1 files changed, 414 insertions, 0 deletions
diff --git a/arch/sh/kernel/cpu/sh4/sq.c b/arch/sh/kernel/cpu/sh4/sq.c
new file mode 100644
index 000000000..8ddfe9989
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh4/sq.c
@@ -0,0 +1,414 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * arch/sh/kernel/cpu/sh4/sq.c
+ *
+ * General management API for SH-4 integrated Store Queues
+ *
+ * Copyright (C) 2001 - 2006  Paul Mundt
+ * Copyright (C) 2001, 2002  M. R. Brown
+ */
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/bitmap.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/io.h>
+#include <linux/prefetch.h>
+#include <asm/page.h>
+#include <asm/cacheflush.h>
+#include <cpu/sq.h>
+
+struct sq_mapping;
+
+struct sq_mapping {
+	const char *name;
+
+	unsigned long sq_addr;
+	unsigned long addr;
+	unsigned int size;
+
+	struct sq_mapping *next;
+};
+
+static struct sq_mapping *sq_mapping_list;
+static DEFINE_SPINLOCK(sq_mapping_lock);
+static struct kmem_cache *sq_cache;
+static unsigned long *sq_bitmap;
+
+#define store_queue_barrier()			\
+do {						\
+	(void)__raw_readl(P4SEG_STORE_QUE);	\
+	__raw_writel(0, P4SEG_STORE_QUE + 0);	\
+	__raw_writel(0, P4SEG_STORE_QUE + 8);	\
+} while (0);
+
+/**
+ * sq_flush_range - Flush (prefetch) a specific SQ range
+ * @start: the store queue address to start flushing from
+ * @len: the length to flush
+ *
+ * Flushes the store queue cache from @start to @start + @len in a
+ * linear fashion.
+ */
+void sq_flush_range(unsigned long start, unsigned int len)
+{
+	unsigned long *sq = (unsigned long *)start;
+
+	/* Flush the queues */
+	for (len >>= 5; len--; sq += 8)
+		prefetchw(sq);
+
+	/* Wait for completion */
+	store_queue_barrier();
+}
+EXPORT_SYMBOL(sq_flush_range);
+
+static inline void sq_mapping_list_add(struct sq_mapping *map)
+{
+	struct sq_mapping **p, *tmp;
+
+	spin_lock_irq(&sq_mapping_lock);
+
+	p = &sq_mapping_list;
+	while ((tmp = *p) != NULL)
+		p = &tmp->next;
+
+	map->next = tmp;
+	*p = map;
+
+	spin_unlock_irq(&sq_mapping_lock);
+}
+
+static inline void sq_mapping_list_del(struct sq_mapping *map)
+{
+	struct sq_mapping **p, *tmp;
+
+	spin_lock_irq(&sq_mapping_lock);
+
+	for (p = &sq_mapping_list; (tmp = *p); p = &tmp->next)
+		if (tmp == map) {
+			*p = tmp->next;
+			break;
+		}
+
+	spin_unlock_irq(&sq_mapping_lock);
+}
+
+static int __sq_remap(struct sq_mapping *map, pgprot_t prot)
+{
+#if defined(CONFIG_MMU)
+	struct vm_struct *vma;
+
+	vma = __get_vm_area_caller(map->size, VM_ALLOC, map->sq_addr,
+			SQ_ADDRMAX, __builtin_return_address(0));
+	if (!vma)
+		return -ENOMEM;
+
+	vma->phys_addr = map->addr;
+
+	if (ioremap_page_range((unsigned long)vma->addr,
+			       (unsigned long)vma->addr + map->size,
+			       vma->phys_addr, prot)) {
+		vunmap(vma->addr);
+		return -EAGAIN;
+	}
+#else
+	/*
+	 * Without an MMU (or with it turned off), this is much more
+	 * straightforward, as we can just load up each queue's QACR with
+	 * the physical address appropriately masked.
+	 */
+	__raw_writel(((map->addr >> 26) << 2) & 0x1c, SQ_QACR0);
+	__raw_writel(((map->addr >> 26) << 2) & 0x1c, SQ_QACR1);
+#endif
+
+	return 0;
+}
+
+/**
+ * sq_remap - Map a physical address through the Store Queues
+ * @phys: Physical address of mapping.
+ * @size: Length of mapping.
+ * @name: User invoking mapping.
+ * @prot: Protection bits.
+ *
+ * Remaps the physical address @phys through the next available store queue
+ * address of @size length. @name is logged at boot time as well as through
+ * the sysfs interface.
+ */
+unsigned long sq_remap(unsigned long phys, unsigned int size,
+		       const char *name, pgprot_t prot)
+{
+	struct sq_mapping *map;
+	unsigned long end;
+	unsigned int psz;
+	int ret, page;
+
+	/* Don't allow wraparound or zero size */
+	end = phys + size - 1;
+	if (unlikely(!size || end < phys))
+		return -EINVAL;
+	/* Don't allow anyone to remap normal memory.. */
+	if (unlikely(phys < virt_to_phys(high_memory)))
+		return -EINVAL;
+
+	phys &= PAGE_MASK;
+	size = PAGE_ALIGN(end + 1) - phys;
+
+	map = kmem_cache_alloc(sq_cache, GFP_KERNEL);
+	if (unlikely(!map))
+		return -ENOMEM;
+
+	map->addr = phys;
+	map->size = size;
+	map->name = name;
+
+	page = bitmap_find_free_region(sq_bitmap, 0x04000000 >> PAGE_SHIFT,
+				       get_order(map->size));
+	if (unlikely(page < 0)) {
+		ret = -ENOSPC;
+		goto out;
+	}
+
+	map->sq_addr = P4SEG_STORE_QUE + (page << PAGE_SHIFT);
+
+	ret = __sq_remap(map, prot);
+	if (unlikely(ret != 0))
+		goto out;
+
+	psz = (size + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
+	pr_info("sqremap: %15s  [%4d page%s]  va 0x%08lx   pa 0x%08lx\n",
+		likely(map->name) ? map->name : "???",
+		psz, psz == 1 ? " " : "s",
+		map->sq_addr, map->addr);
+
+	sq_mapping_list_add(map);
+
+	return map->sq_addr;
+
+out:
+	kmem_cache_free(sq_cache, map);
+	return ret;
+}
+EXPORT_SYMBOL(sq_remap);
+
+/**
+ * sq_unmap - Unmap a Store Queue allocation
+ * @vaddr: Pre-allocated Store Queue mapping.
+ *
+ * Unmaps the store queue allocation @map that was previously created by
+ * sq_remap(). Also frees up the pte that was previously inserted into
+ * the kernel page table and discards the UTLB translation.
+ */
+void sq_unmap(unsigned long vaddr)
+{
+	struct sq_mapping **p, *map;
+	int page;
+
+	for (p = &sq_mapping_list; (map = *p); p = &map->next)
+		if (map->sq_addr == vaddr)
+			break;
+
+	if (unlikely(!map)) {
+		printk("%s: bad store queue address 0x%08lx\n",
+		       __func__, vaddr);
+		return;
+	}
+
+	page = (map->sq_addr - P4SEG_STORE_QUE) >> PAGE_SHIFT;
+	bitmap_release_region(sq_bitmap, page, get_order(map->size));
+
+#ifdef CONFIG_MMU
+	{
+		/*
+		 * Tear down the VMA in the MMU case.
+		 */
+		struct vm_struct *vma;
+
+		vma = remove_vm_area((void *)(map->sq_addr & PAGE_MASK));
+		if (!vma) {
+			printk(KERN_ERR "%s: bad address 0x%08lx\n",
+			       __func__, map->sq_addr);
+			return;
+		}
+	}
+#endif
+
+	sq_mapping_list_del(map);
+
+	kmem_cache_free(sq_cache, map);
+}
+EXPORT_SYMBOL(sq_unmap);
+
+/*
+ * Needlessly complex sysfs interface. Unfortunately it doesn't seem like
+ * there is any other easy way to add things on a per-cpu basis without
+ * putting the directory entries somewhere stupid and having to create
+ * links in sysfs by hand back in to the per-cpu directories.
+ *
+ * Some day we may want to have an additional abstraction per store
+ * queue, but considering the kobject hell we already have to deal with,
+ * it's simply not worth the trouble.
+ */
+static struct kobject *sq_kobject[NR_CPUS];
+
+struct sq_sysfs_attr {
+	struct attribute attr;
+	ssize_t (*show)(char *buf);
+	ssize_t (*store)(const char *buf, size_t count);
+};
+
+#define to_sq_sysfs_attr(a)	container_of(a, struct sq_sysfs_attr, attr)
+
+static ssize_t sq_sysfs_show(struct kobject *kobj, struct attribute *attr,
+			     char *buf)
+{
+	struct sq_sysfs_attr *sattr = to_sq_sysfs_attr(attr);
+
+	if (likely(sattr->show))
+		return sattr->show(buf);
+
+	return -EIO;
+}
+
+static ssize_t sq_sysfs_store(struct kobject *kobj, struct attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct sq_sysfs_attr *sattr = to_sq_sysfs_attr(attr);
+
+	if (likely(sattr->store))
+		return sattr->store(buf, count);
+
+	return -EIO;
+}
+
+static ssize_t mapping_show(char *buf)
+{
+	struct sq_mapping **list, *entry;
+	char *p = buf;
+
+	for (list = &sq_mapping_list; (entry = *list); list = &entry->next)
+		p += sprintf(p, "%08lx-%08lx [%08lx]: %s\n",
+			     entry->sq_addr, entry->sq_addr + entry->size,
+			     entry->addr, entry->name);
+
+	return p - buf;
+}
+
+static ssize_t mapping_store(const char *buf, size_t count)
+{
+	unsigned long base = 0, len = 0;
+
+	sscanf(buf, "%lx %lx", &base, &len);
+	if (!base)
+		return -EIO;
+
+	if (likely(len)) {
+		int ret = sq_remap(base, len, "Userspace", PAGE_SHARED);
+		if (ret < 0)
+			return ret;
+	} else
+		sq_unmap(base);
+
+	return count;
+}
+
+static struct sq_sysfs_attr mapping_attr =
+	__ATTR(mapping, 0644, mapping_show, mapping_store);
+
+static struct attribute *sq_sysfs_attrs[] = {
+	&mapping_attr.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(sq_sysfs);
+
+static const struct sysfs_ops sq_sysfs_ops = {
+	.show	= sq_sysfs_show,
+	.store	= sq_sysfs_store,
+};
+
+static struct kobj_type ktype_percpu_entry = {
+	.sysfs_ops	= &sq_sysfs_ops,
+	.default_groups	= sq_sysfs_groups,
+};
+
+static int sq_dev_add(struct device *dev, struct subsys_interface *sif)
+{
+	unsigned int cpu = dev->id;
+	struct kobject *kobj;
+	int error;
+
+	sq_kobject[cpu] = kzalloc(sizeof(struct kobject), GFP_KERNEL);
+	if (unlikely(!sq_kobject[cpu]))
+		return -ENOMEM;
+
+	kobj = sq_kobject[cpu];
+	error = kobject_init_and_add(kobj, &ktype_percpu_entry, &dev->kobj,
+				     "%s", "sq");
+	if (!error)
+		kobject_uevent(kobj, KOBJ_ADD);
+	return error;
+}
+
+static void sq_dev_remove(struct device *dev, struct subsys_interface *sif)
+{
+	unsigned int cpu = dev->id;
+	struct kobject *kobj = sq_kobject[cpu];
+
+	kobject_put(kobj);
+}
+
+static struct subsys_interface sq_interface = {
+	.name		= "sq",
+	.subsys		= &cpu_subsys,
+	.add_dev	= sq_dev_add,
+	.remove_dev	= sq_dev_remove,
+};
+
+static int __init sq_api_init(void)
+{
+	unsigned int nr_pages = 0x04000000 >> PAGE_SHIFT;
+	unsigned int size = (nr_pages + (BITS_PER_LONG - 1)) / BITS_PER_LONG;
+	int ret = -ENOMEM;
+
+	printk(KERN_NOTICE "sq: Registering store queue API.\n");
+
+	sq_cache = kmem_cache_create("store_queue_cache",
+				sizeof(struct sq_mapping), 0, 0, NULL);
+	if (unlikely(!sq_cache))
+		return ret;
+
+	sq_bitmap = kcalloc(size, sizeof(long), GFP_KERNEL);
+	if (unlikely(!sq_bitmap))
+		goto out;
+
+	ret = subsys_interface_register(&sq_interface);
+	if (unlikely(ret != 0))
+		goto out;
+
+	return 0;
+
+out:
+	kfree(sq_bitmap);
+	kmem_cache_destroy(sq_cache);
+
+	return ret;
+}
+
+static void __exit sq_api_exit(void)
+{
+	subsys_interface_unregister(&sq_interface);
+	kfree(sq_bitmap);
+	kmem_cache_destroy(sq_cache);
+}
+
+module_init(sq_api_init);
+module_exit(sq_api_exit);
+
+MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, M. R. Brown <mrbrown@0xd6.org>");
+MODULE_DESCRIPTION("Simple API for SH-4 integrated Store Queues");
+MODULE_LICENSE("GPL");