[RFC PATCH 05/25] hw/cxl/device: Implement the CAP array (8.2.8.1-2)

[Ben Widawsky]

This implements all device MMIO up to the first capability .That
includes the CXL Device Capabilities Array Register, as well as all of
the CXL Device Capability Header Registers. The latter are filled in as
they are implemented in the following patches.

Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
---
 hw/cxl/cxl-device-utils.c | 73 +++++++++++++++++++++++++++++++++++++++
 hw/cxl/meson.build        |  1 +
 2 files changed, 74 insertions(+)

diff --git a/hw/cxl/cxl-device-utils.c b/hw/cxl/cxl-device-utils.c
index e69de29bb2..a391bb15c6 100644
--- a/hw/cxl/cxl-device-utils.c
+++ b/hw/cxl/cxl-device-utils.c
@@ -0,0 +1,73 @@
+/*
+ * CXL Utility library for devices
+ *
+ * Copyright(C) 2020 Intel Corporation.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See the
+ * COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "hw/cxl/cxl.h"
+
+static uint64_t caps_reg_read(void *opaque, hwaddr offset, unsigned size)
+{
+    CXLDeviceState *cxl_dstate = opaque;
+
+    switch (size) {
+    case 4:
+        if (unlikely(offset & (sizeof(uint32_t) - 1))) {
+            qemu_log_mask(LOG_UNIMP, "Unaligned register read\n");
+            return 0;
+        }
+        break;
+    case 8:
+        if (unlikely(offset & (sizeof(uint64_t) - 1))) {
+            qemu_log_mask(LOG_UNIMP, "Unaligned register read\n");
+            return 0;
+        }
+        break;
+    }
+
+    return ldn_le_p(cxl_dstate->caps_reg_state + offset, size);
+}
+
+static const MemoryRegionOps caps_ops = {
+    .read = caps_reg_read,
+    .write = NULL,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 8,
+    },
+    .impl = {
+        .min_access_size = 4,
+        .max_access_size = 8,
+    },
+};
+
+void cxl_device_register_block_init(Object *obj, CXLDeviceState *cxl_dstate)
+{
+    /* This will be a BAR, so needs to be rounded up to pow2 for PCI spec */
+    memory_region_init(
+        &cxl_dstate->device_registers, obj, "device-registers",
+        pow2ceil(CXL_MAILBOX_REGISTERS_LENGTH + CXL_MAILBOX_REGISTERS_OFFSET));
+
+    memory_region_init_io(&cxl_dstate->caps, obj, &caps_ops, cxl_dstate,
+                          "cap-array", CXL_DEVICE_REGISTERS_OFFSET - 0);
+
+    memory_region_add_subregion(&cxl_dstate->device_registers, 0,
+                                &cxl_dstate->caps);
+}
+
+void cxl_device_register_init_common(CXLDeviceState *cxl_dstate)
+{
+    uint32_t *cap_hdrs = cxl_dstate->caps_reg_state32;
+    const int cap_count = 0;
+
+    /* CXL Device Capabilities Array Register */
+    ARRAY_FIELD_DP32(cap_hdrs, CXL_DEV_CAP_ARRAY, CAP_ID, 0);
+    ARRAY_FIELD_DP32(cap_hdrs, CXL_DEV_CAP_ARRAY, CAP_VERSION, 1);
+    ARRAY_FIELD_DP32(cap_hdrs, CXL_DEV_CAP_ARRAY2, CAP_COUNT, cap_count);
+}
diff --git a/hw/cxl/meson.build b/hw/cxl/meson.build
index 00c3876a0f..47154d6850 100644
--- a/hw/cxl/meson.build
+++ b/hw/cxl/meson.build
@@ -1,3 +1,4 @@
 softmmu_ss.add(when: 'CONFIG_CXL', if_true: files(
   'cxl-component-utils.c',
+  'cxl-device-utils.c',
 ))
-- 
2.29.2