Re: [PATCH v2 03/10] cxl/mbox: Add SET_FEATURE mailbox command

[Davidlohr Bueso <dave@stgolabs.net>]

On Tue, 21 Nov 2023, shiju.jose@huawei.com wrote:

>From: Shiju Jose <shiju.jose@huawei.com>
>
>Add support for SET_FEATURE mailbox command.
>
>CXL spec 3.0 section 8.2.9.6 describes optional device specific features.
>CXL devices supports features with changeable attributes.
>The settings of a feature can be optionally modified using Set Feature
>command.
>
>Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
>---
> drivers/cxl/core/mbox.c      | 15 +++++++++++++++
> drivers/cxl/cxlmem.h         | 27 +++++++++++++++++++++++++++
> include/uapi/linux/cxl_mem.h |  1 +
> 3 files changed, 43 insertions(+)
>
>diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
>index 2675c616caec..d892b07446ca 100644
>--- a/drivers/cxl/core/mbox.c
>+++ b/drivers/cxl/core/mbox.c
>@@ -65,6 +65,7 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = {
> 	CXL_CMD(GET_SCAN_MEDIA_CAPS, 0x10, 0x4, 0),
> 	CXL_CMD(GET_SUPPORTED_FEATURES, 0x8, CXL_VARIABLE_PAYLOAD, 0),
> 	CXL_CMD(GET_FEATURE, 0x15, CXL_VARIABLE_PAYLOAD, 0),
>+	CXL_CMD(SET_FEATURE, CXL_VARIABLE_PAYLOAD, 0, 0),
> };
>
> /*
>@@ -1350,6 +1351,20 @@ int cxl_get_feature(struct cxl_memdev_state *mds,
> }
> EXPORT_SYMBOL_NS_GPL(cxl_get_feature, CXL);
>
>+int cxl_set_feature(struct cxl_memdev_state *mds, void *feat_in, size_t size)
>+{
>+	struct cxl_mbox_cmd mbox_cmd;
>+
>+	mbox_cmd = (struct cxl_mbox_cmd) {
>+		.opcode = CXL_MBOX_OP_SET_FEATURE,
>+		.size_in = size,
>+		.payload_in = feat_in,
>+	};
>+
>+	return cxl_internal_send_cmd(mds, &mbox_cmd);
>+}
>+EXPORT_SYMBOL_NS_GPL(cxl_set_feature, CXL);
>+
> int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
> 		       struct cxl_region *cxlr)
> {
>diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
>index 92c1f2a44713..46131dcd0900 100644
>--- a/drivers/cxl/cxlmem.h
>+++ b/drivers/cxl/cxlmem.h
>@@ -508,6 +508,7 @@ enum cxl_opcode {
> 	CXL_MBOX_OP_GET_LOG		= 0x0401,
> 	CXL_MBOX_OP_GET_SUPPORTED_FEATURES	= 0x0500,
> 	CXL_MBOX_OP_GET_FEATURE		= 0x0501,
>+	CXL_MBOX_OP_SET_FEATURE		= 0x0502,
> 	CXL_MBOX_OP_IDENTIFY		= 0x4000,
> 	CXL_MBOX_OP_GET_PARTITION_INFO	= 0x4100,
> 	CXL_MBOX_OP_SET_PARTITION_INFO	= 0x4101,
>@@ -817,6 +818,31 @@ struct cxl_mbox_get_feat_in {
> 	u8 selection;
> }  __packed;
>
>+/* Set Feature CXL 3.0 Spec 8.2.9.6.3 */
>+/*
>+ * Set Feature input payload
>+ * CXL rev 3.0 section 8.2.9.6.3; Table 8-81
>+ */
>+/* Set Feature : Payload in flags */
>+#define CXL_SET_FEAT_FLAG_DATA_TRANSFER_MASK	GENMASK(2, 0)
>+enum cxl_set_feat_flag_data_transfer {
>+	CXL_SET_FEAT_FLAG_FULL_DATA_TRANSFER = 0x0,
>+	CXL_SET_FEAT_FLAG_INITIATE_DATA_TRANSFER = 0x1,
>+	CXL_SET_FEAT_FLAG_CONTINUE_DATA_TRANSFER = 0x2,
>+	CXL_SET_FEAT_FLAG_FINISH_DATA_TRANSFER = 0x3,
>+	CXL_SET_FEAT_FLAG_ABORT_DATA_TRANSFER = 0x4,
>+	CXL_SET_FEAT_FLAG_DATA_TRANSFER_MAX
>+};
>+#define CXL_SET_FEAT_FLAG_MOD_VALUE_SAVED_ACROSS_RESET	BIT(3)
>+
>+struct cxl_mbox_set_feat_in {
>+	uuid_t uuid;
>+	__le32 flags;
>+	__le16 offset;
>+	u8 version;
>+	u8 rsvd[9];
>+}  __packed;
>+
> /* Get Poison List  CXL 3.0 Spec 8.2.9.8.4.1 */
> struct cxl_mbox_poison_in {
> 	__le64 offset;
>@@ -949,6 +975,7 @@ int cxl_get_supported_features(struct cxl_memdev_state *mds,
> 			       void *feats_out);
> int cxl_get_feature(struct cxl_memdev_state *mds,
> 		    struct cxl_mbox_get_feat_in *pi, void *feat_out);
>+int cxl_set_feature(struct cxl_memdev_state *mds, void *feat_in, size_t size);
> int cxl_poison_state_init(struct cxl_memdev_state *mds);
> int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
> 		       struct cxl_region *cxlr);
>diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h
>index b20de60bfc71..8c89d323cc41 100644
>--- a/include/uapi/linux/cxl_mem.h
>+++ b/include/uapi/linux/cxl_mem.h
>@@ -48,6 +48,7 @@
> 	___DEPRECATED(GET_SCAN_MEDIA, "Get Scan Media Results"),          \
> 	___C(GET_SUPPORTED_FEATURES, "Get Supported Features"),           \
> 	___C(GET_FEATURE, "Get Feature"),                                 \
>+	___C(SET_FEATURE, "Set Feature"),                                 \

I don't think we want to export this to userspace, and you are
already using the scrub driver for setting feat attributes.

> 	___C(MAX, "invalid / last command")
>
> #define ___C(a, b) CXL_MEM_COMMAND_ID_##a
>-- 
>2.34.1
>