Merge tag 'drm-intel-gt-next-2022-11-03' of git://anongit.freedesktop.org/drm/drm-intel into drm-next

Driver Changes:

- Fix for #7306: [Arc A380] white flickering when using arc as a
  secondary gpu (Matt A)
- Add Wa_18017747507 for DG2 (Wayne)
- Avoid spurious WARN on DG1 due to incorrect cache_dirty flag
  (Niranjana, Matt A)
- Corrections to CS timestamp support for Gen5 and earlier (Ville)

- Fix a build error used with clang compiler on hwmon (GG)
- Improvements to LMEM handling with RPM (Anshuman, Matt A)
- Cleanups in dmabuf code (Mike)

- Selftest improvements (Matt A)

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/Y2N11wu175p6qeEN@jlahtine-mobl.ger.corp.intel.com

8 files changed, 370 insertions, 33 deletions

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 46aa3554e97b..1fbe127ff633 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -13,6 +13,7 @@
 #include <linux/slab.h>
 #include <linux/mutex.h>
 #include <linux/interrupt.h>
+#include <linux/scatterlist.h>
 #include <linux/mei_cl_bus.h>
 
 #include "mei_dev.h"
@@ -100,9 +101,18 @@ ssize_t __mei_cl_send(struct mei_cl *cl, const u8 *buf, size_t length, u8 vtag,
 	cb->internal = !!(mode & MEI_CL_IO_TX_INTERNAL);
 	cb->blocking = !!(mode & MEI_CL_IO_TX_BLOCKING);
 	memcpy(cb->buf.data, buf, length);
+	/* hack we point data to header */
+	if (mode & MEI_CL_IO_SGL) {
+		cb->ext_hdr = (struct mei_ext_hdr *)cb->buf.data;
+		cb->buf.data = NULL;
+		cb->buf.size = 0;
+	}
 
 	rets = mei_cl_write(cl, cb);
 
+	if (mode & MEI_CL_IO_SGL && rets == 0)
+		rets = length;
+
 out:
 	mutex_unlock(&bus->device_lock);
 
@@ -205,9 +215,16 @@ copy:
 		goto free;
 	}
 
-	r_length = min_t(size_t, length, cb->buf_idx);
-	memcpy(buf, cb->buf.data, r_length);
+	/* for the GSC type - copy the extended header to the buffer */
+	if (cb->ext_hdr && cb->ext_hdr->type == MEI_EXT_HDR_GSC) {
+		r_length = min_t(size_t, length, cb->ext_hdr->length * sizeof(u32));
+		memcpy(buf, cb->ext_hdr, r_length);
+	} else {
+		r_length = min_t(size_t, length, cb->buf_idx);
+		memcpy(buf, cb->buf.data, r_length);
+	}
 	rets = r_length;
+
 	if (vtag)
 		*vtag = cb->vtag;
 
@@ -823,6 +840,131 @@ out:
 EXPORT_SYMBOL_GPL(mei_cldev_disable);
 
 /**
+ * mei_cldev_send_gsc_command - sends a gsc command, by sending
+ * a gsl mei message to gsc and receiving reply from gsc
+ *
+ * @cldev: me client device
+ * @client_id: client id to send the command to
+ * @fence_id: fence id to send the command to
+ * @sg_in: scatter gather list containing addresses for rx message buffer
+ * @total_in_len: total length of data in 'in' sg, can be less than the sum of buffers sizes
+ * @sg_out: scatter gather list containing addresses for tx message buffer
+ *
+ * Return:
+ *  * written size in bytes
+ *  * < 0 on error
+ */
+ssize_t mei_cldev_send_gsc_command(struct mei_cl_device *cldev,
+				   u8 client_id, u32 fence_id,
+				   struct scatterlist *sg_in,
+				   size_t total_in_len,
+				   struct scatterlist *sg_out)
+{
+	struct mei_cl *cl;
+	struct mei_device *bus;
+	ssize_t ret = 0;
+
+	struct mei_ext_hdr_gsc_h2f *ext_hdr;
+	size_t buf_sz = sizeof(struct mei_ext_hdr_gsc_h2f);
+	int sg_out_nents, sg_in_nents;
+	int i;
+	struct scatterlist *sg;
+	struct mei_ext_hdr_gsc_f2h rx_msg;
+	unsigned int sg_len;
+
+	if (!cldev || !sg_in || !sg_out)
+		return -EINVAL;
+
+	cl = cldev->cl;
+	bus = cldev->bus;
+
+	dev_dbg(bus->dev, "client_id %u, fence_id %u\n", client_id, fence_id);
+
+	if (!bus->hbm_f_gsc_supported)
+		return -EOPNOTSUPP;
+
+	sg_out_nents = sg_nents(sg_out);
+	sg_in_nents = sg_nents(sg_in);
+	/* at least one entry in tx and rx sgls must be present */
+	if (sg_out_nents <= 0 || sg_in_nents <= 0)
+		return -EINVAL;
+
+	buf_sz += (sg_out_nents + sg_in_nents) * sizeof(struct mei_gsc_sgl);
+	ext_hdr = kzalloc(buf_sz, GFP_KERNEL);
+	if (!ext_hdr)
+		return -ENOMEM;
+
+	/* construct the GSC message */
+	ext_hdr->hdr.type = MEI_EXT_HDR_GSC;
+	ext_hdr->hdr.length = buf_sz / sizeof(u32); /* length is in dw */
+
+	ext_hdr->client_id = client_id;
+	ext_hdr->addr_type = GSC_ADDRESS_TYPE_PHYSICAL_SGL;
+	ext_hdr->fence_id = fence_id;
+	ext_hdr->input_address_count = sg_in_nents;
+	ext_hdr->output_address_count = sg_out_nents;
+	ext_hdr->reserved[0] = 0;
+	ext_hdr->reserved[1] = 0;
+
+	/* copy in-sgl to the message */
+	for (i = 0, sg = sg_in; i < sg_in_nents; i++, sg++) {
+		ext_hdr->sgl[i].low = lower_32_bits(sg_dma_address(sg));
+		ext_hdr->sgl[i].high = upper_32_bits(sg_dma_address(sg));
+		sg_len = min_t(unsigned int, sg_dma_len(sg), PAGE_SIZE);
+		ext_hdr->sgl[i].length = (sg_len <= total_in_len) ? sg_len : total_in_len;
+		total_in_len -= ext_hdr->sgl[i].length;
+	}
+
+	/* copy out-sgl to the message */
+	for (i = sg_in_nents, sg = sg_out; i < sg_in_nents + sg_out_nents; i++, sg++) {
+		ext_hdr->sgl[i].low = lower_32_bits(sg_dma_address(sg));
+		ext_hdr->sgl[i].high = upper_32_bits(sg_dma_address(sg));
+		sg_len = min_t(unsigned int, sg_dma_len(sg), PAGE_SIZE);
+		ext_hdr->sgl[i].length = sg_len;
+	}
+
+	/* send the message to GSC */
+	ret = __mei_cl_send(cl, (u8 *)ext_hdr, buf_sz, 0, MEI_CL_IO_SGL);
+	if (ret < 0) {
+		dev_err(bus->dev, "__mei_cl_send failed, returned %zd\n", ret);
+		goto end;
+	}
+	if (ret != buf_sz) {
+		dev_err(bus->dev, "__mei_cl_send returned %zd instead of expected %zd\n",
+			ret, buf_sz);
+		ret = -EIO;
+		goto end;
+	}
+
+	/* receive the reply from GSC, note that at this point sg_in should contain the reply */
+	ret = __mei_cl_recv(cl, (u8 *)&rx_msg, sizeof(rx_msg), NULL, MEI_CL_IO_SGL, 0);
+
+	if (ret != sizeof(rx_msg)) {
+		dev_err(bus->dev, "__mei_cl_recv returned %zd instead of expected %zd\n",
+			ret, sizeof(rx_msg));
+		if (ret >= 0)
+			ret = -EIO;
+		goto end;
+	}
+
+	/* check rx_msg.client_id and rx_msg.fence_id match the ones we send */
+	if (rx_msg.client_id != client_id || rx_msg.fence_id != fence_id) {
+		dev_err(bus->dev, "received client_id/fence_id  %u/%u  instead of %u/%u sent\n",
+			rx_msg.client_id, rx_msg.fence_id, client_id, fence_id);
+		ret = -EFAULT;
+		goto end;
+	}
+
+	dev_dbg(bus->dev, "gsc command: successfully written %u bytes\n",  rx_msg.written);
+	ret = rx_msg.written;
+
+end:
+	kfree(ext_hdr);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(mei_cldev_send_gsc_command);
+
+/**
  * mei_cl_device_find - find matching entry in the driver id table
  *
  * @cldev: me client device
diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 0b2fbe1335a7..6c8b71ae32c8 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -322,6 +322,7 @@ void mei_io_cb_free(struct mei_cl_cb *cb)
 
 	list_del(&cb->list);
 	kfree(cb->buf.data);
+	kfree(cb->ext_hdr);
 	kfree(cb);
 }
 
@@ -401,6 +402,7 @@ static struct mei_cl_cb *mei_io_cb_init(struct mei_cl *cl,
 	cb->buf_idx = 0;
 	cb->fop_type = type;
 	cb->vtag = 0;
+	cb->ext_hdr = NULL;
 
 	return cb;
 }
@@ -1740,6 +1742,17 @@ static inline u8 mei_ext_hdr_set_vtag(void *ext, u8 vtag)
 	return vtag_hdr->hdr.length;
 }
 
+static inline bool mei_ext_hdr_is_gsc(struct mei_ext_hdr *ext)
+{
+	return ext && ext->type == MEI_EXT_HDR_GSC;
+}
+
+static inline u8 mei_ext_hdr_set_gsc(struct mei_ext_hdr *ext, struct mei_ext_hdr *gsc_hdr)
+{
+	memcpy(ext, gsc_hdr, mei_ext_hdr_len(gsc_hdr));
+	return ext->length;
+}
+
 /**
  * mei_msg_hdr_init - allocate and initialize mei message header
  *
@@ -1752,14 +1765,17 @@ static struct mei_msg_hdr *mei_msg_hdr_init(const struct mei_cl_cb *cb)
 	size_t hdr_len;
 	struct mei_ext_meta_hdr *meta;
 	struct mei_msg_hdr *mei_hdr;
-	bool is_ext, is_vtag;
+	bool is_ext, is_hbm, is_gsc, is_vtag;
+	struct mei_ext_hdr *next_ext;
 
 	if (!cb)
 		return ERR_PTR(-EINVAL);
 
 	/* Extended header for vtag is attached only on the first fragment */
 	is_vtag = (cb->vtag && cb->buf_idx == 0);
-	is_ext = is_vtag;
+	is_hbm = cb->cl->me_cl->client_id == 0;
+	is_gsc = ((!is_hbm) && cb->cl->dev->hbm_f_gsc_supported && mei_ext_hdr_is_gsc(cb->ext_hdr));
+	is_ext = is_vtag || is_gsc;
 
 	/* Compute extended header size */
 	hdr_len = sizeof(*mei_hdr);
@@ -1771,6 +1787,9 @@ static struct mei_msg_hdr *mei_msg_hdr_init(const struct mei_cl_cb *cb)
 	if (is_vtag)
 		hdr_len += sizeof(struct mei_ext_hdr_vtag);
 
+	if (is_gsc)
+		hdr_len += mei_ext_hdr_len(cb->ext_hdr);
+
 setup_hdr:
 	mei_hdr = kzalloc(hdr_len, GFP_KERNEL);
 	if (!mei_hdr)
@@ -1785,10 +1804,20 @@ setup_hdr:
 		goto out;
 
 	meta = (struct mei_ext_meta_hdr *)mei_hdr->extension;
+	meta->size = 0;
+	next_ext = (struct mei_ext_hdr *)meta->hdrs;
 	if (is_vtag) {
 		meta->count++;
-		meta->size += mei_ext_hdr_set_vtag(meta->hdrs, cb->vtag);
+		meta->size += mei_ext_hdr_set_vtag(next_ext, cb->vtag);
+		next_ext = mei_ext_next(next_ext);
+	}
+
+	if (is_gsc) {
+		meta->count++;
+		meta->size += mei_ext_hdr_set_gsc(next_ext, cb->ext_hdr);
+		next_ext = mei_ext_next(next_ext);
 	}
+
 out:
 	mei_hdr->length = hdr_len - sizeof(*mei_hdr);
 	return mei_hdr;
@@ -1812,14 +1841,14 @@ int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 	struct mei_msg_hdr *mei_hdr = NULL;
 	size_t hdr_len;
 	size_t hbuf_len, dr_len;
-	size_t buf_len;
+	size_t buf_len = 0;
 	size_t data_len;
 	int hbuf_slots;
 	u32 dr_slots;
 	u32 dma_len;
 	int rets;
 	bool first_chunk;
-	const void *data;
+	const void *data = NULL;
 
 	if (WARN_ON(!cl || !cl->dev))
 		return -ENODEV;
@@ -1839,8 +1868,10 @@ int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 		return 0;
 	}
 
-	buf_len = buf->size - cb->buf_idx;
-	data = buf->data + cb->buf_idx;
+	if (buf->data) {
+		buf_len = buf->size - cb->buf_idx;
+		data = buf->data + cb->buf_idx;
+	}
 	hbuf_slots = mei_hbuf_empty_slots(dev);
 	if (hbuf_slots < 0) {
 		rets = -EOVERFLOW;
@@ -1858,9 +1889,6 @@ int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 		goto err;
 	}
 
-	cl_dbg(dev, cl, "Extended Header %d vtag = %d\n",
-	       mei_hdr->extended, cb->vtag);
-
 	hdr_len = sizeof(*mei_hdr) + mei_hdr->length;
 
 	/**
@@ -1889,7 +1917,7 @@ int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 	}
 	mei_hdr->length += data_len;
 
-	if (mei_hdr->dma_ring)
+	if (mei_hdr->dma_ring && buf->data)
 		mei_dma_ring_write(dev, buf->data + cb->buf_idx, buf_len);
 	rets = mei_write_message(dev, mei_hdr, hdr_len, data, data_len);
 
@@ -1983,9 +2011,6 @@ ssize_t mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb)
 		goto err;
 	}
 
-	cl_dbg(dev, cl, "Extended Header %d vtag = %d\n",
-	       mei_hdr->extended, cb->vtag);
-
 	hdr_len = sizeof(*mei_hdr) + mei_hdr->length;
 
 	if (rets == 0) {
@@ -2030,7 +2055,7 @@ ssize_t mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb)
 
 	mei_hdr->length += data_len;
 
-	if (mei_hdr->dma_ring)
+	if (mei_hdr->dma_ring && buf->data)
 		mei_dma_ring_write(dev, buf->data, buf_len);
 	rets = mei_write_message(dev, mei_hdr, hdr_len, data, data_len);
 
diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c
index de712cbf5d07..12a62a911e42 100644
--- a/drivers/misc/mei/hbm.c
+++ b/drivers/misc/mei/hbm.c
@@ -340,9 +340,13 @@ static int mei_hbm_capabilities_req(struct mei_device *dev)
 	req.hbm_cmd = MEI_HBM_CAPABILITIES_REQ_CMD;
 	if (dev->hbm_f_vt_supported)
 		req.capability_requested[0] |= HBM_CAP_VT;
+
 	if (dev->hbm_f_cd_supported)
 		req.capability_requested[0] |= HBM_CAP_CD;
 
+	if (dev->hbm_f_gsc_supported)
+		req.capability_requested[0] |= HBM_CAP_GSC;
+
 	ret = mei_hbm_write_message(dev, &mei_hdr, &req);
 	if (ret) {
 		dev_err(dev->dev,
@@ -1200,6 +1204,12 @@ static void mei_hbm_config_features(struct mei_device *dev)
 	     dev->version.minor_version >= HBM_MINOR_VERSION_VT))
 		dev->hbm_f_vt_supported = 1;
 
+	/* GSC support */
+	if (dev->version.major_version > HBM_MAJOR_VERSION_GSC ||
+	    (dev->version.major_version == HBM_MAJOR_VERSION_GSC &&
+	     dev->version.minor_version >= HBM_MINOR_VERSION_GSC))
+		dev->hbm_f_gsc_supported = 1;
+
 	/* Capability message Support */
 	dev->hbm_f_cap_supported = 0;
 	if (dev->version.major_version > HBM_MAJOR_VERSION_CAP ||
@@ -1367,6 +1377,9 @@ int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
 		if (!(capability_res->capability_granted[0] & HBM_CAP_CD))
 			dev->hbm_f_cd_supported = 0;
 
+		if (!(capability_res->capability_granted[0] & HBM_CAP_GSC))
+			dev->hbm_f_gsc_supported = 0;
+
 		if (dev->hbm_f_dr_supported) {
 			if (mei_dmam_ring_alloc(dev))
 				dev_info(dev->dev, "running w/o dma ring\n");
diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index 9e2f781c6ed5..da4ef0b51954 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -590,9 +590,14 @@ static int mei_me_hbuf_write(struct mei_device *dev,
 	u32 dw_cnt;
 	int empty_slots;
 
-	if (WARN_ON(!hdr || !data || hdr_len & 0x3))
+	if (WARN_ON(!hdr || hdr_len & 0x3))
 		return -EINVAL;
 
+	if (!data && data_len) {
+		dev_err(dev->dev, "wrong parameters null data with data_len = %zu\n", data_len);
+		return -EINVAL;
+	}
+
 	dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM((struct mei_msg_hdr *)hdr));
 
 	empty_slots = mei_hbuf_empty_slots(dev);
diff --git a/drivers/misc/mei/hw.h b/drivers/misc/mei/hw.h
index e7e020dba6b1..319418ddf4fb 100644
--- a/drivers/misc/mei/hw.h
+++ b/drivers/misc/mei/hw.h
@@ -93,6 +93,12 @@
 #define HBM_MAJOR_VERSION_VT               2
 
 /*
+ * MEI version with GSC support
+ */
+#define HBM_MINOR_VERSION_GSC              2
+#define HBM_MAJOR_VERSION_GSC              2
+
+/*
  * MEI version with capabilities message support
  */
 #define HBM_MINOR_VERSION_CAP              2
@@ -229,18 +235,19 @@ enum mei_cl_disconnect_status {
  *
  * @MEI_EXT_HDR_NONE: sentinel
  * @MEI_EXT_HDR_VTAG: vtag header
+ * @MEI_EXT_HDR_GSC: gsc header
  */
 enum mei_ext_hdr_type {
 	MEI_EXT_HDR_NONE = 0,
 	MEI_EXT_HDR_VTAG = 1,
+	MEI_EXT_HDR_GSC = 2,
 };
 
 /**
  * struct mei_ext_hdr - extend header descriptor (TLV)
  * @type: enum mei_ext_hdr_type
  * @length: length excluding descriptor
- * @ext_payload: payload of the specific extended header
- * @hdr: place holder for actual header
+ * @data: the extended header payload
  */
 struct mei_ext_hdr {
 	u8 type;
@@ -279,12 +286,11 @@ struct mei_ext_hdr_vtag {
  * Extended header iterator functions
  */
 /**
- * mei_ext_hdr - extended header iterator begin
+ * mei_ext_begin - extended header iterator begin
  *
  * @meta: meta header of the extended header list
  *
- * Return:
- *     The first extended header
+ * Return: The first extended header
  */
 static inline struct mei_ext_hdr *mei_ext_begin(struct mei_ext_meta_hdr *meta)
 {
@@ -305,6 +311,60 @@ static inline bool mei_ext_last(struct mei_ext_meta_hdr *meta,
 	return (u8 *)ext >= (u8 *)meta + sizeof(*meta) + (meta->size * 4);
 }
 
+struct mei_gsc_sgl {
+	u32 low;
+	u32 high;
+	u32 length;
+} __packed;
+
+#define GSC_HECI_MSG_KERNEL 0
+#define GSC_HECI_MSG_USER   1
+
+#define GSC_ADDRESS_TYPE_GTT   0
+#define GSC_ADDRESS_TYPE_PPGTT 1
+#define GSC_ADDRESS_TYPE_PHYSICAL_CONTINUOUS 2 /* max of 64K */
+#define GSC_ADDRESS_TYPE_PHYSICAL_SGL 3
+
+/**
+ * struct mei_ext_hdr_gsc_h2f - extended header: gsc host to firmware interface
+ *
+ * @hdr: extended header
+ * @client_id: GSC_HECI_MSG_KERNEL or GSC_HECI_MSG_USER
+ * @addr_type: GSC_ADDRESS_TYPE_{GTT, PPGTT, PHYSICAL_CONTINUOUS, PHYSICAL_SGL}
+ * @fence_id: synchronization marker
+ * @input_address_count: number of input sgl buffers
+ * @output_address_count: number of output sgl buffers
+ * @reserved: reserved
+ * @sgl: sg list
+ */
+struct mei_ext_hdr_gsc_h2f {
+	struct mei_ext_hdr hdr;
+	u8                 client_id;
+	u8                 addr_type;
+	u32                fence_id;
+	u8                 input_address_count;
+	u8                 output_address_count;
+	u8                 reserved[2];
+	struct mei_gsc_sgl sgl[];
+} __packed;
+
+/**
+ * struct mei_ext_hdr_gsc_f2h - gsc firmware to host interface
+ *
+ * @hdr: extended header
+ * @client_id: GSC_HECI_MSG_KERNEL or GSC_HECI_MSG_USER
+ * @reserved: reserved
+ * @fence_id: synchronization marker
+ * @written: number of bytes written to firmware
+ */
+struct mei_ext_hdr_gsc_f2h {
+	struct mei_ext_hdr hdr;
+	u8                 client_id;
+	u8                 reserved;
+	u32                fence_id;
+	u32                written;
+} __packed;
+
 /**
  * mei_ext_next - following extended header on the TLV list
  *
@@ -321,6 +381,21 @@ static inline struct mei_ext_hdr *mei_ext_next(struct mei_ext_hdr *ext)
 }
 
 /**
+ * mei_ext_hdr_len - get ext header length in bytes
+ *
+ * @ext: extend header
+ *
+ * Return: extend header length in bytes
+ */
+static inline u32 mei_ext_hdr_len(const struct mei_ext_hdr *ext)
+{
+	if (!ext)
+		return 0;
+
+	return ext->length * sizeof(u32);
+}
+
+/**
  * struct mei_msg_hdr - MEI BUS Interface Section
  *
  * @me_addr: device address
@@ -682,6 +757,10 @@ struct hbm_dma_ring_ctrl {
 
 /* virtual tag supported */
 #define HBM_CAP_VT BIT(0)
+
+/* gsc extended header support */
+#define HBM_CAP_GSC BIT(1)
+
 /* client dma supported */
 #define HBM_CAP_CD BIT(2)
 
diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index 0706322154cb..0a0e984e5673 100644
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -98,9 +98,12 @@ static int mei_cl_irq_read_msg(struct mei_cl *cl,
 	struct mei_device *dev = cl->dev;
 	struct mei_cl_cb *cb;
 
+	struct mei_ext_hdr_vtag *vtag_hdr = NULL;
+	struct mei_ext_hdr_gsc_f2h *gsc_f2h = NULL;
+
 	size_t buf_sz;
 	u32 length;
-	int ext_len;
+	u32 ext_len;
 
 	length = mei_hdr->length;
 	ext_len = 0;
@@ -122,18 +125,24 @@ static int mei_cl_irq_read_msg(struct mei_cl *cl,
 	}
 
 	if (mei_hdr->extended) {
-		struct mei_ext_hdr *ext;
-		struct mei_ext_hdr_vtag *vtag_hdr = NULL;
-
-		ext = mei_ext_begin(meta);
+		struct mei_ext_hdr *ext = mei_ext_begin(meta);
 		do {
 			switch (ext->type) {
 			case MEI_EXT_HDR_VTAG:
 				vtag_hdr = (struct mei_ext_hdr_vtag *)ext;
 				break;
+			case MEI_EXT_HDR_GSC:
+				gsc_f2h = (struct mei_ext_hdr_gsc_f2h *)ext;
+				cb->ext_hdr = kzalloc(sizeof(*gsc_f2h), GFP_KERNEL);
+				if (!cb->ext_hdr) {
+					cb->status = -ENOMEM;
+					goto discard;
+				}
+				break;
 			case MEI_EXT_HDR_NONE:
 				fallthrough;
 			default:
+				cl_err(dev, cl, "unknown extended header\n");
 				cb->status = -EPROTO;
 				break;
 			}
@@ -141,12 +150,14 @@ static int mei_cl_irq_read_msg(struct mei_cl *cl,
 			ext = mei_ext_next(ext);
 		} while (!mei_ext_last(meta, ext));
 
-		if (!vtag_hdr) {
-			cl_dbg(dev, cl, "vtag not found in extended header.\n");
+		if (!vtag_hdr && !gsc_f2h) {
+			cl_dbg(dev, cl, "no vtag or gsc found in extended header.\n");
 			cb->status = -EPROTO;
 			goto discard;
 		}
+	}
 
+	if (vtag_hdr) {
 		cl_dbg(dev, cl, "vtag: %d\n", vtag_hdr->vtag);
 		if (cb->vtag && cb->vtag != vtag_hdr->vtag) {
 			cl_err(dev, cl, "mismatched tag: %d != %d\n",
@@ -157,6 +168,28 @@ static int mei_cl_irq_read_msg(struct mei_cl *cl,
 		cb->vtag = vtag_hdr->vtag;
 	}
 
+	if (gsc_f2h) {
+		u32 ext_hdr_len = mei_ext_hdr_len(&gsc_f2h->hdr);
+
+		if (!dev->hbm_f_gsc_supported) {
+			cl_err(dev, cl, "gsc extended header is not supported\n");
+			cb->status = -EPROTO;
+			goto discard;
+		}
+
+		if (length) {
+			cl_err(dev, cl, "no data allowed in cb with gsc\n");
+			cb->status = -EPROTO;
+			goto discard;
+		}
+		if (ext_hdr_len > sizeof(*gsc_f2h)) {
+			cl_err(dev, cl, "gsc extended header is too big %u\n", ext_hdr_len);
+			cb->status = -EPROTO;
+			goto discard;
+		}
+		memcpy(cb->ext_hdr, gsc_f2h, ext_hdr_len);
+	}
+
 	if (!mei_cl_is_connected(cl)) {
 		cl_dbg(dev, cl, "not connected\n");
 		cb->status = -ENODEV;
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 6bb3e1ba9ded..8d8018428d9d 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -116,12 +116,16 @@ enum mei_cb_file_ops {
  * @MEI_CL_IO_TX_INTERNAL: internal communication between driver and FW
  *
  * @MEI_CL_IO_RX_NONBLOCK: recv is non-blocking
+ *
+ * @MEI_CL_IO_SGL: send command with sgl list.
  */
 enum mei_cl_io_mode {
 	MEI_CL_IO_TX_BLOCKING = BIT(0),
 	MEI_CL_IO_TX_INTERNAL = BIT(1),
 
 	MEI_CL_IO_RX_NONBLOCK = BIT(2),
+
+	MEI_CL_IO_SGL         = BIT(3),
 };
 
 /*
@@ -206,6 +210,7 @@ struct mei_cl;
  * @status: io status of the cb
  * @internal: communication between driver and FW flag
  * @blocking: transmission blocking mode
+ * @ext_hdr: extended header
  */
 struct mei_cl_cb {
 	struct list_head list;
@@ -218,6 +223,7 @@ struct mei_cl_cb {
 	int status;
 	u32 internal:1;
 	u32 blocking:1;
+	struct mei_ext_hdr *ext_hdr;
 };
 
 /**
@@ -494,6 +500,7 @@ struct mei_dev_timeouts {
  * @hbm_f_vt_supported  : hbm feature vtag supported
  * @hbm_f_cap_supported : hbm feature capabilities message supported
  * @hbm_f_cd_supported  : hbm feature client dma supported
+ * @hbm_f_gsc_supported : hbm feature gsc supported
  *
  * @fw_ver : FW versions
  *
@@ -585,6 +592,7 @@ struct mei_device {
 	unsigned int hbm_f_vt_supported:1;
 	unsigned int hbm_f_cap_supported:1;
 	unsigned int hbm_f_cd_supported:1;
+	unsigned int hbm_f_gsc_supported:1;
 
 	struct mei_fw_version fw_ver[MEI_MAX_FW_VER_BLOCKS];
 
diff --git a/drivers/misc/mei/pxp/mei_pxp.c b/drivers/misc/mei/pxp/mei_pxp.c
index 5c39457e3f53..8dd09b1722eb 100644
--- a/drivers/misc/mei/pxp/mei_pxp.c
+++ b/drivers/misc/mei/pxp/mei_pxp.c
@@ -77,10 +77,35 @@ mei_pxp_receive_message(struct device *dev, void *buffer, size_t size)
 	return byte;
 }
 
+/**
+ * mei_pxp_gsc_command() - sends a gsc command, by sending
+ * a sgl mei message to gsc and receiving reply from gsc
+ *
+ * @dev: device corresponding to the mei_cl_device
+ * @client_id: client id to send the command to
+ * @fence_id: fence id to send the command to
+ * @sg_in: scatter gather list containing addresses for rx message buffer
+ * @total_in_len: total length of data in 'in' sg, can be less than the sum of buffers sizes
+ * @sg_out: scatter gather list containing addresses for tx message buffer
+ *
+ * Return: bytes sent on Success, <0 on Failure
+ */
+static ssize_t mei_pxp_gsc_command(struct device *dev, u8 client_id, u32 fence_id,
+				   struct scatterlist *sg_in, size_t total_in_len,
+				   struct scatterlist *sg_out)
+{
+	struct mei_cl_device *cldev;
+
+	cldev = to_mei_cl_device(dev);
+
+	return mei_cldev_send_gsc_command(cldev, client_id, fence_id, sg_in, total_in_len, sg_out);
+}
+
 static const struct i915_pxp_component_ops mei_pxp_ops = {
 	.owner = THIS_MODULE,
 	.send = mei_pxp_send_message,
 	.recv = mei_pxp_receive_message,
+	.gsc_command = mei_pxp_gsc_command,
 };
 
 static int mei_component_master_bind(struct device *dev)
@@ -131,17 +156,24 @@ static int mei_pxp_component_match(struct device *dev, int subcomponent,
 {
 	struct device *base = data;
 
+	if (!dev)
+		return 0;
+
 	if (!dev->driver || strcmp(dev->driver->name, "i915") ||
 	    subcomponent != I915_COMPONENT_PXP)
 		return 0;
 
 	base = base->parent;
-	if (!base)
+	if (!base) /* mei device */
 		return 0;
 
-	base = base->parent;
-	dev = dev->parent;
+	base = base->parent; /* pci device */
+	/* for dgfx */
+	if (base && dev == base)
+		return 1;
 
+	/* for pch */
+	dev = dev->parent;
 	return (base && dev && dev == base);
 }