hw/misc: Support 8-bytes memop in NPCM GCR module

The NPCM8xx GCR device can be accessed with 64-bit memory operations.
This patch supports that.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Hao Wu <wuhaotsh@google.com>
Reviewed-by: Philippe Mathieu-Daude <philmd@linaro.org>
Message-id: 20250219184609.1839281-10-wuhaotsh@google.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/misc/npcm_gcr.c

@@ -200,6 +200,7 @@ static uint64_t npcm_gcr_read(void *opaque, hwaddr offset, unsigned size)
     uint32_t reg = offset / sizeof(uint32_t);
     NPCMGCRState *s = opaque;
     NPCMGCRClass *c = NPCM_GCR_GET_CLASS(s);
+    uint64_t value;
 
     if (reg >= c->nr_regs) {
         qemu_log_mask(LOG_GUEST_ERROR,
@@ -208,9 +209,21 @@ static uint64_t npcm_gcr_read(void *opaque, hwaddr offset, unsigned size)
         return 0;
     }
 
-    trace_npcm_gcr_read(offset, s->regs[reg]);
+    switch (size) {
+    case 4:
+        value = s->regs[reg];
+        break;
+
+    case 8:
+        value = deposit64(s->regs[reg], 32, 32, s->regs[reg + 1]);
+        break;
+
+    default:
+        g_assert_not_reached();
+    }
 
-    return s->regs[reg];
+    trace_npcm_gcr_read(offset, value);
+    return value;
 }
 
 static void npcm_gcr_write(void *opaque, hwaddr offset,
@@ -230,29 +243,65 @@ static void npcm_gcr_write(void *opaque, hwaddr offset,
         return;
     }
 
-    switch (reg) {
-    case NPCM7XX_GCR_PDID:
-    case NPCM7XX_GCR_PWRON:
-    case NPCM7XX_GCR_INTSR:
-        qemu_log_mask(LOG_GUEST_ERROR,
-                      "%s: register @ 0x%04" HWADDR_PRIx " is read-only\n",
-                      __func__, offset);
-        return;
-
-    case NPCM7XX_GCR_RESSR:
-    case NPCM7XX_GCR_CP2BST:
-        /* Write 1 to clear */
-        value = s->regs[reg] & ~value;
+    switch (size) {
+    case 4:
+        switch (reg) {
+        case NPCM7XX_GCR_PDID:
+        case NPCM7XX_GCR_PWRON:
+        case NPCM7XX_GCR_INTSR:
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: register @ 0x%04" HWADDR_PRIx " is read-only\n",
+                          __func__, offset);
+            return;
+
+        case NPCM7XX_GCR_RESSR:
+        case NPCM7XX_GCR_CP2BST:
+            /* Write 1 to clear */
+            value = s->regs[reg] & ~value;
+            break;
+
+        case NPCM7XX_GCR_RLOCKR1:
+        case NPCM7XX_GCR_MDLR:
+            /* Write 1 to set */
+            value |= s->regs[reg];
+            break;
+        };
+        s->regs[reg] = value;
         break;
 
-    case NPCM7XX_GCR_RLOCKR1:
-    case NPCM7XX_GCR_MDLR:
-        /* Write 1 to set */
-        value |= s->regs[reg];
+    case 8:
+        s->regs[reg] = value;
+        s->regs[reg + 1] = extract64(v, 32, 32);
         break;
-    };
 
-    s->regs[reg] = value;
+    default:
+        g_assert_not_reached();
+    }
+}
+
+static bool npcm_gcr_check_mem_op(void *opaque, hwaddr offset,
+                                  unsigned size, bool is_write,
+                                  MemTxAttrs attrs)
+{
+    NPCMGCRClass *c = NPCM_GCR_GET_CLASS(opaque);
+
+    if (offset >= c->nr_regs * sizeof(uint32_t)) {
+        return false;
+    }
+
+    switch (size) {
+    case 4:
+        return true;
+    case 8:
+        if (offset >= NPCM8XX_GCR_SCRPAD_00 * sizeof(uint32_t) &&
+            offset < (NPCM8XX_GCR_NR_REGS - 1) * sizeof(uint32_t)) {
+            return true;
+        } else {
+            return false;
+        }
+    default:
+        return false;
+    }
 }
 
 static const struct MemoryRegionOps npcm_gcr_ops = {
@@ -261,7 +310,8 @@ static const struct MemoryRegionOps npcm_gcr_ops = {
     .endianness = DEVICE_LITTLE_ENDIAN,
     .valid      = {
         .min_access_size        = 4,
-        .max_access_size        = 4,
+        .max_access_size        = 8,
+        .accepts                = npcm_gcr_check_mem_op,
         .unaligned              = false,
     },
 };

hw/misc/trace-events

@@ -135,8 +135,8 @@ npcm7xx_clk_read(uint64_t offset, uint32_t value) " offset: 0x%04" PRIx64 " valu
 npcm7xx_clk_write(uint64_t offset, uint32_t value) "offset: 0x%04" PRIx64 " value: 0x%08" PRIx32
 
 # npcm_gcr.c
-npcm_gcr_read(uint64_t offset, uint32_t value) " offset: 0x%04" PRIx64 " value: 0x%08" PRIx32
-npcm_gcr_write(uint64_t offset, uint32_t value) "offset: 0x%04" PRIx64 " value: 0x%08" PRIx32
+npcm_gcr_read(uint64_t offset, uint64_t value) " offset: 0x%04" PRIx64 " value: 0x%08" PRIx64
+npcm_gcr_write(uint64_t offset, uint64_t value) "offset: 0x%04" PRIx64 " value: 0x%08" PRIx64
 
 # npcm7xx_mft.c
 npcm7xx_mft_read(const char *name, uint64_t offset, uint16_t value) "%s: offset: 0x%04" PRIx64 " value: 0x%04" PRIx16