[RFC 1/4] s390/pci: track alignment/length strictness for zpci_dev

Matthew Rosato
2020-12-09T20:30:28Z

Some zpci device types (e.g., ISM) follow different rules for length
and alignment of pci instructions. Recognize this and keep track of
it in the zpci_dev.

Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
---
arch/s390/include/asm/pci.h | 3 ++-
arch/s390/include/asm/pci_clp.h | 4 +++-
arch/s390/pci/pci_clp.c | 1 +
3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index 2126289..f16ffba 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -133,7 +133,8 @@ struct zpci_dev {
u8 has_hp_slot : 1;
u8 is_physfn : 1;
u8 util_str_avail : 1;
- u8 reserved : 4;
+ u8 relaxed_align : 1;
+ u8 reserved : 3;
unsigned int devfn; /* DEVFN part of the RID*/

struct mutex lock;
diff --git a/arch/s390/include/asm/pci_clp.h b/arch/s390/include/asm/pci_clp.h
index 1f4b666..9fb7cbf 100644
--- a/arch/s390/include/asm/pci_clp.h
+++ b/arch/s390/include/asm/pci_clp.h
@@ -150,7 +150,9 @@ struct clp_rsp_query_pci_grp {
u16 : 4;
u16 noi : 12; /* number of interrupts */
u8 version;
- u8 : 6;
+ u8 : 4;
+ u8 relaxed_align : 1; /* Relax length and alignment rules */
+ u8 : 1;
u8 frame : 1;
u8 refresh : 1; /* TLB refresh mode */
u16 reserved2;
diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
index 153720d..630f8fc 100644
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -103,6 +103,7 @@ static void clp_store_query_pci_fngrp(struct zpci_dev *zdev,
zdev->max_msi = response->noi;
zdev->fmb_update = response->mui;
zdev->version = response->version;
+ zdev->relaxed_align = response->relaxed_align;

switch (response->version) {
case 1:
--
1.8.3.1