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From:   Logan Gunthorpe <logang@deltatee.com>
To:     linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
        linux-block@vger.kernel.org, linux-pci@vger.kernel.org,
        linux-mm@kvack.org, iommu@lists.linux-foundation.org
Cc:     Stephen Bates <sbates@raithlin.com>,
        Christoph Hellwig <hch@lst.de>,
        Dan Williams <dan.j.williams@intel.com>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>,
        Ira Weiny <iweiny@intel.com>,
        John Hubbard <jhubbard@nvidia.com>,
        Don Dutile <ddutile@redhat.com>,
        Matthew Wilcox <willy@infradead.org>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        Jakowski Andrzej <andrzej.jakowski@intel.com>,
        Minturn Dave B <dave.b.minturn@intel.com>,
        Jason Ekstrand <jason@jlekstrand.net>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Xiong Jianxin <jianxin.xiong@intel.com>,
        Logan Gunthorpe <logang@deltatee.com>
Date:   Thu, 11 Mar 2021 16:31:39 -0700
Message-Id: <20210311233142.7900-10-logang@deltatee.com>
In-Reply-To: <20210311233142.7900-1-logang@deltatee.com>
References: <20210311233142.7900-1-logang@deltatee.com>
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Subject: [RFC PATCH v2 09/11] block: Add BLK_STS_P2PDMA
Precedence: bulk

Create a specific error code for when P2PDMA pages are passed to a block
devices that cannot map them (due to no IOMMU support or ACS protections).

This makes request errors in these cases more informative of as to what
caused the error.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 block/blk-core.c          | 2 ++
 include/linux/blk_types.h | 7 +++++++
 2 files changed, 9 insertions(+)

diff --git a/block/blk-core.c b/block/blk-core.c
index fc60ff208497..2cc75b56ac43 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -192,6 +192,8 @@ static const struct {
 	[BLK_STS_ZONE_OPEN_RESOURCE]	= { -ETOOMANYREFS, "open zones exceeded" },
 	[BLK_STS_ZONE_ACTIVE_RESOURCE]	= { -EOVERFLOW, "active zones exceeded" },
 
+	[BLK_STS_P2PDMA] = { -EREMOTEIO, "P2PDMA to invalid device" },
+
 	/* everything else not covered above: */
 	[BLK_STS_IOERR]		= { -EIO,	"I/O" },
 };
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index db026b6ec15a..728a0898cb34 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -142,6 +142,13 @@ typedef u8 __bitwise blk_status_t;
  */
 #define BLK_STS_ZONE_ACTIVE_RESOURCE	((__force blk_status_t)16)
 
+/*
+ * BLK_STS_P2PDMA is returned from the driver if P2PDMA memory fails to be
+ * mapped to the target device. This is a permanent error and the request
+ * should not be retried.
+ */
+#define BLK_STS_P2PDMA		((__force blk_status_t)17)
+
 /**
  * blk_path_error - returns true if error may be path related
  * @error: status the request was completed with
-- 
2.20.1