linux-kernel - [PATCH 4/5] iommu: Introduce map_sg() as an IOMMU op for IOMMU drivers

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1610157031-26301-5-git-send-email-isaacm@codeaurora.org>
Date:   Fri,  8 Jan 2021 17:50:30 -0800
From:   "Isaac J. Manjarres" <isaacm@...eaurora.org>
To:     will@...nel.org, robin.murphy@....com, joro@...tes.org
Cc:     "Isaac J. Manjarres" <isaacm@...eaurora.org>, pdaly@...eaurora.org,
        pratikp@...eaurora.org, linux-arm-kernel@...ts.infradead.org,
        iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org
Subject: [PATCH 4/5] iommu: Introduce map_sg() as an IOMMU op for IOMMU drivers

Add support for IOMMU drivers to have their own map_sg() callbacks.
This completes the path for having iommu_map_sg() invoke an IOMMU
driver's map_sg() callback, which can then invoke the io-pgtable
map_sg() callback with the entire scatter-gather list, so that it
can be processed entirely in the io-pgtable layer.

For IOMMU drivers that do not provide a callback, the default
implementation of iterating through the scatter-gather list, while
calling iommu_map() will be used.

Signed-off-by: Isaac J. Manjarres <isaacm@...eaurora.org>
---
 drivers/iommu/iommu.c | 13 +++++++++++++
 include/linux/iommu.h |  5 +++++
 2 files changed, 18 insertions(+)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 0da0687..46acd5c 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2535,11 +2535,24 @@ static size_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
 			     struct scatterlist *sg, unsigned int nents, int prot,
 			     gfp_t gfp)
 {
+	const struct iommu_ops *ops = domain->ops;
 	size_t len = 0, mapped = 0;
 	phys_addr_t start;
 	unsigned int i = 0;
 	int ret;
 
+	if (ops->map_sg) {
+		ret = ops->map_sg(domain, iova, sg, nents, prot, gfp, &mapped);
+
+		if (ops->iotlb_sync_map)
+			ops->iotlb_sync_map(domain);
+
+		if (ret)
+			goto out_err;
+
+		return mapped;
+	}
+
 	while (i <= nents) {
 		phys_addr_t s_phys = sg_phys(sg);
 
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 0e40a38..bac7681 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -192,6 +192,8 @@ struct iommu_iotlb_gather {
  * @attach_dev: attach device to an iommu domain
  * @detach_dev: detach device from an iommu domain
  * @map: map a physically contiguous memory region to an iommu domain
+ * @map_sg: map a scatter-gather list of physically contiguous chunks to
+ *          an iommu domain.
  * @unmap: unmap a physically contiguous memory region from an iommu domain
  * @flush_iotlb_all: Synchronously flush all hardware TLBs for this domain
  * @iotlb_sync_map: Sync mappings created recently using @map to the hardware
@@ -243,6 +245,9 @@ struct iommu_ops {
 	void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
 	int (*map)(struct iommu_domain *domain, unsigned long iova,
 		   phys_addr_t paddr, size_t size, int prot, gfp_t gfp);
+	int (*map_sg)(struct iommu_domain *domain, unsigned long iova,
+		      struct scatterlist *sg, unsigned int nents, int prot,
+		      gfp_t gfp, size_t *mapped);
 	size_t (*unmap)(struct iommu_domain *domain, unsigned long iova,
 		     size_t size, struct iommu_iotlb_gather *iotlb_gather);
 	void (*flush_iotlb_all)(struct iommu_domain *domain);
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project