void cxl_probe_device_regs()

in core/regs.c [103:158]

• 49 lines of code
• 8 McCabe index (conditional complexity)

void cxl_probe_device_regs(struct device *dev, void __iomem *base,
			   struct cxl_device_reg_map *map)
{
	int cap, cap_count;
	u64 cap_array;

	*map = (struct cxl_device_reg_map){ 0 };

	cap_array = readq(base + CXLDEV_CAP_ARRAY_OFFSET);
	if (FIELD_GET(CXLDEV_CAP_ARRAY_ID_MASK, cap_array) !=
	    CXLDEV_CAP_ARRAY_CAP_ID)
		return;

	cap_count = FIELD_GET(CXLDEV_CAP_ARRAY_COUNT_MASK, cap_array);

	for (cap = 1; cap <= cap_count; cap++) {
		u32 offset, length;
		u16 cap_id;

		cap_id = FIELD_GET(CXLDEV_CAP_HDR_CAP_ID_MASK,
				   readl(base + cap * 0x10));
		offset = readl(base + cap * 0x10 + 0x4);
		length = readl(base + cap * 0x10 + 0x8);

		switch (cap_id) {
		case CXLDEV_CAP_CAP_ID_DEVICE_STATUS:
			dev_dbg(dev, "found Status capability (0x%x)\n", offset);

			map->status.valid = true;
			map->status.offset = offset;
			map->status.size = length;
			break;
		case CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX:
			dev_dbg(dev, "found Mailbox capability (0x%x)\n", offset);
			map->mbox.valid = true;
			map->mbox.offset = offset;
			map->mbox.size = length;
			break;
		case CXLDEV_CAP_CAP_ID_SECONDARY_MAILBOX:
			dev_dbg(dev, "found Secondary Mailbox capability (0x%x)\n", offset);
			break;
		case CXLDEV_CAP_CAP_ID_MEMDEV:
			dev_dbg(dev, "found Memory Device capability (0x%x)\n", offset);
			map->memdev.valid = true;
			map->memdev.offset = offset;
			map->memdev.size = length;
			break;
		default:
			if (cap_id >= 0x8000)
				dev_dbg(dev, "Vendor cap ID: %#x offset: %#x\n", cap_id, offset);
			else
				dev_dbg(dev, "Unknown cap ID: %#x offset: %#x\n", cap_id, offset);
			break;
		}
	}
}