From: Pierre Morel <pmorel@linux.ibm.com>
Date: Fri, 7 Feb 2020 13:35:08 +0100
Subject: s390/pci: define kernel parameters for PCI multifunction
Git-commit: 6cf17f9a67c124aa4739b79709008d942635b975
Patch-mainline: v5.8-rc1
References: jsc#SLE-13818 bsc#1177117 LTC#186574

Using PCI multifunctions in S390 is a new feature we may want
to ignore to continue provide the same topology as in the past
to userland even if the configuration supports exposing the
topology of a multi-Function device.

A new boolean parameters allows to overwrite the kernel
pci configuration:

- pci=norid when on, disallow the use a new firmware field,
  RID, which provides the PCI <bus>:<device>.<function> part
  of the PCI address.

To be used in the following patches and satisfy the checkpatch.pl
the variable is exposed in pci.h

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 arch/s390/include/asm/pci.h |    1 +
 arch/s390/pci/pci.c         |    6 ++++++
 2 files changed, 7 insertions(+)

--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -167,6 +167,7 @@ static inline bool zdev_enabled(struct z
 
 extern const struct attribute_group *zpci_attr_groups[];
 extern unsigned int s390_pci_force_floating __initdata;
+extern unsigned int s390_pci_no_rid;
 
 /* -----------------------------------------------------------------------------
   Prototypes
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -47,6 +47,8 @@ static unsigned int zpci_num_domains_all
 	min(((unsigned long) ZPCI_NR_DEVICES * PCI_STD_NUM_BARS / 2),	\
 	    ZPCI_IOMAP_MAX_ENTRIES)
 
+unsigned int s390_pci_no_rid;
+
 static DEFINE_SPINLOCK(zpci_iomap_lock);
 static unsigned long *zpci_iomap_bitmap;
 struct zpci_iomap_entry *zpci_iomap_start;
@@ -884,6 +886,10 @@ char * __init pcibios_setup(char *str)
 		s390_pci_force_floating = 1;
 		return NULL;
 	}
+	if (!strcmp(str, "norid")) {
+		s390_pci_no_rid = 1;
+		return NULL;
+	}
 	return str;
 }