1 files changed, 453 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 0000000..8437ea7
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh4/sq.c
@@ -0,0 +1,453 @@
+/*
+ * arch/sh/kernel/cpu/sq.c
+ *
+ * General management API for SH-4 integrated Store Queues
+ *
+ * Copyright (C) 2001, 2002, 2003, 2004  Paul Mundt
+ * Copyright (C) 2001, 2002  M. R. Brown
+ *
+ * Some of this code has been adopted directly from the old arch/sh/mm/sq.c
+ * hack that was part of the LinuxDC project. For all intents and purposes,
+ * this is a completely new interface that really doesn't have much in common
+ * with the old zone-based approach at all. In fact, it's only listed here for
+ * general completeness.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/config.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/proc_fs.h>
+#include <linux/miscdevice.h>
+#include <linux/vmalloc.h>
+
+#include <asm/io.h>
+#include <asm/page.h>
+#include <asm/mmu_context.h>
+#include <asm/cpu/sq.h>
+
+static LIST_HEAD(sq_mapping_list);
+static DEFINE_SPINLOCK(sq_mapping_lock);
+
+/**
+ * sq_flush - Flush (prefetch) the store queue cache
+ * @addr: the store queue address to flush
+ *
+ * Executes a prefetch instruction on the specified store queue cache,
+ * so that the cached data is written to physical memory.
+ */
+inline void sq_flush(void *addr)
+{
+	__asm__ __volatile__ ("pref @%0" : : "r" (addr) : "memory");
+}
+
+/**
+ * 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)
+{
+	volatile unsigned long *sq = (unsigned long *)start;
+	unsigned long dummy;
+
+	/* Flush the queues */
+	for (len >>= 5; len--; sq += 8)
+		sq_flush((void *)sq);
+
+	/* Wait for completion */
+	dummy = ctrl_inl(P4SEG_STORE_QUE);
+
+	ctrl_outl(0, P4SEG_STORE_QUE + 0);
+	ctrl_outl(0, P4SEG_STORE_QUE + 8);
+}
+
+static struct sq_mapping *__sq_alloc_mapping(unsigned long virt, unsigned long phys, unsigned long size, const char *name)
+{
+	struct sq_mapping *map;
+
+	if (virt + size > SQ_ADDRMAX)
+		return ERR_PTR(-ENOSPC);
+
+	map = kmalloc(sizeof(struct sq_mapping), GFP_KERNEL);
+	if (!map)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&map->list);
+
+	map->sq_addr	= virt;
+	map->addr	= phys;
+	map->size	= size + 1;
+	map->name	= name;
+
+	list_add(&map->list, &sq_mapping_list);
+
+	return map;
+}
+
+static unsigned long __sq_get_next_addr(void)
+{
+	if (!list_empty(&sq_mapping_list)) {
+		struct list_head *pos, *tmp;
+
+		/*
+		 * Read one off the list head, as it will have the highest
+		 * mapped allocation. Set the next one up right above it.
+		 *
+		 * This is somewhat sub-optimal, as we don't look at
+		 * gaps between allocations or anything lower then the
+		 * highest-level allocation.
+		 *
+		 * However, in the interest of performance and the general
+		 * lack of desire to do constant list rebalancing, we don't
+		 * worry about it.
+		 */
+		list_for_each_safe(pos, tmp, &sq_mapping_list) {
+			struct sq_mapping *entry;
+
+			entry = list_entry(pos, typeof(*entry), list);
+
+			return entry->sq_addr + entry->size;
+		}
+	}
+
+	return P4SEG_STORE_QUE;
+}
+
+/**
+ * __sq_remap - Perform a translation from the SQ to a phys addr
+ * @map: sq mapping containing phys and store queue addresses.
+ *
+ * Maps the store queue address specified in the mapping to the physical
+ * address specified in the mapping.
+ */
+static struct sq_mapping *__sq_remap(struct sq_mapping *map)
+{
+	unsigned long flags, pteh, ptel;
+	struct vm_struct *vma;
+	pgprot_t pgprot;
+
+	/*
+	 * 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.
+	 */
+
+	ctrl_outl(((map->addr >> 26) << 2) & 0x1c, SQ_QACR0);
+	ctrl_outl(((map->addr >> 26) << 2) & 0x1c, SQ_QACR1);
+
+#ifdef CONFIG_MMU
+	/*
+	 * With an MMU on the other hand, things are slightly more involved.
+	 * Namely, we have to have a direct mapping between the SQ addr and
+	 * the associated physical address in the UTLB by way of setting up
+	 * a virt<->phys translation by hand. We do this by simply specifying
+	 * the SQ addr in UTLB.VPN and the associated physical address in
+	 * UTLB.PPN.
+	 *
+	 * Notably, even though this is a special case translation, and some
+	 * of the configuration bits are meaningless, we're still required
+	 * to have a valid ASID context in PTEH.
+	 *
+	 * We could also probably get by without explicitly setting PTEA, but
+	 * we do it here just for good measure.
+	 */
+	spin_lock_irqsave(&sq_mapping_lock, flags);
+
+	pteh = map->sq_addr;
+	ctrl_outl((pteh & MMU_VPN_MASK) | get_asid(), MMU_PTEH);
+
+	ptel = map->addr & PAGE_MASK;
+	ctrl_outl(((ptel >> 28) & 0xe) | (ptel & 0x1), MMU_PTEA);
+
+	pgprot = pgprot_noncached(PAGE_KERNEL);
+
+	ptel &= _PAGE_FLAGS_HARDWARE_MASK;
+	ptel |= pgprot_val(pgprot);
+	ctrl_outl(ptel, MMU_PTEL);
+
+	__asm__ __volatile__ ("ldtlb" : : : "memory");
+
+	spin_unlock_irqrestore(&sq_mapping_lock, flags);
+
+	/*
+	 * Next, we need to map ourselves in the kernel page table, so that
+	 * future accesses after a TLB flush will be handled when we take a
+	 * page fault.
+	 *
+	 * Theoretically we could just do this directly and not worry about
+	 * setting up the translation by hand ahead of time, but for the
+	 * cases where we want a one-shot SQ mapping followed by a quick
+	 * writeout before we hit the TLB flush, we do it anyways. This way
+	 * we at least save ourselves the initial page fault overhead.
+	 */
+	vma = __get_vm_area(map->size, VM_ALLOC, map->sq_addr, SQ_ADDRMAX);
+	if (!vma)
+		return ERR_PTR(-ENOMEM);
+
+	vma->phys_addr = map->addr;
+
+	if (remap_area_pages((unsigned long)vma->addr, vma->phys_addr,
+			     map->size, pgprot_val(pgprot))) {
+		vunmap(vma->addr);
+		return NULL;
+	}
+#endif /* CONFIG_MMU */
+
+	return map;
+}
+
+/**
+ * sq_remap - Map a physical address through the Store Queues
+ * @phys: Physical address of mapping.
+ * @size: Length of mapping.
+ * @name: User invoking mapping.
+ *
+ * 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 procfs interface.
+ *
+ * A pre-allocated and filled sq_mapping pointer is returned, and must be
+ * cleaned up with a call to sq_unmap() when the user is done with the
+ * mapping.
+ */
+struct sq_mapping *sq_remap(unsigned long phys, unsigned int size, const char *name)
+{
+	struct sq_mapping *map;
+	unsigned long virt, end;
+	unsigned int psz;
+
+	/* Don't allow wraparound or zero size */
+	end = phys + size - 1;
+	if (!size || end < phys)
+		return NULL;
+	/* Don't allow anyone to remap normal memory.. */
+	if (phys < virt_to_phys(high_memory))
+		return NULL;
+
+	phys &= PAGE_MASK;
+
+	size  = PAGE_ALIGN(end + 1) - phys;
+	virt  = __sq_get_next_addr();
+	psz   = (size + (PAGE_SIZE - 1)) / PAGE_SIZE;
+	map   = __sq_alloc_mapping(virt, phys, size, name);
+
+	printk("sqremap: %15s  [%4d page%s]  va 0x%08lx   pa 0x%08lx\n",
+	       map->name ? map->name : "???",
+	       psz, psz == 1 ? " " : "s",
+	       map->sq_addr, map->addr);
+
+	return __sq_remap(map);
+}
+
+/**
+ * sq_unmap - Unmap a Store Queue allocation
+ * @map: 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(struct sq_mapping *map)
+{
+	if (map->sq_addr > (unsigned long)high_memory)
+		vfree((void *)(map->sq_addr & PAGE_MASK));
+
+	list_del(&map->list);
+	kfree(map);
+}
+
+/**
+ * sq_clear - Clear a store queue range
+ * @addr: Address to start clearing from.
+ * @len: Length to clear.
+ *
+ * A quick zero-fill implementation for clearing out memory that has been
+ * remapped through the store queues.
+ */
+void sq_clear(unsigned long addr, unsigned int len)
+{
+	int i;
+
+	/* Clear out both queues linearly */
+	for (i = 0; i < 8; i++) {
+		ctrl_outl(0, addr + i + 0);
+		ctrl_outl(0, addr + i + 8);
+	}
+
+	sq_flush_range(addr, len);
+}
+
+/**
+ * sq_vma_unmap - Unmap a VMA range
+ * @area: VMA containing range.
+ * @addr: Start of range.
+ * @len: Length of range.
+ *
+ * Searches the sq_mapping_list for a mapping matching the sq addr @addr,
+ * and subsequently frees up the entry. Further cleanup is done by generic
+ * code.
+ */
+static void sq_vma_unmap(struct vm_area_struct *area,
+			 unsigned long addr, size_t len)
+{
+	struct list_head *pos, *tmp;
+
+	list_for_each_safe(pos, tmp, &sq_mapping_list) {
+		struct sq_mapping *entry;
+
+		entry = list_entry(pos, typeof(*entry), list);
+
+		if (entry->sq_addr == addr) {
+			/*
+			 * We could probably get away without doing the tlb flush
+			 * here, as generic code should take care of most of this
+			 * when unmapping the rest of the VMA range for us. Leave
+			 * it in for added sanity for the time being..
+			 */
+			__flush_tlb_page(get_asid(), entry->sq_addr & PAGE_MASK);
+
+			list_del(&entry->list);
+			kfree(entry);
+
+			return;
+		}
+	}
+}
+
+/**
+ * sq_vma_sync - Sync a VMA range
+ * @area: VMA containing range.
+ * @start: Start of range.
+ * @len: Length of range.
+ * @flags: Additional flags.
+ *
+ * Synchronizes an sq mapped range by flushing the store queue cache for
+ * the duration of the mapping.
+ *
+ * Used internally for user mappings, which must use msync() to prefetch
+ * the store queue cache.
+ */
+static int sq_vma_sync(struct vm_area_struct *area,
+		       unsigned long start, size_t len, unsigned int flags)
+{
+	sq_flush_range(start, len);
+
+	return 0;
+}
+
+static struct vm_operations_struct sq_vma_ops = {
+	.unmap	= sq_vma_unmap,
+	.sync	= sq_vma_sync,
+};
+
+/**
+ * sq_mmap - mmap() for /dev/cpu/sq
+ * @file: unused.
+ * @vma: VMA to remap.
+ *
+ * Remap the specified vma @vma through the store queues, and setup associated
+ * information for the new mapping. Also build up the page tables for the new
+ * area.
+ */
+static int sq_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
+	unsigned long size = vma->vm_end - vma->vm_start;
+	struct sq_mapping *map;
+
+	/*
+	 * We're not interested in any arbitrary virtual address that has
+	 * been stuck in the VMA, as we already know what addresses we
+	 * want. Save off the size, and reposition the VMA to begin at
+	 * the next available sq address.
+	 */
+	vma->vm_start = __sq_get_next_addr();
+	vma->vm_end   = vma->vm_start + size;
+
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+	vma->vm_flags |= VM_IO | VM_RESERVED;
+
+	map = __sq_alloc_mapping(vma->vm_start, offset, size, "Userspace");
+
+	if (io_remap_pfn_range(vma, map->sq_addr, map->addr >> PAGE_SHIFT,
+				size, vma->vm_page_prot))
+		return -EAGAIN;
+
+	vma->vm_ops = &sq_vma_ops;
+
+	return 0;
+}
+
+#ifdef CONFIG_PROC_FS
+static int sq_mapping_read_proc(char *buf, char **start, off_t off,
+				int len, int *eof, void *data)
+{
+	struct list_head *pos;
+	char *p = buf;
+
+	list_for_each_prev(pos, &sq_mapping_list) {
+		struct sq_mapping *entry;
+
+		entry = list_entry(pos, typeof(*entry), list);
+
+		p += sprintf(p, "%08lx-%08lx [%08lx]: %s\n", entry->sq_addr,
+			     entry->sq_addr + entry->size - 1, entry->addr,
+			     entry->name);
+	}
+
+	return p - buf;
+}
+#endif
+
+static struct file_operations sq_fops = {
+	.owner		= THIS_MODULE,
+	.mmap		= sq_mmap,
+};
+
+static struct miscdevice sq_dev = {
+	.minor		= STORE_QUEUE_MINOR,
+	.name		= "sq",
+	.devfs_name	= "cpu/sq",
+	.fops		= &sq_fops,
+};
+
+static int __init sq_api_init(void)
+{
+	printk(KERN_NOTICE "sq: Registering store queue API.\n");
+
+#ifdef CONFIG_PROC_FS
+	create_proc_read_entry("sq_mapping", 0, 0, sq_mapping_read_proc, 0);
+#endif
+
+	return misc_register(&sq_dev);
+}
+
+static void __exit sq_api_exit(void)
+{
+	misc_deregister(&sq_dev);
+}
+
+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");
+MODULE_ALIAS_MISCDEV(STORE_QUEUE_MINOR);
+
+EXPORT_SYMBOL(sq_remap);
+EXPORT_SYMBOL(sq_unmap);
+EXPORT_SYMBOL(sq_clear);
+EXPORT_SYMBOL(sq_flush);
+EXPORT_SYMBOL(sq_flush_range);
+