[PATCH] Intel IXP4xx network drivers v.3 - QMGR

Krzysztof Halasa
2007-05-08T00:46:35Z

Adds a driver for built-in IXP4xx hardware Queue Manager.

Signed-off-by: Krzysztof Halasa <khc@pm.waw.pl>

diff --git a/arch/arm/mach-ixp4xx/Kconfig b/arch/arm/mach-ixp4xx/Kconfig
index 9715ef5..71ef55f 100644
--- a/arch/arm/mach-ixp4xx/Kconfig
+++ b/arch/arm/mach-ixp4xx/Kconfig
@@ -176,6 +176,12 @@ config IXP4XX_INDIRECT_PCI
need to use the indirect method instead. If you don't know
what you need, leave this option unselected.

+config IXP4XX_QMGR
+ tristate "IXP4xx Queue Manager support"
+ help
+ This driver supports IXP4xx built-in hardware queue manager
+ and is automatically selected by Ethernet and HSS drivers.
+
endmenu

endif
diff --git a/arch/arm/mach-ixp4xx/Makefile b/arch/arm/mach-ixp4xx/Makefile
index 3b87c47..f8e1afc 100644
--- a/arch/arm/mach-ixp4xx/Makefile
+++ b/arch/arm/mach-ixp4xx/Makefile
@@ -26,3 +26,4 @@ obj-$(CONFIG_MACH_NAS100D) += nas100d-setup.o nas100d-power.o
obj-$(CONFIG_MACH_DSMG600) += dsmg600-setup.o dsmg600-power.o

obj-$(CONFIG_PCI) += $(obj-pci-$(CONFIG_PCI)) common-pci.o
+obj-$(CONFIG_IXP4XX_QMGR) += ixp4xx_qmgr.o
diff --git a/arch/arm/mach-ixp4xx/ixp4xx_qmgr.c b/arch/arm/mach-ixp4xx/ixp4xx_qmgr.c
new file mode 100644
index 0000000..b9e9bd6
--- /dev/null
+++ b/arch/arm/mach-ixp4xx/ixp4xx_qmgr.c
@@ -0,0 +1,273 @@
+/*
+ * 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/interrupt.h>
+#include <linux/kernel.h>
+#include <asm/io.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;
+ }
+
+ 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_resource(mem_res);
+ return err;
+}
+
+static void qmgr_remove(void)
+{
+ free_irq(IRQ_IXP4XX_QM1, NULL);
+ synchronize_irq(IRQ_IXP4XX_QM1);
+ iounmap(qmgr_regs);
+ release_resource(mem_res);
+}
+
+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);
diff --git a/include/asm-arm/arch-ixp4xx/qmgr.h b/include/asm-arm/arch-ixp4xx/qmgr.h
new file mode 100644
index 0000000..d03464a
--- /dev/null
+++ b/include/asm-arm/arch-ixp4xx/qmgr.h
@@ -0,0 +1,124 @@
+/*
+ * 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.
+ */
+
+#ifndef IXP4XX_QMGR_H
+#define IXP4XX_QMGR_H
+
+#include <linux/kernel.h>
+#include <asm/io.h>
+
+#define HALF_QUEUES 32
+#define QUEUES 64 /* only 32 lower queues currently supported */
+#define MAX_QUEUE_LENGTH 4 /* in dwords */
+
+#define QUEUE_STAT1_EMPTY 1 /* queue status bits */
+#define QUEUE_STAT1_NEARLY_EMPTY 2
+#define QUEUE_STAT1_NEARLY_FULL 4
+#define QUEUE_STAT1_FULL 8
+#define QUEUE_STAT2_UNDERFLOW 1
+#define QUEUE_STAT2_OVERFLOW 2
+
+#define QUEUE_WATERMARK_0_ENTRIES 0
+#define QUEUE_WATERMARK_1_ENTRY 1
+#define QUEUE_WATERMARK_2_ENTRIES 2
+#define QUEUE_WATERMARK_4_ENTRIES 3
+#define QUEUE_WATERMARK_8_ENTRIES 4
+#define QUEUE_WATERMARK_16_ENTRIES 5
+#define QUEUE_WATERMARK_32_ENTRIES 6
+#define QUEUE_WATERMARK_64_ENTRIES 7
+
+/* queue interrupt request conditions */
+#define QUEUE_IRQ_SRC_EMPTY 0
+#define QUEUE_IRQ_SRC_NEARLY_EMPTY 1
+#define QUEUE_IRQ_SRC_NEARLY_FULL 2
+#define QUEUE_IRQ_SRC_FULL 3
+#define QUEUE_IRQ_SRC_NOT_EMPTY 4
+#define QUEUE_IRQ_SRC_NOT_NEARLY_EMPTY 5
+#define QUEUE_IRQ_SRC_NOT_NEARLY_FULL 6
+#define QUEUE_IRQ_SRC_NOT_FULL 7
+
+struct qmgr_regs {
+ u32 acc[QUEUES][MAX_QUEUE_LENGTH]; /* 0x000 - 0x3FF */
+ u32 stat1[4]; /* 0x400 - 0x40F */
+ u32 stat2[2]; /* 0x410 - 0x417 */
+ u32 statne_h; /* 0x418 - queue nearly empty */
+ u32 statf_h; /* 0x41C - queue full */
+ u32 irqsrc[4]; /* 0x420 - 0x42F IRC source */
+ u32 irqen[2]; /* 0x430 - 0x437 IRQ enabled */
+ u32 irqstat[2]; /* 0x438 - 0x43F - IRQ access only */
+ u32 reserved[1776];
+ u32 sram[2048]; /* 0x2000 - 0x3FFF - config and buffer */
+};
+
+extern struct qmgr_regs __iomem *qmgr_regs;
+
+void qmgr_set_irq(unsigned int queue, int src,
+ void (*handler)(void *pdev), void *pdev);
+void qmgr_enable_irq(unsigned int queue);
+void qmgr_disable_irq(unsigned int queue);
+
+/* request_ and release_queue() must be called from non-IRQ context */
+int qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */,
+ unsigned int nearly_empty_watermark,
+ unsigned int nearly_full_watermark);
+void qmgr_release_queue(unsigned int queue);
+
+
+static inline void qmgr_put_entry(unsigned int queue, u32 val)
+{
+ __raw_writel(val, &qmgr_regs->acc[queue][0]);
+}
+
+static inline u32 qmgr_get_entry(unsigned int queue)
+{
+ return __raw_readl(&qmgr_regs->acc[queue][0]);
+}
+
+static inline int qmgr_get_stat1(unsigned int queue)
+{
+ return (__raw_readl(&qmgr_regs->stat1[queue >> 3])
+ >> ((queue & 7) << 2)) & 0xF;
+}
+
+static inline int qmgr_get_stat2(unsigned int queue)
+{
+ return (__raw_readl(&qmgr_regs->stat2[queue >> 4])
+ >> ((queue & 0xF) << 1)) & 0x3;
+}
+
+static inline int qmgr_stat_empty(unsigned int queue)
+{
+ return !!(qmgr_get_stat1(queue) & QUEUE_STAT1_EMPTY);
+}
+
+static inline int qmgr_stat_nearly_empty(unsigned int queue)
+{
+ return !!(qmgr_get_stat1(queue) & QUEUE_STAT1_NEARLY_EMPTY);
+}
+
+static inline int qmgr_stat_nearly_full(unsigned int queue)
+{
+ return !!(qmgr_get_stat1(queue) & QUEUE_STAT1_NEARLY_FULL);
+}
+
+static inline int qmgr_stat_full(unsigned int queue)
+{
+ return !!(qmgr_get_stat1(queue) & QUEUE_STAT1_FULL);
+}
+
+static inline int qmgr_stat_underflow(unsigned int queue)
+{
+ return !!(qmgr_get_stat2(queue) & QUEUE_STAT2_UNDERFLOW);
+}
+
+static inline int qmgr_stat_overflow(unsigned int queue)
+{
+ return !!(qmgr_get_stat2(queue) & QUEUE_STAT2_OVERFLOW);
+}
+
+#endif