kernel-ark/drivers/misc/hpilo.h
David Altobelli 68ea809af4 hpilo: add locking comment
Add explanation about lock nesting and purpose of each lock in hpilo.

Signed-off-by: David Altobelli <david.altobelli@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11 11:24:51 -08:00

213 lines
5.5 KiB
C

/*
* linux/drivers/char/hpilo.h
*
* Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
* David Altobelli <david.altobelli@hp.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __HPILO_H
#define __HPILO_H
#define ILO_NAME "hpilo"
/* max number of open channel control blocks per device, hw limited to 32 */
#define MAX_CCB 8
/* max number of supported devices */
#define MAX_ILO_DEV 1
/* max number of files */
#define MAX_OPEN (MAX_CCB * MAX_ILO_DEV)
/* total wait time in usec */
#define MAX_WAIT_TIME 10000
/* per spin wait time in usec */
#define WAIT_TIME 10
/* spin counter for open/close delay */
#define MAX_WAIT (MAX_WAIT_TIME / WAIT_TIME)
/*
* Per device, used to track global memory allocations.
*/
struct ilo_hwinfo {
/* mmio registers on device */
char __iomem *mmio_vaddr;
/* doorbell registers on device */
char __iomem *db_vaddr;
/* shared memory on device used for channel control blocks */
char __iomem *ram_vaddr;
/* files corresponding to this device */
struct ccb_data *ccb_alloc[MAX_CCB];
struct pci_dev *ilo_dev;
/*
* open_lock serializes ccb_cnt during open and close
* [ irq disabled ]
* -> alloc_lock used when adding/removing/searching ccb_alloc,
* which represents all ccbs open on the device
* --> fifo_lock controls access to fifo queues shared with hw
*
* Locks must be taken in this order, but open_lock and alloc_lock
* are optional, they do not need to be held in order to take a
* lower level lock.
*/
spinlock_t open_lock;
spinlock_t alloc_lock;
spinlock_t fifo_lock;
struct cdev cdev;
};
/* offset from mmio_vaddr for enabling doorbell interrupts */
#define DB_IRQ 0xB2
/* offset from mmio_vaddr for outbound communications */
#define DB_OUT 0xD4
/* DB_OUT reset bit */
#define DB_RESET 26
/*
* Channel control block. Used to manage hardware queues.
* The format must match hw's version. The hw ccb is 128 bytes,
* but the context area shouldn't be touched by the driver.
*/
#define ILOSW_CCB_SZ 64
#define ILOHW_CCB_SZ 128
struct ccb {
union {
char *send_fifobar;
u64 padding1;
} ccb_u1;
union {
char *send_desc;
u64 padding2;
} ccb_u2;
u64 send_ctrl;
union {
char *recv_fifobar;
u64 padding3;
} ccb_u3;
union {
char *recv_desc;
u64 padding4;
} ccb_u4;
u64 recv_ctrl;
union {
char __iomem *db_base;
u64 padding5;
} ccb_u5;
u64 channel;
/* unused context area (64 bytes) */
};
/* ccb queue parameters */
#define SENDQ 1
#define RECVQ 2
#define NR_QENTRY 4
#define L2_QENTRY_SZ 12
/* ccb ctrl bitfields */
#define CTRL_BITPOS_L2SZ 0
#define CTRL_BITPOS_FIFOINDEXMASK 4
#define CTRL_BITPOS_DESCLIMIT 18
#define CTRL_BITPOS_A 30
#define CTRL_BITPOS_G 31
/* ccb doorbell macros */
#define L2_DB_SIZE 14
#define ONE_DB_SIZE (1 << L2_DB_SIZE)
/*
* Per fd structure used to track the ccb allocated to that dev file.
*/
struct ccb_data {
/* software version of ccb, using virtual addrs */
struct ccb driver_ccb;
/* hardware version of ccb, using physical addrs */
struct ccb ilo_ccb;
/* hardware ccb is written to this shared mapped device memory */
struct ccb __iomem *mapped_ccb;
/* dma'able memory used for send/recv queues */
void *dma_va;
dma_addr_t dma_pa;
size_t dma_size;
/* pointer to hardware device info */
struct ilo_hwinfo *ilo_hw;
/* queue for this ccb to wait for recv data */
wait_queue_head_t ccb_waitq;
/* usage count, to allow for shared ccb's */
int ccb_cnt;
/* open wanted exclusive access to this ccb */
int ccb_excl;
};
/*
* FIFO queue structure, shared with hw.
*/
#define ILO_START_ALIGN 4096
#define ILO_CACHE_SZ 128
struct fifo {
u64 nrents; /* user requested number of fifo entries */
u64 imask; /* mask to extract valid fifo index */
u64 merge; /* O/C bits to merge in during enqueue operation */
u64 reset; /* set to non-zero when the target device resets */
u8 pad_0[ILO_CACHE_SZ - (sizeof(u64) * 4)];
u64 head;
u8 pad_1[ILO_CACHE_SZ - (sizeof(u64))];
u64 tail;
u8 pad_2[ILO_CACHE_SZ - (sizeof(u64))];
u64 fifobar[1];
};
/* convert between struct fifo, and the fifobar, which is saved in the ccb */
#define FIFOHANDLESIZE (sizeof(struct fifo) - sizeof(u64))
#define FIFOBARTOHANDLE(_fifo) \
((struct fifo *)(((char *)(_fifo)) - FIFOHANDLESIZE))
/* the number of qwords to consume from the entry descriptor */
#define ENTRY_BITPOS_QWORDS 0
/* descriptor index number (within a specified queue) */
#define ENTRY_BITPOS_DESCRIPTOR 10
/* state bit, fifo entry consumed by consumer */
#define ENTRY_BITPOS_C 22
/* state bit, fifo entry is occupied */
#define ENTRY_BITPOS_O 23
#define ENTRY_BITS_QWORDS 10
#define ENTRY_BITS_DESCRIPTOR 12
#define ENTRY_BITS_C 1
#define ENTRY_BITS_O 1
#define ENTRY_BITS_TOTAL \
(ENTRY_BITS_C + ENTRY_BITS_O + \
ENTRY_BITS_QWORDS + ENTRY_BITS_DESCRIPTOR)
/* extract various entry fields */
#define ENTRY_MASK ((1 << ENTRY_BITS_TOTAL) - 1)
#define ENTRY_MASK_C (((1 << ENTRY_BITS_C) - 1) << ENTRY_BITPOS_C)
#define ENTRY_MASK_O (((1 << ENTRY_BITS_O) - 1) << ENTRY_BITPOS_O)
#define ENTRY_MASK_QWORDS \
(((1 << ENTRY_BITS_QWORDS) - 1) << ENTRY_BITPOS_QWORDS)
#define ENTRY_MASK_DESCRIPTOR \
(((1 << ENTRY_BITS_DESCRIPTOR) - 1) << ENTRY_BITPOS_DESCRIPTOR)
#define ENTRY_MASK_NOSTATE (ENTRY_MASK >> (ENTRY_BITS_C + ENTRY_BITS_O))
#endif /* __HPILO_H */