[PATCH] ARM: Support for IXP4xx hardware Queue Manager.
Krzysztof Halasa
khc at pm.waw.pl
Sun Apr 7 15:55:18 EDT 2013
Signed-off-by: Krzysztof Hałasa <khc at pm.waw.pl>
diff --git a/arch/arm/mach-ixp4xx/Kconfig b/arch/arm/mach-ixp4xx/Kconfig
index e69de29..9244be9 100644
--- a/arch/arm/mach-ixp4xx/Kconfig
+++ b/arch/arm/mach-ixp4xx/Kconfig
@@ -0,0 +1,9 @@
+if ARCH_IXP4XX
+
+config IXP4XX_QMGR
+ tristate "IXP4xx Queue Manager support"
+ help
+ This driver supports IXP4xx built-in hardware queue manager
+ and is required by the Ethernet driver.
+
+endif
diff --git a/arch/arm/mach-ixp4xx/Makefile b/arch/arm/mach-ixp4xx/Makefile
index d8a3d7f..09a0d63 100644
--- a/arch/arm/mach-ixp4xx/Makefile
+++ b/arch/arm/mach-ixp4xx/Makefile
@@ -1 +1,2 @@
obj-y += generic.o
+obj-$(CONFIG_IXP4XX_QMGR) += qmgr.o
diff --git a/arch/arm/mach-ixp4xx/include/mach/qmgr.h b/arch/arm/mach-ixp4xx/include/mach/qmgr.h
new file mode 100644
index 0000000..4e9b8d4
--- /dev/null
+++ b/arch/arm/mach-ixp4xx/include/mach/qmgr.h
@@ -0,0 +1,164 @@
+/*
+ * Copyright (C) 2007 Krzysztof Halasa <khc at 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 <common.h>
+#include <mach/ixp4xx-regs.h>
+#include <asm/io.h>
+
+#define DEBUG_QMGR 0
+
+#define HALF_QUEUES 32
+#define QUEUES 64
+#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 */
+};
+
+static const struct qmgr_regs *qmgr_regs = (struct qmgr_regs *)IXP4XX_QMGR_BASE;
+
+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 */
+
+#if DEBUG_QMGR
+extern char qmgr_queue_descs[HALF_QUEUES][32];
+
+void qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */,
+ unsigned int nearly_empty_watermark,
+ unsigned int nearly_full_watermark,
+ const char *desc_format, const char* name);
+#else
+void __qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */,
+ unsigned int nearly_empty_watermark,
+ unsigned int nearly_full_watermark);
+#define qmgr_request_queue(queue, len, nearly_empty_watermark, \
+ nearly_full_watermark, desc_format, name) \
+ __qmgr_request_queue(queue, len, nearly_empty_watermark, \
+ nearly_full_watermark)
+#endif
+
+void qmgr_release_queue(unsigned int queue);
+
+
+static inline void qmgr_put_entry(unsigned int queue, u32 val)
+{
+#if DEBUG_QMGR
+ BUG_ON(!qmgr_queue_descs[queue]); /* not yet requested */
+
+ fprintf(stderr, "Queue %s(%i) put %X\n",
+ qmgr_queue_descs[queue], queue, val);
+#endif
+ __raw_writel(val, &qmgr_regs->acc[queue][0]);
+}
+
+static inline u32 qmgr_get_entry(unsigned int queue)
+{
+ u32 val;
+ val = __raw_readl(&qmgr_regs->acc[queue][0]);
+#if DEBUG_QMGR
+ BUG_ON(!qmgr_queue_descs[queue]); /* not yet requested */
+
+ fprintf(stderr, "Queue %s(%i) get %X\n",
+ qmgr_queue_descs[queue], queue, val);
+#endif
+ return val;
+}
+
+static inline int __qmgr_get_stat1(unsigned int queue)
+{
+ return (__raw_readl(&qmgr_regs->stat1[queue >> 3])
+ >> ((queue & 7) << 2)) & 0xF;
+}
+
+/**
+ * qmgr_stat_empty() - checks if a hardware queue is empty
+ * @queue: queue number
+ *
+ * Returns non-zero value if the queue is empty.
+ */
+static inline int qmgr_stat_empty(unsigned int queue)
+{
+ return __qmgr_get_stat1(queue) & QUEUE_STAT1_EMPTY;
+}
+
+/**
+ * qmgr_stat_below_low_watermark() - checks if a queue is below low watermark
+ * @queue: queue number
+ *
+ * Returns non-zero value if the queue is below low watermark.
+ */
+static inline int qmgr_stat_below_low_watermark(unsigned int queue)
+{
+ return __qmgr_get_stat1(queue) & QUEUE_STAT1_NEARLY_EMPTY;
+}
+
+/**
+ * qmgr_stat_above_high_watermark() - checks if a queue is above high watermark
+ * @queue: queue number
+ *
+ * Returns non-zero value if the queue is above high watermark
+ */
+static inline int qmgr_stat_above_high_watermark(unsigned int queue)
+{
+ return __qmgr_get_stat1(queue) & QUEUE_STAT1_NEARLY_FULL;
+}
+
+/**
+ * qmgr_stat_full() - checks if a hardware queue is full
+ * @queue: queue number
+ *
+ * Returns non-zero value if the queue is full.
+ */
+static inline int qmgr_stat_full(unsigned int queue)
+{
+ return __qmgr_get_stat1(queue) & QUEUE_STAT1_FULL;
+}
+
+#endif
diff --git a/arch/arm/mach-ixp4xx/qmgr.c b/arch/arm/mach-ixp4xx/qmgr.c
new file mode 100644
index 0000000..81b6522
--- /dev/null
+++ b/arch/arm/mach-ixp4xx/qmgr.c
@@ -0,0 +1,259 @@
+/*
+ * Intel IXP4xx Queue Manager driver for Linux
+ *
+ * Copyright (C) 2007 Krzysztof Halasa <khc at 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 <init.h>
+#include <errno.h>
+#include <mach/qmgr.h>
+
+static u32 used_sram_bitmap[4]; /* 128 16-dword pages */
+
+#if DEBUG_QMGR
+char qmgr_queue_descs[HALF_QUEUES][32];
+#endif
+
+#ifdef CONFIG_USE_IRQ
+
+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)
+{
+ const u32 *reg;
+ int bit;
+ BUG_ON(src > QUEUE_IRQ_SRC_NOT_FULL);
+ reg = &qmgr_regs->irqsrc[queue >> 3]; /* 8 queues per u32 */
+ bit = (queue % 8) * 4; /* 3 bits + 1 reserved bit per queue */
+ __raw_writel((__raw_readl(reg) & ~(7 << bit)) | (src << bit), reg);
+
+ irq_handlers[queue] = handler;
+ irq_pdevs[queue] = pdev;
+}
+
+
+static void qmgr_irq1_a0(void *data)
+{
+ int i;
+ u32 en_bitmap, src, stat;
+
+ /* ACK - it may clear any bits so don't rely on it */
+ __raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[0]);
+
+ en_bitmap = qmgr_regs->irqen[0];
+ while (en_bitmap) {
+ i = fls(en_bitmap) - 1; /* number of the last "low" queue */
+ en_bitmap &= ~BIT(i);
+ src = qmgr_regs->irqsrc[i >> 3];
+ stat = qmgr_regs->stat1[i >> 3];
+ if (src & 4) /* the IRQ condition is inverted */
+ stat = ~stat;
+ if (stat & BIT(src & 3))
+ irq_handlers[i](irq_pdevs[i]);
+ }
+}
+
+
+static void qmgr_irq1(void *data)
+{
+ int i;
+ u32 req_bitmap = __raw_readl(&qmgr_regs->irqstat[0]);
+
+ if (!req_bitmap)
+ return;
+ __raw_writel(req_bitmap, &qmgr_regs->irqstat[0]); /* ACK */
+
+ while (req_bitmap) {
+ i = fls(req_bitmap) - 1; /* number of the last queue */
+ req_bitmap &= ~BIT(i);
+ irq_handlers[i](irq_pdevs[i]);
+ }
+}
+
+
+void qmgr_enable_irq(unsigned int queue)
+{
+ u32 mask = 1 << queue;
+
+ __raw_writel(__raw_readl(&qmgr_regs->irqen[0]) | mask,
+ &qmgr_regs->irqen[0]);
+}
+
+void qmgr_disable_irq(unsigned int queue)
+{
+ u32 mask = 1 << queue;
+
+ __raw_writel(__raw_readl(&qmgr_regs->irqen[0]) & ~mask,
+ &qmgr_regs->irqen[0]);
+ __raw_writel(mask, &qmgr_regs->irqstat[0]); /* clear */
+}
+
+#endif /* CONFIG_USE_IRQ */
+
+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;
+}
+
+#if DEBUG_QMGR
+void qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */,
+ unsigned int nearly_empty_watermark,
+ unsigned int nearly_full_watermark,
+ const char *desc_format, const char* name)
+#else
+void __qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */,
+ unsigned int nearly_empty_watermark,
+ unsigned int nearly_full_watermark)
+#endif
+{
+ u32 cfg, addr = 0, mask[4]; /* in 16-dwords */
+
+ BUG_ON(queue >= HALF_QUEUES);
+ BUG_ON((nearly_empty_watermark | nearly_full_watermark) & ~7);
+
+ 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:
+ BUG();
+ }
+
+ 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;
+
+ BUG_ON(__raw_readl(&qmgr_regs->sram[queue]));
+
+ 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)) {
+ fprintf(stderr, "qmgr: no free SRAM space for"
+ " queue %i\n", queue);
+ BUG();
+ }
+ }
+
+ 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]);
+#if DEBUG_QMGR
+ /* no snprintf() */
+ sprintf(qmgr_queue_descs[queue], desc_format, name);
+ fprintf(stderr, "qmgr: requested queue %s(%i) addr = 0x%02X\n",
+ qmgr_queue_descs[queue], queue, addr);
+#endif
+}
+
+void qmgr_release_queue(unsigned int queue)
+{
+ u32 cfg, addr, mask[4];
+
+ BUG_ON(queue >= HALF_QUEUES); /* not in valid range */
+
+ 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);
+
+#if DEBUG_QMGR
+ fprintf(stderr, "qmgr: releasing queue %s(%i)\n",
+ qmgr_queue_descs[queue], queue);
+ qmgr_queue_descs[queue][0] = '\x0';
+#endif
+ __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];
+#ifdef CONFIG_USE_IRQ
+ irq_handlers[queue] = NULL; /* catch IRQ bugs */
+#endif
+
+ while ((addr = qmgr_get_entry(queue)))
+ fprintf(stderr, "qmgr: released queue %i not empty: 0x%08X\n",
+ queue, addr);
+}
+
+static int __init qmgr_init(void)
+{
+ int i;
+#ifdef CONFIG_USE_IRQ
+ interrupt_handler_t *handler;
+#endif
+
+ /* 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]);
+ }
+
+ __raw_writel(0xFFFFFFFF, &qmgr_regs->statne_h);
+ __raw_writel(0, &qmgr_regs->statf_h);
+
+ for (i = 0; i < QUEUES; i++)
+ __raw_writel(0, &qmgr_regs->sram[i]);
+
+#ifdef CONFIG_USE_IRQ
+ if (cpu_is_ixp42x_rev_a0())
+ handler = qmgr_irq1_a0;
+ else
+ handler = qmgr_irq1;
+
+ irq_install_handler(IXP425_QM1_IRQ, handler, NULL);
+#endif
+ used_sram_bitmap[0] = 0xF; /* 4 first pages reserved for config */
+ return 0;
+}
+
+coredevice_initcall(qmgr_init);
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