Commit ea85af3e87 for qemu.org

commit ea85af3e87453736f3d9996e333dbc4ae92b4d6d
Author: Philippe Mathieu-Daudé <philmd@linaro.org>
Date:   Tue Dec 16 11:03:41 2025 +0100

    hw/net/opencores: Clarify MMIO read/write handlers expect 32-bit access

    The read/write handlers access array of 32-bit register by index:

     277 struct OpenEthState {
      ..
     287     uint32_t regs[REG_MAX];
      ..
     291 };

     546 static uint64_t open_eth_reg_read(void *opaque,
     547                                   hwaddr addr, unsigned int size)
     548 {
      ..
     551     OpenEthState *s = opaque;
     552     unsigned idx = addr / 4;
      ..
     559             v = s->regs[idx];
      ..
     563     return v;
     564 }

    This is a 32-bit implementation. Make that explicit in the
    MemoryRegionOps structure (this doesn't change the maximum
    access size, which -- being unset -- is 64-bit).

    Move the structure just after the handlers to ease code review.

    Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
    Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
    Message-Id: <20251224134644.85582-3-philmd@linaro.org>

diff --git a/hw/net/opencores_eth.c b/hw/net/opencores_eth.c
index 6abeffcc9c..a25f8eccff 100644
--- a/hw/net/opencores_eth.c
+++ b/hw/net/opencores_eth.c
@@ -683,6 +683,15 @@ static void open_eth_reg_write(void *opaque,
     }
 }

+static const MemoryRegionOps open_eth_reg_ops = {
+    .read = open_eth_reg_read,
+    .write = open_eth_reg_write,
+    .impl = {
+        .min_access_size = 4,
+        .max_access_size = 4,
+    },
+};
+
 static uint64_t open_eth_desc_read(void *opaque,
         hwaddr addr, unsigned int size)
 {
@@ -706,12 +715,6 @@ static void open_eth_desc_write(void *opaque,
     open_eth_check_start_xmit(s);
 }

-
-static const MemoryRegionOps open_eth_reg_ops = {
-    .read = open_eth_reg_read,
-    .write = open_eth_reg_write,
-};
-
 static const MemoryRegionOps open_eth_desc_ops = {
     .read = open_eth_desc_read,
     .write = open_eth_desc_write,