Spdk/lib/idxd/idxd.h
paul luse 10808e45d4 idxd: refactor flow control for idxd engine
Recent work identified race conditions having to do with the
dynamic flow control mechanism for the idxd engine. In order
to both address the issue and simplify the code a new scheme
is now in place.  Essentially every DSA device will be allowed
to accomodate 8 channels and each channel will get a fixed 1/8
the number of work queue entries regardless of how many
channels there are.  Assignment of channels to devices is round
robin and if/when no more channels can be accommodated the get
channel request will fail.

The performance tests also revealed another issue that was
masked before, it's a one-line so is in this patch for convenience.
In the idxd poller we limit the number of completions allowed
during one run to avoid the poller thread from starving other
threads since as operations complete on this thread they are
immediately replaced up to the limit for the channel.

Signed-off-by: paul luse <paul.e.luse@intel.com>
Change-Id: I913e809a934b562feb495815a9b9c605d622285c
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/8171
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
2021-06-29 00:46:25 +00:00

213 lines
5.9 KiB
C

/*-
* BSD LICENSE
*
* Copyright (c) Intel Corporation.
* All rights reserved.
*
* 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
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* * Redistributions in binary form must reproduce the above copyright
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* the documentation and/or other materials provided with the
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* * Neither the name of Intel Corporation nor the names of its
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* 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
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* 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.
*/
#ifndef __IDXD_H__
#define __IDXD_H__
#include "spdk/stdinc.h"
#include "spdk/idxd.h"
#include "spdk/queue.h"
#include "spdk/mmio.h"
#include "spdk/bit_array.h"
#include "idxd_spec.h"
#ifdef __cplusplus
extern "C" {
#endif
/* TODO: get the gcc intrinsic to work. */
#define nop() asm volatile ("nop")
static inline void movdir64b(void *dst, const void *src)
{
asm volatile(".byte 0x66, 0x0f, 0x38, 0xf8, 0x02"
: "=m"(*(char *)dst)
: "d"(src), "a"(dst));
}
#define IDXD_REGISTER_TIMEOUT_US 50
#define IDXD_DRAIN_TIMEOUT_US 500000
#define WQ_MODE_DEDICATED 1
/* TODO: consider setting the max per batch limit via RPC. */
/* The following sets up a max desc count per batch of 16 */
#define LOG2_WQ_MAX_BATCH 4 /* 2^4 = 16 */
#define DESC_PER_BATCH (1 << LOG2_WQ_MAX_BATCH)
/* We decide how many batches we want to support based on what max queue
* depth makes sense resource wise. There is a small price to pay with
* larger numbers wrt polling for completions.
*/
#define NUM_BATCHES_PER_CHANNEL 0x400
#define MIN_USER_DESC_COUNT 2
#define LOG2_WQ_MAX_XFER 30 /* 2^30 = 1073741824 */
#define WQCFG_NUM_DWORDS 8
#define WQ_PRIORITY_1 1
#define IDXD_MAX_QUEUES 64
/* Each pre-allocated batch structure goes on a per channel list and
* contains the memory for both user descriptors.
*/
struct idxd_batch {
struct idxd_hw_desc *user_desc;
struct idxd_comp *user_completions;
uint32_t remaining;
uint8_t index;
TAILQ_ENTRY(idxd_batch) link;
};
struct device_config {
uint8_t config_num;
uint8_t num_groups;
uint16_t total_wqs;
uint16_t total_engines;
};
struct idxd_comp ;
struct spdk_idxd_io_channel {
struct spdk_idxd_device *idxd;
/* The portal is the address that we write descriptors to for submission. */
void *portal;
uint16_t ring_size;
/*
* Descriptors and completions share the same index. User descriptors
* (those included in a batch) are managed independently from data descriptors
* and are located in the batch structure.
*/
struct idxd_hw_desc *desc;
struct idxd_comp *completions;
/* Current list of oustanding completion addresses to poll. */
TAILQ_HEAD(, idxd_comp) comp_ctx_oustanding;
/*
* We use one bit array to track ring slots for both
* desc and completions.
*
*/
struct spdk_bit_array *ring_slots;
/* Lists of batches, free and in use. */
TAILQ_HEAD(, idxd_batch) batch_pool;
TAILQ_HEAD(, idxd_batch) batches;
void *batch_base;
};
struct pci_dev_id {
int vendor_id;
int device_id;
};
struct idxd_group {
struct spdk_idxd_device *idxd;
struct idxd_grpcfg grpcfg;
struct pci_dev_id pcidev;
int num_engines;
int num_wqs;
int id;
uint8_t tokens_allowed;
bool use_token_limit;
uint8_t tokens_reserved;
int tc_a;
int tc_b;
};
/*
* This struct wraps the hardware completion record which is 32 bytes in
* size and must be 32 byte aligned.
*/
struct idxd_comp {
struct idxd_hw_comp_record hw;
void *cb_arg;
spdk_idxd_req_cb cb_fn;
struct idxd_batch *batch;
struct idxd_hw_desc *desc;
uint32_t *crc_dst;
uint32_t index;
bool batch_op;
char pad[3];
TAILQ_ENTRY(idxd_comp) link;
};
SPDK_STATIC_ASSERT(sizeof(struct idxd_comp) == 96, "size mismatch");
struct idxd_wq {
struct spdk_idxd_device *idxd;
struct idxd_group *group;
union idxd_wqcfg wqcfg;
};
struct spdk_idxd_impl {
const char *name;
void (*set_config)(struct device_config *g_dev_cfg, uint32_t config_num);
int (*probe)(void *cb_ctx, spdk_idxd_attach_cb attach_cb);
void (*destruct)(struct spdk_idxd_device *idxd);
uint64_t (*read_8)(struct spdk_idxd_device *idxd, void *portal, uint32_t offset);
char *(*portal_get_addr)(struct spdk_idxd_device *idxd);
/* It is a workround for simulator */
bool (*nop_check)(struct spdk_idxd_device *idxd);
STAILQ_ENTRY(spdk_idxd_impl) link;
};
struct spdk_idxd_device {
struct spdk_idxd_impl *impl;
void *portals;
int wq_id;
uint32_t num_channels;
uint32_t total_wq_size;
pthread_mutex_t num_channels_lock;
struct idxd_group *groups;
struct idxd_wq *queues;
};
void idxd_impl_register(struct spdk_idxd_impl *impl);
#define SPDK_IDXD_IMPL_REGISTER(name, impl) \
static void __attribute__((constructor)) idxd_impl_register_##name(void) \
{ \
idxd_impl_register(impl); \
}
#ifdef __cplusplus
}
#endif
#endif /* __IDXD_H__ */