s390/pci: use unique UIDs for domain enumeration

Use UIDs as domain numbers if the UID checking rules apply (in this
case the FW guarantees uniqueness of these values).

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/include/asm/pci_clp.h b/arch/s390/include/asm/pci_clp.h
index e75c64c..c232ef9 100644 (file)
--- a/arch/s390/include/asm/pci_clp.h
+++ b/arch/s390/include/asm/pci_clp.h
@@ -46,6 +46,8 @@ struct clp_fh_list_entry {
 #define CLP_UTIL_STR_LEN       64
 #define CLP_PFIP_NR_SEGMENTS   4
 
+extern bool zpci_unique_uid;
+
 /* List PCI functions request */
 struct clp_req_list_pci {
        struct clp_req_hdr hdr;
@@ -59,7 +61,8 @@ struct clp_rsp_list_pci {
        u64 resume_token;
        u32 reserved2;
        u16 max_fn;
-       u8 reserved3;
+       u8                      : 7;
+       u8 uid_checking         : 1;
        u8 entry_size;
        struct clp_fh_list_entry fh_list[CLP_FH_LIST_NR_ENTRIES];
 } __packed;

diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 15ffc19..64e1734 100644 (file)
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -722,6 +722,11 @@ struct dev_pm_ops pcibios_pm_ops = {
 
 static int zpci_alloc_domain(struct zpci_dev *zdev)
 {
+       if (zpci_unique_uid) {
+               zdev->domain = (u16) zdev->uid;
+               return 0;
+       }
+
        spin_lock(&zpci_domain_lock);
        zdev->domain = find_first_zero_bit(zpci_domain, ZPCI_NR_DEVICES);
        if (zdev->domain == ZPCI_NR_DEVICES) {
@@ -735,6 +740,9 @@ static int zpci_alloc_domain(struct zpci_dev *zdev)
 
 static void zpci_free_domain(struct zpci_dev *zdev)
 {
+       if (zpci_unique_uid)
+               return;
+
        spin_lock(&zpci_domain_lock);
        clear_bit(zdev->domain, zpci_domain);
        spin_unlock(&zpci_domain_lock);

diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
index 1a4512c..e3ef63b 100644 (file)
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -22,6 +22,8 @@
 #include <asm/clp.h>
 #include <uapi/asm/clp.h>
 
+bool zpci_unique_uid;
+
 static inline void zpci_err_clp(unsigned int rsp, int rc)
 {
        struct {
@@ -315,6 +317,7 @@ static int clp_list_pci(struct clp_req_rsp_list_pci *rrb,
                        goto out;
                }
 
+               zpci_unique_uid = rrb->response.uid_checking;
                WARN_ON_ONCE(rrb->response.entry_size !=
                        sizeof(struct clp_fh_list_entry));