From: Arnd Bergmann <arnd@arndb.de>
To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>, Christoph Hellwig <hch@lst.de>,
Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
Stefano Stabellini <sstabellini@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
Mike Rapoport <rppt@linux.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Joerg Roedel <jroedel@suse.de>,
xen-devel@lists.xenproject.org, iommu@lists.linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] Revert "swiotlb: remove SWIOTLB_MAP_ERROR"
Date: Mon, 4 Mar 2019 20:59:03 +0100 [thread overview]
Message-ID: <20190304195951.1118807-1-arnd@arndb.de> (raw)
This reverts commit b907e20508d0 ("swiotlb: remove SWIOTLB_MAP_ERROR"), which
introduced an overflow warning in configurations that have a larger
dma_addr_t than phys_addr_t:
In file included from include/linux/dma-direct.h:5,
from kernel/dma/swiotlb.c:23:
kernel/dma/swiotlb.c: In function 'swiotlb_tbl_map_single':
include/linux/dma-mapping.h:136:28: error: conversion from 'long long unsigned int' to 'phys_addr_t' {aka 'unsigned int'} changes value from '18446744073709551615' to '4294967295' [-Werror=overflow]
#define DMA_MAPPING_ERROR (~(dma_addr_t)0)
^
kernel/dma/swiotlb.c:544:9: note: in expansion of macro 'DMA_MAPPING_ERROR'
return DMA_MAPPING_ERROR;
The configuration that caused this is on 32-bit ARM, where the DMA address
space depends on the enabled hardware platforms, while the physical
address space depends on the type of MMU chosen (classic vs LPAE).
I tried a couple of alternative approaches, but the previous version
seems as good as any other, so I went back to that.
Fixes: b907e20508d0 ("swiotlb: remove SWIOTLB_MAP_ERROR")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/xen/swiotlb-xen.c | 4 ++--
include/linux/swiotlb.h | 3 +++
kernel/dma/swiotlb.c | 4 ++--
3 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 877baf2a94f4..57a98279bf4f 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -406,7 +406,7 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir,
attrs);
- if (map == DMA_MAPPING_ERROR)
+ if (map == SWIOTLB_MAP_ERROR)
return DMA_MAPPING_ERROR;
dev_addr = xen_phys_to_bus(map);
@@ -557,7 +557,7 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
sg_phys(sg),
sg->length,
dir, attrs);
- if (map == DMA_MAPPING_ERROR) {
+ if (map == SWIOTLB_MAP_ERROR) {
dev_warn(hwdev, "swiotlb buffer is full\n");
/* Don't panic here, we expect map_sg users
to do proper error handling. */
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 361f62bb4a8e..a65a36551f58 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -44,6 +44,9 @@ enum dma_sync_target {
SYNC_FOR_DEVICE = 1,
};
+/* define the last possible byte of physical address space as a mapping error */
+#define SWIOTLB_MAP_ERROR (~(phys_addr_t)0x0)
+
extern phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
dma_addr_t tbl_dma_addr,
phys_addr_t phys, size_t size,
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 12059b78b631..922880b84387 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -541,7 +541,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
spin_unlock_irqrestore(&io_tlb_lock, flags);
if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit())
dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes)\n", size);
- return DMA_MAPPING_ERROR;
+ return SWIOTLB_MAP_ERROR;
found:
io_tlb_used += nslots;
spin_unlock_irqrestore(&io_tlb_lock, flags);
@@ -659,7 +659,7 @@ bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr,
/* Oh well, have to allocate and map a bounce buffer. */
*phys = swiotlb_tbl_map_single(dev, __phys_to_dma(dev, io_tlb_start),
*phys, size, dir, attrs);
- if (*phys == DMA_MAPPING_ERROR)
+ if (*phys == SWIOTLB_MAP_ERROR)
return false;
/* Ensure that the address returned is DMA'ble */
--
2.20.0
next reply other threads:[~2019-03-04 20:00 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-04 19:59 Arnd Bergmann [this message]
2019-03-04 22:00 ` [PATCH] Revert "swiotlb: remove SWIOTLB_MAP_ERROR" Konrad Rzeszutek Wilk
2019-03-04 23:56 ` Robin Murphy
2019-03-05 8:16 ` Arnd Bergmann
2019-03-05 9:41 ` [Xen-devel] " Julien Grall
2019-03-08 15:23 ` Christoph Hellwig
2019-03-08 17:25 ` Julien Grall
2019-03-13 18:32 ` Christoph Hellwig
2019-03-13 19:44 ` Arnd Bergmann
2019-03-05 9:36 ` Julien Grall
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