eepro100: Fix alignment requirement for statistical counters

PATCH New Stefan Weil 1 participant 1 message Nov 14, 2011

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Stefan Weil

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2011-11-14 19:10 UTC #0 lore raw

PATCH 1/1 eepro100: Fix alignment requirement for statistical counters

Sorry, I just noticed that I sent this patch to the wrong list address. It's a patch for QEMU 1.0, so I hope it's not too late for 1.0-rc2.

Regards,
Stefan Weil

-------- Original-Nachricht --------
Betreff: [PATCH] eepro100: Fix alignment requirement for statistical counters
Datum: Sat, 5 Nov 2011 12:50:30 +0100
Von: Stefan Weil <[email protected]>
An: [email protected]
CC: Michael S. Tsirkin <[email protected]>, Stefan Weil <[email protected]>

According to Intel's Open Source Software Developer Manual, the dump counters address must be Dword aligned.

The new code enforces this alignment, so s->statsaddr may now be used with stw_le_pci_dma() and stl_le_pci_dma().

Signed-off-by Stefan Weil<[email protected]>

---
 hw/eepro100.c |   10 +++++++++-
 1 files changed, 9 insertions(+), 1 deletions(-)

hw/eepro100.c +9 -1

index 7d59e71..29ec5b4 100644
@@ -976,7 +976,15 @@ static void eepro100_cu_command(EEPRO100State * s, uint8_t val)
     case CU_STATSADDR:
         /* Load dump counters address. */
         s->statsaddr = e100_read_reg4(s, SCBPointer);
-        TRACE(OTHER, logout("val=0x%02x (status address)\n", val));
+        TRACE(OTHER, logout("val=0x%02x (dump counters address)\n", val));
+        if (s->statsaddr&  3) {
+            /* Memory must be Dword aligned. */
+            logout("unaligned dump counters address\n");
+            /* Handling of misaligned addresses is undefined.
+             * Here we align the address by ignoring the lower bits. */
+            /* TODO: Test unaligned dump counter address on real hardware. */
+            s->statsaddr&= ~3;
+        }
         break;
     case CU_SHOWSTATS:
         /* Dump statistical counters. */

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