[RFC PATCH 08/12] iommu/riscv: Add riscv_iommu_hw_info

[Gong Shuai]

From: Wu Fei <wu.fei9 at sanechips.com.cn>

Implement the hw_info op, report the IOMMU Capabilities register value
to user space as IOMMU_HW_INFO_TYPE_RISCV so VMMs can discover the
hardware capabilities of the physical IOMMU.

Signed-off-by: Wu Fei <wu.fei9 at sanechips.com.cn>
Signed-off-by: Gong Shuai <gong.shuai at sanechips.com.cn>
---
 drivers/iommu/riscv/iommu.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c
index c34331bcd661..e59a6a97589e 100644
--- a/drivers/iommu/riscv/iommu.c
+++ b/drivers/iommu/riscv/iommu.c
@@ -2220,9 +2220,27 @@ static void riscv_iommu_get_resv_regions(struct device *dev, struct list_head *h
 	iommu_dma_get_resv_regions(dev, head);
 }
 
+static void *riscv_iommu_hw_info(struct device *dev, u32 *length,
+				 enum iommu_hw_info_type *type)
+{
+	struct iommu_hw_info_riscv *info;
+	struct riscv_iommu_device *iommu = dev_to_iommu(dev);
+
+	info = kzalloc_obj(*info);
+	if (!info)
+		return ERR_PTR(-ENOMEM);
+
+	info->capabilities = iommu->caps;
+	*length = sizeof(*info);
+	*type = IOMMU_HW_INFO_TYPE_RISCV;
+
+	return info;
+}
+
 static const struct iommu_ops riscv_iommu_ops = {
 	.of_xlate = riscv_iommu_of_xlate,
 	.capable = riscv_iommu_capable,
+	.hw_info = riscv_iommu_hw_info,
 	.identity_domain = &riscv_iommu_identity_domain,
 	.blocked_domain = &riscv_iommu_blocking_domain,
 	.release_domain = &riscv_iommu_blocking_domain,
-- 
2.53.0