s390/pci: handle FH state mismatch only on disable

Instead of always treating CLP_RC_SETPCIFN_ALRDY as success and blindly
updating the function handle restrict this special handling to the
disable case by moving it into zpci_disable_device() and still treating
it as an error while also updating the function handle such that
a subsequent zpci_disable_device() succeeds or the caller can ignore the
error when aborting is not an option such as for zPCI event 0x304.
Also print this occurrence to the log such that an admin can tell why
a disable operation returned an error.

A mismatch between the state of the underlying device and our view of it
can naturally happen when the device suddenly enters the error state but
we haven't gotten the error notification yet, it must not happen on
enable though.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index 5509b224c2ecaac9757876d4c3bb95b6d41a7a7f..a5eec44104217815a5e43c4db2ca64f8f866690e 100644 (file)
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -219,6 +219,7 @@ int clp_query_pci_fn(struct zpci_dev *zdev);
 int clp_enable_fh(struct zpci_dev *, u8);
 int clp_disable_fh(struct zpci_dev *);
 int clp_get_state(u32 fid, enum zpci_state *state);
+int clp_refresh_fh(u32 fid);
 
 /* UID */
 void update_uid_checking(bool new);

diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 4eafa81601843859eea250f8a7fd57ab0e4d2451..6be5ee3201940c500d947328046967401c375a3c 100644 (file)
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -674,12 +674,25 @@ out:
 
 int zpci_disable_device(struct zpci_dev *zdev)
 {
+       int cc, rc = 0;
+
        zpci_dma_exit_device(zdev);
        /*
         * The zPCI function may already be disabled by the platform, this is
         * detected in clp_disable_fh() which becomes a no-op.
         */
-       return clp_disable_fh(zdev) ? -EIO : 0;
+       cc = clp_disable_fh(zdev);
+       if (cc == CLP_RC_SETPCIFN_ALRDY) {
+               pr_info("Disabling PCI function %08x had no effect as it was already disabled\n",
+                       zdev->fid);
+               /* Function is already disabled - update handle */
+               rc = clp_refresh_fh(zdev->fid);
+               if (!rc)
+                       rc = -EINVAL;
+       } else if (cc) {
+               rc = -EIO;
+       }
+       return rc;
 }
 
 /**

diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
index 0a0e8b8293bef74d678c44b92fcc414f68efc7f7..04147f28d1598dd1f0cee13e83ce8c1e207a9886 100644 (file)
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -212,7 +212,6 @@ out:
        return rc;
 }
 
-static int clp_refresh_fh(u32 fid);
 /**
  * clp_set_pci_fn() - Execute a command on a PCI function
  * @zdev: Function that will be affected
@@ -251,9 +250,6 @@ static int clp_set_pci_fn(struct zpci_dev *zdev, u8 nr_dma_as, u8 command)
 
        if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
                zdev->fh = rrb->response.fh;
-       } else if (!rc && rrb->response.hdr.rsp == CLP_RC_SETPCIFN_ALRDY) {
-               /* Function is already in desired state - update handle */
-               rc = clp_refresh_fh(zdev->fid);
        } else {
                zpci_err("Set PCI FN:\n");
                zpci_err_clp(rrb->response.hdr.rsp, rc);
@@ -409,7 +405,7 @@ static void __clp_refresh_fh(struct clp_fh_list_entry *entry, void *data)
 /*
  * Refresh the function handle of the function matching @fid
  */
-static int clp_refresh_fh(u32 fid)
+int clp_refresh_fh(u32 fid)
 {
        struct clp_req_rsp_list_pci *rrb;
        int rc;