diff options
| author | Robin Holt <holt@sgi.com> | 2006-09-01 10:41:39 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-09-08 14:51:39 -0700 |
| commit | d6b7fe9e1d58514758c6dfe54f949333e830485e (patch) | |
| tree | 42246f435cb768276905ae4a2621ad6580790db9 /include | |
| parent | 4ccc9a4b06b170b88d25bfd2d50fce487ed1471c (diff) | |
Silent data corruption caused by XPC
Jack Steiner identified a problem where XPC can cause a silent
data corruption. On module load, the placement may cause the
xpc_remote_copy_buffer to span two physical pages. DMA transfers are
done to the start virtual address translated to physical.
This patch changes the buffer from a statically allocated buffer to a
kmalloc'd buffer. Dean Nelson reviewed this before posting. I have
tested it in the configuration that was showing the memory corruption
and verified it works. I also added a BUG_ON statement to help catch
this if a similar situation is encountered.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-ia64/sn/xp.h | 22 | ||||
| -rw-r--r-- | include/asm-ia64/sn/xpc.h | 4 |
2 files changed, 21 insertions, 5 deletions
diff --git a/include/asm-ia64/sn/xp.h b/include/asm-ia64/sn/xp.h index 9bd2f9bf329b..6f807e0193b7 100644 --- a/include/asm-ia64/sn/xp.h +++ b/include/asm-ia64/sn/xp.h @@ -60,23 +60,37 @@ * the bte_copy() once in the hope that the failure was due to a temporary * aberration (i.e., the link going down temporarily). * - * See bte_copy for definition of the input parameters. + * src - physical address of the source of the transfer. + * vdst - virtual address of the destination of the transfer. + * len - number of bytes to transfer from source to destination. + * mode - see bte_copy() for definition. + * notification - see bte_copy() for definition. * * Note: xp_bte_copy() should never be called while holding a spinlock. */ static inline bte_result_t -xp_bte_copy(u64 src, u64 dest, u64 len, u64 mode, void *notification) +xp_bte_copy(u64 src, u64 vdst, u64 len, u64 mode, void *notification) { bte_result_t ret; + u64 pdst = ia64_tpa(vdst); - ret = bte_copy(src, dest, len, mode, notification); + /* + * Ensure that the physically mapped memory is contiguous. + * + * We do this by ensuring that the memory is from region 7 only. + * If the need should arise to use memory from one of the other + * regions, then modify the BUG_ON() statement to ensure that the + * memory from that region is always physically contiguous. + */ + BUG_ON(REGION_NUMBER(vdst) != RGN_KERNEL); + ret = bte_copy(src, pdst, len, mode, notification); if (ret != BTE_SUCCESS) { if (!in_interrupt()) { cond_resched(); } - ret = bte_copy(src, dest, len, mode, notification); + ret = bte_copy(src, pdst, len, mode, notification); } return ret; diff --git a/include/asm-ia64/sn/xpc.h b/include/asm-ia64/sn/xpc.h index aa3b8ace9030..b454ad4e2e54 100644 --- a/include/asm-ia64/sn/xpc.h +++ b/include/asm-ia64/sn/xpc.h @@ -684,7 +684,9 @@ extern struct xpc_vars *xpc_vars; extern struct xpc_rsvd_page *xpc_rsvd_page; extern struct xpc_vars_part *xpc_vars_part; extern struct xpc_partition xpc_partitions[XP_MAX_PARTITIONS + 1]; -extern char xpc_remote_copy_buffer[]; +extern char *xpc_remote_copy_buffer; +extern void *xpc_remote_copy_buffer_base; +extern void *xpc_kmalloc_cacheline_aligned(size_t, gfp_t, void **); extern struct xpc_rsvd_page *xpc_rsvd_page_init(void); extern void xpc_allow_IPI_ops(void); extern void xpc_restrict_IPI_ops(void); |