On 23/10/25 06:35, [email protected] wrote:
From: Djordje Todorovic <[email protected]>

Add RISC-V implementation of the Coherent Manager Global Control
Register (CMGCR) device. It is based on the existing MIPS CMGCR
implementation but adapted for RISC-V systems.

The CMGCR device provides global system control for multi-core
configurations in RISC-V systems.

This is needed for the MIPS BOSTON AIA board.

Signed-off-by: Chao-ying Fu <[email protected]>
Signed-off-by: Djordje Todorovic <[email protected]>
Reviewed-by: Daniel Henrique Barboza <[email protected]>
Message-ID: <[email protected]>
Signed-off-by: Alistair Francis <[email protected]>
---
  include/hw/misc/riscv_cmgcr.h |  50 +++++++
  hw/misc/riscv_cmgcr.c         | 248 ++++++++++++++++++++++++++++++++++
  hw/misc/Kconfig               |   9 ++
  hw/misc/meson.build           |   2 +
  4 files changed, 309 insertions(+)
  create mode 100644 include/hw/misc/riscv_cmgcr.h
  create mode 100644 hw/misc/riscv_cmgcr.c


+static inline void update_gcr_base(RISCVGCRState *gcr, uint64_t val)
+{
+    gcr->gcr_base = val & GCR_BASE_GCRBASE_MSK;
+    memory_region_set_address(&gcr->iomem, gcr->gcr_base);
+
+    /*
+     * For boston-aia, cpc_base is set to gcr_base + 0x8001 to enable
+     * cpc automatically.
+     */
+    update_cpc_base(gcr, val + 0x8001);
+}
+
+/* Read GCR registers */
+static uint64_t gcr_read(void *opaque, hwaddr addr, unsigned size)
+{
+    RISCVGCRState *gcr = (RISCVGCRState *) opaque;
+
+    switch (addr) {
+    /* Global Control Block Register */
+    case GCR_CONFIG_OFS:
+        /* Set PCORES to 0 */
+        return 0;
+    case GCR_BASE_OFS:
+        return gcr->gcr_base;
+    case GCR_REV_OFS:
+        return gcr->gcr_rev;
+    case GCR_CPC_STATUS_OFS:
+        return is_cpc_connected(gcr);
+    case GCR_L2_CONFIG_OFS:
+        /* L2 BYPASS */
+        return GCR_L2_CONFIG_BYPASS_MSK;
+    default:
+        qemu_log_mask(LOG_UNIMP, "Read %d bytes at GCR offset 0x%" HWADDR_PRIx
+                      "\n", size, addr);
+    }
+    return 0;
+}
+
+static inline target_ulong get_exception_base(RISCVGCRVPState *vps)
+{
+    return vps->reset_base & GCR_CL_RESET_BASE_RESETBASE_MSK;
+}
+
+/* Write GCR registers */
+static void gcr_write(void *opaque, hwaddr addr, uint64_t data, unsigned size)
+{
+    RISCVGCRState *gcr = (RISCVGCRState *)opaque;
+    RISCVGCRVPState *current_vps;
+    int cpu_index, c, h;
+
+    for (c = 0; c < gcr->num_core; c++) {
+        for (h = 0; h < gcr->num_hart; h++) {
+            if (addr == RISCV_CLCB_OFS + c * RISCV_CORE_REG_STRIDE + h * 8) {
+                cpu_index = c * gcr->num_hart + h;
+                current_vps = &gcr->vps[cpu_index];
+                current_vps->reset_base = data & GCR_CL_RESET_BASE_MSK;
+                cpu_set_exception_base(cpu_index + gcr->cluster_id *
+                                       gcr->num_core * gcr->num_hart,
+                                       get_exception_base(current_vps));
+                return;
+            }
+        }
+    }
+
+    switch (addr) {
+    case GCR_BASE_OFS:
+        update_gcr_base(gcr, data);
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP, "Write %d bytes at GCR offset 0x%" HWADDR_PRIx
+                      " 0x%" PRIx64 "\n", size, addr, data);
+        break;
+    }
+}
+
+static const MemoryRegionOps gcr_ops = {
+    .read = gcr_read,
+    .write = gcr_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,

Dubious DEVICE_NATIVE_ENDIAN use, do you mean DEVICE_LITTLE_ENDIAN?

Maybe we can alter checkpatch to no accept new DEVICE_NATIVE_ENDIAN
in our code base.

+    .impl = {
+        .max_access_size = 8,
+    },
+};

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