linux/drivers/scsi/cxgb3i/cxgb3i_ddp.h
Karen Xie 295ab1b543 cxgb3i: use kref to track ddp usage
The iscsi ddp functionality could be used by multiple iscsi entities,
add a refcnt to keep track of it, so we would not release it pre-maturely.

Signed-off-by: Karen Xie <kxie@chelsio.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-06-21 10:52:39 -05:00

312 lines
8.1 KiB
C

/*
* cxgb3i_ddp.h: Chelsio S3xx iSCSI DDP Manager.
*
* Copyright (c) 2008 Chelsio Communications, 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.
*
* Written by: Karen Xie (kxie@chelsio.com)
*/
#ifndef __CXGB3I_ULP2_DDP_H__
#define __CXGB3I_ULP2_DDP_H__
#include <linux/vmalloc.h>
/**
* struct cxgb3i_tag_format - cxgb3i ulp tag format for an iscsi entity
*
* @sw_bits: # of bits used by iscsi software layer
* @rsvd_bits: # of bits used by h/w
* @rsvd_shift: h/w bits shift left
* @rsvd_mask: reserved bit mask
*/
struct cxgb3i_tag_format {
unsigned char sw_bits;
unsigned char rsvd_bits;
unsigned char rsvd_shift;
unsigned char filler[1];
u32 rsvd_mask;
};
/**
* struct cxgb3i_gather_list - cxgb3i direct data placement memory
*
* @tag: ddp tag
* @length: total data buffer length
* @offset: initial offset to the 1st page
* @nelem: # of pages
* @pages: page pointers
* @phys_addr: physical address
*/
struct cxgb3i_gather_list {
u32 tag;
unsigned int length;
unsigned int offset;
unsigned int nelem;
struct page **pages;
dma_addr_t phys_addr[0];
};
/**
* struct cxgb3i_ddp_info - cxgb3i direct data placement for pdu payload
*
* @list: list head to link elements
* @refcnt: ref. count
* @tdev: pointer to t3cdev used by cxgb3 driver
* @max_txsz: max tx packet size for ddp
* @max_rxsz: max rx packet size for ddp
* @llimit: lower bound of the page pod memory
* @ulimit: upper bound of the page pod memory
* @nppods: # of page pod entries
* @idx_last: page pod entry last used
* @idx_bits: # of bits the pagepod index would take
* @idx_mask: pagepod index mask
* @rsvd_tag_mask: tag mask
* @map_lock: lock to synchonize access to the page pod map
* @gl_map: ddp memory gather list
* @gl_skb: skb used to program the pagepod
*/
struct cxgb3i_ddp_info {
struct list_head list;
struct kref refcnt;
struct t3cdev *tdev;
struct pci_dev *pdev;
unsigned int max_txsz;
unsigned int max_rxsz;
unsigned int llimit;
unsigned int ulimit;
unsigned int nppods;
unsigned int idx_last;
unsigned char idx_bits;
unsigned char filler[3];
u32 idx_mask;
u32 rsvd_tag_mask;
spinlock_t map_lock;
struct cxgb3i_gather_list **gl_map;
struct sk_buff **gl_skb;
};
#define ISCSI_PDU_NONPAYLOAD_LEN 312 /* bhs(48) + ahs(256) + digest(8) */
#define ULP2_MAX_PKT_SIZE 16224
#define ULP2_MAX_PDU_PAYLOAD (ULP2_MAX_PKT_SIZE - ISCSI_PDU_NONPAYLOAD_LEN)
#define PPOD_PAGES_MAX 4
#define PPOD_PAGES_SHIFT 2 /* 4 pages per pod */
/*
* struct pagepod_hdr, pagepod - pagepod format
*/
struct pagepod_hdr {
u32 vld_tid;
u32 pgsz_tag_clr;
u32 maxoffset;
u32 pgoffset;
u64 rsvd;
};
struct pagepod {
struct pagepod_hdr hdr;
u64 addr[PPOD_PAGES_MAX + 1];
};
#define PPOD_SIZE sizeof(struct pagepod) /* 64 */
#define PPOD_SIZE_SHIFT 6
#define PPOD_COLOR_SHIFT 0
#define PPOD_COLOR_SIZE 6
#define PPOD_COLOR_MASK ((1 << PPOD_COLOR_SIZE) - 1)
#define PPOD_IDX_SHIFT PPOD_COLOR_SIZE
#define PPOD_IDX_MAX_SIZE 24
#define S_PPOD_TID 0
#define M_PPOD_TID 0xFFFFFF
#define V_PPOD_TID(x) ((x) << S_PPOD_TID)
#define S_PPOD_VALID 24
#define V_PPOD_VALID(x) ((x) << S_PPOD_VALID)
#define F_PPOD_VALID V_PPOD_VALID(1U)
#define S_PPOD_COLOR 0
#define M_PPOD_COLOR 0x3F
#define V_PPOD_COLOR(x) ((x) << S_PPOD_COLOR)
#define S_PPOD_TAG 6
#define M_PPOD_TAG 0xFFFFFF
#define V_PPOD_TAG(x) ((x) << S_PPOD_TAG)
#define S_PPOD_PGSZ 30
#define M_PPOD_PGSZ 0x3
#define V_PPOD_PGSZ(x) ((x) << S_PPOD_PGSZ)
/*
* large memory chunk allocation/release
* use vmalloc() if kmalloc() fails
*/
static inline void *cxgb3i_alloc_big_mem(unsigned int size,
gfp_t gfp)
{
void *p = kmalloc(size, gfp);
if (!p)
p = vmalloc(size);
if (p)
memset(p, 0, size);
return p;
}
static inline void cxgb3i_free_big_mem(void *addr)
{
if (is_vmalloc_addr(addr))
vfree(addr);
else
kfree(addr);
}
/*
* cxgb3i ddp tag are 32 bits, it consists of reserved bits used by h/w and
* non-reserved bits that can be used by the iscsi s/w.
* The reserved bits are identified by the rsvd_bits and rsvd_shift fields
* in struct cxgb3i_tag_format.
*
* The upper most reserved bit can be used to check if a tag is ddp tag or not:
* if the bit is 0, the tag is a valid ddp tag
*/
/**
* cxgb3i_is_ddp_tag - check if a given tag is a hw/ddp tag
* @tformat: tag format information
* @tag: tag to be checked
*
* return true if the tag is a ddp tag, false otherwise.
*/
static inline int cxgb3i_is_ddp_tag(struct cxgb3i_tag_format *tformat, u32 tag)
{
return !(tag & (1 << (tformat->rsvd_bits + tformat->rsvd_shift - 1)));
}
/**
* cxgb3i_sw_tag_usable - check if s/w tag has enough bits left for hw bits
* @tformat: tag format information
* @sw_tag: s/w tag to be checked
*
* return true if the tag can be used for hw ddp tag, false otherwise.
*/
static inline int cxgb3i_sw_tag_usable(struct cxgb3i_tag_format *tformat,
u32 sw_tag)
{
sw_tag >>= (32 - tformat->rsvd_bits);
return !sw_tag;
}
/**
* cxgb3i_set_non_ddp_tag - mark a given s/w tag as an invalid ddp tag
* @tformat: tag format information
* @sw_tag: s/w tag to be checked
*
* insert 1 at the upper most reserved bit to mark it as an invalid ddp tag.
*/
static inline u32 cxgb3i_set_non_ddp_tag(struct cxgb3i_tag_format *tformat,
u32 sw_tag)
{
unsigned char shift = tformat->rsvd_bits + tformat->rsvd_shift - 1;
u32 mask = (1 << shift) - 1;
if (sw_tag && (sw_tag & ~mask)) {
u32 v1 = sw_tag & ((1 << shift) - 1);
u32 v2 = (sw_tag >> (shift - 1)) << shift;
return v2 | v1 | 1 << shift;
}
return sw_tag | 1 << shift;
}
/**
* cxgb3i_ddp_tag_base - shift s/w tag bits so that reserved bits are not used
* @tformat: tag format information
* @sw_tag: s/w tag to be checked
*/
static inline u32 cxgb3i_ddp_tag_base(struct cxgb3i_tag_format *tformat,
u32 sw_tag)
{
u32 mask = (1 << tformat->rsvd_shift) - 1;
if (sw_tag && (sw_tag & ~mask)) {
u32 v1 = sw_tag & mask;
u32 v2 = sw_tag >> tformat->rsvd_shift;
v2 <<= tformat->rsvd_shift + tformat->rsvd_bits;
return v2 | v1;
}
return sw_tag;
}
/**
* cxgb3i_tag_rsvd_bits - get the reserved bits used by the h/w
* @tformat: tag format information
* @tag: tag to be checked
*
* return the reserved bits in the tag
*/
static inline u32 cxgb3i_tag_rsvd_bits(struct cxgb3i_tag_format *tformat,
u32 tag)
{
if (cxgb3i_is_ddp_tag(tformat, tag))
return (tag >> tformat->rsvd_shift) & tformat->rsvd_mask;
return 0;
}
/**
* cxgb3i_tag_nonrsvd_bits - get the non-reserved bits used by the s/w
* @tformat: tag format information
* @tag: tag to be checked
*
* return the non-reserved bits in the tag.
*/
static inline u32 cxgb3i_tag_nonrsvd_bits(struct cxgb3i_tag_format *tformat,
u32 tag)
{
unsigned char shift = tformat->rsvd_bits + tformat->rsvd_shift - 1;
u32 v1, v2;
if (cxgb3i_is_ddp_tag(tformat, tag)) {
v1 = tag & ((1 << tformat->rsvd_shift) - 1);
v2 = (tag >> (shift + 1)) << tformat->rsvd_shift;
} else {
u32 mask = (1 << shift) - 1;
tag &= ~(1 << shift);
v1 = tag & mask;
v2 = (tag >> 1) & ~mask;
}
return v1 | v2;
}
int cxgb3i_ddp_tag_reserve(struct t3cdev *, unsigned int tid,
struct cxgb3i_tag_format *, u32 *tag,
struct cxgb3i_gather_list *, gfp_t gfp);
void cxgb3i_ddp_tag_release(struct t3cdev *, u32 tag);
struct cxgb3i_gather_list *cxgb3i_ddp_make_gl(unsigned int xferlen,
struct scatterlist *sgl,
unsigned int sgcnt,
struct pci_dev *pdev,
gfp_t gfp);
void cxgb3i_ddp_release_gl(struct cxgb3i_gather_list *gl,
struct pci_dev *pdev);
int cxgb3i_setup_conn_host_pagesize(struct t3cdev *, unsigned int tid,
int reply);
int cxgb3i_setup_conn_pagesize(struct t3cdev *, unsigned int tid, int reply,
unsigned long pgsz);
int cxgb3i_setup_conn_digest(struct t3cdev *, unsigned int tid,
int hcrc, int dcrc, int reply);
int cxgb3i_ddp_find_page_index(unsigned long pgsz);
int cxgb3i_adapter_ddp_info(struct t3cdev *, struct cxgb3i_tag_format *,
unsigned int *txsz, unsigned int *rxsz);
void cxgb3i_ddp_init(struct t3cdev *);
void cxgb3i_ddp_cleanup(struct t3cdev *);
#endif