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Diffstat (limited to 'arch/sh/kernel/cpu/sh4/sq.c')
-rw-r--r-- | arch/sh/kernel/cpu/sh4/sq.c | 453 |
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 000000000000..8437ea7430fe --- /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); + |