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Release 4.14 arch/mips/include/asm/octeon/cvmx-cmd-queue.h

/***********************license start***************
 * Author: Cavium Networks
 *
 * Contact: support@caviumnetworks.com
 * This file is part of the OCTEON SDK
 *
 * Copyright (c) 2003-2008 Cavium Networks
 *
 * This file 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.
 *
 * This file is distributed in the hope that it will be useful, but
 * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
 * NONINFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this file; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 * or visit http://www.gnu.org/licenses/.
 *
 * This file may also be available under a different license from Cavium.
 * Contact Cavium Networks for more information
 ***********************license end**************************************/

/*
 *
 * Support functions for managing command queues used for
 * various hardware blocks.
 *
 * The common command queue infrastructure abstracts out the
 * software necessary for adding to Octeon's chained queue
 * structures. These structures are used for commands to the
 * PKO, ZIP, DFA, RAID, and DMA engine blocks. Although each
 * hardware unit takes commands and CSRs of different types,
 * they all use basic linked command buffers to store the
 * pending request. In general, users of the CVMX API don't
 * call cvmx-cmd-queue functions directly. Instead the hardware
 * unit specific wrapper should be used. The wrappers perform
 * unit specific validation and CSR writes to submit the
 * commands.
 *
 * Even though most software will never directly interact with
 * cvmx-cmd-queue, knowledge of its internal working can help
 * in diagnosing performance problems and help with debugging.
 *
 * Command queue pointers are stored in a global named block
 * called "cvmx_cmd_queues". Except for the PKO queues, each
 * hardware queue is stored in its own cache line to reduce SMP
 * contention on spin locks. The PKO queues are stored such that
 * every 16th queue is next to each other in memory. This scheme
 * allows for queues being in separate cache lines when there
 * are low number of queues per port. With 16 queues per port,
 * the first queue for each port is in the same cache area. The
 * second queues for each port are in another area, etc. This
 * allows software to implement very efficient lockless PKO with
 * 16 queues per port using a minimum of cache lines per core.
 * All queues for a given core will be isolated in the same
 * cache area.
 *
 * In addition to the memory pointer layout, cvmx-cmd-queue
 * provides an optimized fair ll/sc locking mechanism for the
 * queues. The lock uses a "ticket / now serving" model to
 * maintain fair order on contended locks. In addition, it uses
 * predicted locking time to limit cache contention. When a core
 * know it must wait in line for a lock, it spins on the
 * internal cycle counter to completely eliminate any causes of
 * bus traffic.
 *
 */

#ifndef __CVMX_CMD_QUEUE_H__

#define __CVMX_CMD_QUEUE_H__

#include <linux/prefetch.h>

#include <asm/compiler.h>

#include <asm/octeon/cvmx-fpa.h>
/**
 * By default we disable the max depth support. Most programs
 * don't use it and it slows down the command queue processing
 * significantly.
 */
#ifndef CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH

#define CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH 0
#endif

/**
 * Enumeration representing all hardware blocks that use command
 * queues. Each hardware block has up to 65536 sub identifiers for
 * multiple command queues. Not all chips support all hardware
 * units.
 */
typedef enum {
	
CVMX_CMD_QUEUE_PKO_BASE = 0x00000,


#define CVMX_CMD_QUEUE_PKO(queue) \
	((cvmx_cmd_queue_id_t)(CVMX_CMD_QUEUE_PKO_BASE + (0xffff&(queue))))

	
CVMX_CMD_QUEUE_ZIP = 0x10000,
	
CVMX_CMD_QUEUE_DFA = 0x20000,
	
CVMX_CMD_QUEUE_RAID = 0x30000,
	
CVMX_CMD_QUEUE_DMA_BASE = 0x40000,


#define CVMX_CMD_QUEUE_DMA(queue) \
	((cvmx_cmd_queue_id_t)(CVMX_CMD_QUEUE_DMA_BASE + (0xffff&(queue))))

	
CVMX_CMD_QUEUE_END = 0x50000,
} 
cvmx_cmd_queue_id_t;

/**
 * Command write operations can fail if the command queue needs
 * a new buffer and the associated FPA pool is empty. It can also
 * fail if the number of queued command words reaches the maximum
 * set at initialization.
 */
typedef enum {
	
CVMX_CMD_QUEUE_SUCCESS = 0,
	
CVMX_CMD_QUEUE_NO_MEMORY = -1,
	
CVMX_CMD_QUEUE_FULL = -2,
	
CVMX_CMD_QUEUE_INVALID_PARAM = -3,
	
CVMX_CMD_QUEUE_ALREADY_SETUP = -4,
} 
cvmx_cmd_queue_result_t;

typedef struct {
	/* You have lock when this is your ticket */
	
uint8_t now_serving;
	
uint64_t unused1:24;
	/* Maximum outstanding command words */
	
uint32_t max_depth;
	/* FPA pool buffers come from */
	
uint64_t fpa_pool:3;
	/* Top of command buffer pointer shifted 7 */
	
uint64_t base_ptr_div128:29;
	
uint64_t unused2:6;
	/* FPA buffer size in 64bit words minus 1 */
	
uint64_t pool_size_m1:13;
	/* Number of commands already used in buffer */
	
uint64_t index:13;

} __cvmx_cmd_queue_state_t;

/**
 * This structure contains the global state of all command queues.
 * It is stored in a bootmem named block and shared by all
 * applications running on Octeon. Tickets are stored in a differnet
 * cache line that queue information to reduce the contention on the
 * ll/sc used to get a ticket. If this is not the case, the update
 * of queue state causes the ll/sc to fail quite often.
 */
typedef struct {
	
uint64_t ticket[(CVMX_CMD_QUEUE_END >> 16) * 256];
	
__cvmx_cmd_queue_state_t state[(CVMX_CMD_QUEUE_END >> 16) * 256];

} __cvmx_cmd_queue_all_state_t;

/**
 * Initialize a command queue for use. The initial FPA buffer is
 * allocated and the hardware unit is configured to point to the
 * new command queue.
 *
 * @queue_id:  Hardware command queue to initialize.
 * @max_depth: Maximum outstanding commands that can be queued.
 * @fpa_pool:  FPA pool the command queues should come from.
 * @pool_size: Size of each buffer in the FPA pool (bytes)
 *
 * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code
 */
cvmx_cmd_queue_result_t cvmx_cmd_queue_initialize(cvmx_cmd_queue_id_t queue_id,
						  int max_depth, int fpa_pool,
						  int pool_size);

/**
 * Shutdown a queue a free it's command buffers to the FPA. The
 * hardware connected to the queue must be stopped before this
 * function is called.
 *
 * @queue_id: Queue to shutdown
 *
 * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code
 */
cvmx_cmd_queue_result_t cvmx_cmd_queue_shutdown(cvmx_cmd_queue_id_t queue_id);

/**
 * Return the number of command words pending in the queue. This
 * function may be relatively slow for some hardware units.
 *
 * @queue_id: Hardware command queue to query
 *
 * Returns Number of outstanding commands
 */
int cvmx_cmd_queue_length(cvmx_cmd_queue_id_t queue_id);

/**
 * Return the command buffer to be written to. The purpose of this
 * function is to allow CVMX routine access t othe low level buffer
 * for initial hardware setup. User applications should not call this
 * function directly.
 *
 * @queue_id: Command queue to query
 *
 * Returns Command buffer or NULL on failure
 */
void *cvmx_cmd_queue_buffer(cvmx_cmd_queue_id_t queue_id);

/**
 * Get the index into the state arrays for the supplied queue id.
 *
 * @queue_id: Queue ID to get an index for
 *
 * Returns Index into the state arrays
 */

static inline int __cvmx_cmd_queue_get_index(cvmx_cmd_queue_id_t queue_id) { /* * Warning: This code currently only works with devices that * have 256 queues or less. Devices with more than 16 queues * are laid out in memory to allow cores quick access to * every 16th queue. This reduces cache thrashing when you are * running 16 queues per port to support lockless operation. */ int unit = queue_id >> 16; int q = (queue_id >> 4) & 0xf; int core = queue_id & 0xf; return unit * 256 + core * 16 + q; }

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/** * Lock the supplied queue so nobody else is updating it at the same * time as us. * * @queue_id: Queue ID to lock * @qptr: Pointer to the queue's global state */
static inline void __cvmx_cmd_queue_lock(cvmx_cmd_queue_id_t queue_id, __cvmx_cmd_queue_state_t *qptr) { extern __cvmx_cmd_queue_all_state_t *__cvmx_cmd_queue_state_ptr; int tmp; int my_ticket; prefetch(qptr); asm volatile ( ".set push\n" ".set noreorder\n" "1:\n" /* Atomic add one to ticket_ptr */ "ll %[my_ticket], %[ticket_ptr]\n" /* and store the original value */ "li %[ticket], 1\n" /* in my_ticket */ "baddu %[ticket], %[my_ticket]\n" "sc %[ticket], %[ticket_ptr]\n" "beqz %[ticket], 1b\n" " nop\n" /* Load the current now_serving ticket */ "lbu %[ticket], %[now_serving]\n" "2:\n" /* Jump out if now_serving == my_ticket */ "beq %[ticket], %[my_ticket], 4f\n" /* Find out how many tickets are in front of me */ " subu %[ticket], %[my_ticket], %[ticket]\n" /* Use tickets in front of me minus one to delay */ "subu %[ticket], 1\n" /* Delay will be ((tickets in front)-1)*32 loops */ "cins %[ticket], %[ticket], 5, 7\n" "3:\n" /* Loop here until our ticket might be up */ "bnez %[ticket], 3b\n" " subu %[ticket], 1\n" /* Jump back up to check out ticket again */ "b 2b\n" /* Load the current now_serving ticket */ " lbu %[ticket], %[now_serving]\n" "4:\n" ".set pop\n" : [ticket_ptr] "=" GCC_OFF_SMALL_ASM()(__cvmx_cmd_queue_state_ptr->ticket[__cvmx_cmd_queue_get_index(queue_id)]), [now_serving] "=m"(qptr->now_serving), [ticket] "=r"(tmp), [my_ticket] "=r"(my_ticket) ); }

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/** * Unlock the queue, flushing all writes. * * @qptr: Queue to unlock */
static inline void __cvmx_cmd_queue_unlock(__cvmx_cmd_queue_state_t *qptr) { qptr->now_serving++; CVMX_SYNCWS; }

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/** * Get the queue state structure for the given queue id * * @queue_id: Queue id to get * * Returns Queue structure or NULL on failure */
static inline __cvmx_cmd_queue_state_t *__cvmx_cmd_queue_get_state(cvmx_cmd_queue_id_t queue_id) { extern __cvmx_cmd_queue_all_state_t *__cvmx_cmd_queue_state_ptr; return &__cvmx_cmd_queue_state_ptr-> state[__cvmx_cmd_queue_get_index(queue_id)]; }

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/** * Write an arbitrary number of command words to a command queue. * This is a generic function; the fixed number of command word * functions yield higher performance. * * @queue_id: Hardware command queue to write to * @use_locking: * Use internal locking to ensure exclusive access for queue * updates. If you don't use this locking you must ensure * exclusivity some other way. Locking is strongly recommended. * @cmd_count: Number of command words to write * @cmds: Array of commands to write * * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code */
static inline cvmx_cmd_queue_result_t cvmx_cmd_queue_write(cvmx_cmd_queue_id_t queue_id, int use_locking, int cmd_count, uint64_t *cmds) { __cvmx_cmd_queue_state_t *qptr = __cvmx_cmd_queue_get_state(queue_id); /* Make sure nobody else is updating the same queue */ if (likely(use_locking)) __cvmx_cmd_queue_lock(queue_id, qptr); /* * If a max queue length was specified then make sure we don't * exceed it. If any part of the command would be below the * limit we allow it. */ if (CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH && unlikely(qptr->max_depth)) { if (unlikely (cvmx_cmd_queue_length(queue_id) > (int)qptr->max_depth)) { if (likely(use_locking)) __cvmx_cmd_queue_unlock(qptr); return CVMX_CMD_QUEUE_FULL; } } /* * Normally there is plenty of room in the current buffer for * the command. */ if (likely(qptr->index + cmd_count < qptr->pool_size_m1)) { uint64_t *ptr = (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr-> base_ptr_div128 << 7); ptr += qptr->index; qptr->index += cmd_count; while (cmd_count--) *ptr++ = *cmds++; } else { uint64_t *ptr; int count; /* * We need a new command buffer. Fail if there isn't * one available. */ uint64_t *new_buffer = (uint64_t *) cvmx_fpa_alloc(qptr->fpa_pool); if (unlikely(new_buffer == NULL)) { if (likely(use_locking)) __cvmx_cmd_queue_unlock(qptr); return CVMX_CMD_QUEUE_NO_MEMORY; } ptr = (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr-> base_ptr_div128 << 7); /* * Figure out how many command words will fit in this * buffer. One location will be needed for the next * buffer pointer. */ count = qptr->pool_size_m1 - qptr->index; ptr += qptr->index; cmd_count -= count; while (count--) *ptr++ = *cmds++; *ptr = cvmx_ptr_to_phys(new_buffer); /* * The current buffer is full and has a link to the * next buffer. Time to write the rest of the commands * into the new buffer. */ qptr->base_ptr_div128 = *ptr >> 7; qptr->index = cmd_count; ptr = new_buffer; while (cmd_count--) *ptr++ = *cmds++; } /* All updates are complete. Release the lock and return */ if (likely(use_locking)) __cvmx_cmd_queue_unlock(qptr); return CVMX_CMD_QUEUE_SUCCESS; }

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/** * Simple function to write two command words to a command * queue. * * @queue_id: Hardware command queue to write to * @use_locking: * Use internal locking to ensure exclusive access for queue * updates. If you don't use this locking you must ensure * exclusivity some other way. Locking is strongly recommended. * @cmd1: Command * @cmd2: Command * * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code */
static inline cvmx_cmd_queue_result_t cvmx_cmd_queue_write2(cvmx_cmd_queue_id_t queue_id, int use_locking, uint64_t cmd1, uint64_t cmd2) { __cvmx_cmd_queue_state_t *qptr = __cvmx_cmd_queue_get_state(queue_id); /* Make sure nobody else is updating the same queue */ if (likely(use_locking)) __cvmx_cmd_queue_lock(queue_id, qptr); /* * If a max queue length was specified then make sure we don't * exceed it. If any part of the command would be below the * limit we allow it. */ if (CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH && unlikely(qptr->max_depth)) { if (unlikely (cvmx_cmd_queue_length(queue_id) > (int)qptr->max_depth)) { if (likely(use_locking)) __cvmx_cmd_queue_unlock(qptr); return CVMX_CMD_QUEUE_FULL; } } /* * Normally there is plenty of room in the current buffer for * the command. */ if (likely(qptr->index + 2 < qptr->pool_size_m1)) { uint64_t *ptr = (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr-> base_ptr_div128 << 7); ptr += qptr->index; qptr->index += 2; ptr[0] = cmd1; ptr[1] = cmd2; } else { uint64_t *ptr; /* * Figure out how many command words will fit in this * buffer. One location will be needed for the next * buffer pointer. */ int count = qptr->pool_size_m1 - qptr->index; /* * We need a new command buffer. Fail if there isn't * one available. */ uint64_t *new_buffer = (uint64_t *) cvmx_fpa_alloc(qptr->fpa_pool); if (unlikely(new_buffer == NULL)) { if (likely(use_locking)) __cvmx_cmd_queue_unlock(qptr); return CVMX_CMD_QUEUE_NO_MEMORY; } count--; ptr = (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr-> base_ptr_div128 << 7); ptr += qptr->index; *ptr++ = cmd1; if (likely(count)) *ptr++ = cmd2; *ptr = cvmx_ptr_to_phys(new_buffer); /* * The current buffer is full and has a link to the * next buffer. Time to write the rest of the commands * into the new buffer. */ qptr->base_ptr_div128 = *ptr >> 7; qptr->index = 0; if (unlikely(count == 0)) { qptr->index = 1; new_buffer[0] = cmd2; } } /* All updates are complete. Release the lock and return */ if (likely(use_locking)) __cvmx_cmd_queue_unlock(qptr); return CVMX_CMD_QUEUE_SUCCESS; }

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/** * Simple function to write three command words to a command * queue. * * @queue_id: Hardware command queue to write to * @use_locking: * Use internal locking to ensure exclusive access for queue * updates. If you don't use this locking you must ensure * exclusivity some other way. Locking is strongly recommended. * @cmd1: Command * @cmd2: Command * @cmd3: Command * * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code */
static inline cvmx_cmd_queue_result_t cvmx_cmd_queue_write3(cvmx_cmd_queue_id_t queue_id, int use_locking, uint64_t cmd1, uint64_t cmd2, uint64_t cmd3) { __cvmx_cmd_queue_state_t *qptr = __cvmx_cmd_queue_get_state(queue_id); /* Make sure nobody else is updating the same queue */ if (likely(use_locking)) __cvmx_cmd_queue_lock(queue_id, qptr); /* * If a max queue length was specified then make sure we don't * exceed it. If any part of the command would be below the * limit we allow it. */ if (CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH && unlikely(qptr->max_depth)) { if (unlikely (cvmx_cmd_queue_length(queue_id) > (int)qptr->max_depth)) { if (likely(use_locking)) __cvmx_cmd_queue_unlock(qptr); return CVMX_CMD_QUEUE_FULL; } } /* * Normally there is plenty of room in the current buffer for * the command. */ if (likely(qptr->index + 3 < qptr->pool_size_m1)) { uint64_t *ptr = (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr-> base_ptr_div128 << 7); ptr += qptr->index; qptr->index += 3; ptr[0] = cmd1; ptr[1] = cmd2; ptr[2] = cmd3; } else { uint64_t *ptr; /* * Figure out how many command words will fit in this * buffer. One location will be needed for the next * buffer pointer */ int count = qptr->pool_size_m1 - qptr->index; /* * We need a new command buffer. Fail if there isn't * one available */ uint64_t *new_buffer = (uint64_t *) cvmx_fpa_alloc(qptr->fpa_pool); if (unlikely(new_buffer == NULL)) { if (likely(use_locking)) __cvmx_cmd_queue_unlock(qptr); return CVMX_CMD_QUEUE_NO_MEMORY; } count--; ptr = (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr-> base_ptr_div128 << 7); ptr += qptr->index; *ptr++ = cmd1; if (count) { *ptr++ = cmd2; if (count > 1) *ptr++ = cmd3; } *ptr = cvmx_ptr_to_phys(new_buffer); /* * The current buffer is full and has a link to the * next buffer. Time to write the rest of the commands * into the new buffer. */ qptr->base_ptr_div128 = *ptr >> 7; qptr->index = 0; ptr = new_buffer; if (count == 0) { *ptr++ = cmd2; qptr->index++; } if (count < 2) { *ptr++ = cmd3; qptr->index++; } } /* All updates are complete. Release the lock and return */ if (likely(use_locking)) __cvmx_cmd_queue_unlock(qptr); return CVMX_CMD_QUEUE_SUCCESS; }

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#endif /* __CVMX_CMD_QUEUE_H__ */

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