src/patches/suse-2.6.27.31/patches.arch/ia64-sn-BTE_MAX_XFER

   1 Date: Wed, 4 Feb 2009 10:47:37 -0600
   2 From: Robin Holt <holt@sgi.com>
   3 Subject: bte_copy of BTE_MAX_XFER trips BUG_ON -V2
   4 References: bnc#472894
   5
   6 BTE_MAX_XFER is wrong.  It is one greater than the number of cache
   7 lines the BTE is actually able to transfer.  If you request a transfer
   8 of exactly BTE_MAX_XFER size, you trip a very cryptic BUG_ON() which
   9 should certainly be made more clear.
  10
  11 This patch fixes that constant and also cleans up the BUG_ON()s in
  12 arch/ia64/sn/kernel/bte.c to test one condition per line.
  13
  14 Signed-off-by: Robin Holt <holt@sgi.com>
  15 Acked-by: Raymund Will <rw@suse.de>
  16
  17 ---
  18
  19 Changes since -V1:
  20         Base the BTE_LEN_MASK upon a 1UL instead of 1 for correctness.
  21
  22
  23  arch/ia64/include/asm/sn/bte.h |    4 ++--
  24  arch/ia64/sn/kernel/bte.c      |    7 ++++---
  25  2 files changed, 6 insertions(+), 5 deletions(-)
  26
  27 Index: bte_fixup/arch/ia64/include/asm/sn/bte.h
  28 ===================================================================
  29 --- bte_fixup.orig/arch/ia64/include/asm/sn/bte.h       2009-02-04 10:37:29.594750841 -0600
  30 +++ bte_fixup/arch/ia64/include/asm/sn/bte.h    2009-02-04 10:40:32.495791608 -0600
  31 @@ -38,8 +38,8 @@
  32
  33  /* BTE status register only supports 16 bits for length field */
  34  #define BTE_LEN_BITS (16)
  35 -#define BTE_LEN_MASK ((1 << BTE_LEN_BITS) - 1)
  36 -#define BTE_MAX_XFER ((1 << BTE_LEN_BITS) * L1_CACHE_BYTES)
  37 +#define BTE_LEN_MASK ((1UL << BTE_LEN_BITS) - 1)
  38 +#define BTE_MAX_XFER (BTE_LEN_MASK << L1_CACHE_SHIFT)
  39
  40
  41  /* Define hardware */
  42 Index: bte_fixup/arch/ia64/sn/kernel/bte.c
  43 ===================================================================
  44 --- bte_fixup.orig/arch/ia64/sn/kernel/bte.c    2009-02-04 10:37:30.026753839 -0600
  45 +++ bte_fixup/arch/ia64/sn/kernel/bte.c 2009-02-04 10:40:11.711701203 -0600
  46 @@ -97,9 +97,10 @@ bte_result_t bte_copy(u64 src, u64 dest,
  47                 return BTE_SUCCESS;
  48         }
  49
  50 -       BUG_ON((len & L1_CACHE_MASK) ||
  51 -                (src & L1_CACHE_MASK) || (dest & L1_CACHE_MASK));
  52 -       BUG_ON(!(len < ((BTE_LEN_MASK + 1) << L1_CACHE_SHIFT)));
  53 +       BUG_ON(len & L1_CACHE_MASK);
  54 +       BUG_ON(src & L1_CACHE_MASK);
  55 +       BUG_ON(dest & L1_CACHE_MASK);
  56 +       BUG_ON(len > BTE_MAX_XFER);
  57
  58         /*
  59          * Start with interface corresponding to cpu number
  60 --
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