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8af8d2970e
linux/drivers/infiniband/hw/hfi1/pio.h
Sebastian Sanchez 8af8d2970e IB/hfi1: Optimize pio_buf and send_context structs 
Both pio_buf and send_context structs have oversized
fields and have cachelines that can be optimized.

Reduce oversized fields for both structs.
Make sure pio_buf struct fits within a cacheline.
Move read-only fields to their own cacheline in
send_context struct.

All of this will avoid cacheline trading as the ring
progresses and pio buffers/send contexts are used.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-11-15 16:37:27 -05:00

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#ifndef _PIO_H
#define _PIO_H
/*
* Copyright(c) 2015, 2016 Intel Corporation.
*
* This file is provided under a dual BSD/GPLv2 license. When using or
* redistributing this file, you may do so under either license.
*
* GPL LICENSE SUMMARY
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License 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.
*
* BSD LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* - Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
/* send context types */
#define SC_KERNEL 0
#define SC_VL15 1
#define SC_ACK 2
#define SC_USER 3 /* must be the last one: it may take all left */
#define SC_MAX 4 /* count of send context types */
/* invalid send context index */
#define INVALID_SCI 0xff
/* PIO buffer release callback function */
typedef void (*pio_release_cb)(void *arg, int code);
/* PIO release codes - in bits, as there could more than one that apply */
#define PRC_OK 0 /* no known error */
#define PRC_STATUS_ERR 0x01 /* credit return due to status error */
#define PRC_PBC 0x02 /* credit return due to PBC */
#define PRC_THRESHOLD 0x04 /* credit return due to threshold */
#define PRC_FILL_ERR 0x08 /* credit return due fill error */
#define PRC_FORCE 0x10 /* credit return due credit force */
#define PRC_SC_DISABLE 0x20 /* clean-up after a context disable */
/* byte helper */
union mix {
u64 val64;
u32 val32[2];
u8 val8[8];
};
/* an allocated PIO buffer */
struct pio_buf {
struct send_context *sc;/* back pointer to owning send context */
pio_release_cb cb; /* called when the buffer is released */
void *arg; /* argument for cb */
void __iomem *start; /* buffer start address */
void __iomem *end; /* context end address */
unsigned long sent_at; /* buffer is sent when <= free */
union mix carry; /* pending unwritten bytes */
u16 qw_written; /* QW written so far */
u8 carry_bytes; /* number of valid bytes in carry */
};
/* cache line aligned pio buffer array */
union pio_shadow_ring {
struct pio_buf pbuf;
} ____cacheline_aligned;
/* per-NUMA send context */
struct send_context {
/* read-only after init */
struct hfi1_devdata *dd; /* device */
union pio_shadow_ring *sr; /* shadow ring */
void __iomem *base_addr; /* start of PIO memory */
u32 __percpu *buffers_allocated;/* count of buffers allocated */
u32 size; /* context size, in bytes */
int node; /* context home node */
u32 sr_size; /* size of the shadow ring */
u16 flags; /* flags */
u8 type; /* context type */
u8 sw_index; /* software index number */
u8 hw_context; /* hardware context number */
u8 group; /* credit return group */
/* allocator fields */
spinlock_t alloc_lock ____cacheline_aligned_in_smp;
u32 sr_head; /* shadow ring head */
unsigned long fill; /* official alloc count */
unsigned long alloc_free; /* copy of free (less cache thrash) */
u32 fill_wrap; /* tracks fill within ring */
u32 credits; /* number of blocks in context */
/* adding a new field here would make it part of this cacheline */
/* releaser fields */
spinlock_t release_lock ____cacheline_aligned_in_smp;
u32 sr_tail; /* shadow ring tail */
unsigned long free; /* official free count */
volatile __le64 *hw_free; /* HW free counter */
/* list for PIO waiters */
struct list_head piowait ____cacheline_aligned_in_smp;
spinlock_t credit_ctrl_lock ____cacheline_aligned_in_smp;
u32 credit_intr_count; /* count of credit intr users */
u64 credit_ctrl; /* cache for credit control */
wait_queue_head_t halt_wait; /* wait until kernel sees interrupt */
struct work_struct halt_work; /* halted context work queue entry */
};
/* send context flags */
#define SCF_ENABLED 0x01
#define SCF_IN_FREE 0x02
#define SCF_HALTED 0x04
#define SCF_FROZEN 0x08
struct send_context_info {
struct send_context *sc; /* allocated working context */
u16 allocated; /* has this been allocated? */
u16 type; /* context type */
u16 base; /* base in PIO array */
u16 credits; /* size in PIO array */
};
/* DMA credit return, index is always (context & 0x7) */
struct credit_return {
volatile __le64 cr[8];
};
/* NUMA indexed credit return array */
struct credit_return_base {
struct credit_return *va;
dma_addr_t dma;
};
/* send context configuration sizes (one per type) */
struct sc_config_sizes {
short int size;
short int count;
};
/*
* The diagram below details the relationship of the mapping structures
*
* Since the mapping now allows for non-uniform send contexts per vl, the
* number of send contexts for a vl is either the vl_scontexts[vl] or
* a computation based on num_kernel_send_contexts/num_vls:
*
* For example:
* nactual = vl_scontexts ? vl_scontexts[vl] : num_kernel_send_contexts/num_vls
*
* n = roundup to next highest power of 2 using nactual
*
* In the case where there are num_kernel_send_contexts/num_vls doesn't divide
* evenly, the extras are added from the last vl downward.
*
* For the case where n > nactual, the send contexts are assigned
* in a round robin fashion wrapping back to the first send context
* for a particular vl.
*
* dd->pio_map
* | pio_map_elem[0]
* | +--------------------+
* v | mask |
* pio_vl_map |--------------------|
* +--------------------------+ | ksc[0] -> sc 1 |
* | list (RCU) | |--------------------|
* |--------------------------| ->| ksc[1] -> sc 2 |
* | mask | --/ |--------------------|
* |--------------------------| -/ | * |
* | actual_vls (max 8) | -/ |--------------------|
* |--------------------------| --/ | ksc[n] -> sc n |
* | vls (max 8) | -/ +--------------------+
* |--------------------------| --/
* | map[0] |-/
* |--------------------------| +--------------------+
* | map[1] |--- | mask |
* |--------------------------| \---- |--------------------|
* | * | \-- | ksc[0] -> sc 1+n |
* | * | \---- |--------------------|
* | * | \->| ksc[1] -> sc 2+n |
* |--------------------------| |--------------------|
* | map[vls - 1] |- | * |
* +--------------------------+ \- |--------------------|
* \- | ksc[m] -> sc m+n |
* \ +--------------------+
* \-
* \
* \- +--------------------+
* \- | mask |
* \ |--------------------|
* \- | ksc[0] -> sc 1+m+n |
* \- |--------------------|
* >| ksc[1] -> sc 2+m+n |
* |--------------------|
* | * |
* |--------------------|
* | ksc[o] -> sc o+m+n |
* +--------------------+
*
*/
/* Initial number of send contexts per VL */
#define INIT_SC_PER_VL 2
/*
* struct pio_map_elem - mapping for a vl
* @mask - selector mask
* @ksc - array of kernel send contexts for this vl
*
* The mask is used to "mod" the selector to
* produce index into the trailing array of
* kscs
*/
struct pio_map_elem {
u32 mask;
struct send_context *ksc[0];
};
/*
* struct pio_vl_map - mapping for a vl
* @list - rcu head for free callback
* @mask - vl mask to "mod" the vl to produce an index to map array
* @actual_vls - number of vls
* @vls - numbers of vls rounded to next power of 2
* @map - array of pio_map_elem entries
*
* This is the parent mapping structure. The trailing members of the
* struct point to pio_map_elem entries, which in turn point to an
* array of kscs for that vl.
*/
struct pio_vl_map {
struct rcu_head list;
u32 mask;
u8 actual_vls;
u8 vls;
struct pio_map_elem *map[0];
};
int pio_map_init(struct hfi1_devdata *dd, u8 port, u8 num_vls,
u8 *vl_scontexts);
void free_pio_map(struct hfi1_devdata *dd);
struct send_context *pio_select_send_context_vl(struct hfi1_devdata *dd,
u32 selector, u8 vl);
struct send_context *pio_select_send_context_sc(struct hfi1_devdata *dd,
u32 selector, u8 sc5);
/* send context functions */
int init_credit_return(struct hfi1_devdata *dd);
void free_credit_return(struct hfi1_devdata *dd);
int init_sc_pools_and_sizes(struct hfi1_devdata *dd);
int init_send_contexts(struct hfi1_devdata *dd);
int init_credit_return(struct hfi1_devdata *dd);
int init_pervl_scs(struct hfi1_devdata *dd);
struct send_context *sc_alloc(struct hfi1_devdata *dd, int type,
uint hdrqentsize, int numa);
void sc_free(struct send_context *sc);
int sc_enable(struct send_context *sc);
void sc_disable(struct send_context *sc);
int sc_restart(struct send_context *sc);
void sc_return_credits(struct send_context *sc);
void sc_flush(struct send_context *sc);
void sc_drop(struct send_context *sc);
void sc_stop(struct send_context *sc, int bit);
struct pio_buf *sc_buffer_alloc(struct send_context *sc, u32 dw_len,
pio_release_cb cb, void *arg);
void sc_release_update(struct send_context *sc);
void sc_return_credits(struct send_context *sc);
void sc_group_release_update(struct hfi1_devdata *dd, u32 hw_context);
void sc_add_credit_return_intr(struct send_context *sc);
void sc_del_credit_return_intr(struct send_context *sc);
void sc_set_cr_threshold(struct send_context *sc, u32 new_threshold);
u32 sc_percent_to_threshold(struct send_context *sc, u32 percent);
u32 sc_mtu_to_threshold(struct send_context *sc, u32 mtu, u32 hdrqentsize);
void hfi1_sc_wantpiobuf_intr(struct send_context *sc, u32 needint);
void sc_wait(struct hfi1_devdata *dd);
void set_pio_integrity(struct send_context *sc);
/* support functions */
void pio_reset_all(struct hfi1_devdata *dd);
void pio_freeze(struct hfi1_devdata *dd);
void pio_kernel_unfreeze(struct hfi1_devdata *dd);
/* global PIO send control operations */
#define PSC_GLOBAL_ENABLE 0
#define PSC_GLOBAL_DISABLE 1
#define PSC_GLOBAL_VLARB_ENABLE 2
#define PSC_GLOBAL_VLARB_DISABLE 3
#define PSC_CM_RESET 4
#define PSC_DATA_VL_ENABLE 5
#define PSC_DATA_VL_DISABLE 6
void __cm_reset(struct hfi1_devdata *dd, u64 sendctrl);
void pio_send_control(struct hfi1_devdata *dd, int op);
/* PIO copy routines */
void pio_copy(struct hfi1_devdata *dd, struct pio_buf *pbuf, u64 pbc,
const void *from, size_t count);
void seg_pio_copy_start(struct pio_buf *pbuf, u64 pbc,
const void *from, size_t nbytes);
void seg_pio_copy_mid(struct pio_buf *pbuf, const void *from, size_t nbytes);
void seg_pio_copy_end(struct pio_buf *pbuf);
#endif /* _PIO_H */
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