linux-stable/drivers/s390/cio/cio.h
Halil Pasic 05668e1d74 s390/cio: fix virtio-ccw DMA without PV
Commit 37db8985b2 ("s390/cio: add basic protected virtualization
support") breaks virtio-ccw devices with VIRTIO_F_IOMMU_PLATFORM for non
Protected Virtualization (PV) guests. The problem is that the dma_mask
of the ccw device, which is used by virtio core, gets changed from 64 to
31 bit, because some of the DMA allocations do require 31 bit
addressable memory. For PV the only drawback is that some of the virtio
structures must end up in ZONE_DMA because we have the bounce the
buffers mapped via DMA API anyway.

But for non PV guests we have a problem: because of the 31 bit mask
guests bigger than 2G are likely to try bouncing buffers. The swiotlb
however is only initialized for PV guests, because we don't want to
bounce anything for non PV guests. The first such map kills the guest.

Since the DMA API won't allow us to specify for each allocation whether
we need memory from ZONE_DMA (31 bit addressable) or any DMA capable
memory will do, let us use coherent_dma_mask (which is used for
allocations) to force allocating form ZONE_DMA while changing dma_mask
to DMA_BIT_MASK(64) so that at least the streaming API will regard
the whole memory DMA capable.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Fixes: 37db8985b2 ("s390/cio: add basic protected virtualization support")
Link: https://lore.kernel.org/lkml/20190930153803.7958-1-pasic@linux.ibm.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-10-10 10:49:46 +02:00

153 lines
4.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef S390_CIO_H
#define S390_CIO_H
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/mod_devicetable.h>
#include <asm/chpid.h>
#include <asm/cio.h>
#include <asm/fcx.h>
#include <asm/schid.h>
#include "chsc.h"
/*
* path management control word
*/
struct pmcw {
u32 intparm; /* interruption parameter */
u32 qf : 1; /* qdio facility */
u32 w : 1;
u32 isc : 3; /* interruption sublass */
u32 res5 : 3; /* reserved zeros */
u32 ena : 1; /* enabled */
u32 lm : 2; /* limit mode */
u32 mme : 2; /* measurement-mode enable */
u32 mp : 1; /* multipath mode */
u32 tf : 1; /* timing facility */
u32 dnv : 1; /* device number valid */
u32 dev : 16; /* device number */
u8 lpm; /* logical path mask */
u8 pnom; /* path not operational mask */
u8 lpum; /* last path used mask */
u8 pim; /* path installed mask */
u16 mbi; /* measurement-block index */
u8 pom; /* path operational mask */
u8 pam; /* path available mask */
u8 chpid[8]; /* CHPID 0-7 (if available) */
u32 unused1 : 8; /* reserved zeros */
u32 st : 3; /* subchannel type */
u32 unused2 : 18; /* reserved zeros */
u32 mbfc : 1; /* measurement block format control */
u32 xmwme : 1; /* extended measurement word mode enable */
u32 csense : 1; /* concurrent sense; can be enabled ...*/
/* ... per MSCH, however, if facility */
/* ... is not installed, this results */
/* ... in an operand exception. */
} __attribute__ ((packed));
/* I/O-Interruption Code as stored by TEST PENDING INTERRUPTION (TPI). */
struct tpi_info {
struct subchannel_id schid;
u32 intparm;
u32 adapter_IO:1;
u32 directed_irq:1;
u32 isc:3;
u32 :27;
u32 type:3;
u32 :12;
} __packed __aligned(4);
/* Target SCHIB configuration. */
struct schib_config {
u64 mba;
u32 intparm;
u16 mbi;
u32 isc:3;
u32 ena:1;
u32 mme:2;
u32 mp:1;
u32 csense:1;
u32 mbfc:1;
} __attribute__ ((packed));
/*
* subchannel information block
*/
struct schib {
struct pmcw pmcw; /* path management control word */
union scsw scsw; /* subchannel status word */
__u64 mba; /* measurement block address */
__u8 mda[4]; /* model dependent area */
} __attribute__ ((packed,aligned(4)));
/*
* When rescheduled, todo's with higher values will overwrite those
* with lower values.
*/
enum sch_todo {
SCH_TODO_NOTHING,
SCH_TODO_EVAL,
SCH_TODO_UNREG,
};
/* subchannel data structure used by I/O subroutines */
struct subchannel {
struct subchannel_id schid;
spinlock_t *lock; /* subchannel lock */
struct mutex reg_mutex;
enum {
SUBCHANNEL_TYPE_IO = 0,
SUBCHANNEL_TYPE_CHSC = 1,
SUBCHANNEL_TYPE_MSG = 2,
SUBCHANNEL_TYPE_ADM = 3,
} st; /* subchannel type */
__u8 vpm; /* verified path mask */
__u8 lpm; /* logical path mask */
__u8 opm; /* operational path mask */
struct schib schib; /* subchannel information block */
int isc; /* desired interruption subclass */
struct chsc_ssd_info ssd_info; /* subchannel description */
struct device dev; /* entry in device tree */
struct css_driver *driver;
enum sch_todo todo;
struct work_struct todo_work;
struct schib_config config;
u64 dma_mask;
char *driver_override; /* Driver name to force a match */
} __attribute__ ((aligned(8)));
DECLARE_PER_CPU_ALIGNED(struct irb, cio_irb);
#define to_subchannel(n) container_of(n, struct subchannel, dev)
extern int cio_enable_subchannel(struct subchannel *, u32);
extern int cio_disable_subchannel (struct subchannel *);
extern int cio_cancel (struct subchannel *);
extern int cio_clear (struct subchannel *);
extern int cio_cancel_halt_clear(struct subchannel *, int *);
extern int cio_resume (struct subchannel *);
extern int cio_halt (struct subchannel *);
extern int cio_start (struct subchannel *, struct ccw1 *, __u8);
extern int cio_start_key (struct subchannel *, struct ccw1 *, __u8, __u8);
extern int cio_set_options (struct subchannel *, int);
extern int cio_update_schib(struct subchannel *sch);
extern int cio_commit_config(struct subchannel *sch);
int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key);
int cio_tm_intrg(struct subchannel *sch);
extern int __init airq_init(void);
/* Use with care. */
#ifdef CONFIG_CCW_CONSOLE
extern struct subchannel *cio_probe_console(void);
extern int cio_is_console(struct subchannel_id);
extern void cio_register_early_subchannels(void);
extern void cio_tsch(struct subchannel *sch);
#else
#define cio_is_console(schid) 0
static inline void cio_register_early_subchannels(void) {}
#endif
#endif