[PATCH v4 3/5] dp8393x: Store CAM registers as 16-bit

[Philippe Mathieu-Daudé]

Per the DP83932C datasheet from July 1995:

  4.0 SONIC Registers
  4.1 THE CAM UNIT

    The Content Addressable Memory (CAM) consists of sixteen
    48-bit entries for complete address filtering of network
    packets. Each entry corresponds to a 48-bit destination
    address that is user programmable and can contain any
    combination of Multicast or Physical addresses. Each entry
    is partitioned into three 16-bit CAM cells accessible
    through CAM Address Ports (CAP 2, CAP 1 and CAP 0) with
    CAP0 corresponding to the least significant 16 bits of
    the Destination Address and CAP2 corresponding to the
    most significant bits.

Store the CAM registers as 16-bit as it simplifies the code.

Having now the CAM registers as arrays of 3 uint16_t, we can avoid
using the VMSTATE_BUFFER_UNSAFE macro by using VMSTATE_UINT16_2DARRAY
which is more appropriate. This breaks the migration stream however.

Co-developed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Co-developed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Finn Thain <fthain@linux-m68k.org>
Message-Id: <20210710174954.2577195-5-f4bug@amsat.org>
---
Missing:
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
---
 hw/net/dp8393x.c | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
index d1e147a82a6..283de9db0bf 100644
--- a/hw/net/dp8393x.c
+++ b/hw/net/dp8393x.c
@@ -158,7 +158,7 @@ struct dp8393xState {
     MemoryRegion mmio;
 
     /* Registers */
-    uint8_t cam[16][6];
+    uint16_t cam[16][3];
     uint16_t regs[SONIC_REG_COUNT];
 
     /* Temporaries */
@@ -281,15 +281,13 @@ static void dp8393x_do_load_cam(dp8393xState *s)
         address_space_read(&s->as, dp8393x_cdp(s),
                            MEMTXATTRS_UNSPECIFIED, s->data, size);
         index = dp8393x_get(s, width, 0) & 0xf;
-        s->cam[index][0] = dp8393x_get(s, width, 1) & 0xff;
-        s->cam[index][1] = dp8393x_get(s, width, 1) >> 8;
-        s->cam[index][2] = dp8393x_get(s, width, 2) & 0xff;
-        s->cam[index][3] = dp8393x_get(s, width, 2) >> 8;
-        s->cam[index][4] = dp8393x_get(s, width, 3) & 0xff;
-        s->cam[index][5] = dp8393x_get(s, width, 3) >> 8;
-        trace_dp8393x_load_cam(index, s->cam[index][0], s->cam[index][1],
-                               s->cam[index][2], s->cam[index][3],
-                               s->cam[index][4], s->cam[index][5]);
+        s->cam[index][0] = dp8393x_get(s, width, 1);
+        s->cam[index][1] = dp8393x_get(s, width, 2);
+        s->cam[index][2] = dp8393x_get(s, width, 3);
+        trace_dp8393x_load_cam(index,
+                               s->cam[index][0] >> 8, s->cam[index][0] & 0xff,
+                               s->cam[index][1] >> 8, s->cam[index][1] & 0xff,
+                               s->cam[index][2] >> 8, s->cam[index][2] & 0xff);
         /* Move to next entry */
         s->regs[SONIC_CDC]--;
         s->regs[SONIC_CDP] += size;
@@ -592,8 +590,7 @@ static uint64_t dp8393x_read(void *opaque, hwaddr addr, 
unsigned int size)
     case SONIC_CAP1:
     case SONIC_CAP0:
         if (s->regs[SONIC_CR] & SONIC_CR_RST) {
-            val = s->cam[s->regs[SONIC_CEP] & 0xf][2 * (SONIC_CAP0 - reg) + 1] 
<< 8;
-            val |= s->cam[s->regs[SONIC_CEP] & 0xf][2 * (SONIC_CAP0 - reg)];
+            val = s->cam[s->regs[SONIC_CEP] & 0xf][SONIC_CAP0 - reg];
         }
         break;
     /* All other registers have no special contraints */
@@ -984,10 +981,10 @@ static void dp8393x_realize(DeviceState *dev, Error 
**errp)
 
 static const VMStateDescription vmstate_dp8393x = {
     .name = "dp8393x",
-    .version_id = 0,
-    .minimum_version_id = 0,
+    .version_id = 1,
+    .minimum_version_id = 1,
     .fields = (VMStateField []) {
-        VMSTATE_BUFFER_UNSAFE(cam, dp8393xState, 0, 16 * 6),
+        VMSTATE_UINT16_2DARRAY(cam, dp8393xState, 16, 3),
         VMSTATE_UINT16_ARRAY(regs, dp8393xState, SONIC_REG_COUNT),
         VMSTATE_END_OF_LIST()
     }
-- 
2.31.1