powerpc/44x: Support OCM(On Chip Memory) for APM821xx SoC and Bluestone board

This patch consists of:
- Add driver for OCM component
- Export OCM Information at /sys/kernel/debug/ppc4xx_ocm/info

Signed-off-by: Vinh Nguyen Huu Tuong <[e-mail]>
Acked-by: Josh Boyer <[e-mail]>
Signed-off-by: Benjamin Herrenschmidt <[e-mail]>

arch/powerpc/boot/dts/bluestone.dts

···
 		interrupt-parent = <&UIC0>;
 	};
 
+	OCM: ocm@400040000 {
+		compatible = "ibm,ocm";
+		status = "ok";
+		cell-index = <1>;
+		/* configured in U-Boot */
+		reg = <4 0x00040000 0x8000>; /* 32K */
+	};
+
 	SDR0: sdr {
 		compatible = "ibm,sdr-apm821xx";
 		dcr-reg = <0x00e 0x002>;

arch/powerpc/include/asm/ppc4xx_ocm.h

···
+/*
+ * PowerPC 4xx OCM memory allocation support
+ *
+ * (C) Copyright 2009, Applied Micro Circuits Corporation
+ * Victor Gallardo ([e-mail])
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef __ASM_POWERPC_PPC4XX_OCM_H__
+#define __ASM_POWERPC_PPC4XX_OCM_H__
+
+#define PPC4XX_OCM_NON_CACHED 0
+#define PPC4XX_OCM_CACHED     1
+
+#if defined(CONFIG_PPC4xx_OCM)
+
+void *ppc4xx_ocm_alloc(phys_addr_t *phys, int size, int align,
+		  int flags, const char *owner);
+void ppc4xx_ocm_free(const void *virt);
+
+#else
+
+#define ppc4xx_ocm_alloc(phys, size, align, flags, owner)	NULL
+#define ppc4xx_ocm_free(addr)	((void)0)
+
+#endif /* CONFIG_PPC4xx_OCM */
+
+#endif  /* __ASM_POWERPC_PPC4XX_OCM_H__ */

arch/powerpc/platforms/44x/Kconfig

···
 	help
 	  Enable gpiolib support for ppc440 based boards
 
+config PPC4xx_OCM
+	bool "PPC4xx On Chip Memory (OCM) support"
+	depends on 4xx
+	select PPC_LIB_RHEAP
+	help
+	  Enable OCM support for PowerPC 4xx platforms with on chip memory,
+	  OCM provides the fast place for memory access to improve performance.
+
 # 44x specific CPU modules, selected based on the board above.
 config 440EP
 	bool

arch/powerpc/sysdev/Makefile

···
 obj-$(CONFIG_PPC_I8259)		+= i8259.o
 obj-$(CONFIG_IPIC)		+= ipic.o
 obj-$(CONFIG_4xx)		+= uic.o
+obj-$(CONFIG_PPC4xx_OCM)	+= ppc4xx_ocm.o
 obj-$(CONFIG_4xx_SOC)		+= ppc4xx_soc.o
 obj-$(CONFIG_XILINX_VIRTEX)	+= xilinx_intc.o
 obj-$(CONFIG_XILINX_PCI)	+= xilinx_pci.o

arch/powerpc/sysdev/ppc4xx_ocm.c

···
+/*
+ * PowerPC 4xx OCM memory allocation support
+ *
+ * (C) Copyright 2009, Applied Micro Circuits Corporation
+ * Victor Gallardo ([e-mail])
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/dma-mapping.h>
+#include <linux/of.h>
+#include <asm/rheap.h>
+#include <asm/ppc4xx_ocm.h>
+#include <linux/slab.h>
+#include <linux/debugfs.h>
+
+#define OCM_DISABLED	0
+#define OCM_ENABLED		1
+
+struct ocm_block {
+	struct list_head	list;
+	void __iomem		*addr;
+	int					size;
+	const char			*owner;
+};
+
+/* non-cached or cached region */
+struct ocm_region {
+	phys_addr_t			phys;
+	void __iomem		*virt;
+
+	int					memtotal;
+	int					memfree;
+
+	rh_info_t			*rh;
+	struct list_head	list;
+};
+
+struct ocm_info {
+	int					index;
+	int					status;
+	int					ready;
+
+	phys_addr_t			phys;
+
+	int					alignment;
+	int					memtotal;
+	int					cache_size;
+
+	struct ocm_region	nc;	/* non-cached region */
+	struct ocm_region	c;	/* cached region */
+};
+
+static struct ocm_info *ocm_nodes;
+static int ocm_count;
+
+static struct ocm_info *ocm_get_node(unsigned int index)
+{
+	if (index >= ocm_count) {
+		printk(KERN_ERR "PPC4XX OCM: invalid index");
+		return NULL;
+	}
+
+	return &ocm_nodes[index];
+}
+
+static int ocm_free_region(struct ocm_region *ocm_reg, const void *addr)
+{
+	struct ocm_block *blk, *tmp;
+	unsigned long offset;
+
+	if (!ocm_reg->virt)
+		return 0;
+
+	list_for_each_entry_safe(blk, tmp, &ocm_reg->list, list) {
+		if (blk->addr == addr) {
+			offset = addr - ocm_reg->virt;
+			ocm_reg->memfree += blk->size;
+			rh_free(ocm_reg->rh, offset);
+			list_del(&blk->list);
+			kfree(blk);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+static void __init ocm_init_node(int count, struct device_node *node)
+{
+	struct ocm_info *ocm;
+
+	const unsigned int *cell_index;
+	const unsigned int *cache_size;
+	int len;
+
+	struct resource rsrc;
+	int ioflags;
+
+	ocm = ocm_get_node(count);
+
+	cell_index = of_get_property(node, "cell-index", &len);
+	if (!cell_index) {
+		printk(KERN_ERR "PPC4XX OCM: missing cell-index property");
+		return;
+	}
+	ocm->index = *cell_index;
+
+	if (of_device_is_available(node))
+		ocm->status = OCM_ENABLED;
+
+	cache_size = of_get_property(node, "cached-region-size", &len);
+	if (cache_size)
+		ocm->cache_size = *cache_size;
+
+	if (of_address_to_resource(node, 0, &rsrc)) {
+		printk(KERN_ERR "PPC4XX OCM%d: could not get resource address\n",
+			ocm->index);
+		return;
+	}
+
+	ocm->phys = rsrc.start;
+	ocm->memtotal = (rsrc.end - rsrc.start + 1);
+
+	printk(KERN_INFO "PPC4XX OCM%d: %d Bytes (%s)\n",
+		ocm->index, ocm->memtotal,
+		(ocm->status == OCM_DISABLED) ? "disabled" : "enabled");
+
+	if (ocm->status == OCM_DISABLED)
+		return;
+
+	/* request region */
+
+	if (!request_mem_region(ocm->phys, ocm->memtotal, "ppc4xx_ocm")) {
+		printk(KERN_ERR "PPC4XX OCM%d: could not request region\n",
+			ocm->index);
+		return;
+	}
+
+	/* Configure non-cached and cached regions */
+
+	ocm->nc.phys = ocm->phys;
+	ocm->nc.memtotal = ocm->memtotal - ocm->cache_size;
+	ocm->nc.memfree = ocm->nc.memtotal;
+
+	ocm->c.phys = ocm->phys + ocm->nc.memtotal;
+	ocm->c.memtotal = ocm->cache_size;
+	ocm->c.memfree = ocm->c.memtotal;
+
+	if (ocm->nc.memtotal == 0)
+		ocm->nc.phys = 0;
+
+	if (ocm->c.memtotal == 0)
+		ocm->c.phys = 0;
+
+	printk(KERN_INFO "PPC4XX OCM%d: %d Bytes (non-cached)\n",
+		ocm->index, ocm->nc.memtotal);
+
+	printk(KERN_INFO "PPC4XX OCM%d: %d Bytes (cached)\n",
+		ocm->index, ocm->c.memtotal);
+
+	/* ioremap the non-cached region */
+	if (ocm->nc.memtotal) {
+		ioflags = _PAGE_NO_CACHE | _PAGE_GUARDED | _PAGE_EXEC;
+		ocm->nc.virt = __ioremap(ocm->nc.phys, ocm->nc.memtotal,
+					  ioflags);
+
+		if (!ocm->nc.virt) {
+			printk(KERN_ERR
+			       "PPC4XX OCM%d: failed to ioremap non-cached memory\n",
+			       ocm->index);
+			ocm->nc.memfree = 0;
+			return;
+		}
+	}
+
+	/* ioremap the cached region */
+
+	if (ocm->c.memtotal) {
+		ioflags = _PAGE_EXEC;
+		ocm->c.virt = __ioremap(ocm->c.phys, ocm->c.memtotal,
+					 ioflags);
+
+		if (!ocm->c.virt) {
+			printk(KERN_ERR
+			       "PPC4XX OCM%d: failed to ioremap cached memory\n",
+			       ocm->index);
+			ocm->c.memfree = 0;
+			return;
+		}
+	}
+
+	/* Create Remote Heaps */
+
+	ocm->alignment = 4; /* default 4 byte alignment */
+
+	if (ocm->nc.virt) {
+		ocm->nc.rh = rh_create(ocm->alignment);
+		rh_attach_region(ocm->nc.rh, 0, ocm->nc.memtotal);
+	}
+
+	if (ocm->c.virt) {
+		ocm->c.rh = rh_create(ocm->alignment);
+		rh_attach_region(ocm->c.rh, 0, ocm->c.memtotal);
+	}
+
+	INIT_LIST_HEAD(&ocm->nc.list);
+	INIT_LIST_HEAD(&ocm->c.list);
+
+	ocm->ready = 1;
+
+	return;
+}
+
+static int ocm_debugfs_show(struct seq_file *m, void *v)
+{
+	struct ocm_block *blk, *tmp;
+	unsigned int i;
+
+	for (i = 0; i < ocm_count; i++) {
+		struct ocm_info *ocm = ocm_get_node(i);
+
+		if (!ocm || !ocm->ready)
+			continue;
+
+		seq_printf(m, "PPC4XX OCM   : %d\n", ocm->index);
+		seq_printf(m, "PhysAddr     : 0x%llx\n", ocm->phys);
+		seq_printf(m, "MemTotal     : %d Bytes\n", ocm->memtotal);
+		seq_printf(m, "MemTotal(NC) : %d Bytes\n", ocm->nc.memtotal);
+		seq_printf(m, "MemTotal(C)  : %d Bytes\n", ocm->c.memtotal);
+
+		seq_printf(m, "\n");
+
+		seq_printf(m, "NC.PhysAddr  : 0x%llx\n", ocm->nc.phys);
+		seq_printf(m, "NC.VirtAddr  : 0x%p\n", ocm->nc.virt);
+		seq_printf(m, "NC.MemTotal  : %d Bytes\n", ocm->nc.memtotal);
+		seq_printf(m, "NC.MemFree   : %d Bytes\n", ocm->nc.memfree);
+
+		list_for_each_entry_safe(blk, tmp, &ocm->nc.list, list) {
+			seq_printf(m, "NC.MemUsed   : %d Bytes (%s)\n",
+							blk->size, blk->owner);
+		}
+
+		seq_printf(m, "\n");
+
+		seq_printf(m, "C.PhysAddr   : 0x%llx\n", ocm->c.phys);
+		seq_printf(m, "C.VirtAddr   : 0x%p\n", ocm->c.virt);
+		seq_printf(m, "C.MemTotal   : %d Bytes\n", ocm->c.memtotal);
+		seq_printf(m, "C.MemFree    : %d Bytes\n", ocm->c.memfree);
+
+		list_for_each_entry_safe(blk, tmp, &ocm->c.list, list) {
+			seq_printf(m, "C.MemUsed    : %d Bytes (%s)\n",
+						blk->size, blk->owner);
+		}
+
+		seq_printf(m, "\n");
+	}
+
+	return 0;
+}
+
+static int ocm_debugfs_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, ocm_debugfs_show, NULL);
+}
+
+static const struct file_operations ocm_debugfs_fops = {
+	.open = ocm_debugfs_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static int ocm_debugfs_init(void)
+{
+	struct dentry *junk;
+
+	junk = debugfs_create_dir("ppc4xx_ocm", 0);
+	if (!junk) {
+		printk(KERN_ALERT "debugfs ppc4xx ocm: failed to create dir\n");
+		return -1;
+	}
+
+	if (debugfs_create_file("info", 0644, junk, NULL, &ocm_debugfs_fops)) {
+		printk(KERN_ALERT "debugfs ppc4xx ocm: failed to create file\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+void *ppc4xx_ocm_alloc(phys_addr_t *phys, int size, int align,
+			int flags, const char *owner)
+{
+	void __iomem *addr = NULL;
+	unsigned long offset;
+	struct ocm_info *ocm;
+	struct ocm_region *ocm_reg;
+	struct ocm_block *ocm_blk;
+	int i;
+
+	for (i = 0; i < ocm_count; i++) {
+		ocm = ocm_get_node(i);
+
+		if (!ocm || !ocm->ready)
+			continue;
+
+		if (flags == PPC4XX_OCM_NON_CACHED)
+			ocm_reg = &ocm->nc;
+		else
+			ocm_reg = &ocm->c;
+
+		if (!ocm_reg->virt)
+			continue;
+
+		if (align < ocm->alignment)
+			align = ocm->alignment;
+
+		offset = rh_alloc_align(ocm_reg->rh, size, align, NULL);
+
+		if (IS_ERR_VALUE(offset))
+			continue;
+
+		ocm_blk = kzalloc(sizeof(struct ocm_block *), GFP_KERNEL);
+		if (!ocm_blk) {
+			printk(KERN_ERR "PPC4XX OCM: could not allocate ocm block");
+			rh_free(ocm_reg->rh, offset);
+			break;
+		}
+
+		*phys = ocm_reg->phys + offset;
+		addr = ocm_reg->virt + offset;
+		size = ALIGN(size, align);
+
+		ocm_blk->addr = addr;
+		ocm_blk->size = size;
+		ocm_blk->owner = owner;
+		list_add_tail(&ocm_blk->list, &ocm_reg->list);
+
+		ocm_reg->memfree -= size;
+
+		break;
+	}
+
+	return addr;
+}
+
+void ppc4xx_ocm_free(const void *addr)
+{
+	int i;
+
+	if (!addr)
+		return;
+
+	for (i = 0; i < ocm_count; i++) {
+		struct ocm_info *ocm = ocm_get_node(i);
+
+		if (!ocm || !ocm->ready)
+			continue;
+
+		if (ocm_free_region(&ocm->nc, addr) ||
+			ocm_free_region(&ocm->c, addr))
+			return;
+	}
+}
+
+static int __init ppc4xx_ocm_init(void)
+{
+	struct device_node *np;
+	int count;
+
+	count = 0;
+	for_each_compatible_node(np, NULL, "ibm,ocm")
+		count++;
+
+	if (!count)
+		return 0;
+
+	ocm_nodes = kzalloc((count * sizeof(struct ocm_info)), GFP_KERNEL);
+	if (!ocm_nodes) {
+		printk(KERN_ERR "PPC4XX OCM: failed to allocate OCM nodes!\n");
+		return -ENOMEM;
+	}
+
+	ocm_count = count;
+	count = 0;
+
+	for_each_compatible_node(np, NULL, "ibm,ocm") {
+		ocm_init_node(count, np);
+		count++;
+	}
+
+	ocm_debugfs_init();
+
+	return 0;
+}
+
+arch_initcall(ppc4xx_ocm_init);