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kernel/include/linux/phy.h
Maciej W. Rozycki 0ac4952731 PHYLIB: IRQ event workqueue handling fixes 
Keep track of disable_irq_nosync() invocations and call enable_irq() the
right number of times if work has been cancelled that would include them.

Now that the call to flush_work_keventd() (problematic because of
rtnl_mutex being held) has been replaced by cancel_work_sync() another
issue has arisen and been left unresolved.  As the MDIO bus cannot be
accessed from the interrupt context the PHY interrupt handler uses
disable_irq_nosync() to prevent from looping and schedules some work to be
done as a softirq, which, apart from handling the state change of the
originating PHY, is responsible for reenabling the interrupt.  Now if the
interrupt line is shared by another device and a call to the softirq
handler has been cancelled, that call to enable_irq() never happens and the
other device cannot use its interrupt anymore as its stuck disabled.

I decided to use a counter rather than a flag because there may be more
than one call to phy_change() cancelled in the queue -- a real one and a
fake one triggered by free_irq() if DEBUG_SHIRQ is used, if nothing else.
Therefore because of its nesting property enable_irq() has to be called the
right number of times to match the number disable_irq_nosync() was called
and restore the original state.  This DEBUG_SHIRQ feature is also the
reason why free_irq() has to be called before cancel_work_sync().

While at it I updated the comment about phy_stop_interrupts() being called
from `keventd' -- this is no longer relevant as the use of
cancel_work_sync() makes such an approach unnecessary.  OTOH a similar
comment referring to flush_scheduled_work() in phy_stop() still applies as
using cancel_work_sync() there would be dangerous.

Checked with checkpatch.pl and at the run time (with and without
DEBUG_SHIRQ).

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Andy Fleming <afleming@freescale.com>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-10-10 16:53:55 -07:00

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/*
* include/linux/phy.h
*
* Framework and drivers for configuring and reading different PHYs
* Based on code in sungem_phy.c and gianfar_phy.c
*
* Author: Andy Fleming
*
* Copyright (c) 2004 Freescale Semiconductor, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
*/
#ifndef __PHY_H
#define __PHY_H
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/ethtool.h>
#include <linux/mii.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <asm/atomic.h>
#define PHY_BASIC_FEATURES (SUPPORTED_10baseT_Half | \
SUPPORTED_10baseT_Full | \
SUPPORTED_100baseT_Half | \
SUPPORTED_100baseT_Full | \
SUPPORTED_Autoneg | \
SUPPORTED_TP | \
SUPPORTED_MII)
#define PHY_GBIT_FEATURES (PHY_BASIC_FEATURES | \
SUPPORTED_1000baseT_Half | \
SUPPORTED_1000baseT_Full)
/* Set phydev->irq to PHY_POLL if interrupts are not supported,
* or not desired for this PHY. Set to PHY_IGNORE_INTERRUPT if
* the attached driver handles the interrupt
*/
#define PHY_POLL -1
#define PHY_IGNORE_INTERRUPT -2
#define PHY_HAS_INTERRUPT 0x00000001
#define PHY_HAS_MAGICANEG 0x00000002
/* Interface Mode definitions */
typedef enum {
PHY_INTERFACE_MODE_MII,
PHY_INTERFACE_MODE_GMII,
PHY_INTERFACE_MODE_SGMII,
PHY_INTERFACE_MODE_TBI,
PHY_INTERFACE_MODE_RMII,
PHY_INTERFACE_MODE_RGMII,
PHY_INTERFACE_MODE_RGMII_ID,
PHY_INTERFACE_MODE_RTBI
} phy_interface_t;
#define MII_BUS_MAX 4
#define PHY_INIT_TIMEOUT 100000
#define PHY_STATE_TIME 1
#define PHY_FORCE_TIMEOUT 10
#define PHY_AN_TIMEOUT 10
#define PHY_MAX_ADDR 32
/* Used when trying to connect to a specific phy (mii bus id:phy device id) */
#define PHY_ID_FMT "%x:%02x"
/* The Bus class for PHYs. Devices which provide access to
* PHYs should register using this structure */
struct mii_bus {
const char *name;
int id;
void *priv;
int (*read)(struct mii_bus *bus, int phy_id, int regnum);
int (*write)(struct mii_bus *bus, int phy_id, int regnum, u16 val);
int (*reset)(struct mii_bus *bus);
/* A lock to ensure that only one thing can read/write
* the MDIO bus at a time */
spinlock_t mdio_lock;
struct device *dev;
/* list of all PHYs on bus */
struct phy_device *phy_map[PHY_MAX_ADDR];
/* Phy addresses to be ignored when probing */
u32 phy_mask;
/* Pointer to an array of interrupts, each PHY's
* interrupt at the index matching its address */
int *irq;
};
#define PHY_INTERRUPT_DISABLED 0x0
#define PHY_INTERRUPT_ENABLED 0x80000000
/* PHY state machine states:
*
* DOWN: PHY device and driver are not ready for anything. probe
* should be called if and only if the PHY is in this state,
* given that the PHY device exists.
* - PHY driver probe function will, depending on the PHY, set
* the state to STARTING or READY
*
* STARTING: PHY device is coming up, and the ethernet driver is
* not ready. PHY drivers may set this in the probe function.
* If they do, they are responsible for making sure the state is
* eventually set to indicate whether the PHY is UP or READY,
* depending on the state when the PHY is done starting up.
* - PHY driver will set the state to READY
* - start will set the state to PENDING
*
* READY: PHY is ready to send and receive packets, but the
* controller is not. By default, PHYs which do not implement
* probe will be set to this state by phy_probe(). If the PHY
* driver knows the PHY is ready, and the PHY state is STARTING,
* then it sets this STATE.
* - start will set the state to UP
*
* PENDING: PHY device is coming up, but the ethernet driver is
* ready. phy_start will set this state if the PHY state is
* STARTING.
* - PHY driver will set the state to UP when the PHY is ready
*
* UP: The PHY and attached device are ready to do work.
* Interrupts should be started here.
* - timer moves to AN
*
* AN: The PHY is currently negotiating the link state. Link is
* therefore down for now. phy_timer will set this state when it
* detects the state is UP. config_aneg will set this state
* whenever called with phydev->autoneg set to AUTONEG_ENABLE.
* - If autonegotiation finishes, but there's no link, it sets
* the state to NOLINK.
* - If aneg finishes with link, it sets the state to RUNNING,
* and calls adjust_link
* - If autonegotiation did not finish after an arbitrary amount
* of time, autonegotiation should be tried again if the PHY
* supports "magic" autonegotiation (back to AN)
* - If it didn't finish, and no magic_aneg, move to FORCING.
*
* NOLINK: PHY is up, but not currently plugged in.
* - If the timer notes that the link comes back, we move to RUNNING
* - config_aneg moves to AN
* - phy_stop moves to HALTED
*
* FORCING: PHY is being configured with forced settings
* - if link is up, move to RUNNING
* - If link is down, we drop to the next highest setting, and
* retry (FORCING) after a timeout
* - phy_stop moves to HALTED
*
* RUNNING: PHY is currently up, running, and possibly sending
* and/or receiving packets
* - timer will set CHANGELINK if we're polling (this ensures the
* link state is polled every other cycle of this state machine,
* which makes it every other second)
* - irq will set CHANGELINK
* - config_aneg will set AN
* - phy_stop moves to HALTED
*
* CHANGELINK: PHY experienced a change in link state
* - timer moves to RUNNING if link
* - timer moves to NOLINK if the link is down
* - phy_stop moves to HALTED
*
* HALTED: PHY is up, but no polling or interrupts are done. Or
* PHY is in an error state.
*
* - phy_start moves to RESUMING
*
* RESUMING: PHY was halted, but now wants to run again.
* - If we are forcing, or aneg is done, timer moves to RUNNING
* - If aneg is not done, timer moves to AN
* - phy_stop moves to HALTED
*/
enum phy_state {
PHY_DOWN=0,
PHY_STARTING,
PHY_READY,
PHY_PENDING,
PHY_UP,
PHY_AN,
PHY_RUNNING,
PHY_NOLINK,
PHY_FORCING,
PHY_CHANGELINK,
PHY_HALTED,
PHY_RESUMING
};
/* phy_device: An instance of a PHY
*
* drv: Pointer to the driver for this PHY instance
* bus: Pointer to the bus this PHY is on
* dev: driver model device structure for this PHY
* phy_id: UID for this device found during discovery
* state: state of the PHY for management purposes
* dev_flags: Device-specific flags used by the PHY driver.
* addr: Bus address of PHY
* link_timeout: The number of timer firings to wait before the
* giving up on the current attempt at acquiring a link
* irq: IRQ number of the PHY's interrupt (-1 if none)
* phy_timer: The timer for handling the state machine
* phy_queue: A work_queue for the interrupt
* attached_dev: The attached enet driver's device instance ptr
* adjust_link: Callback for the enet controller to respond to
* changes in the link state.
* adjust_state: Callback for the enet driver to respond to
* changes in the state machine.
*
* speed, duplex, pause, supported, advertising, and
* autoneg are used like in mii_if_info
*
* interrupts currently only supports enabled or disabled,
* but could be changed in the future to support enabling
* and disabling specific interrupts
*
* Contains some infrastructure for polling and interrupt
* handling, as well as handling shifts in PHY hardware state
*/
struct phy_device {
/* Information about the PHY type */
/* And management functions */
struct phy_driver *drv;
struct mii_bus *bus;
struct device dev;
u32 phy_id;
enum phy_state state;
u32 dev_flags;
phy_interface_t interface;
/* Bus address of the PHY (0-32) */
int addr;
/* forced speed & duplex (no autoneg)
* partner speed & duplex & pause (autoneg)
*/
int speed;
int duplex;
int pause;
int asym_pause;
/* The most recently read link state */
int link;
/* Enabled Interrupts */
u32 interrupts;
/* Union of PHY and Attached devices' supported modes */
/* See mii.h for more info */
u32 supported;
u32 advertising;
int autoneg;
int link_timeout;
/* Interrupt number for this PHY
* -1 means no interrupt */
int irq;
/* private data pointer */
/* For use by PHYs to maintain extra state */
void *priv;
/* Interrupt and Polling infrastructure */
struct work_struct phy_queue;
struct timer_list phy_timer;
atomic_t irq_disable;
spinlock_t lock;
struct net_device *attached_dev;
void (*adjust_link)(struct net_device *dev);
void (*adjust_state)(struct net_device *dev);
};
#define to_phy_device(d) container_of(d, struct phy_device, dev)
/* struct phy_driver: Driver structure for a particular PHY type
*
* phy_id: The result of reading the UID registers of this PHY
* type, and ANDing them with the phy_id_mask. This driver
* only works for PHYs with IDs which match this field
* name: The friendly name of this PHY type
* phy_id_mask: Defines the important bits of the phy_id
* features: A list of features (speed, duplex, etc) supported
* by this PHY
* flags: A bitfield defining certain other features this PHY
* supports (like interrupts)
*
* The drivers must implement config_aneg and read_status. All
* other functions are optional. Note that none of these
* functions should be called from interrupt time. The goal is
* for the bus read/write functions to be able to block when the
* bus transaction is happening, and be freed up by an interrupt
* (The MPC85xx has this ability, though it is not currently
* supported in the driver).
*/
struct phy_driver {
u32 phy_id;
char *name;
unsigned int phy_id_mask;
u32 features;
u32 flags;
/* Called to initialize the PHY,
* including after a reset */
int (*config_init)(struct phy_device *phydev);
/* Called during discovery. Used to set
* up device-specific structures, if any */
int (*probe)(struct phy_device *phydev);
/* PHY Power Management */
int (*suspend)(struct phy_device *phydev);
int (*resume)(struct phy_device *phydev);
/* Configures the advertisement and resets
* autonegotiation if phydev->autoneg is on,
* forces the speed to the current settings in phydev
* if phydev->autoneg is off */
int (*config_aneg)(struct phy_device *phydev);
/* Determines the negotiated speed and duplex */
int (*read_status)(struct phy_device *phydev);
/* Clears any pending interrupts */
int (*ack_interrupt)(struct phy_device *phydev);
/* Enables or disables interrupts */
int (*config_intr)(struct phy_device *phydev);
/* Clears up any memory if needed */
void (*remove)(struct phy_device *phydev);
struct device_driver driver;
};
#define to_phy_driver(d) container_of(d, struct phy_driver, driver)
int phy_read(struct phy_device *phydev, u16 regnum);
int phy_write(struct phy_device *phydev, u16 regnum, u16 val);
struct phy_device* get_phy_device(struct mii_bus *bus, int addr);
int phy_clear_interrupt(struct phy_device *phydev);
int phy_config_interrupt(struct phy_device *phydev, u32 interrupts);
struct phy_device * phy_attach(struct net_device *dev,
const char *phy_id, u32 flags, phy_interface_t interface);
struct phy_device * phy_connect(struct net_device *dev, const char *phy_id,
void (*handler)(struct net_device *), u32 flags,
phy_interface_t interface);
void phy_disconnect(struct phy_device *phydev);
void phy_detach(struct phy_device *phydev);
void phy_start(struct phy_device *phydev);
void phy_stop(struct phy_device *phydev);
int phy_start_aneg(struct phy_device *phydev);
int mdiobus_register(struct mii_bus *bus);
void mdiobus_unregister(struct mii_bus *bus);
void phy_sanitize_settings(struct phy_device *phydev);
int phy_stop_interrupts(struct phy_device *phydev);
static inline int phy_read_status(struct phy_device *phydev) {
return phydev->drv->read_status(phydev);
}
int genphy_config_advert(struct phy_device *phydev);
int genphy_setup_forced(struct phy_device *phydev);
int genphy_restart_aneg(struct phy_device *phydev);
int genphy_config_aneg(struct phy_device *phydev);
int genphy_update_link(struct phy_device *phydev);
int genphy_read_status(struct phy_device *phydev);
void phy_driver_unregister(struct phy_driver *drv);
int phy_driver_register(struct phy_driver *new_driver);
void phy_prepare_link(struct phy_device *phydev,
void (*adjust_link)(struct net_device *));
void phy_start_machine(struct phy_device *phydev,
void (*handler)(struct net_device *));
void phy_stop_machine(struct phy_device *phydev);
int phy_ethtool_sset(struct phy_device *phydev, struct ethtool_cmd *cmd);
int phy_ethtool_gset(struct phy_device *phydev, struct ethtool_cmd *cmd);
int phy_mii_ioctl(struct phy_device *phydev,
struct mii_ioctl_data *mii_data, int cmd);
int phy_start_interrupts(struct phy_device *phydev);
void phy_print_status(struct phy_device *phydev);
struct phy_device* phy_device_create(struct mii_bus *bus, int addr, int phy_id);
extern struct bus_type mdio_bus_type;
#endif /* __PHY_H */
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