Received-SPF: pass (google.com: domain of linux-kernel+bounces-92074-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1;
From: Leon Romanovsky <leon@kernel.org>
To: Christoph Hellwig <hch@lst.de>,
	Robin Murphy <robin.murphy@arm.com>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Joerg Roedel <joro@8bytes.org>,
	Will Deacon <will@kernel.org>,
	Jason Gunthorpe <jgg@ziepe.ca>,
	Chaitanya Kulkarni <chaitanyak@nvidia.com>
Cc: Leon Romanovsky <leonro@nvidia.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Jens Axboe <axboe@kernel.dk>,
	Keith Busch <kbusch@kernel.org>,
	Sagi Grimberg <sagi@grimberg.me>,
	Yishai Hadas <yishaih@nvidia.com>,
	Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>,
	Kevin Tian <kevin.tian@intel.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	=?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= <jglisse@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-block@vger.kernel.org,
	linux-rdma@vger.kernel.org,
	iommu@lists.linux.dev,
	linux-nvme@lists.infradead.org,
	kvm@vger.kernel.org,
	linux-mm@kvack.org,
	Bart Van Assche <bvanassche@acm.org>,
	Damien Le Moal <damien.lemoal@opensource.wdc.com>,
	Amir Goldstein <amir73il@gmail.com>,
	"josef@toxicpanda.com" <josef@toxicpanda.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	"daniel@iogearbox.net" <daniel@iogearbox.net>,
	Dan Williams <dan.j.williams@intel.com>,
	"jack@suse.com" <jack@suse.com>,
	Zhu Yanjun <zyjzyj2000@gmail.com>
Subject: [RFC 04/16] iommu/dma: Provide an interface to allow preallocate IOVA
Date: Tue,  5 Mar 2024 12:15:14 +0200
Message-ID: <e580473eb571d56c8e3952ebcdab05151a7efe7c.1709631413.git.leon@kernel.org>
In-Reply-To: <a77609c9c9a09214e38b04133e44eee67fe50ab0.1709631413.git.leon@kernel.org>
References: <a77609c9c9a09214e38b04133e44eee67fe50ab0.1709631413.git.leon@kernel.org>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

From: Leon Romanovsky <leonro@nvidia.com>

Separate IOVA allocation to dedicated callback so it will allow
cache of IOVA and reuse it in fast paths for devices which support
ODP (on-demand-paging) mechanism.

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 drivers/iommu/dma-iommu.c | 50 +++++++++++++++++++++++++++++----------
 1 file changed, 38 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 50ccc4f1ef81..e55726783501 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -356,7 +356,7 @@ int iommu_dma_init_fq(struct iommu_domain *domain)
 	atomic_set(&cookie->fq_timer_on, 0);
 	/*
 	 * Prevent incomplete fq state being observable. Pairs with path from
-	 * __iommu_dma_unmap() through iommu_dma_free_iova() to queue_iova()
+	 * __iommu_dma_unmap() through __iommu_dma_free_iova() to queue_iova()
 	 */
 	smp_wmb();
 	WRITE_ONCE(cookie->fq_domain, domain);
@@ -760,7 +760,7 @@ static int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
 	}
 }
 
-static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
+static dma_addr_t __iommu_dma_alloc_iova(struct iommu_domain *domain,
 		size_t size, u64 dma_limit, struct device *dev)
 {
 	struct iommu_dma_cookie *cookie = domain->iova_cookie;
@@ -806,7 +806,7 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
 	return (dma_addr_t)iova << shift;
 }
 
-static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
+static void __iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
 		dma_addr_t iova, size_t size, struct iommu_iotlb_gather *gather)
 {
 	struct iova_domain *iovad = &cookie->iovad;
@@ -843,7 +843,7 @@ static void __iommu_dma_unmap(struct device *dev, dma_addr_t dma_addr,
 
 	if (!iotlb_gather.queued)
 		iommu_iotlb_sync(domain, &iotlb_gather);
-	iommu_dma_free_iova(cookie, dma_addr, size, &iotlb_gather);
+	__iommu_dma_free_iova(cookie, dma_addr, size, &iotlb_gather);
 }
 
 static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
@@ -861,12 +861,12 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
 
 	size = iova_align(iovad, size + iova_off);
 
-	iova = iommu_dma_alloc_iova(domain, size, dma_mask, dev);
+	iova = __iommu_dma_alloc_iova(domain, size, dma_mask, dev);
 	if (!iova)
 		return DMA_MAPPING_ERROR;
 
 	if (iommu_map(domain, iova, phys - iova_off, size, prot, GFP_ATOMIC)) {
-		iommu_dma_free_iova(cookie, iova, size, NULL);
+		__iommu_dma_free_iova(cookie, iova, size, NULL);
 		return DMA_MAPPING_ERROR;
 	}
 	return iova + iova_off;
@@ -970,7 +970,7 @@ static struct page **__iommu_dma_alloc_noncontiguous(struct device *dev,
 		return NULL;
 
 	size = iova_align(iovad, size);
-	iova = iommu_dma_alloc_iova(domain, size, dev->coherent_dma_mask, dev);
+	iova = __iommu_dma_alloc_iova(domain, size, dev->coherent_dma_mask, dev);
 	if (!iova)
 		goto out_free_pages;
 
@@ -1004,7 +1004,7 @@ static struct page **__iommu_dma_alloc_noncontiguous(struct device *dev,
 out_free_sg:
 	sg_free_table(sgt);
 out_free_iova:
-	iommu_dma_free_iova(cookie, iova, size, NULL);
+	__iommu_dma_free_iova(cookie, iova, size, NULL);
 out_free_pages:
 	__iommu_dma_free_pages(pages, count);
 	return NULL;
@@ -1436,7 +1436,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
 	if (!iova_len)
 		return __finalise_sg(dev, sg, nents, 0);
 
-	iova = iommu_dma_alloc_iova(domain, iova_len, dma_get_mask(dev), dev);
+	iova = __iommu_dma_alloc_iova(domain, iova_len, dma_get_mask(dev), dev);
 	if (!iova) {
 		ret = -ENOMEM;
 		goto out_restore_sg;
@@ -1453,7 +1453,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
 	return __finalise_sg(dev, sg, nents, iova);
 
 out_free_iova:
-	iommu_dma_free_iova(cookie, iova, iova_len, NULL);
+	__iommu_dma_free_iova(cookie, iova, iova_len, NULL);
 out_restore_sg:
 	__invalidate_sg(sg, nents);
 out:
@@ -1706,6 +1706,30 @@ static size_t iommu_dma_opt_mapping_size(void)
 	return iova_rcache_range();
 }
 
+static dma_addr_t iommu_dma_alloc_iova(struct device *dev, size_t size)
+{
+	struct iommu_domain *domain = iommu_get_dma_domain(dev);
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
+	dma_addr_t dma_mask = dma_get_mask(dev);
+
+	size = iova_align(iovad, size);
+	return __iommu_dma_alloc_iova(domain, size, dma_mask, dev);
+}
+
+static void iommu_dma_free_iova(struct device *dev, dma_addr_t iova,
+				size_t size)
+{
+	struct iommu_domain *domain = iommu_get_dma_domain(dev);
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
+	struct iommu_iotlb_gather iotlb_gather;
+
+	size = iova_align(iovad, size);
+	iommu_iotlb_gather_init(&iotlb_gather);
+	__iommu_dma_free_iova(cookie, iova, size, &iotlb_gather);
+}
+
 static const struct dma_map_ops iommu_dma_ops = {
 	.flags			= DMA_F_PCI_P2PDMA_SUPPORTED,
 	.alloc			= iommu_dma_alloc,
@@ -1728,6 +1752,8 @@ static const struct dma_map_ops iommu_dma_ops = {
 	.unmap_resource		= iommu_dma_unmap_resource,
 	.get_merge_boundary	= iommu_dma_get_merge_boundary,
 	.opt_mapping_size	= iommu_dma_opt_mapping_size,
+	.alloc_iova		= iommu_dma_alloc_iova,
+	.free_iova		= iommu_dma_free_iova,
 };
 
 /*
@@ -1776,7 +1802,7 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 	if (!msi_page)
 		return NULL;
 
-	iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev);
+	iova = __iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev);
 	if (!iova)
 		goto out_free_page;
 
@@ -1790,7 +1816,7 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 	return msi_page;
 
 out_free_iova:
-	iommu_dma_free_iova(cookie, iova, size, NULL);
+	__iommu_dma_free_iova(cookie, iova, size, NULL);
 out_free_page:
 	kfree(msi_page);
 	return NULL;
-- 
2.44.0