Re: [PATCH v2 01/24] iommu: Pull IOVA cookie management into the core

Lu Baolu
2021-07-30T06:11:06Z

On 7/28/21 11:58 PM, Robin Murphy wrote:
> Now that everyone has converged on iommu-dma for IOMMU_DOMAIN_DMA
> support, we can abandon the notion of drivers being responsible for the
> cookie type, and consolidate all the management into the core code.
>
> CC: Marek Szyprowski <m.szyprowski@samsung.com>
> CC: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> CC: Geert Uytterhoeven <geert+renesas@glider.be>
> CC: Yong Wu <yong.wu@mediatek.com>
> CC: Heiko Stuebner <heiko@sntech.de>
> CC: Chunyan Zhang <chunyan.zhang@unisoc.com>
> CC: Chunyan Zhang <chunyan.zhang@unisoc.com>
> CC: Maxime Ripard <mripard@kernel.org>
> CC: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
> drivers/iommu/iommu.c | 7 +++++++
> include/linux/iommu.h | 3 ++-
> 2 files changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index f2cda9950bd5..ea5a9ea8d431 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -7,6 +7,7 @@
> #define pr_fmt(fmt) "iommu: " fmt
>
> #include <linux/device.h>
> +#include <linux/dma-iommu.h>
> #include <linux/kernel.h>
> #include <linux/bits.h>
> #include <linux/bug.h>
> @@ -1946,6 +1947,11 @@ static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
> /* Assume all sizes by default; the driver may override this later */
> domain->pgsize_bitmap = bus->iommu_ops->pgsize_bitmap;
>
> + /* Temporarily ignore -EEXIST while drivers still get their own cookies */
> + if (type == IOMMU_DOMAIN_DMA && iommu_get_dma_cookie(domain) == -ENOMEM) {
> + iommu_domain_free(domain);
> + domain = NULL;
> + }
> return domain;
> }
>
> @@ -1957,6 +1963,7 @@ EXPORT_SYMBOL_GPL(iommu_domain_alloc);
>
> void iommu_domain_free(struct iommu_domain *domain)
> {
> + iommu_put_dma_cookie(domain);
> domain->ops->domain_free(domain);
> }
> EXPORT_SYMBOL_GPL(iommu_domain_free);
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 4997c78e2670..141779d76035 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -40,6 +40,7 @@ struct iommu_domain;
> struct notifier_block;
> struct iommu_sva;
> struct iommu_fault_event;
> +struct iommu_dma_cookie;
>
> /* iommu fault flags */
> #define IOMMU_FAULT_READ 0x0
> @@ -86,7 +87,7 @@ struct iommu_domain {
> iommu_fault_handler_t handler;
> void *handler_token;
> struct iommu_domain_geometry geometry;
> - void *iova_cookie;
> + struct iommu_dma_cookie *iova_cookie;
> };
>
> enum iommu_cap {
>

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>

Best regards,
baolu