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Commit | Line | Data |
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00e5a55c BS |
1 | Subject: Correct VIO bus/device CMO accounting problems |
2 | From: Robert Jennings <rcj@linux.vnet.ibm.com> | |
3 | References: 468304 - LTC51205 | |
4 | ||
5 | This corrects three entitlement accounting issues that are all small in | |
6 | scope but at least two of them are critical. | |
7 | ||
8 | In the VIO bus code the wrappers for dma alloc_coherent and free_coherent | |
9 | calls are rounding to IOMMU_PAGE_SIZE. Taking a look at the underlying | |
10 | calls, the actual mapping is promoted to PAGE_SIZE. Changing the | |
11 | rounding in these two functions fixes under reporting the entitlement | |
12 | used. Without this change, the system could run out of entitlement before | |
13 | it believes it has and incur mapping failures at the firmware level. | |
14 | ||
15 | Also in the VIO bus code, the wrapper for dma map_sg is not exiting in | |
16 | an error path where it should. Rather than fall through to code for the | |
17 | success case, this patch adds the return that is needed in the error path. | |
18 | ||
19 | The ibmvscsi client driver is not unmapping the scsi command after | |
20 | encountering a dma mapping error while trying to map an indirect | |
21 | scattergather list. This leads to a leak of dma entitlement that could | |
22 | result in the device failing future dma operations. | |
23 | ||
24 | Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> | |
25 | Signed-off-by: Olaf Hering <olh@suse.de> | |
26 | ||
27 | -- | |
28 | arch/powerpc/kernel/vio.c | 7 ++++--- | |
29 | drivers/scsi/ibmvscsi/ibmvfc.c | 4 +++- | |
30 | drivers/scsi/ibmvscsi/ibmvscsi.c | 1 + | |
31 | 3 files changed, 8 insertions(+), 4 deletions(-) | |
32 | ||
33 | --- a/arch/powerpc/kernel/vio.c | |
34 | +++ b/arch/powerpc/kernel/vio.c | |
35 | @@ -492,14 +492,14 @@ static void *vio_dma_iommu_alloc_coheren | |
36 | struct vio_dev *viodev = to_vio_dev(dev); | |
37 | void *ret; | |
38 | ||
39 | - if (vio_cmo_alloc(viodev, roundup(size, IOMMU_PAGE_SIZE))) { | |
40 | + if (vio_cmo_alloc(viodev, roundup(size, PAGE_SIZE))) { | |
41 | atomic_inc(&viodev->cmo.allocs_failed); | |
42 | return NULL; | |
43 | } | |
44 | ||
45 | ret = dma_iommu_ops.alloc_coherent(dev, size, dma_handle, flag); | |
46 | if (unlikely(ret == NULL)) { | |
47 | - vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE)); | |
48 | + vio_cmo_dealloc(viodev, roundup(size, PAGE_SIZE)); | |
49 | atomic_inc(&viodev->cmo.allocs_failed); | |
50 | } | |
51 | ||
52 | @@ -513,7 +513,7 @@ static void vio_dma_iommu_free_coherent( | |
53 | ||
54 | dma_iommu_ops.free_coherent(dev, size, vaddr, dma_handle); | |
55 | ||
56 | - vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE)); | |
57 | + vio_cmo_dealloc(viodev, roundup(size, PAGE_SIZE)); | |
58 | } | |
59 | ||
60 | static dma_addr_t vio_dma_iommu_map_single(struct device *dev, void *vaddr, | |
61 | @@ -572,6 +572,7 @@ static int vio_dma_iommu_map_sg(struct d | |
62 | if (unlikely(!ret)) { | |
63 | vio_cmo_dealloc(viodev, alloc_size); | |
64 | atomic_inc(&viodev->cmo.allocs_failed); | |
65 | + return ret; | |
66 | } | |
67 | ||
68 | for (sgl = sglist, count = 0; count < ret; count++, sgl++) | |
69 | --- a/drivers/scsi/ibmvscsi/ibmvfc.c | |
70 | +++ b/drivers/scsi/ibmvscsi/ibmvfc.c | |
71 | @@ -1323,7 +1323,9 @@ static int ibmvfc_map_sg_data(struct scs | |
72 | &evt->ext_list_token); | |
73 | ||
74 | if (!evt->ext_list) { | |
75 | - scmd_printk(KERN_ERR, scmd, "Can't allocate memory for scatterlist\n"); | |
76 | + scsi_dma_unmap(scmd); | |
77 | + if (vhost->log_level > IBMVFC_DEFAULT_LOG_LEVEL) | |
78 | + scmd_printk(KERN_ERR, scmd, "Can't allocate memory for scatterlist\n"); | |
79 | return -ENOMEM; | |
80 | } | |
81 | } | |
82 | --- a/drivers/scsi/ibmvscsi/ibmvscsi.c | |
83 | +++ b/drivers/scsi/ibmvscsi/ibmvscsi.c | |
84 | @@ -435,6 +435,7 @@ static int map_sg_data(struct scsi_cmnd | |
85 | sdev_printk(KERN_ERR, cmd->device, | |
86 | "Can't allocate memory " | |
87 | "for indirect table\n"); | |
88 | + scsi_dma_unmap(cmd); | |
89 | return 0; | |
90 | } | |
91 | } |