[Qemu-devel] Fwd: [PATCH 1.0] eepro100: Fix alignment requirement for statistical counters

[Stefan Weil]

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 <address@hidden>
An:	address@hidden
CC:	Michael S. Tsirkin <address@hidden>, Stefan Weil <address@hidden>

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 <address@hidden>
---
 hw/eepro100.c |   10 +++++++++-
 1 files changed, 9 insertions(+), 1 deletions(-)

diff --git a/hw/eepro100.c b/hw/eepro100.c
index 7d59e71..29ec5b4 100644
--- a/hw/eepro100.c
+++ b/hw/eepro100.c
@@ -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. */
-- 
1.7.0.4