ -690,3 +697,72 @@ static int __init swiotlb_create_default_debugfs(void)
> late_initcall(swiotlb_create_default_debugfs);
>
> #endif
> +
> +#ifdef CONFIG_DMA_RESTRICTED_POOL
> +static int rmem_swiotlb_device_init(struct reserved_mem *rmem,
> + struct device *dev)
> +{
> + struct io_tlb_mem *mem = rmem->priv;
> + unsigned long nslabs = rmem->size >> IO_TLB_SHIFT;
> +
> + if (dev->dma_io_tlb_mem)
> + return 0;
> +
> + /*
> + * Since multiple devices can share the same pool, the private data,
> + * io_tlb_mem struct, will be initialized by the first device attached
> + * to it.
> + */
> + if (!mem) {
> + mem = kzalloc(struct_size(mem, slots, nslabs), GFP_KERNEL);
> + if (!mem)
> + return -ENOMEM;
> +
> + if (PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) {
> + kfree(mem);
> + return -EINVAL;
This could probably deserve a warning here to indicate that the reserved
area must be accessible within the linear mapping as I would expect a
lot of people to trip over that.
Reviewed-by: Florian Fainelli <f.fainelli@...il.com>
--
Florian
Powered by blists - more mailing lists