[PATCH 3.16 086/192] parisc: DMA API: return error instead of BUG_ON for dma ops on non dma devs

Ben Hutchings
2017-10-09T12:52:12Z

From: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

commit 33f9e02495d15a061f0c94ef46f5103a2d0c20f3 upstream.

Enabling parport pc driver on a B2600 (and probably other 64bit PARISC
systems) produced following BUG:

CPU: 0 PID: 1 Comm: swapper Not tainted 4.12.0-rc5-30198-g1132d5e #156
task: 000000009e050000 task.stack: 000000009e04c000

YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00001000000001101111111100001111 Not tainted
r00-03 000000ff0806ff0f 000000009e04c990 0000000040871b78 000000009e04cac0
r04-07 0000000040c14de0 ffffffffffffffff 000000009e07f098 000000009d82d200
r08-11 000000009d82d210 0000000000000378 0000000000000000 0000000040c345e0
r12-15 0000000000000005 0000000040c345e0 0000000000000000 0000000040c9d5e0
r16-19 0000000040c345e0 00000000f00001c4 00000000f00001bc 0000000000000061
r20-23 000000009e04ce28 0000000000000010 0000000000000010 0000000040b89e40
r24-27 0000000000000003 0000000000ffffff 000000009d82d210 0000000040c14de0
r28-31 0000000000000000 000000009e04ca90 000000009e04cb40 0000000000000000
sr00-03 0000000000000000 0000000000000000 0000000000000000 0000000000000000
sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000

IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000404aece0 00000000404aece4
IIR: 03ffe01f ISR: 0000000010340000 IOR: 000001781304cac8
CPU: 0 CR30: 000000009e04c000 CR31: 00000000e2976de2
ORIG_R28: 0000000000000200
IAOQ[0]: sba_dma_supported+0x80/0xd0
IAOQ[1]: sba_dma_supported+0x84/0xd0
RP(r2): parport_pc_probe_port+0x178/0x1200

Cause is a call to dma_coerce_mask_and_coherenet in parport_pc_probe_port,
which PARISC DMA API doesn't handle very nicely. This commit gives back
DMA_ERROR_CODE for DMA API calls, if device isn't capable of DMA
transaction.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/parisc/include/asm/dma-mapping.h | 11 +++++++----
drivers/parisc/ccio-dma.c | 12 ++++++++++++
drivers/parisc/dino.c | 5 ++++-
drivers/parisc/lba_pci.c | 6 ++++--
drivers/parisc/sba_iommu.c | 14 ++++++++++++++
5 files changed, 41 insertions(+), 7 deletions(-)

--- a/arch/parisc/include/asm/dma-mapping.h
+++ b/arch/parisc/include/asm/dma-mapping.h
@@ -39,6 +39,8 @@ struct hppa_dma_ops {
** flush/purge and allocate "regular" cacheable pages for everything.
*/

+#define DMA_ERROR_CODE (~(dma_addr_t)0)
+
#ifdef CONFIG_PA11
extern struct hppa_dma_ops pcxl_dma_ops;
extern struct hppa_dma_ops pcx_dma_ops;
@@ -209,12 +211,13 @@ parisc_walk_tree(struct device *dev)
break;
}
}
- BUG_ON(!dev->platform_data);
return dev->platform_data;
}
-
-#define GET_IOC(dev) (HBA_DATA(parisc_walk_tree(dev))->iommu)
-
+
+#define GET_IOC(dev) ({ \
+ void *__pdata = parisc_walk_tree(dev); \
+ __pdata ? HBA_DATA(__pdata)->iommu : NULL; \
+})

#ifdef CONFIG_IOMMU_CCIO
struct parisc_device;
--- a/drivers/parisc/ccio-dma.c
+++ b/drivers/parisc/ccio-dma.c
@@ -743,6 +743,8 @@ ccio_map_single(struct device *dev, void

BUG_ON(!dev);
ioc = GET_IOC(dev);
+ if (!ioc)
+ return DMA_ERROR_CODE;

BUG_ON(size <= 0);

@@ -807,6 +809,10 @@ ccio_unmap_single(struct device *dev, dm

BUG_ON(!dev);
ioc = GET_IOC(dev);
+ if (!ioc) {
+ WARN_ON(!ioc);
+ return;
+ }

DBG_RUN("%s() iovp 0x%lx/%x\n",
__func__, (long)iova, size);
@@ -910,6 +916,8 @@ ccio_map_sg(struct device *dev, struct s

BUG_ON(!dev);
ioc = GET_IOC(dev);
+ if (!ioc)
+ return 0;

DBG_RUN_SG("%s() START %d entries\n", __func__, nents);

@@ -982,6 +990,10 @@ ccio_unmap_sg(struct device *dev, struct

BUG_ON(!dev);
ioc = GET_IOC(dev);
+ if (!ioc) {
+ WARN_ON(!ioc);
+ return;
+ }

DBG_RUN_SG("%s() START %d entries, %08lx,%x\n",
__func__, nents, sg_virt_addr(sglist), sglist->length);
--- a/drivers/parisc/dino.c
+++ b/drivers/parisc/dino.c
@@ -154,7 +154,10 @@ struct dino_device
};

/* Looks nice and keeps the compiler happy */
-#define DINO_DEV(d) ((struct dino_device *) d)
+#define DINO_DEV(d) ({ \
+ void *__pdata = d; \
+ BUG_ON(!__pdata); \
+ (struct dino_device *)__pdata; })

/*
--- a/drivers/parisc/lba_pci.c
+++ b/drivers/parisc/lba_pci.c
@@ -111,8 +111,10 @@ static u32 lba_t32;

/* Looks nice and keeps the compiler happy */
-#define LBA_DEV(d) ((struct lba_device *) (d))
-
+#define LBA_DEV(d) ({ \
+ void *__pdata = d; \
+ BUG_ON(!__pdata); \
+ (struct lba_device *)__pdata; })

/*
** Only allow 8 subsidiary busses per LBA
--- a/drivers/parisc/sba_iommu.c
+++ b/drivers/parisc/sba_iommu.c
@@ -691,6 +691,8 @@ static int sba_dma_supported( struct dev
return 0;

ioc = GET_IOC(dev);
+ if (!ioc)
+ return 0;

/*
* check if mask is >= than the current max IO Virt Address
@@ -722,6 +724,8 @@ sba_map_single(struct device *dev, void
int pide;

ioc = GET_IOC(dev);
+ if (!ioc)
+ return DMA_ERROR_CODE;

/* save offset bits */
offset = ((dma_addr_t) (long) addr) & ~IOVP_MASK;
@@ -803,6 +807,10 @@ sba_unmap_single(struct device *dev, dma
DBG_RUN("%s() iovp 0x%lx/%x\n", __func__, (long) iova, size);

ioc = GET_IOC(dev);
+ if (!ioc) {
+ WARN_ON(!ioc);
+ return;
+ }
offset = iova & ~IOVP_MASK;
iova ^= offset; /* clear offset bits */
size += offset;
@@ -942,6 +950,8 @@ sba_map_sg(struct device *dev, struct sc
DBG_RUN_SG("%s() START %d entries\n", __func__, nents);

ioc = GET_IOC(dev);
+ if (!ioc)
+ return 0;

/* Fast path single entry scatterlists. */
if (nents == 1) {
@@ -1028,6 +1038,10 @@ sba_unmap_sg(struct device *dev, struct
__func__, nents, sg_virt_addr(sglist), sglist->length);

ioc = GET_IOC(dev);
+ if (!ioc) {
+ WARN_ON(!ioc);
+ return;
+ }

#ifdef SBA_COLLECT_STATS
ioc->usg_calls++;