diff mbox series

[v4,4/7] cxl: emulate HDM decoder from DVSEC range registers

Message ID 167588408051.1155956.11059438224070853644.stgit@djiang5-mobl3.local
State New, archived
Headers show
Series cxl: Introduce HDM decoder emulation from DVSEC range registers | expand

Commit Message

Dave Jiang Feb. 8, 2023, 7:21 p.m. UTC 
In the case where HDM decoder register block exists but is not programmed
and at the same time the DVSEC range register range is active, populate the
CXL decoder object 'cxl_decoder' with info from DVSEC range registers.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

---
v4:
- Direct assign range to range. (Dan)
- Add comment for why emulated decoder is locked. (Dan)
- Check range_len() instead of content of .start. (Dan)
- Fix too long line formatting. (Dan)
v2:
- Set target_type to CXL_DECODER_EXPANDER (type 3). (Jonathan)
- Skip HDM enabling if DVSEC range is active. (Jonathan)
---
 drivers/cxl/core/hdm.c |   36 +++++++++++++++++++++++++++++++++---
 drivers/cxl/core/pci.c |    2 +-
 drivers/cxl/cxl.h      |    3 ++-
 drivers/cxl/port.c     |    2 +-
 4 files changed, 37 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index dcc16d7cb8f3..c0f224454447 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -679,9 +679,34 @@  static int cxl_decoder_reset(struct cxl_decoder *cxld)
 	return 0;
 }
 
+static int cxl_setup_hdm_decoder_from_dvsec(struct cxl_port *port,
+					    struct cxl_decoder *cxld, int which,
+					    struct cxl_endpoint_dvsec_info *info)
+{
+	if (!is_cxl_endpoint(port))
+		return -EOPNOTSUPP;
+
+	if (!range_len(&info->dvsec_range[which]))
+		return -ENOENT;
+
+	cxld->target_type = CXL_DECODER_EXPANDER;
+	cxld->commit = NULL;
+	cxld->reset = NULL;
+	cxld->hpa_range = info->dvsec_range[which];
+
+	/*
+	 * Set the emulated decoder as locked pending additional support to
+	 * change the range registers at run time.
+	 */
+	cxld->flags |= CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK;
+	port->commit_end = cxld->id;
+
+	return 0;
+}
+
 static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
 			    int *target_map, void __iomem *hdm, int which,
-			    u64 *dpa_base)
+			    u64 *dpa_base, struct cxl_endpoint_dvsec_info *info)
 {
 	struct cxl_endpoint_decoder *cxled = NULL;
 	u64 size, base, skip, dpa_size;
@@ -717,6 +742,9 @@  static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
 		.end = base + size - 1,
 	};
 
+	if (cxled && !committed && range_len(&info->dvsec_range[which]))
+		return cxl_setup_hdm_decoder_from_dvsec(port, cxld, which, info);
+
 	/* decoders are enabled if committed */
 	if (committed) {
 		cxld->flags |= CXL_DECODER_F_ENABLE;
@@ -790,7 +818,8 @@  static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
  * devm_cxl_enumerate_decoders - add decoder objects per HDM register set
  * @cxlhdm: Structure to populate with HDM capabilities
  */
-int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
+int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
+				struct cxl_endpoint_dvsec_info *info)
 {
 	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
 	struct cxl_port *port = cxlhdm->port;
@@ -842,7 +871,8 @@  int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
 			cxld = &cxlsd->cxld;
 		}
 
-		rc = init_hdm_decoder(port, cxld, target_map, hdm, i, &dpa_base);
+		rc = init_hdm_decoder(port, cxld, target_map, hdm, i,
+				      &dpa_base, info);
 		if (rc) {
 			put_device(&cxld->dev);
 			return rc;
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 2e86c209e24d..2e0976446053 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -427,7 +427,7 @@  int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm,
 	 * Decoder Capability Enable.
 	 */
 	if (info->mem_enabled)
-		return -EBUSY;
+		return 0;
 
 	rc = devm_cxl_enable_hdm(&port->dev, cxlhdm);
 	if (rc)
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 1057affb2db0..ea9548cbc7eb 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -644,7 +644,8 @@  struct cxl_endpoint_dvsec_info {
 
 struct cxl_hdm;
 struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port);
-int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm);
+int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
+				struct cxl_endpoint_dvsec_info *info);
 int devm_cxl_add_passthrough_decoder(struct cxl_port *port);
 int cxl_dvsec_rr_decode(struct pci_dev *pdev, int dvsec,
 			struct cxl_endpoint_dvsec_info *info);
diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c
index 404639a1c3d0..7f1b71c5cf15 100644
--- a/drivers/cxl/port.c
+++ b/drivers/cxl/port.c
@@ -79,7 +79,7 @@  static int cxl_port_probe(struct device *dev)
 		}
 	}
 
-	rc = devm_cxl_enumerate_decoders(cxlhdm);
+	rc = devm_cxl_enumerate_decoders(cxlhdm, &info);
 	if (rc) {
 		dev_err(dev, "Couldn't enumerate decoders (%d)\n", rc);
 		return rc;