cxl/hdm: Emulate HDM decoder from DVSEC range registers

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>
Link: https://lore.kernel.org/r/167640368454.935665.13806415120298330717.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index dcc16d7..c0f2244 100644 (file)
--- 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 d0b2548..4df0b35 100644 (file)
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -426,7 +426,7 @@ 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 fc01ce9..fe9d759 100644 (file)
--- 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 device *dev, int dvsec,
                        struct cxl_endpoint_dvsec_info *info);

diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c
index 9e09728..d3a708e 100644 (file)
--- a/drivers/cxl/port.c
+++ b/drivers/cxl/port.c
@@ -78,7 +78,7 @@ 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;

diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 30ee680..3b4916a 100644 (file)
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -701,7 +701,8 @@ static int mock_decoder_reset(struct cxl_decoder *cxld)
        return 0;
 }
 
-static int mock_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
+static int mock_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
+                                      struct cxl_endpoint_dvsec_info *info)
 {
        struct cxl_port *port = cxlhdm->port;
        struct cxl_port *parent_port = to_cxl_port(port->dev.parent);

diff --git a/tools/testing/cxl/test/mock.c b/tools/testing/cxl/test/mock.c
index 2a13f47..3116c9f 100644 (file)
--- a/tools/testing/cxl/test/mock.c
+++ b/tools/testing/cxl/test/mock.c
@@ -162,16 +162,17 @@ int __wrap_devm_cxl_add_passthrough_decoder(struct cxl_port *port)
 }
 EXPORT_SYMBOL_NS_GPL(__wrap_devm_cxl_add_passthrough_decoder, CXL);
 
-int __wrap_devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
+int __wrap_devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
+                                      struct cxl_endpoint_dvsec_info *info)
 {
        int rc, index;
        struct cxl_port *port = cxlhdm->port;
        struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
 
        if (ops && ops->is_mock_port(port->uport))
-               rc = ops->devm_cxl_enumerate_decoders(cxlhdm);
+               rc = ops->devm_cxl_enumerate_decoders(cxlhdm, info);
        else
-               rc = devm_cxl_enumerate_decoders(cxlhdm);
+               rc = devm_cxl_enumerate_decoders(cxlhdm, info);
        put_cxl_mock_ops(index);
 
        return rc;

diff --git a/tools/testing/cxl/test/mock.h b/tools/testing/cxl/test/mock.h
index ef33f15..e377ced 100644 (file)
--- a/tools/testing/cxl/test/mock.h
+++ b/tools/testing/cxl/test/mock.h
@@ -25,7 +25,8 @@ struct cxl_mock_ops {
        int (*devm_cxl_port_enumerate_dports)(struct cxl_port *port);
        struct cxl_hdm *(*devm_cxl_setup_hdm)(struct cxl_port *port);
        int (*devm_cxl_add_passthrough_decoder)(struct cxl_port *port);
-       int (*devm_cxl_enumerate_decoders)(struct cxl_hdm *hdm);
+       int (*devm_cxl_enumerate_decoders)(
+               struct cxl_hdm *hdm, struct cxl_endpoint_dvsec_info *info);
 };
 
 void register_cxl_mock_ops(struct cxl_mock_ops *ops);