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linux/drivers/usb/host/uhci-hcd.h
Alan Stern 17230acdc7 UHCI: Eliminate asynchronous skeleton Queue Headers 
This patch (as856) attempts to improve the performance of uhci-hcd by
removing the asynchronous skeleton Queue Headers.  They don't contain
any useful information but the controller has to read through them at
least once every millisecond, incurring a non-zero DMA overhead.

Now all the asynchronous queues are combined, along with the period-1
interrupt queue, into a single list with a single skeleton QH.  The
start of the low-speed control, full-speed control, and bulk sublists
is determined by linear search.  Since there should rarely be more
than a couple of QHs in the list, the searches should incur a much
smaller total load than keeping the skeleton QHs.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-23 15:03:45 -08:00

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#ifndef __LINUX_UHCI_HCD_H
#define __LINUX_UHCI_HCD_H
#include <linux/list.h>
#include <linux/usb.h>
#define usb_packetid(pipe) (usb_pipein(pipe) ? USB_PID_IN : USB_PID_OUT)
#define PIPE_DEVEP_MASK 0x0007ff00
/*
* Universal Host Controller Interface data structures and defines
*/
/* Command register */
#define USBCMD 0
#define USBCMD_RS 0x0001 /* Run/Stop */
#define USBCMD_HCRESET 0x0002 /* Host reset */
#define USBCMD_GRESET 0x0004 /* Global reset */
#define USBCMD_EGSM 0x0008 /* Global Suspend Mode */
#define USBCMD_FGR 0x0010 /* Force Global Resume */
#define USBCMD_SWDBG 0x0020 /* SW Debug mode */
#define USBCMD_CF 0x0040 /* Config Flag (sw only) */
#define USBCMD_MAXP 0x0080 /* Max Packet (0 = 32, 1 = 64) */
/* Status register */
#define USBSTS 2
#define USBSTS_USBINT 0x0001 /* Interrupt due to IOC */
#define USBSTS_ERROR 0x0002 /* Interrupt due to error */
#define USBSTS_RD 0x0004 /* Resume Detect */
#define USBSTS_HSE 0x0008 /* Host System Error: PCI problems */
#define USBSTS_HCPE 0x0010 /* Host Controller Process Error:
* the schedule is buggy */
#define USBSTS_HCH 0x0020 /* HC Halted */
/* Interrupt enable register */
#define USBINTR 4
#define USBINTR_TIMEOUT 0x0001 /* Timeout/CRC error enable */
#define USBINTR_RESUME 0x0002 /* Resume interrupt enable */
#define USBINTR_IOC 0x0004 /* Interrupt On Complete enable */
#define USBINTR_SP 0x0008 /* Short packet interrupt enable */
#define USBFRNUM 6
#define USBFLBASEADD 8
#define USBSOF 12
#define USBSOF_DEFAULT 64 /* Frame length is exactly 1 ms */
/* USB port status and control registers */
#define USBPORTSC1 16
#define USBPORTSC2 18
#define USBPORTSC_CCS 0x0001 /* Current Connect Status
* ("device present") */
#define USBPORTSC_CSC 0x0002 /* Connect Status Change */
#define USBPORTSC_PE 0x0004 /* Port Enable */
#define USBPORTSC_PEC 0x0008 /* Port Enable Change */
#define USBPORTSC_DPLUS 0x0010 /* D+ high (line status) */
#define USBPORTSC_DMINUS 0x0020 /* D- high (line status) */
#define USBPORTSC_RD 0x0040 /* Resume Detect */
#define USBPORTSC_RES1 0x0080 /* reserved, always 1 */
#define USBPORTSC_LSDA 0x0100 /* Low Speed Device Attached */
#define USBPORTSC_PR 0x0200 /* Port Reset */
/* OC and OCC from Intel 430TX and later (not UHCI 1.1d spec) */
#define USBPORTSC_OC 0x0400 /* Over Current condition */
#define USBPORTSC_OCC 0x0800 /* Over Current Change R/WC */
#define USBPORTSC_SUSP 0x1000 /* Suspend */
#define USBPORTSC_RES2 0x2000 /* reserved, write zeroes */
#define USBPORTSC_RES3 0x4000 /* reserved, write zeroes */
#define USBPORTSC_RES4 0x8000 /* reserved, write zeroes */
/* Legacy support register */
#define USBLEGSUP 0xc0
#define USBLEGSUP_DEFAULT 0x2000 /* only PIRQ enable set */
#define USBLEGSUP_RWC 0x8f00 /* the R/WC bits */
#define USBLEGSUP_RO 0x5040 /* R/O and reserved bits */
#define UHCI_PTR_BITS __constant_cpu_to_le32(0x000F)
#define UHCI_PTR_TERM __constant_cpu_to_le32(0x0001)
#define UHCI_PTR_QH __constant_cpu_to_le32(0x0002)
#define UHCI_PTR_DEPTH __constant_cpu_to_le32(0x0004)
#define UHCI_PTR_BREADTH __constant_cpu_to_le32(0x0000)
#define UHCI_NUMFRAMES 1024 /* in the frame list [array] */
#define UHCI_MAX_SOF_NUMBER 2047 /* in an SOF packet */
#define CAN_SCHEDULE_FRAMES 1000 /* how far in the future frames
* can be scheduled */
#define MAX_PHASE 32 /* Periodic scheduling length */
/* When no queues need Full-Speed Bandwidth Reclamation,
* delay this long before turning FSBR off */
#define FSBR_OFF_DELAY msecs_to_jiffies(10)
/* If a queue hasn't advanced after this much time, assume it is stuck */
#define QH_WAIT_TIMEOUT msecs_to_jiffies(200)
/*
* Queue Headers
*/
/*
* One role of a QH is to hold a queue of TDs for some endpoint. One QH goes
* with each endpoint, and qh->element (updated by the HC) is either:
* - the next unprocessed TD in the endpoint's queue, or
* - UHCI_PTR_TERM (when there's no more traffic for this endpoint).
*
* The other role of a QH is to serve as a "skeleton" framelist entry, so we
* can easily splice a QH for some endpoint into the schedule at the right
* place. Then qh->element is UHCI_PTR_TERM.
*
* In the schedule, qh->link maintains a list of QHs seen by the HC:
* skel1 --> ep1-qh --> ep2-qh --> ... --> skel2 --> ...
*
* qh->node is the software equivalent of qh->link. The differences
* are that the software list is doubly-linked and QHs in the UNLINKING
* state are on the software list but not the hardware schedule.
*
* For bookkeeping purposes we maintain QHs even for Isochronous endpoints,
* but they never get added to the hardware schedule.
*/
#define QH_STATE_IDLE 1 /* QH is not being used */
#define QH_STATE_UNLINKING 2 /* QH has been removed from the
* schedule but the hardware may
* still be using it */
#define QH_STATE_ACTIVE 3 /* QH is on the schedule */
struct uhci_qh {
/* Hardware fields */
__le32 link; /* Next QH in the schedule */
__le32 element; /* Queue element (TD) pointer */
/* Software fields */
dma_addr_t dma_handle;
struct list_head node; /* Node in the list of QHs */
struct usb_host_endpoint *hep; /* Endpoint information */
struct usb_device *udev;
struct list_head queue; /* Queue of urbps for this QH */
struct uhci_td *dummy_td; /* Dummy TD to end the queue */
struct uhci_td *post_td; /* Last TD completed */
struct usb_iso_packet_descriptor *iso_packet_desc;
/* Next urb->iso_frame_desc entry */
unsigned long advance_jiffies; /* Time of last queue advance */
unsigned int unlink_frame; /* When the QH was unlinked */
unsigned int period; /* For Interrupt and Isochronous QHs */
short phase; /* Between 0 and period-1 */
short load; /* Periodic time requirement, in us */
unsigned int iso_frame; /* Frame # for iso_packet_desc */
int iso_status; /* Status for Isochronous URBs */
int state; /* QH_STATE_xxx; see above */
int type; /* Queue type (control, bulk, etc) */
int skel; /* Skeleton queue number */
unsigned int initial_toggle:1; /* Endpoint's current toggle value */
unsigned int needs_fixup:1; /* Must fix the TD toggle values */
unsigned int is_stopped:1; /* Queue was stopped by error/unlink */
unsigned int wait_expired:1; /* QH_WAIT_TIMEOUT has expired */
unsigned int bandwidth_reserved:1; /* Periodic bandwidth has
* been allocated */
} __attribute__((aligned(16)));
/*
* We need a special accessor for the element pointer because it is
* subject to asynchronous updates by the controller.
*/
static inline __le32 qh_element(struct uhci_qh *qh) {
__le32 element = qh->element;
barrier();
return element;
}
#define LINK_TO_QH(qh) (UHCI_PTR_QH | cpu_to_le32((qh)->dma_handle))
/*
* Transfer Descriptors
*/
/*
* for TD <status>:
*/
#define TD_CTRL_SPD (1 << 29) /* Short Packet Detect */
#define TD_CTRL_C_ERR_MASK (3 << 27) /* Error Counter bits */
#define TD_CTRL_C_ERR_SHIFT 27
#define TD_CTRL_LS (1 << 26) /* Low Speed Device */
#define TD_CTRL_IOS (1 << 25) /* Isochronous Select */
#define TD_CTRL_IOC (1 << 24) /* Interrupt on Complete */
#define TD_CTRL_ACTIVE (1 << 23) /* TD Active */
#define TD_CTRL_STALLED (1 << 22) /* TD Stalled */
#define TD_CTRL_DBUFERR (1 << 21) /* Data Buffer Error */
#define TD_CTRL_BABBLE (1 << 20) /* Babble Detected */
#define TD_CTRL_NAK (1 << 19) /* NAK Received */
#define TD_CTRL_CRCTIMEO (1 << 18) /* CRC/Time Out Error */
#define TD_CTRL_BITSTUFF (1 << 17) /* Bit Stuff Error */
#define TD_CTRL_ACTLEN_MASK 0x7FF /* actual length, encoded as n - 1 */
#define TD_CTRL_ANY_ERROR (TD_CTRL_STALLED | TD_CTRL_DBUFERR | \
TD_CTRL_BABBLE | TD_CTRL_CRCTIME | \
TD_CTRL_BITSTUFF)
#define uhci_maxerr(err) ((err) << TD_CTRL_C_ERR_SHIFT)
#define uhci_status_bits(ctrl_sts) ((ctrl_sts) & 0xF60000)
#define uhci_actual_length(ctrl_sts) (((ctrl_sts) + 1) & \
TD_CTRL_ACTLEN_MASK) /* 1-based */
/*
* for TD <info>: (a.k.a. Token)
*/
#define td_token(td) le32_to_cpu((td)->token)
#define TD_TOKEN_DEVADDR_SHIFT 8
#define TD_TOKEN_TOGGLE_SHIFT 19
#define TD_TOKEN_TOGGLE (1 << 19)
#define TD_TOKEN_EXPLEN_SHIFT 21
#define TD_TOKEN_EXPLEN_MASK 0x7FF /* expected length, encoded as n-1 */
#define TD_TOKEN_PID_MASK 0xFF
#define uhci_explen(len) ((((len) - 1) & TD_TOKEN_EXPLEN_MASK) << \
TD_TOKEN_EXPLEN_SHIFT)
#define uhci_expected_length(token) ((((token) >> TD_TOKEN_EXPLEN_SHIFT) + \
1) & TD_TOKEN_EXPLEN_MASK)
#define uhci_toggle(token) (((token) >> TD_TOKEN_TOGGLE_SHIFT) & 1)
#define uhci_endpoint(token) (((token) >> 15) & 0xf)
#define uhci_devaddr(token) (((token) >> TD_TOKEN_DEVADDR_SHIFT) & 0x7f)
#define uhci_devep(token) (((token) >> TD_TOKEN_DEVADDR_SHIFT) & 0x7ff)
#define uhci_packetid(token) ((token) & TD_TOKEN_PID_MASK)
#define uhci_packetout(token) (uhci_packetid(token) != USB_PID_IN)
#define uhci_packetin(token) (uhci_packetid(token) == USB_PID_IN)
/*
* The documentation says "4 words for hardware, 4 words for software".
*
* That's silly, the hardware doesn't care. The hardware only cares that
* the hardware words are 16-byte aligned, and we can have any amount of
* sw space after the TD entry.
*
* td->link points to either another TD (not necessarily for the same urb or
* even the same endpoint), or nothing (PTR_TERM), or a QH.
*/
struct uhci_td {
/* Hardware fields */
__le32 link;
__le32 status;
__le32 token;
__le32 buffer;
/* Software fields */
dma_addr_t dma_handle;
struct list_head list;
int frame; /* for iso: what frame? */
struct list_head fl_list;
} __attribute__((aligned(16)));
/*
* We need a special accessor for the control/status word because it is
* subject to asynchronous updates by the controller.
*/
static inline u32 td_status(struct uhci_td *td) {
__le32 status = td->status;
barrier();
return le32_to_cpu(status);
}
#define LINK_TO_TD(td) (cpu_to_le32((td)->dma_handle))
/*
* Skeleton Queue Headers
*/
/*
* The UHCI driver uses QHs with Interrupt, Control and Bulk URBs for
* automatic queuing. To make it easy to insert entries into the schedule,
* we have a skeleton of QHs for each predefined Interrupt latency.
* Asynchronous QHs (low-speed control, full-speed control, and bulk)
* go onto the period-1 interrupt list, since they all get accessed on
* every frame.
*
* When we want to add a new QH, we add it to the list starting from the
* appropriate skeleton QH. For instance, the schedule can look like this:
*
* skel int128 QH
* dev 1 interrupt QH
* dev 5 interrupt QH
* skel int64 QH
* skel int32 QH
* ...
* skel int1 + async QH
* dev 5 low-speed control QH
* dev 1 bulk QH
* dev 2 bulk QH
*
* There is a special terminating QH used to keep full-speed bandwidth
* reclamation active when no full-speed control or bulk QHs are linked
* into the schedule. It has an inactive TD (to work around a PIIX bug,
* see the Intel errata) and it points back to itself.
*
* There's a special skeleton QH for Isochronous QHs which never appears
* on the schedule. Isochronous TDs go on the schedule before the
* the skeleton QHs. The hardware accesses them directly rather than
* through their QH, which is used only for bookkeeping purposes.
* While the UHCI spec doesn't forbid the use of QHs for Isochronous,
* it doesn't use them either. And the spec says that queues never
* advance on an error completion status, which makes them totally
* unsuitable for Isochronous transfers.
*
* There's also a special skeleton QH used for QHs which are in the process
* of unlinking and so may still be in use by the hardware. It too never
* appears on the schedule.
*/
#define UHCI_NUM_SKELQH 11
#define SKEL_UNLINK 0
#define skel_unlink_qh skelqh[SKEL_UNLINK]
#define SKEL_ISO 1
#define skel_iso_qh skelqh[SKEL_ISO]
/* int128, int64, ..., int1 = 2, 3, ..., 9 */
#define SKEL_INDEX(exponent) (9 - exponent)
#define SKEL_ASYNC 9
#define skel_async_qh skelqh[SKEL_ASYNC]
#define SKEL_TERM 10
#define skel_term_qh skelqh[SKEL_TERM]
/* The following entries refer to sublists of skel_async_qh */
#define SKEL_LS_CONTROL 20
#define SKEL_FS_CONTROL 21
#define SKEL_FSBR SKEL_FS_CONTROL
#define SKEL_BULK 22
/*
* The UHCI controller and root hub
*/
/*
* States for the root hub:
*
* To prevent "bouncing" in the presence of electrical noise,
* when there are no devices attached we delay for 1 second in the
* RUNNING_NODEVS state before switching to the AUTO_STOPPED state.
*
* (Note that the AUTO_STOPPED state won't be necessary once the hub
* driver learns to autosuspend.)
*/
enum uhci_rh_state {
/* In the following states the HC must be halted.
* These two must come first. */
UHCI_RH_RESET,
UHCI_RH_SUSPENDED,
UHCI_RH_AUTO_STOPPED,
UHCI_RH_RESUMING,
/* In this state the HC changes from running to halted,
* so it can legally appear either way. */
UHCI_RH_SUSPENDING,
/* In the following states it's an error if the HC is halted.
* These two must come last. */
UHCI_RH_RUNNING, /* The normal state */
UHCI_RH_RUNNING_NODEVS, /* Running with no devices attached */
};
/*
* The full UHCI controller information:
*/
struct uhci_hcd {
/* debugfs */
struct dentry *dentry;
/* Grabbed from PCI */
unsigned long io_addr;
struct dma_pool *qh_pool;
struct dma_pool *td_pool;
struct uhci_td *term_td; /* Terminating TD, see UHCI bug */
struct uhci_qh *skelqh[UHCI_NUM_SKELQH]; /* Skeleton QHs */
struct uhci_qh *next_qh; /* Next QH to scan */
spinlock_t lock;
dma_addr_t frame_dma_handle; /* Hardware frame list */
__le32 *frame;
void **frame_cpu; /* CPU's frame list */
enum uhci_rh_state rh_state;
unsigned long auto_stop_time; /* When to AUTO_STOP */
unsigned int frame_number; /* As of last check */
unsigned int is_stopped;
#define UHCI_IS_STOPPED 9999 /* Larger than a frame # */
unsigned int last_iso_frame; /* Frame of last scan */
unsigned int cur_iso_frame; /* Frame for current scan */
unsigned int scan_in_progress:1; /* Schedule scan is running */
unsigned int need_rescan:1; /* Redo the schedule scan */
unsigned int dead:1; /* Controller has died */
unsigned int working_RD:1; /* Suspended root hub doesn't
need to be polled */
unsigned int is_initialized:1; /* Data structure is usable */
unsigned int fsbr_is_on:1; /* FSBR is turned on */
unsigned int fsbr_is_wanted:1; /* Does any URB want FSBR? */
unsigned int fsbr_expiring:1; /* FSBR is timing out */
struct timer_list fsbr_timer; /* For turning off FBSR */
/* Support for port suspend/resume/reset */
unsigned long port_c_suspend; /* Bit-arrays of ports */
unsigned long resuming_ports;
unsigned long ports_timeout; /* Time to stop signalling */
struct list_head idle_qh_list; /* Where the idle QHs live */
int rh_numports; /* Number of root-hub ports */
wait_queue_head_t waitqh; /* endpoint_disable waiters */
int num_waiting; /* Number of waiters */
int total_load; /* Sum of array values */
short load[MAX_PHASE]; /* Periodic allocations */
};
/* Convert between a usb_hcd pointer and the corresponding uhci_hcd */
static inline struct uhci_hcd *hcd_to_uhci(struct usb_hcd *hcd)
{
return (struct uhci_hcd *) (hcd->hcd_priv);
}
static inline struct usb_hcd *uhci_to_hcd(struct uhci_hcd *uhci)
{
return container_of((void *) uhci, struct usb_hcd, hcd_priv);
}
#define uhci_dev(u) (uhci_to_hcd(u)->self.controller)
/* Utility macro for comparing frame numbers */
#define uhci_frame_before_eq(f1, f2) (0 <= (int) ((f2) - (f1)))
/*
* Private per-URB data
*/
struct urb_priv {
struct list_head node; /* Node in the QH's urbp list */
struct urb *urb;
struct uhci_qh *qh; /* QH for this URB */
struct list_head td_list;
unsigned fsbr:1; /* URB wants FSBR */
};
/*
* Locking in uhci.c
*
* Almost everything relating to the hardware schedule and processing
* of URBs is protected by uhci->lock. urb->status is protected by
* urb->lock; that's the one exception.
*
* To prevent deadlocks, never lock uhci->lock while holding urb->lock.
* The safe order of locking is:
*
* #1 uhci->lock
* #2 urb->lock
*/
/* Some special IDs */
#define PCI_VENDOR_ID_GENESYS 0x17a0
#define PCI_DEVICE_ID_GL880S_UHCI 0x8083
#endif
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