[PATCH 1/5] cxl/hdm: Moving HDM specific code to core/hdm.c.

[Robert Richter <rrichter@amd.com>]

Code to handle HDM specifics is implemented in core/pci.c and
core/hdm.c. In both files helper functions will be needed for address
translation. To simplify the introduction of static helper functions,
move all HDM code to core/hdm.c.

The function devm_cxl_enable_mem() is no longer static and is shared
now within the core module. No functional changes otherwise.

Signed-off-by: Robert Richter <rrichter@amd.com>
---
 drivers/cxl/core/core.h |   2 +
 drivers/cxl/core/hdm.c  | 117 +++++++++++++++++++++++++++++++++++++++
 drivers/cxl/core/pci.c  | 119 +---------------------------------------
 drivers/cxl/cxlmem.h    |   3 +
 drivers/cxl/cxlpci.h    |   3 -
 5 files changed, 123 insertions(+), 121 deletions(-)

diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 625394486459..d8c3c27ce100 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -70,6 +70,8 @@ int cxl_query_cmd(struct cxl_memdev *cxlmd,
 int cxl_send_cmd(struct cxl_memdev *cxlmd, struct cxl_send_command __user *s);
 void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr,
 				   resource_size_t length);
+struct cxl_dev_state;
+int devm_cxl_enable_mem(struct device *host, struct cxl_dev_state *cxlds);
 
 struct dentry *cxl_debugfs_create_dir(const char *dir);
 int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 784843fa2a22..605da9a55d89 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -1027,3 +1027,120 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
 	return 0;
 }
 EXPORT_SYMBOL_NS_GPL(devm_cxl_enumerate_decoders, CXL);
+
+/* require dvsec ranges to be covered by a locked platform window */
+static int dvsec_range_allowed(struct device *dev, void *arg)
+{
+	struct range *dev_range = arg;
+	struct cxl_decoder *cxld;
+
+	if (!is_root_decoder(dev))
+		return 0;
+
+	cxld = to_cxl_decoder(dev);
+
+	if (!(cxld->flags & CXL_DECODER_F_RAM))
+		return 0;
+
+	return range_contains(&cxld->hpa_range, dev_range);
+}
+
+static void disable_hdm(void *_cxlhdm)
+{
+	u32 global_ctrl;
+	struct cxl_hdm *cxlhdm = _cxlhdm;
+	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
+
+	global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET);
+	writel(global_ctrl & ~CXL_HDM_DECODER_ENABLE,
+	       hdm + CXL_HDM_DECODER_CTRL_OFFSET);
+}
+
+static int devm_cxl_enable_hdm(struct device *host, struct cxl_hdm *cxlhdm)
+{
+	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
+	u32 global_ctrl;
+
+	global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET);
+	writel(global_ctrl | CXL_HDM_DECODER_ENABLE,
+	       hdm + CXL_HDM_DECODER_CTRL_OFFSET);
+
+	return devm_add_action_or_reset(host, disable_hdm, cxlhdm);
+}
+
+/**
+ * cxl_hdm_decode_init() - Setup HDM decoding for the endpoint
+ * @cxlds: Device state
+ * @cxlhdm: Mapped HDM decoder Capability
+ * @info: Cached DVSEC range registers info
+ *
+ * Try to enable the endpoint's HDM Decoder Capability
+ */
+int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm,
+			struct cxl_endpoint_dvsec_info *info)
+{
+	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
+	struct cxl_port *port = cxlhdm->port;
+	struct device *dev = cxlds->dev;
+	struct cxl_port *root;
+	int i, rc, allowed;
+	u32 global_ctrl = 0;
+
+	if (hdm)
+		global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET);
+
+	/*
+	 * If the HDM Decoder Capability is already enabled then assume
+	 * that some other agent like platform firmware set it up.
+	 */
+	if (global_ctrl & CXL_HDM_DECODER_ENABLE || (!hdm && info->mem_enabled))
+		return devm_cxl_enable_mem(&port->dev, cxlds);
+	else if (!hdm)
+		return -ENODEV;
+
+	root = to_cxl_port(port->dev.parent);
+	while (!is_cxl_root(root) && is_cxl_port(root->dev.parent))
+		root = to_cxl_port(root->dev.parent);
+	if (!is_cxl_root(root)) {
+		dev_err(dev, "Failed to acquire root port for HDM enable\n");
+		return -ENODEV;
+	}
+
+	for (i = 0, allowed = 0; info->mem_enabled && i < info->ranges; i++) {
+		struct device *cxld_dev;
+
+		cxld_dev = device_find_child(&root->dev, &info->dvsec_range[i],
+					     dvsec_range_allowed);
+		if (!cxld_dev) {
+			dev_dbg(dev, "DVSEC Range%d denied by platform\n", i);
+			continue;
+		}
+		dev_dbg(dev, "DVSEC Range%d allowed by platform\n", i);
+		put_device(cxld_dev);
+		allowed++;
+	}
+
+	if (!allowed && info->mem_enabled) {
+		dev_err(dev, "Range register decodes outside platform defined CXL ranges.\n");
+		return -ENXIO;
+	}
+
+	/*
+	 * Per CXL 2.0 Section 8.1.3.8.3 and 8.1.3.8.4 DVSEC CXL Range 1 Base
+	 * [High,Low] when HDM operation is enabled the range register values
+	 * are ignored by the device, but the spec also recommends matching the
+	 * DVSEC Range 1,2 to HDM Decoder Range 0,1. So, non-zero info->ranges
+	 * are expected even though Linux does not require or maintain that
+	 * match. If at least one DVSEC range is enabled and allowed, skip HDM
+	 * Decoder Capability Enable.
+	 */
+	if (info->mem_enabled)
+		return 0;
+
+	rc = devm_cxl_enable_hdm(&port->dev, cxlhdm);
+	if (rc)
+		return rc;
+
+	return devm_cxl_enable_mem(&port->dev, cxlds);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_hdm_decode_init, CXL);
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 8567dd11eaac..4f67e3ae7a05 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -270,7 +270,7 @@ static void clear_mem_enable(void *cxlds)
 	cxl_set_mem_enable(cxlds, 0);
 }
 
-static int devm_cxl_enable_mem(struct device *host, struct cxl_dev_state *cxlds)
+int devm_cxl_enable_mem(struct device *host, struct cxl_dev_state *cxlds)
 {
 	int rc;
 
@@ -282,46 +282,6 @@ static int devm_cxl_enable_mem(struct device *host, struct cxl_dev_state *cxlds)
 	return devm_add_action_or_reset(host, clear_mem_enable, cxlds);
 }
 
-/* require dvsec ranges to be covered by a locked platform window */
-static int dvsec_range_allowed(struct device *dev, void *arg)
-{
-	struct range *dev_range = arg;
-	struct cxl_decoder *cxld;
-
-	if (!is_root_decoder(dev))
-		return 0;
-
-	cxld = to_cxl_decoder(dev);
-
-	if (!(cxld->flags & CXL_DECODER_F_RAM))
-		return 0;
-
-	return range_contains(&cxld->hpa_range, dev_range);
-}
-
-static void disable_hdm(void *_cxlhdm)
-{
-	u32 global_ctrl;
-	struct cxl_hdm *cxlhdm = _cxlhdm;
-	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
-
-	global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET);
-	writel(global_ctrl & ~CXL_HDM_DECODER_ENABLE,
-	       hdm + CXL_HDM_DECODER_CTRL_OFFSET);
-}
-
-static int devm_cxl_enable_hdm(struct device *host, struct cxl_hdm *cxlhdm)
-{
-	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
-	u32 global_ctrl;
-
-	global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET);
-	writel(global_ctrl | CXL_HDM_DECODER_ENABLE,
-	       hdm + CXL_HDM_DECODER_CTRL_OFFSET);
-
-	return devm_add_action_or_reset(host, disable_hdm, cxlhdm);
-}
-
 int cxl_dvsec_rr_decode(struct device *dev, int d,
 			struct cxl_endpoint_dvsec_info *info)
 {
@@ -425,83 +385,6 @@ int cxl_dvsec_rr_decode(struct device *dev, int d,
 }
 EXPORT_SYMBOL_NS_GPL(cxl_dvsec_rr_decode, CXL);
 
-/**
- * cxl_hdm_decode_init() - Setup HDM decoding for the endpoint
- * @cxlds: Device state
- * @cxlhdm: Mapped HDM decoder Capability
- * @info: Cached DVSEC range registers info
- *
- * Try to enable the endpoint's HDM Decoder Capability
- */
-int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm,
-			struct cxl_endpoint_dvsec_info *info)
-{
-	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
-	struct cxl_port *port = cxlhdm->port;
-	struct device *dev = cxlds->dev;
-	struct cxl_port *root;
-	int i, rc, allowed;
-	u32 global_ctrl = 0;
-
-	if (hdm)
-		global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET);
-
-	/*
-	 * If the HDM Decoder Capability is already enabled then assume
-	 * that some other agent like platform firmware set it up.
-	 */
-	if (global_ctrl & CXL_HDM_DECODER_ENABLE || (!hdm && info->mem_enabled))
-		return devm_cxl_enable_mem(&port->dev, cxlds);
-	else if (!hdm)
-		return -ENODEV;
-
-	root = to_cxl_port(port->dev.parent);
-	while (!is_cxl_root(root) && is_cxl_port(root->dev.parent))
-		root = to_cxl_port(root->dev.parent);
-	if (!is_cxl_root(root)) {
-		dev_err(dev, "Failed to acquire root port for HDM enable\n");
-		return -ENODEV;
-	}
-
-	for (i = 0, allowed = 0; info->mem_enabled && i < info->ranges; i++) {
-		struct device *cxld_dev;
-
-		cxld_dev = device_find_child(&root->dev, &info->dvsec_range[i],
-					     dvsec_range_allowed);
-		if (!cxld_dev) {
-			dev_dbg(dev, "DVSEC Range%d denied by platform\n", i);
-			continue;
-		}
-		dev_dbg(dev, "DVSEC Range%d allowed by platform\n", i);
-		put_device(cxld_dev);
-		allowed++;
-	}
-
-	if (!allowed && info->mem_enabled) {
-		dev_err(dev, "Range register decodes outside platform defined CXL ranges.\n");
-		return -ENXIO;
-	}
-
-	/*
-	 * Per CXL 2.0 Section 8.1.3.8.3 and 8.1.3.8.4 DVSEC CXL Range 1 Base
-	 * [High,Low] when HDM operation is enabled the range register values
-	 * are ignored by the device, but the spec also recommends matching the
-	 * DVSEC Range 1,2 to HDM Decoder Range 0,1. So, non-zero info->ranges
-	 * are expected even though Linux does not require or maintain that
-	 * match. If at least one DVSEC range is enabled and allowed, skip HDM
-	 * Decoder Capability Enable.
-	 */
-	if (info->mem_enabled)
-		return 0;
-
-	rc = devm_cxl_enable_hdm(&port->dev, cxlhdm);
-	if (rc)
-		return rc;
-
-	return devm_cxl_enable_mem(&port->dev, cxlds);
-}
-EXPORT_SYMBOL_NS_GPL(cxl_hdm_decode_init, CXL);
-
 #define CXL_DOE_TABLE_ACCESS_REQ_CODE		0x000000ff
 #define   CXL_DOE_TABLE_ACCESS_REQ_CODE_READ	0
 #define CXL_DOE_TABLE_ACCESS_TABLE_TYPE		0x0000ff00
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 19aba81cdf13..61d9f4e00921 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -862,4 +862,7 @@ struct cxl_hdm {
 struct seq_file;
 struct dentry *cxl_debugfs_create_dir(const char *dir);
 void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds);
+int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm,
+			struct cxl_endpoint_dvsec_info *info);
+
 #endif /* __CXL_MEM_H__ */
diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h
index 4da07727ab9c..fe01793af1cb 100644
--- a/drivers/cxl/cxlpci.h
+++ b/drivers/cxl/cxlpci.h
@@ -122,9 +122,6 @@ static inline bool cxl_pci_flit_256(struct pci_dev *pdev)
 }
 
 int devm_cxl_port_enumerate_dports(struct cxl_port *port);
-struct cxl_dev_state;
-int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm,
-			struct cxl_endpoint_dvsec_info *info);
 void read_cdat_data(struct cxl_port *port);
 void cxl_cor_error_detected(struct pci_dev *pdev);
 pci_ers_result_t cxl_error_detected(struct pci_dev *pdev,
-- 
2.39.2