| /* Copyright (C) 2010 - 2013 UNISYS CORPORATION |
| * All rights reserved. |
| * |
| * 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; either version 2 of the License, or (at |
| * your option) any later version. |
| * |
| * 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, GOOD TITLE or |
| * NON INFRINGEMENT. See the GNU General Public License for more |
| * details. |
| */ |
| |
| #include <linux/kernel.h> |
| #ifdef CONFIG_MODVERSIONS |
| #include <config/modversions.h> |
| #endif |
| #include <linux/module.h> |
| #include <linux/init.h> /* for module_init and module_exit */ |
| #include <linux/slab.h> /* for memcpy */ |
| #include <linux/types.h> |
| |
| /* Implementation of exported functions for Supervisor channels */ |
| #include "channel.h" |
| |
| /* |
| * Routine Description: |
| * Tries to insert the prebuilt signal pointed to by pSignal into the nth |
| * Queue of the Channel pointed to by pChannel |
| * |
| * Parameters: |
| * pChannel: (IN) points to the IO Channel |
| * Queue: (IN) nth Queue of the IO Channel |
| * pSignal: (IN) pointer to the signal |
| * |
| * Assumptions: |
| * - pChannel, Queue and pSignal are valid. |
| * - If insertion fails due to a full queue, the caller will determine the |
| * retry policy (e.g. wait & try again, report an error, etc.). |
| * |
| * Return value: |
| * 1 if the insertion succeeds, 0 if the queue was full. |
| */ |
| unsigned char spar_signal_insert(struct channel_header __iomem *ch, u32 queue, |
| void *sig) |
| { |
| void __iomem *psignal; |
| unsigned int head, tail, nof; |
| |
| struct signal_queue_header __iomem *pqhdr = |
| (struct signal_queue_header __iomem *) |
| ((char __iomem *)ch + readq(&ch->ch_space_offset)) |
| + queue; |
| |
| /* capture current head and tail */ |
| head = readl(&pqhdr->head); |
| tail = readl(&pqhdr->tail); |
| |
| /* queue is full if (head + 1) % n equals tail */ |
| if (((head + 1) % readl(&pqhdr->max_slots)) == tail) { |
| nof = readq(&pqhdr->num_overflows) + 1; |
| writeq(nof, &pqhdr->num_overflows); |
| return 0; |
| } |
| |
| /* increment the head index */ |
| head = (head + 1) % readl(&pqhdr->max_slots); |
| |
| /* copy signal to the head location from the area pointed to |
| * by pSignal |
| */ |
| psignal = (char __iomem *)pqhdr + readq(&pqhdr->sig_base_offset) + |
| (head * readl(&pqhdr->signal_size)); |
| memcpy_toio(psignal, sig, readl(&pqhdr->signal_size)); |
| |
| mb(); /* channel synch */ |
| writel(head, &pqhdr->head); |
| |
| writeq(readq(&pqhdr->num_sent) + 1, &pqhdr->num_sent); |
| return 1; |
| } |
| EXPORT_SYMBOL_GPL(spar_signal_insert); |
| |
| /* |
| * Routine Description: |
| * Removes one signal from Channel pChannel's nth Queue at the |
| * time of the call and copies it into the memory pointed to by |
| * pSignal. |
| * |
| * Parameters: |
| * pChannel: (IN) points to the IO Channel |
| * Queue: (IN) nth Queue of the IO Channel |
| * pSignal: (IN) pointer to where the signals are to be copied |
| * |
| * Assumptions: |
| * - pChannel and Queue are valid. |
| * - pSignal points to a memory area large enough to hold queue's SignalSize |
| * |
| * Return value: |
| * 1 if the removal succeeds, 0 if the queue was empty. |
| */ |
| unsigned char |
| spar_signal_remove(struct channel_header __iomem *ch, u32 queue, void *sig) |
| { |
| void __iomem *psource; |
| unsigned int head, tail; |
| struct signal_queue_header __iomem *pqhdr = |
| (struct signal_queue_header __iomem *)((char __iomem *)ch + |
| readq(&ch->ch_space_offset)) + queue; |
| |
| /* capture current head and tail */ |
| head = readl(&pqhdr->head); |
| tail = readl(&pqhdr->tail); |
| |
| /* queue is empty if the head index equals the tail index */ |
| if (head == tail) { |
| writeq(readq(&pqhdr->num_empty) + 1, &pqhdr->num_empty); |
| return 0; |
| } |
| |
| /* advance past the 'empty' front slot */ |
| tail = (tail + 1) % readl(&pqhdr->max_slots); |
| |
| /* copy signal from tail location to the area pointed to by pSignal */ |
| psource = (char __iomem *)pqhdr + readq(&pqhdr->sig_base_offset) + |
| (tail * readl(&pqhdr->signal_size)); |
| memcpy_fromio(sig, psource, readl(&pqhdr->signal_size)); |
| |
| mb(); /* channel synch */ |
| writel(tail, &pqhdr->tail); |
| |
| writeq(readq(&pqhdr->num_received) + 1, |
| &pqhdr->num_received); |
| return 1; |
| } |
| EXPORT_SYMBOL_GPL(spar_signal_remove); |
| |
| /* |
| * Routine Description: |
| * Removes all signals present in Channel pChannel's nth Queue at the |
| * time of the call and copies them into the memory pointed to by |
| * pSignal. Returns the # of signals copied as the value of the routine. |
| * |
| * Parameters: |
| * pChannel: (IN) points to the IO Channel |
| * Queue: (IN) nth Queue of the IO Channel |
| * pSignal: (IN) pointer to where the signals are to be copied |
| * |
| * Assumptions: |
| * - pChannel and Queue are valid. |
| * - pSignal points to a memory area large enough to hold Queue's MaxSignals |
| * # of signals, each of which is Queue's SignalSize. |
| * |
| * Return value: |
| * # of signals copied. |
| */ |
| unsigned int spar_signal_remove_all(struct channel_header *ch, u32 queue, |
| void *sig) |
| { |
| void *psource; |
| unsigned int head, tail, count = 0; |
| struct signal_queue_header *pqhdr = |
| (struct signal_queue_header *)((char *)ch + |
| ch->ch_space_offset) + queue; |
| |
| /* capture current head and tail */ |
| head = pqhdr->head; |
| tail = pqhdr->tail; |
| |
| /* queue is empty if the head index equals the tail index */ |
| if (head == tail) |
| return 0; |
| |
| while (head != tail) { |
| /* advance past the 'empty' front slot */ |
| tail = (tail + 1) % pqhdr->max_slots; |
| |
| /* copy signal from tail location to the area pointed |
| * to by pSignal |
| */ |
| psource = |
| (char *)pqhdr + pqhdr->sig_base_offset + |
| (tail * pqhdr->signal_size); |
| memcpy((char *)sig + (pqhdr->signal_size * count), |
| psource, pqhdr->signal_size); |
| |
| mb(); /* channel synch */ |
| pqhdr->tail = tail; |
| |
| count++; |
| pqhdr->num_received++; |
| } |
| |
| return count; |
| } |
| |
| /* |
| * Routine Description: |
| * Determine whether a signal queue is empty. |
| * |
| * Parameters: |
| * pChannel: (IN) points to the IO Channel |
| * Queue: (IN) nth Queue of the IO Channel |
| * |
| * Return value: |
| * 1 if the signal queue is empty, 0 otherwise. |
| */ |
| unsigned char spar_signalqueue_empty(struct channel_header __iomem *ch, |
| u32 queue) |
| { |
| struct signal_queue_header __iomem *pqhdr = |
| (struct signal_queue_header __iomem *)((char __iomem *)ch + |
| readq(&ch->ch_space_offset)) + queue; |
| return readl(&pqhdr->head) == readl(&pqhdr->tail); |
| } |
| EXPORT_SYMBOL_GPL(spar_signalqueue_empty); |
| |