| /* |
| * linux/kernel/resource.c |
| * |
| * Copyright (C) 1999 Linus Torvalds |
| * Copyright (C) 1999 Martin Mares <mj@ucw.cz> |
| * |
| * Arbitrary resource management. |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/errno.h> |
| #include <linux/ioport.h> |
| #include <linux/init.h> |
| #include <linux/slab.h> |
| #include <linux/spinlock.h> |
| #include <linux/seq_file.h> |
| #include <asm/io.h> |
| |
| struct resource ioport_resource = { "PCI IO", 0x0000, IO_SPACE_LIMIT, IORESOURCE_IO }; |
| struct resource iomem_resource = { "PCI mem", 0x00000000, 0xffffffff, IORESOURCE_MEM }; |
| |
| static rwlock_t resource_lock = RW_LOCK_UNLOCKED; |
| |
| enum { MAX_IORES_LEVEL = 5 }; |
| |
| static void *r_next(struct seq_file *m, void *v, loff_t *pos) |
| { |
| struct resource *p = v; |
| (*pos)++; |
| if (p->child) |
| return p->child; |
| while (!p->sibling && p->parent) |
| p = p->parent; |
| return p->sibling; |
| } |
| |
| static void *r_start(struct seq_file *m, loff_t *pos) |
| { |
| struct resource *p = m->private; |
| loff_t l = 0; |
| read_lock(&resource_lock); |
| for (p = p->child; p && l < *pos; p = r_next(m, p, &l)) |
| ; |
| return p; |
| } |
| |
| static void r_stop(struct seq_file *m, void *v) |
| { |
| read_unlock(&resource_lock); |
| } |
| |
| static int r_show(struct seq_file *m, void *v) |
| { |
| struct resource *root = m->private; |
| struct resource *r = v, *p; |
| int width = root->end < 0x10000 ? 4 : 8; |
| int depth; |
| |
| for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent) |
| if (p->parent == root) |
| break; |
| seq_printf(m, "%*s%0*lx-%0*lx : %s\n", |
| depth * 2, "", |
| width, r->start, |
| width, r->end, |
| r->name ? r->name : "<BAD>"); |
| return 0; |
| } |
| |
| static struct seq_operations resource_op = { |
| .start = r_start, |
| .next = r_next, |
| .stop = r_stop, |
| .show = r_show, |
| }; |
| |
| static int ioports_open(struct inode *inode, struct file *file) |
| { |
| int res = seq_open(file, &resource_op); |
| if (!res) { |
| struct seq_file *m = file->private_data; |
| m->private = &ioport_resource; |
| } |
| return res; |
| } |
| |
| static int iomem_open(struct inode *inode, struct file *file) |
| { |
| int res = seq_open(file, &resource_op); |
| if (!res) { |
| struct seq_file *m = file->private_data; |
| m->private = &iomem_resource; |
| } |
| return res; |
| } |
| |
| struct file_operations proc_ioports_operations = { |
| .open = ioports_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release, |
| }; |
| |
| struct file_operations proc_iomem_operations = { |
| .open = iomem_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release, |
| }; |
| |
| /* Return the conflict entry if you can't request it */ |
| static struct resource * __request_resource(struct resource *root, struct resource *new) |
| { |
| unsigned long start = new->start; |
| unsigned long end = new->end; |
| struct resource *tmp, **p; |
| |
| if (end < start) |
| return root; |
| if (start < root->start) |
| return root; |
| if (end > root->end) |
| return root; |
| p = &root->child; |
| for (;;) { |
| tmp = *p; |
| if (!tmp || tmp->start > end) { |
| new->sibling = tmp; |
| *p = new; |
| new->parent = root; |
| return NULL; |
| } |
| p = &tmp->sibling; |
| if (tmp->end < start) |
| continue; |
| return tmp; |
| } |
| } |
| |
| static int __release_resource(struct resource *old) |
| { |
| struct resource *tmp, **p; |
| |
| p = &old->parent->child; |
| for (;;) { |
| tmp = *p; |
| if (!tmp) |
| break; |
| if (tmp == old) { |
| *p = tmp->sibling; |
| old->parent = NULL; |
| return 0; |
| } |
| p = &tmp->sibling; |
| } |
| return -EINVAL; |
| } |
| |
| int request_resource(struct resource *root, struct resource *new) |
| { |
| struct resource *conflict; |
| |
| write_lock(&resource_lock); |
| conflict = __request_resource(root, new); |
| write_unlock(&resource_lock); |
| return conflict ? -EBUSY : 0; |
| } |
| |
| int release_resource(struct resource *old) |
| { |
| int retval; |
| |
| write_lock(&resource_lock); |
| retval = __release_resource(old); |
| write_unlock(&resource_lock); |
| return retval; |
| } |
| |
| int check_resource(struct resource *root, unsigned long start, unsigned long len) |
| { |
| struct resource *conflict, tmp; |
| |
| tmp.start = start; |
| tmp.end = start + len - 1; |
| write_lock(&resource_lock); |
| conflict = __request_resource(root, &tmp); |
| if (!conflict) |
| __release_resource(&tmp); |
| write_unlock(&resource_lock); |
| return conflict ? -EBUSY : 0; |
| } |
| |
| /* |
| * Find empty slot in the resource tree given range and alignment. |
| */ |
| static int find_resource(struct resource *root, struct resource *new, |
| unsigned long size, |
| unsigned long min, unsigned long max, |
| unsigned long align, |
| void (*alignf)(void *, struct resource *, |
| unsigned long, unsigned long), |
| void *alignf_data) |
| { |
| struct resource *this = root->child; |
| |
| new->start = root->start; |
| for(;;) { |
| if (this) |
| new->end = this->start; |
| else |
| new->end = root->end; |
| if (new->start < min) |
| new->start = min; |
| if (new->end > max) |
| new->end = max; |
| new->start = (new->start + align - 1) & ~(align - 1); |
| if (alignf) |
| alignf(alignf_data, new, size, align); |
| if (new->start < new->end && new->end - new->start + 1 >= size) { |
| new->end = new->start + size - 1; |
| return 0; |
| } |
| if (!this) |
| break; |
| new->start = this->end + 1; |
| this = this->sibling; |
| } |
| return -EBUSY; |
| } |
| |
| /* |
| * Allocate empty slot in the resource tree given range and alignment. |
| */ |
| int allocate_resource(struct resource *root, struct resource *new, |
| unsigned long size, |
| unsigned long min, unsigned long max, |
| unsigned long align, |
| void (*alignf)(void *, struct resource *, |
| unsigned long, unsigned long), |
| void *alignf_data) |
| { |
| int err; |
| |
| write_lock(&resource_lock); |
| err = find_resource(root, new, size, min, max, align, alignf, alignf_data); |
| if (err >= 0 && __request_resource(root, new)) |
| err = -EBUSY; |
| write_unlock(&resource_lock); |
| return err; |
| } |
| |
| /* |
| * This is compatibility stuff for IO resources. |
| * |
| * Note how this, unlike the above, knows about |
| * the IO flag meanings (busy etc). |
| * |
| * Request-region creates a new busy region. |
| * |
| * Check-region returns non-zero if the area is already busy |
| * |
| * Release-region releases a matching busy region. |
| */ |
| struct resource * __request_region(struct resource *parent, unsigned long start, unsigned long n, const char *name) |
| { |
| struct resource *res = kmalloc(sizeof(*res), GFP_KERNEL); |
| |
| if (res) { |
| memset(res, 0, sizeof(*res)); |
| res->name = name; |
| res->start = start; |
| res->end = start + n - 1; |
| res->flags = IORESOURCE_BUSY; |
| |
| write_lock(&resource_lock); |
| |
| for (;;) { |
| struct resource *conflict; |
| |
| conflict = __request_resource(parent, res); |
| if (!conflict) |
| break; |
| if (conflict != parent) { |
| parent = conflict; |
| if (!(conflict->flags & IORESOURCE_BUSY)) |
| continue; |
| } |
| |
| /* Uhhuh, that didn't work out.. */ |
| kfree(res); |
| res = NULL; |
| break; |
| } |
| write_unlock(&resource_lock); |
| } |
| return res; |
| } |
| |
| int __check_region(struct resource *parent, unsigned long start, unsigned long n) |
| { |
| struct resource * res; |
| |
| res = __request_region(parent, start, n, "check-region"); |
| if (!res) |
| return -EBUSY; |
| |
| release_resource(res); |
| kfree(res); |
| return 0; |
| } |
| |
| void __release_region(struct resource *parent, unsigned long start, unsigned long n) |
| { |
| struct resource **p; |
| unsigned long end; |
| |
| p = &parent->child; |
| end = start + n - 1; |
| |
| for (;;) { |
| struct resource *res = *p; |
| |
| if (!res) |
| break; |
| if (res->start <= start && res->end >= end) { |
| if (!(res->flags & IORESOURCE_BUSY)) { |
| p = &res->child; |
| continue; |
| } |
| if (res->start != start || res->end != end) |
| break; |
| *p = res->sibling; |
| kfree(res); |
| return; |
| } |
| p = &res->sibling; |
| } |
| printk("Trying to free nonexistent resource <%08lx-%08lx>\n", start, end); |
| } |
| |
| /* |
| * Called from init/main.c to reserve IO ports. |
| */ |
| #define MAXRESERVE 4 |
| static int __init reserve_setup(char *str) |
| { |
| static int reserved = 0; |
| static struct resource reserve[MAXRESERVE]; |
| |
| for (;;) { |
| unsigned int io_start, io_num; |
| int x = reserved; |
| |
| if (get_option (&str, &io_start) != 2) |
| break; |
| if (get_option (&str, &io_num) == 0) |
| break; |
| if (x < MAXRESERVE) { |
| struct resource *res = reserve + x; |
| res->name = "reserved"; |
| res->start = io_start; |
| res->end = io_start + io_num - 1; |
| res->flags = IORESOURCE_BUSY; |
| res->child = NULL; |
| if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0) |
| reserved = x+1; |
| } |
| } |
| return 1; |
| } |
| |
| __setup("reserve=", reserve_setup); |