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/*
* Intel IXP4xx Queue Manager driver for Linux
*
* Copyright (C) 2007 Krzysztof Halasa <khc@pm.waw.pl>
*
* 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.
*/
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/arch/qmgr.h>
#define DEBUG 0
struct qmgr_regs __iomem *qmgr_regs;
static struct resource *mem_res;
static spinlock_t qmgr_lock;
static u32 used_sram_bitmap[4]; /* 128 16-dword pages */
static void (*irq_handlers[HALF_QUEUES])(void *pdev);
static void *irq_pdevs[HALF_QUEUES];
void qmgr_set_irq(unsigned int queue, int src,
void (*handler)(void *pdev), void *pdev)
{
u32 __iomem *reg = &qmgr_regs->irqsrc[queue / 8]; /* 8 queues / u32 */
int bit = (queue % 8) * 4; /* 3 bits + 1 reserved bit per queue */
unsigned long flags;
src &= 7;
spin_lock_irqsave(&qmgr_lock, flags);
__raw_writel((__raw_readl(reg) & ~(7 << bit)) | (src << bit), reg);
irq_handlers[queue] = handler;
irq_pdevs[queue] = pdev;
spin_unlock_irqrestore(&qmgr_lock, flags);
}
static irqreturn_t qmgr_irq1(int irq, void *pdev)
{
int i;
u32 val = __raw_readl(&qmgr_regs->irqstat[0]);
__raw_writel(val, &qmgr_regs->irqstat[0]); /* ACK */
for (i = 0; i < HALF_QUEUES; i++)
if (val & (1 << i))
irq_handlers[i](irq_pdevs[i]);
return val ? IRQ_HANDLED : 0;
}
void qmgr_enable_irq(unsigned int queue)
{
unsigned long flags;
spin_lock_irqsave(&qmgr_lock, flags);
__raw_writel(__raw_readl(&qmgr_regs->irqen[0]) | (1 << queue),
&qmgr_regs->irqen[0]);
spin_unlock_irqrestore(&qmgr_lock, flags);
}
void qmgr_disable_irq(unsigned int queue)
{
unsigned long flags;
spin_lock_irqsave(&qmgr_lock, flags);
__raw_writel(__raw_readl(&qmgr_regs->irqen[0]) & ~(1 << queue),
&qmgr_regs->irqen[0]);
spin_unlock_irqrestore(&qmgr_lock, flags);
}
static inline void shift_mask(u32 *mask)
{
mask[3] = mask[3] << 1 | mask[2] >> 31;
mask[2] = mask[2] << 1 | mask[1] >> 31;
mask[1] = mask[1] << 1 | mask[0] >> 31;
mask[0] <<= 1;
}
int qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */,
unsigned int nearly_empty_watermark,
unsigned int nearly_full_watermark)
{
u32 cfg, addr = 0, mask[4]; /* in 16-dwords */
int err;
if (queue >= HALF_QUEUES)
return -ERANGE;
if ((nearly_empty_watermark | nearly_full_watermark) & ~7)
return -EINVAL;
switch (len) {
case 16:
cfg = 0 << 24;
mask[0] = 0x1;
break;
case 32:
cfg = 1 << 24;
mask[0] = 0x3;
break;
case 64:
cfg = 2 << 24;
mask[0] = 0xF;
break;
case 128:
cfg = 3 << 24;
mask[0] = 0xFF;
break;
default:
return -EINVAL;
}
cfg |= nearly_empty_watermark << 26;
cfg |= nearly_full_watermark << 29;
len /= 16; /* in 16-dwords: 1, 2, 4 or 8 */
mask[1] = mask[2] = mask[3] = 0;
if (!try_module_get(THIS_MODULE))
return -ENODEV;
spin_lock_irq(&qmgr_lock);
if (__raw_readl(&qmgr_regs->sram[queue])) {
err = -EBUSY;
goto err;
}
while (1) {
if (!(used_sram_bitmap[0] & mask[0]) &&
!(used_sram_bitmap[1] & mask[1]) &&
!(used_sram_bitmap[2] & mask[2]) &&
!(used_sram_bitmap[3] & mask[3]))
break; /* found free space */
addr++;
shift_mask(mask);
if (addr + len > ARRAY_SIZE(qmgr_regs->sram)) {
printk(KERN_ERR "qmgr: no free SRAM space for"
" queue %i\n", queue);
err = -ENOMEM;
goto err;
}
}
used_sram_bitmap[0] |= mask[0];
used_sram_bitmap[1] |= mask[1];
used_sram_bitmap[2] |= mask[2];
used_sram_bitmap[3] |= mask[3];
__raw_writel(cfg | (addr << 14), &qmgr_regs->sram[queue]);
spin_unlock_irq(&qmgr_lock);
#if DEBUG
printk(KERN_DEBUG "qmgr: requested queue %i, addr = 0x%02X\n",
queue, addr);
#endif
return 0;
err:
spin_unlock_irq(&qmgr_lock);
module_put(THIS_MODULE);
return err;
}
void qmgr_release_queue(unsigned int queue)
{
u32 cfg, addr, mask[4];
BUG_ON(queue >= HALF_QUEUES); /* not in valid range */
spin_lock_irq(&qmgr_lock);
cfg = __raw_readl(&qmgr_regs->sram[queue]);
addr = (cfg >> 14) & 0xFF;
BUG_ON(!addr); /* not requested */
switch ((cfg >> 24) & 3) {
case 0: mask[0] = 0x1; break;
case 1: mask[0] = 0x3; break;
case 2: mask[0] = 0xF; break;
case 3: mask[0] = 0xFF; break;
}
mask[1] = mask[2] = mask[3] = 0;
while (addr--)
shift_mask(mask);
__raw_writel(0, &qmgr_regs->sram[queue]);
used_sram_bitmap[0] &= ~mask[0];
used_sram_bitmap[1] &= ~mask[1];
used_sram_bitmap[2] &= ~mask[2];
used_sram_bitmap[3] &= ~mask[3];
irq_handlers[queue] = NULL; /* catch IRQ bugs */
spin_unlock_irq(&qmgr_lock);
module_put(THIS_MODULE);
#if DEBUG
printk(KERN_DEBUG "qmgr: released queue %i\n", queue);
#endif
}
static int qmgr_init(void)
{
int i, err;
mem_res = request_mem_region(IXP4XX_QMGR_BASE_PHYS,
IXP4XX_QMGR_REGION_SIZE,
"IXP4xx Queue Manager");
if (mem_res == NULL)
return -EBUSY;
qmgr_regs = ioremap(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE);
if (qmgr_regs == NULL) {
err = -ENOMEM;
goto error_map;
}
/* reset qmgr registers */
for (i = 0; i < 4; i++) {
__raw_writel(0x33333333, &qmgr_regs->stat1[i]);
__raw_writel(0, &qmgr_regs->irqsrc[i]);
}
for (i = 0; i < 2; i++) {
__raw_writel(0, &qmgr_regs->stat2[i]);
__raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[i]); /* clear */
__raw_writel(0, &qmgr_regs->irqen[i]);
}
for (i = 0; i < QUEUES; i++)
__raw_writel(0, &qmgr_regs->sram[i]);
err = request_irq(IRQ_IXP4XX_QM1, qmgr_irq1, 0,
"IXP4xx Queue Manager", NULL);
if (err) {
printk(KERN_ERR "qmgr: failed to request IRQ%i\n",
IRQ_IXP4XX_QM1);
goto error_irq;
}
used_sram_bitmap[0] = 0xF; /* 4 first pages reserved for config */
spin_lock_init(&qmgr_lock);
printk(KERN_INFO "IXP4xx Queue Manager initialized.\n");
return 0;
error_irq:
iounmap(qmgr_regs);
error_map:
release_mem_region(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE);
return err;
}
static void qmgr_remove(void)
{
free_irq(IRQ_IXP4XX_QM1, NULL);
synchronize_irq(IRQ_IXP4XX_QM1);
iounmap(qmgr_regs);
release_mem_region(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE);
}
module_init(qmgr_init);
module_exit(qmgr_remove);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Krzysztof Halasa");
EXPORT_SYMBOL(qmgr_regs);
EXPORT_SYMBOL(qmgr_set_irq);
EXPORT_SYMBOL(qmgr_enable_irq);
EXPORT_SYMBOL(qmgr_disable_irq);
EXPORT_SYMBOL(qmgr_request_queue);
EXPORT_SYMBOL(qmgr_release_queue);
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