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Diffstat (limited to 'drivers/staging/octeon/cvmx-cmd-queue.h')
| -rw-r--r-- | drivers/staging/octeon/cvmx-cmd-queue.h | 617 |
1 files changed, 617 insertions, 0 deletions
diff --git a/drivers/staging/octeon/cvmx-cmd-queue.h b/drivers/staging/octeon/cvmx-cmd-queue.h new file mode 100644 index 000000000000..f0cb20ffa39a --- /dev/null +++ b/drivers/staging/octeon/cvmx-cmd-queue.h @@ -0,0 +1,617 @@ +/***********************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 "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 comamnd 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 comamnds already used in buffer */ + uint64_t index:13; +} __cvmx_cmd_queue_state_t; + +/** + * This structure contains the global state of all comamnd queues. + * It is stored in a bootmem named block and shared by all + * applications running on Octeon. Tickets are stored in a differnet + * cahce 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 layed 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; +} + +/** + * 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] "=m"(__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) + ); +} + +/** + * 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; +} + +/** + * 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)]; +} + +/** + * Write an arbitrary number of command words to a command queue. + * This is a generic function; the fixed number of comamnd 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 comamnds 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 comamnd 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; +} + +/** + * 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 comamnd 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; +} + +/** + * 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 comamnd 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; +} + +#endif /* __CVMX_CMD_QUEUE_H__ */ |