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-rw-r--r--arch/sh/kernel/cpu/sh4/sq.c453
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
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+++ b/arch/sh/kernel/cpu/sh4/sq.c
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+/*
+ * 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);
+