Revision 2548d546d40c0014efdde88a53bf7896e917dcce authored by Peter Zijlstra on 21 April 2016, 16:03:15 UTC, committed by Ingo Molnar on 28 April 2016, 08:28:55 UTC
Chris Metcalf reported a that sched_can_stop_tick() sometimes fails to re-enable the tick. His observed problem is that rq->cfs.nr_running can be 1 even though there are multiple runnable CFS tasks. This happens in the cgroup case, in which case cfs.nr_running is the number of runnable entities for that level. If there is a single runnable cgroup (which can have an arbitrary number of runnable child entries itself) rq->cfs.nr_running will be 1. However, looking at that function I think there's more problems with it. It seems to assume that if there's FIFO tasks, those will run. This is incorrect. The FIFO task can have a lower prio than an RR task, in which case the RR task will run. So the whole fifo_nr_running test seems misplaced, it should go after the rr_nr_running tests. That is, only if !rr_nr_running, can we use fifo_nr_running like this. Reported-by: Chris Metcalf <cmetcalf@mellanox.com> Tested-by: Chris Metcalf <cmetcalf@mellanox.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Wanpeng Li <kernellwp@gmail.com> Fixes: 76d92ac305f2 ("sched: Migrate sched to use new tick dependency mask model") Link: http://lkml.kernel.org/r/20160421160315.GK24771@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
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card_base.h
#ifndef __CARD_BASE_H__
#define __CARD_BASE_H__
/**
* IBM Accelerator Family 'GenWQE'
*
* (C) Copyright IBM Corp. 2013
*
* Author: Frank Haverkamp <haver@linux.vnet.ibm.com>
* Author: Joerg-Stephan Vogt <jsvogt@de.ibm.com>
* Author: Michael Jung <mijung@gmx.net>
* Author: Michael Ruettger <michael@ibmra.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (version 2 only)
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
/*
* Interfaces within the GenWQE module. Defines genwqe_card and
* ddcb_queue as well as ddcb_requ.
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/cdev.h>
#include <linux/stringify.h>
#include <linux/pci.h>
#include <linux/semaphore.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/debugfs.h>
#include <linux/slab.h>
#include <linux/genwqe/genwqe_card.h>
#include "genwqe_driver.h"
#define GENWQE_MSI_IRQS 4 /* Just one supported, no MSIx */
#define GENWQE_FLAG_MSI_ENABLED (1 << 0)
#define GENWQE_MAX_VFS 15 /* maximum 15 VFs are possible */
#define GENWQE_MAX_FUNCS 16 /* 1 PF and 15 VFs */
#define GENWQE_CARD_NO_MAX (16 * GENWQE_MAX_FUNCS)
/* Compile parameters, some of them appear in debugfs for later adjustment */
#define genwqe_ddcb_max 32 /* DDCBs on the work-queue */
#define genwqe_polling_enabled 0 /* in case of irqs not working */
#define genwqe_ddcb_software_timeout 10 /* timeout per DDCB in seconds */
#define genwqe_kill_timeout 8 /* time until process gets killed */
#define genwqe_vf_jobtimeout_msec 250 /* 250 msec */
#define genwqe_pf_jobtimeout_msec 8000 /* 8 sec should be ok */
#define genwqe_health_check_interval 4 /* <= 0: disabled */
/* Sysfs attribute groups used when we create the genwqe device */
extern const struct attribute_group *genwqe_attribute_groups[];
/*
* Config space for Genwqe5 A7:
* 00:[14 10 4b 04]40 00 10 00[00 00 00 12]00 00 00 00
* 10: 0c 00 00 f0 07 3c 00 00 00 00 00 00 00 00 00 00
* 20: 00 00 00 00 00 00 00 00 00 00 00 00[14 10 4b 04]
* 30: 00 00 00 00 50 00 00 00 00 00 00 00 00 00 00 00
*/
#define PCI_DEVICE_GENWQE 0x044b /* Genwqe DeviceID */
#define PCI_SUBSYSTEM_ID_GENWQE5 0x035f /* Genwqe A5 Subsystem-ID */
#define PCI_SUBSYSTEM_ID_GENWQE5_NEW 0x044b /* Genwqe A5 Subsystem-ID */
#define PCI_CLASSCODE_GENWQE5 0x1200 /* UNKNOWN */
#define PCI_SUBVENDOR_ID_IBM_SRIOV 0x0000
#define PCI_SUBSYSTEM_ID_GENWQE5_SRIOV 0x0000 /* Genwqe A5 Subsystem-ID */
#define PCI_CLASSCODE_GENWQE5_SRIOV 0x1200 /* UNKNOWN */
#define GENWQE_SLU_ARCH_REQ 2 /* Required SLU architecture level */
/**
* struct genwqe_reg - Genwqe data dump functionality
*/
struct genwqe_reg {
u32 addr;
u32 idx;
u64 val;
};
/*
* enum genwqe_dbg_type - Specify chip unit to dump/debug
*/
enum genwqe_dbg_type {
GENWQE_DBG_UNIT0 = 0, /* captured before prev errs cleared */
GENWQE_DBG_UNIT1 = 1,
GENWQE_DBG_UNIT2 = 2,
GENWQE_DBG_UNIT3 = 3,
GENWQE_DBG_UNIT4 = 4,
GENWQE_DBG_UNIT5 = 5,
GENWQE_DBG_UNIT6 = 6,
GENWQE_DBG_UNIT7 = 7,
GENWQE_DBG_REGS = 8,
GENWQE_DBG_DMA = 9,
GENWQE_DBG_UNITS = 10, /* max number of possible debug units */
};
/* Software error injection to simulate card failures */
#define GENWQE_INJECT_HARDWARE_FAILURE 0x00000001 /* injects -1 reg reads */
#define GENWQE_INJECT_BUS_RESET_FAILURE 0x00000002 /* pci_bus_reset fail */
#define GENWQE_INJECT_GFIR_FATAL 0x00000004 /* GFIR = 0x0000ffff */
#define GENWQE_INJECT_GFIR_INFO 0x00000008 /* GFIR = 0xffff0000 */
/*
* Genwqe card description and management data.
*
* Error-handling in case of card malfunction
* ------------------------------------------
*
* If the card is detected to be defective the outside environment
* will cause the PCI layer to call deinit (the cleanup function for
* probe). This is the same effect like doing a unbind/bind operation
* on the card.
*
* The genwqe card driver implements a health checking thread which
* verifies the card function. If this detects a problem the cards
* device is being shutdown and restarted again, along with a reset of
* the card and queue.
*
* All functions accessing the card device return either -EIO or -ENODEV
* code to indicate the malfunction to the user. The user has to close
* the file descriptor and open a new one, once the card becomes
* available again.
*
* If the open file descriptor is setup to receive SIGIO, the signal is
* genereated for the application which has to provide a handler to
* react on it. If the application does not close the open
* file descriptor a SIGKILL is send to enforce freeing the cards
* resources.
*
* I did not find a different way to prevent kernel problems due to
* reference counters for the cards character devices getting out of
* sync. The character device deallocation does not block, even if
* there is still an open file descriptor pending. If this pending
* descriptor is closed, the data structures used by the character
* device is reinstantiated, which will lead to the reference counter
* dropping below the allowed values.
*
* Card recovery
* -------------
*
* To test the internal driver recovery the following command can be used:
* sudo sh -c 'echo 0xfffff > /sys/class/genwqe/genwqe0_card/err_inject'
*/
/**
* struct dma_mapping_type - Mapping type definition
*
* To avoid memcpying data arround we use user memory directly. To do
* this we need to pin/swap-in the memory and request a DMA address
* for it.
*/
enum dma_mapping_type {
GENWQE_MAPPING_RAW = 0, /* contignous memory buffer */
GENWQE_MAPPING_SGL_TEMP, /* sglist dynamically used */
GENWQE_MAPPING_SGL_PINNED, /* sglist used with pinning */
};
/**
* struct dma_mapping - Information about memory mappings done by the driver
*/
struct dma_mapping {
enum dma_mapping_type type;
void *u_vaddr; /* user-space vaddr/non-aligned */
void *k_vaddr; /* kernel-space vaddr/non-aligned */
dma_addr_t dma_addr; /* physical DMA address */
struct page **page_list; /* list of pages used by user buff */
dma_addr_t *dma_list; /* list of dma addresses per page */
unsigned int nr_pages; /* number of pages */
unsigned int size; /* size in bytes */
struct list_head card_list; /* list of usr_maps for card */
struct list_head pin_list; /* list of pinned memory for dev */
};
static inline void genwqe_mapping_init(struct dma_mapping *m,
enum dma_mapping_type type)
{
memset(m, 0, sizeof(*m));
m->type = type;
}
/**
* struct ddcb_queue - DDCB queue data
* @ddcb_max: Number of DDCBs on the queue
* @ddcb_next: Next free DDCB
* @ddcb_act: Next DDCB supposed to finish
* @ddcb_seq: Sequence number of last DDCB
* @ddcbs_in_flight: Currently enqueued DDCBs
* @ddcbs_completed: Number of already completed DDCBs
* @return_on_busy: Number of -EBUSY returns on full queue
* @wait_on_busy: Number of waits on full queue
* @ddcb_daddr: DMA address of first DDCB in the queue
* @ddcb_vaddr: Kernel virtual address of first DDCB in the queue
* @ddcb_req: Associated requests (one per DDCB)
* @ddcb_waitqs: Associated wait queues (one per DDCB)
* @ddcb_lock: Lock to protect queuing operations
* @ddcb_waitq: Wait on next DDCB finishing
*/
struct ddcb_queue {
int ddcb_max; /* amount of DDCBs */
int ddcb_next; /* next available DDCB num */
int ddcb_act; /* DDCB to be processed */
u16 ddcb_seq; /* slc seq num */
unsigned int ddcbs_in_flight; /* number of ddcbs in processing */
unsigned int ddcbs_completed;
unsigned int ddcbs_max_in_flight;
unsigned int return_on_busy; /* how many times -EBUSY? */
unsigned int wait_on_busy;
dma_addr_t ddcb_daddr; /* DMA address */
struct ddcb *ddcb_vaddr; /* kernel virtual addr for DDCBs */
struct ddcb_requ **ddcb_req; /* ddcb processing parameter */
wait_queue_head_t *ddcb_waitqs; /* waitqueue per ddcb */
spinlock_t ddcb_lock; /* exclusive access to queue */
wait_queue_head_t busy_waitq; /* wait for ddcb processing */
/* registers or the respective queue to be used */
u32 IO_QUEUE_CONFIG;
u32 IO_QUEUE_STATUS;
u32 IO_QUEUE_SEGMENT;
u32 IO_QUEUE_INITSQN;
u32 IO_QUEUE_WRAP;
u32 IO_QUEUE_OFFSET;
u32 IO_QUEUE_WTIME;
u32 IO_QUEUE_ERRCNTS;
u32 IO_QUEUE_LRW;
};
/*
* GFIR, SLU_UNITCFG, APP_UNITCFG
* 8 Units with FIR/FEC + 64 * 2ndary FIRS/FEC.
*/
#define GENWQE_FFDC_REGS (3 + (8 * (2 + 2 * 64)))
struct genwqe_ffdc {
unsigned int entries;
struct genwqe_reg *regs;
};
/**
* struct genwqe_dev - GenWQE device information
* @card_state: Card operation state, see above
* @ffdc: First Failure Data Capture buffers for each unit
* @card_thread: Working thread to operate the DDCB queue
* @card_waitq: Wait queue used in card_thread
* @queue: DDCB queue
* @health_thread: Card monitoring thread (only for PFs)
* @health_waitq: Wait queue used in health_thread
* @pci_dev: Associated PCI device (function)
* @mmio: Base address of 64-bit register space
* @mmio_len: Length of register area
* @file_lock: Lock to protect access to file_list
* @file_list: List of all processes with open GenWQE file descriptors
*
* This struct contains all information needed to communicate with a
* GenWQE card. It is initialized when a GenWQE device is found and
* destroyed when it goes away. It holds data to maintain the queue as
* well as data needed to feed the user interfaces.
*/
struct genwqe_dev {
enum genwqe_card_state card_state;
spinlock_t print_lock;
int card_idx; /* card index 0..CARD_NO_MAX-1 */
u64 flags; /* general flags */
/* FFDC data gathering */
struct genwqe_ffdc ffdc[GENWQE_DBG_UNITS];
/* DDCB workqueue */
struct task_struct *card_thread;
wait_queue_head_t queue_waitq;
struct ddcb_queue queue; /* genwqe DDCB queue */
unsigned int irqs_processed;
/* Card health checking thread */
struct task_struct *health_thread;
wait_queue_head_t health_waitq;
int use_platform_recovery; /* use platform recovery mechanisms */
/* char device */
dev_t devnum_genwqe; /* major/minor num card */
struct class *class_genwqe; /* reference to class object */
struct device *dev; /* for device creation */
struct cdev cdev_genwqe; /* char device for card */
struct dentry *debugfs_root; /* debugfs card root directory */
struct dentry *debugfs_genwqe; /* debugfs driver root directory */
/* pci resources */
struct pci_dev *pci_dev; /* PCI device */
void __iomem *mmio; /* BAR-0 MMIO start */
unsigned long mmio_len;
int num_vfs;
u32 vf_jobtimeout_msec[GENWQE_MAX_VFS];
int is_privileged; /* access to all regs possible */
/* config regs which we need often */
u64 slu_unitcfg;
u64 app_unitcfg;
u64 softreset;
u64 err_inject;
u64 last_gfir;
char app_name[5];
spinlock_t file_lock; /* lock for open files */
struct list_head file_list; /* list of open files */
/* debugfs parameters */
int ddcb_software_timeout; /* wait until DDCB times out */
int skip_recovery; /* circumvention if recovery fails */
int kill_timeout; /* wait after sending SIGKILL */
};
/**
* enum genwqe_requ_state - State of a DDCB execution request
*/
enum genwqe_requ_state {
GENWQE_REQU_NEW = 0,
GENWQE_REQU_ENQUEUED = 1,
GENWQE_REQU_TAPPED = 2,
GENWQE_REQU_FINISHED = 3,
GENWQE_REQU_STATE_MAX,
};
/**
* struct genwqe_sgl - Scatter gather list describing user-space memory
* @sgl: scatter gather list needs to be 128 byte aligned
* @sgl_dma_addr: dma address of sgl
* @sgl_size: size of area used for sgl
* @user_addr: user-space address of memory area
* @user_size: size of user-space memory area
* @page: buffer for partial pages if needed
* @page_dma_addr: dma address partial pages
*/
struct genwqe_sgl {
dma_addr_t sgl_dma_addr;
struct sg_entry *sgl;
size_t sgl_size; /* size of sgl */
void __user *user_addr; /* user-space base-address */
size_t user_size; /* size of memory area */
unsigned long nr_pages;
unsigned long fpage_offs;
size_t fpage_size;
size_t lpage_size;
void *fpage;
dma_addr_t fpage_dma_addr;
void *lpage;
dma_addr_t lpage_dma_addr;
};
int genwqe_alloc_sync_sgl(struct genwqe_dev *cd, struct genwqe_sgl *sgl,
void __user *user_addr, size_t user_size);
int genwqe_setup_sgl(struct genwqe_dev *cd, struct genwqe_sgl *sgl,
dma_addr_t *dma_list);
int genwqe_free_sync_sgl(struct genwqe_dev *cd, struct genwqe_sgl *sgl);
/**
* struct ddcb_requ - Kernel internal representation of the DDCB request
* @cmd: User space representation of the DDCB execution request
*/
struct ddcb_requ {
/* kernel specific content */
enum genwqe_requ_state req_state; /* request status */
int num; /* ddcb_no for this request */
struct ddcb_queue *queue; /* associated queue */
struct dma_mapping dma_mappings[DDCB_FIXUPS];
struct genwqe_sgl sgls[DDCB_FIXUPS];
/* kernel/user shared content */
struct genwqe_ddcb_cmd cmd; /* ddcb_no for this request */
struct genwqe_debug_data debug_data;
};
/**
* struct genwqe_file - Information for open GenWQE devices
*/
struct genwqe_file {
struct genwqe_dev *cd;
struct genwqe_driver *client;
struct file *filp;
struct fasync_struct *async_queue;
struct task_struct *owner;
struct list_head list; /* entry in list of open files */
spinlock_t map_lock; /* lock for dma_mappings */
struct list_head map_list; /* list of dma_mappings */
spinlock_t pin_lock; /* lock for pinned memory */
struct list_head pin_list; /* list of pinned memory */
};
int genwqe_setup_service_layer(struct genwqe_dev *cd); /* for PF only */
int genwqe_finish_queue(struct genwqe_dev *cd);
int genwqe_release_service_layer(struct genwqe_dev *cd);
/**
* genwqe_get_slu_id() - Read Service Layer Unit Id
* Return: 0x00: Development code
* 0x01: SLC1 (old)
* 0x02: SLC2 (sept2012)
* 0x03: SLC2 (feb2013, generic driver)
*/
static inline int genwqe_get_slu_id(struct genwqe_dev *cd)
{
return (int)((cd->slu_unitcfg >> 32) & 0xff);
}
int genwqe_ddcbs_in_flight(struct genwqe_dev *cd);
u8 genwqe_card_type(struct genwqe_dev *cd);
int genwqe_card_reset(struct genwqe_dev *cd);
int genwqe_set_interrupt_capability(struct genwqe_dev *cd, int count);
void genwqe_reset_interrupt_capability(struct genwqe_dev *cd);
int genwqe_device_create(struct genwqe_dev *cd);
int genwqe_device_remove(struct genwqe_dev *cd);
/* debugfs */
int genwqe_init_debugfs(struct genwqe_dev *cd);
void genqwe_exit_debugfs(struct genwqe_dev *cd);
int genwqe_read_softreset(struct genwqe_dev *cd);
/* Hardware Circumventions */
int genwqe_recovery_on_fatal_gfir_required(struct genwqe_dev *cd);
int genwqe_flash_readback_fails(struct genwqe_dev *cd);
/**
* genwqe_write_vreg() - Write register in VF window
* @cd: genwqe device
* @reg: register address
* @val: value to write
* @func: 0: PF, 1: VF0, ..., 15: VF14
*/
int genwqe_write_vreg(struct genwqe_dev *cd, u32 reg, u64 val, int func);
/**
* genwqe_read_vreg() - Read register in VF window
* @cd: genwqe device
* @reg: register address
* @func: 0: PF, 1: VF0, ..., 15: VF14
*
* Return: content of the register
*/
u64 genwqe_read_vreg(struct genwqe_dev *cd, u32 reg, int func);
/* FFDC Buffer Management */
int genwqe_ffdc_buff_size(struct genwqe_dev *cd, int unit_id);
int genwqe_ffdc_buff_read(struct genwqe_dev *cd, int unit_id,
struct genwqe_reg *regs, unsigned int max_regs);
int genwqe_read_ffdc_regs(struct genwqe_dev *cd, struct genwqe_reg *regs,
unsigned int max_regs, int all);
int genwqe_ffdc_dump_dma(struct genwqe_dev *cd,
struct genwqe_reg *regs, unsigned int max_regs);
int genwqe_init_debug_data(struct genwqe_dev *cd,
struct genwqe_debug_data *d);
void genwqe_init_crc32(void);
int genwqe_read_app_id(struct genwqe_dev *cd, char *app_name, int len);
/* Memory allocation/deallocation; dma address handling */
int genwqe_user_vmap(struct genwqe_dev *cd, struct dma_mapping *m,
void *uaddr, unsigned long size,
struct ddcb_requ *req);
int genwqe_user_vunmap(struct genwqe_dev *cd, struct dma_mapping *m,
struct ddcb_requ *req);
static inline bool dma_mapping_used(struct dma_mapping *m)
{
if (!m)
return 0;
return m->size != 0;
}
/**
* __genwqe_execute_ddcb() - Execute DDCB request with addr translation
*
* This function will do the address translation changes to the DDCBs
* according to the definitions required by the ATS field. It looks up
* the memory allocation buffer or does vmap/vunmap for the respective
* user-space buffers, inclusive page pinning and scatter gather list
* buildup and teardown.
*/
int __genwqe_execute_ddcb(struct genwqe_dev *cd,
struct genwqe_ddcb_cmd *cmd, unsigned int f_flags);
/**
* __genwqe_execute_raw_ddcb() - Execute DDCB request without addr translation
*
* This version will not do address translation or any modification of
* the DDCB data. It is used e.g. for the MoveFlash DDCB which is
* entirely prepared by the driver itself. That means the appropriate
* DMA addresses are already in the DDCB and do not need any
* modification.
*/
int __genwqe_execute_raw_ddcb(struct genwqe_dev *cd,
struct genwqe_ddcb_cmd *cmd,
unsigned int f_flags);
int __genwqe_enqueue_ddcb(struct genwqe_dev *cd,
struct ddcb_requ *req,
unsigned int f_flags);
int __genwqe_wait_ddcb(struct genwqe_dev *cd, struct ddcb_requ *req);
int __genwqe_purge_ddcb(struct genwqe_dev *cd, struct ddcb_requ *req);
/* register access */
int __genwqe_writeq(struct genwqe_dev *cd, u64 byte_offs, u64 val);
u64 __genwqe_readq(struct genwqe_dev *cd, u64 byte_offs);
int __genwqe_writel(struct genwqe_dev *cd, u64 byte_offs, u32 val);
u32 __genwqe_readl(struct genwqe_dev *cd, u64 byte_offs);
void *__genwqe_alloc_consistent(struct genwqe_dev *cd, size_t size,
dma_addr_t *dma_handle);
void __genwqe_free_consistent(struct genwqe_dev *cd, size_t size,
void *vaddr, dma_addr_t dma_handle);
/* Base clock frequency in MHz */
int genwqe_base_clock_frequency(struct genwqe_dev *cd);
/* Before FFDC is captured the traps should be stopped. */
void genwqe_stop_traps(struct genwqe_dev *cd);
void genwqe_start_traps(struct genwqe_dev *cd);
/* Hardware circumvention */
bool genwqe_need_err_masking(struct genwqe_dev *cd);
/**
* genwqe_is_privileged() - Determine operation mode for PCI function
*
* On Intel with SRIOV support we see:
* PF: is_physfn = 1 is_virtfn = 0
* VF: is_physfn = 0 is_virtfn = 1
*
* On Systems with no SRIOV support _and_ virtualized systems we get:
* is_physfn = 0 is_virtfn = 0
*
* Other vendors have individual pci device ids to distinguish between
* virtual function drivers and physical function drivers. GenWQE
* unfortunately has just on pci device id for both, VFs and PF.
*
* The following code is used to distinguish if the card is running in
* privileged mode, either as true PF or in a virtualized system with
* full register access e.g. currently on PowerPC.
*
* if (pci_dev->is_virtfn)
* cd->is_privileged = 0;
* else
* cd->is_privileged = (__genwqe_readq(cd, IO_SLU_BITSTREAM)
* != IO_ILLEGAL_VALUE);
*/
static inline int genwqe_is_privileged(struct genwqe_dev *cd)
{
return cd->is_privileged;
}
#endif /* __CARD_BASE_H__ */
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