[PATCH v4 1/4] s390: pci: Exporting access to CLP PCI function and PCI group

[Matthew Rosato <mjrosato@xxxxxxxxxxxxx>]

From: Pierre Morel <pmorel@xxxxxxxxxxxxx>

For the generic implementation of VFIO PCI we need to retrieve
the hardware configuration for the PCI functions and the
PCI function groups.

We modify the internal function using CLP Query PCI function and
CLP query PCI function group so that they can be called from
outside the S390 architecture PCI code and prefix the two
functions with "zdev" to make clear that they can be called
knowing only the associated zdevice.

Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
Reviewed-by: Sebastian Ott <sebott@xxxxxxxxxxxxx>
---
 arch/s390/include/asm/pci.h |  3 ++
 arch/s390/pci/pci_clp.c     | 71 +++++++++++++++++++++++----------------------
 2 files changed, 40 insertions(+), 34 deletions(-)

diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index a2399ef..dd03212 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -266,4 +266,7 @@ static inline int __pcibus_to_node(const struct pci_bus *bus)
 
 #endif /* CONFIG_NUMA */
 
+int zdev_query_pci_fngrp(struct zpci_dev *zdev,
+			 struct clp_req_rsp_query_pci_grp *rrb);
+int zdev_query_pci_fn(struct zpci_dev *zdev, struct clp_req_rsp_query_pci *rrb);
 #endif
diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
index 9bdff4d..df06fdf 100644
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -113,32 +113,18 @@ static void clp_store_query_pci_fngrp(struct zpci_dev *zdev,
 	}
 }
 
-static int clp_query_pci_fngrp(struct zpci_dev *zdev, u8 pfgid)
+int zdev_query_pci_fngrp(struct zpci_dev *zdev,
+			 struct clp_req_rsp_query_pci_grp *rrb)
 {
-	struct clp_req_rsp_query_pci_grp *rrb;
-	int rc;
-
-	rrb = clp_alloc_block(GFP_KERNEL);
-	if (!rrb)
-		return -ENOMEM;
-
 	memset(rrb, 0, sizeof(*rrb));
 	rrb->request.hdr.len = sizeof(rrb->request);
 	rrb->request.hdr.cmd = CLP_QUERY_PCI_FNGRP;
 	rrb->response.hdr.len = sizeof(rrb->response);
-	rrb->request.pfgid = pfgid;
+	rrb->request.pfgid = zdev->pfgid;
 
-	rc = clp_req(rrb, CLP_LPS_PCI);
-	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK)
-		clp_store_query_pci_fngrp(zdev, &rrb->response);
-	else {
-		zpci_err("Q PCI FGRP:\n");
-		zpci_err_clp(rrb->response.hdr.rsp, rc);
-		rc = -EIO;
-	}
-	clp_free_block(rrb);
-	return rc;
+	return clp_req(rrb, CLP_LPS_PCI);
 }
+EXPORT_SYMBOL(zdev_query_pci_fngrp);
 
 static int clp_store_query_pci_fn(struct zpci_dev *zdev,
 				  struct clp_rsp_query_pci *response)
@@ -174,32 +160,49 @@ static int clp_store_query_pci_fn(struct zpci_dev *zdev,
 	return 0;
 }
 
-static int clp_query_pci_fn(struct zpci_dev *zdev, u32 fh)
+int zdev_query_pci_fn(struct zpci_dev *zdev, struct clp_req_rsp_query_pci *rrb)
+{
+
+	memset(rrb, 0, sizeof(*rrb));
+	rrb->request.hdr.len = sizeof(rrb->request);
+	rrb->request.hdr.cmd = CLP_QUERY_PCI_FN;
+	rrb->response.hdr.len = sizeof(rrb->response);
+	rrb->request.fh = zdev->fh;
+
+	return clp_req(rrb, CLP_LPS_PCI);
+}
+
+static int clp_query_pci(struct zpci_dev *zdev)
 {
 	struct clp_req_rsp_query_pci *rrb;
+	struct clp_req_rsp_query_pci_grp *grrb;
 	int rc;
 
 	rrb = clp_alloc_block(GFP_KERNEL);
 	if (!rrb)
 		return -ENOMEM;
 
-	memset(rrb, 0, sizeof(*rrb));
-	rrb->request.hdr.len = sizeof(rrb->request);
-	rrb->request.hdr.cmd = CLP_QUERY_PCI_FN;
-	rrb->response.hdr.len = sizeof(rrb->response);
-	rrb->request.fh = fh;
-
-	rc = clp_req(rrb, CLP_LPS_PCI);
-	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
-		rc = clp_store_query_pci_fn(zdev, &rrb->response);
-		if (rc)
-			goto out;
-		rc = clp_query_pci_fngrp(zdev, rrb->response.pfgid);
-	} else {
+	rc = zdev_query_pci_fn(zdev, rrb);
+	if (rc || rrb->response.hdr.rsp != CLP_RC_OK) {
 		zpci_err("Q PCI FN:\n");
 		zpci_err_clp(rrb->response.hdr.rsp, rc);
 		rc = -EIO;
+		goto out;
 	}
+	rc = clp_store_query_pci_fn(zdev, &rrb->response);
+	if (rc)
+		goto out;
+
+	grrb = (struct clp_req_rsp_query_pci_grp *)rrb;
+	rc = zdev_query_pci_fngrp(zdev, grrb);
+	if (rc || grrb->response.hdr.rsp != CLP_RC_OK) {
+		zpci_err("Q PCI FGRP:\n");
+		zpci_err_clp(grrb->response.hdr.rsp, rc);
+		rc = -EIO;
+		goto out;
+	}
+	clp_store_query_pci_fngrp(zdev, &grrb->response);
+
 out:
 	clp_free_block(rrb);
 	return rc;
@@ -219,7 +222,7 @@ int clp_add_pci_device(u32 fid, u32 fh, int configured)
 	zdev->fid = fid;
 
 	/* Query function properties and update zdev */
-	rc = clp_query_pci_fn(zdev, fh);
+	rc = clp_query_pci(zdev);
 	if (rc)
 		goto error;
 
-- 
1.8.3.1