forked from Minki/linux
7e0bdbe5c2
The current AP bus, AP devices and AP device drivers implementation
uses a clearly defined mapping for binding AP devices to AP device
drivers. So for example a CEX6C queue will always be bound to the
cex4queue device driver.
The Linux Device Driver model has no sensitivity for more than one
device driver eligible for one device type. If there exist more than
one drivers matching to the device type, simple all drivers are tried
consecutively. There is no way to determine and influence the probing
order of the drivers.
With KVM there is a need to provide additional device drivers matching
to the very same type of AP devices. With a simple implementation the
KVM drivers run in competition to the regular drivers. Whichever
'wins' a device depends on build order and implementation details
within the common Linux Device Driver Model and is not
deterministic. However, a userspace process could figure out which
device should be bound to which driver and sort out the correct
binding by manipulating attributes in the sysfs.
If for security reasons a AP device must not get bound to the 'wrong'
device driver the sorting out has to be done within the Linux kernel
by the AP bus code. This patch modifies the behavior of the AP bus
for probing drivers for devices in a way that two sets of drivers are
usable. Two new bitmasks 'apmask' and 'aqmask' are used to mark a
subset of the APQN range for 'usable by the ap bus and the default
drivers' or 'not usable by the default drivers and thus available for
alternate drivers like vfio-xxx'. So an APQN which is addressed by
this masking only the default drivers will be probed. In contrary an
APQN which is not addressed by the masks will never be probed and
bound to default drivers but onny to alternate drivers.
Eventually the two masks give a way to divide the range of APQNs into
two pools: one pool of APQNs used by the AP bus and the default
drivers and thus via zcrypt drivers available to the userspace of the
system. And another pool where no zcrypt drivers are bound to and
which can be used by alternate drivers (like vfio-xxx) for their
needs. This division is hot-plug save and makes sure a APQN assigned
to an alternate driver is at no time somehow exploitable by the wrong
party.
The two masks are located in sysfs at /sys/bus/ap/apmask and
/sys/bus/ap/aqmask. The mask syntax is exactly the same as the
already existing mask attributes in the /sys/bus/ap directory (for
example ap_usage_domain_mask and ap_control_domain_mask).
By default all APQNs belong to the ap bus and the default drivers:
cat /sys/bus/ap/apmask
0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
cat /sys/bus/ap/aqmask
0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
The masks can be changed at boot time with the kernel command line
like this:
... ap.apmask=0xffff ap.aqmask=0x40
This would give these two pools:
default drivers pool: adapter 0 - 15, domain 1
alternate drivers pool: adapter 0 - 15, all but domain 1
adapter 16-255, all domains
The sysfs attributes for this two masks are writeable and an
administrator is able to reconfigure the assignements on the fly by
writing new mask values into. With changing the mask(s) a revision of
the existing queue to driver bindings is done. So all APQNs which are
bound to the 'wrong' driver are reprobed via kernel function
device_reprobe() and thus the new correct driver will be assigned with
respect of the changed apmask and aqmask bits.
The mask values are bitmaps in big endian order starting with bit 0.
So adapter number 0 is the leftmost bit, mask is 0x8000... The sysfs
attributes accept 2 different formats:
- Absolute hex string starting with 0x like "0x12345678" does set
the mask starting from left to right. If the given string is shorter
than the mask it is padded with 0s on the right. If the string is
longer than the mask an error comes back (EINVAL).
- '+' or '-' followed by a numerical value. Valid examples are "+1",
"-13", "+0x41", "-0xff" and even "+0" and "-0". Only the addressed
bit in the mask is switched on ('+') or off ('-').
This patch will also be the base for an upcoming extension to the
zcrypt drivers to be able to provide additional zcrypt device nodes
with filtering based on ap and aq masks.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
284 lines
8.5 KiB
C
284 lines
8.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0+ */
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/*
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* Copyright IBM Corp. 2006, 2012
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* Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
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* Martin Schwidefsky <schwidefsky@de.ibm.com>
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* Ralph Wuerthner <rwuerthn@de.ibm.com>
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* Felix Beck <felix.beck@de.ibm.com>
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* Holger Dengler <hd@linux.vnet.ibm.com>
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*
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* Adjunct processor bus header file.
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*/
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#ifndef _AP_BUS_H_
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#define _AP_BUS_H_
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#include <linux/device.h>
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#include <linux/types.h>
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#include <asm/isc.h>
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#include <asm/ap.h>
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#define AP_DEVICES 256 /* Number of AP devices. */
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#define AP_DOMAINS 256 /* Number of AP domains. */
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#define AP_RESET_TIMEOUT (HZ*0.7) /* Time in ticks for reset timeouts. */
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#define AP_CONFIG_TIME 30 /* Time in seconds between AP bus rescans. */
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#define AP_POLL_TIME 1 /* Time in ticks between receive polls. */
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extern int ap_domain_index;
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extern spinlock_t ap_list_lock;
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extern struct list_head ap_card_list;
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static inline int ap_test_bit(unsigned int *ptr, unsigned int nr)
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{
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return (*ptr & (0x80000000u >> nr)) != 0;
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}
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#define AP_RESPONSE_NORMAL 0x00
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#define AP_RESPONSE_Q_NOT_AVAIL 0x01
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#define AP_RESPONSE_RESET_IN_PROGRESS 0x02
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#define AP_RESPONSE_DECONFIGURED 0x03
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#define AP_RESPONSE_CHECKSTOPPED 0x04
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#define AP_RESPONSE_BUSY 0x05
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#define AP_RESPONSE_INVALID_ADDRESS 0x06
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#define AP_RESPONSE_OTHERWISE_CHANGED 0x07
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#define AP_RESPONSE_Q_FULL 0x10
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#define AP_RESPONSE_NO_PENDING_REPLY 0x10
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#define AP_RESPONSE_INDEX_TOO_BIG 0x11
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#define AP_RESPONSE_NO_FIRST_PART 0x13
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#define AP_RESPONSE_MESSAGE_TOO_BIG 0x15
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#define AP_RESPONSE_REQ_FAC_NOT_INST 0x16
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/*
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* Known device types
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*/
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#define AP_DEVICE_TYPE_PCICC 3
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#define AP_DEVICE_TYPE_PCICA 4
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#define AP_DEVICE_TYPE_PCIXCC 5
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#define AP_DEVICE_TYPE_CEX2A 6
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#define AP_DEVICE_TYPE_CEX2C 7
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#define AP_DEVICE_TYPE_CEX3A 8
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#define AP_DEVICE_TYPE_CEX3C 9
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#define AP_DEVICE_TYPE_CEX4 10
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#define AP_DEVICE_TYPE_CEX5 11
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#define AP_DEVICE_TYPE_CEX6 12
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/*
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* Known function facilities
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*/
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#define AP_FUNC_MEX4K 1
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#define AP_FUNC_CRT4K 2
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#define AP_FUNC_COPRO 3
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#define AP_FUNC_ACCEL 4
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#define AP_FUNC_EP11 5
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#define AP_FUNC_APXA 6
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/*
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* AP interrupt states
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*/
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#define AP_INTR_DISABLED 0 /* AP interrupt disabled */
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#define AP_INTR_ENABLED 1 /* AP interrupt enabled */
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/*
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* AP device states
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*/
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enum ap_state {
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AP_STATE_RESET_START,
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AP_STATE_RESET_WAIT,
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AP_STATE_SETIRQ_WAIT,
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AP_STATE_IDLE,
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AP_STATE_WORKING,
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AP_STATE_QUEUE_FULL,
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AP_STATE_SUSPEND_WAIT,
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AP_STATE_BORKED,
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NR_AP_STATES
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};
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/*
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* AP device events
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*/
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enum ap_event {
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AP_EVENT_POLL,
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AP_EVENT_TIMEOUT,
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NR_AP_EVENTS
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};
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/*
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* AP wait behaviour
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*/
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enum ap_wait {
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AP_WAIT_AGAIN, /* retry immediately */
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AP_WAIT_TIMEOUT, /* wait for timeout */
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AP_WAIT_INTERRUPT, /* wait for thin interrupt (if available) */
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AP_WAIT_NONE, /* no wait */
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NR_AP_WAIT
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};
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struct ap_device;
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struct ap_message;
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/*
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* The ap driver struct includes a flags field which holds some info for
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* the ap bus about the driver. Currently only one flag is supported and
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* used: The DEFAULT flag marks an ap driver as a default driver which is
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* used together with the apmask and aqmask whitelisting of the ap bus.
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*/
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#define AP_DRIVER_FLAG_DEFAULT 0x0001
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struct ap_driver {
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struct device_driver driver;
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struct ap_device_id *ids;
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unsigned int flags;
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int (*probe)(struct ap_device *);
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void (*remove)(struct ap_device *);
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void (*suspend)(struct ap_device *);
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void (*resume)(struct ap_device *);
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};
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#define to_ap_drv(x) container_of((x), struct ap_driver, driver)
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int ap_driver_register(struct ap_driver *, struct module *, char *);
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void ap_driver_unregister(struct ap_driver *);
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struct ap_device {
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struct device device;
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struct ap_driver *drv; /* Pointer to AP device driver. */
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int device_type; /* AP device type. */
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};
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#define to_ap_dev(x) container_of((x), struct ap_device, device)
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struct ap_card {
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struct ap_device ap_dev;
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struct list_head list; /* Private list of AP cards. */
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struct list_head queues; /* List of assoc. AP queues */
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void *private; /* ap driver private pointer. */
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int raw_hwtype; /* AP raw hardware type. */
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unsigned int functions; /* AP device function bitfield. */
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int queue_depth; /* AP queue depth.*/
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int id; /* AP card number. */
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atomic_t total_request_count; /* # requests ever for this AP device.*/
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};
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#define to_ap_card(x) container_of((x), struct ap_card, ap_dev.device)
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struct ap_queue {
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struct ap_device ap_dev;
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struct list_head list; /* Private list of AP queues. */
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struct ap_card *card; /* Ptr to assoc. AP card. */
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spinlock_t lock; /* Per device lock. */
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void *private; /* ap driver private pointer. */
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ap_qid_t qid; /* AP queue id. */
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int interrupt; /* indicate if interrupts are enabled */
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int queue_count; /* # messages currently on AP queue. */
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enum ap_state state; /* State of the AP device. */
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int pendingq_count; /* # requests on pendingq list. */
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int requestq_count; /* # requests on requestq list. */
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int total_request_count; /* # requests ever for this AP device.*/
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int request_timeout; /* Request timeout in jiffies. */
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struct timer_list timeout; /* Timer for request timeouts. */
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struct list_head pendingq; /* List of message sent to AP queue. */
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struct list_head requestq; /* List of message yet to be sent. */
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struct ap_message *reply; /* Per device reply message. */
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};
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#define to_ap_queue(x) container_of((x), struct ap_queue, ap_dev.device)
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typedef enum ap_wait (ap_func_t)(struct ap_queue *queue);
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struct ap_message {
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struct list_head list; /* Request queueing. */
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unsigned long long psmid; /* Message id. */
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void *message; /* Pointer to message buffer. */
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size_t length; /* Message length. */
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int rc; /* Return code for this message */
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void *private; /* ap driver private pointer. */
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unsigned int special:1; /* Used for special commands. */
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/* receive is called from tasklet context */
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void (*receive)(struct ap_queue *, struct ap_message *,
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struct ap_message *);
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};
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/**
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* ap_init_message() - Initialize ap_message.
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* Initialize a message before using. Otherwise this might result in
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* unexpected behaviour.
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*/
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static inline void ap_init_message(struct ap_message *ap_msg)
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{
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memset(ap_msg, 0, sizeof(*ap_msg));
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}
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/**
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* ap_release_message() - Release ap_message.
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* Releases all memory used internal within the ap_message struct
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* Currently this is the message and private field.
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*/
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static inline void ap_release_message(struct ap_message *ap_msg)
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{
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kzfree(ap_msg->message);
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kzfree(ap_msg->private);
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}
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#define for_each_ap_card(_ac) \
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list_for_each_entry(_ac, &ap_card_list, list)
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#define for_each_ap_queue(_aq, _ac) \
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list_for_each_entry(_aq, &(_ac)->queues, list)
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/*
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* Note: don't use ap_send/ap_recv after using ap_queue_message
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* for the first time. Otherwise the ap message queue will get
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* confused.
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*/
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int ap_send(ap_qid_t, unsigned long long, void *, size_t);
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int ap_recv(ap_qid_t, unsigned long long *, void *, size_t);
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enum ap_wait ap_sm_event(struct ap_queue *aq, enum ap_event event);
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enum ap_wait ap_sm_event_loop(struct ap_queue *aq, enum ap_event event);
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void ap_queue_message(struct ap_queue *aq, struct ap_message *ap_msg);
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void ap_cancel_message(struct ap_queue *aq, struct ap_message *ap_msg);
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void ap_flush_queue(struct ap_queue *aq);
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void *ap_airq_ptr(void);
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void ap_wait(enum ap_wait wait);
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void ap_request_timeout(struct timer_list *t);
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void ap_bus_force_rescan(void);
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void ap_queue_init_reply(struct ap_queue *aq, struct ap_message *ap_msg);
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struct ap_queue *ap_queue_create(ap_qid_t qid, int device_type);
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void ap_queue_remove(struct ap_queue *aq);
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void ap_queue_suspend(struct ap_device *ap_dev);
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void ap_queue_resume(struct ap_device *ap_dev);
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struct ap_card *ap_card_create(int id, int queue_depth, int raw_device_type,
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int comp_device_type, unsigned int functions);
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/*
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* check APQN for owned/reserved by ap bus and default driver(s).
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* Checks if this APQN is or will be in use by the ap bus
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* and the default set of drivers.
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* If yes, returns 1, if not returns 0. On error a negative
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* errno value is returned.
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*/
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int ap_owned_by_def_drv(int card, int queue);
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/*
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* check 'matrix' of APQNs for owned/reserved by ap bus and
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* default driver(s).
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* Checks if there is at least one APQN in the given 'matrix'
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* marked as owned/reserved by the ap bus and default driver(s).
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* If such an APQN is found the return value is 1, otherwise
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* 0 is returned. On error a negative errno value is returned.
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* The parameter apm is a bitmask which should be declared
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* as DECLARE_BITMAP(apm, AP_DEVICES), the aqm parameter is
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* similar, should be declared as DECLARE_BITMAP(aqm, AP_DOMAINS).
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*/
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int ap_apqn_in_matrix_owned_by_def_drv(unsigned long *apm,
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unsigned long *aqm);
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#endif /* _AP_BUS_H_ */
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