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author | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
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committer | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
commit | 849369d6c66d3054688672f97d31fceb8e8230fb (patch) | |
tree | 6135abc790ca67dedbe07c39806591e70eda81ce /arch/arm/mm/vmregion.c | |
download | linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.gz linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.bz2 linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.zip |
initial_commit
Diffstat (limited to 'arch/arm/mm/vmregion.c')
-rw-r--r-- | arch/arm/mm/vmregion.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/arch/arm/mm/vmregion.c b/arch/arm/mm/vmregion.c new file mode 100644 index 00000000..036fdbfd --- /dev/null +++ b/arch/arm/mm/vmregion.c @@ -0,0 +1,131 @@ +#include <linux/spinlock.h> +#include <linux/list.h> +#include <linux/slab.h> + +#include "vmregion.h" + +/* + * VM region handling support. + * + * This should become something generic, handling VM region allocations for + * vmalloc and similar (ioremap, module space, etc). + * + * I envisage vmalloc()'s supporting vm_struct becoming: + * + * struct vm_struct { + * struct vmregion region; + * unsigned long flags; + * struct page **pages; + * unsigned int nr_pages; + * unsigned long phys_addr; + * }; + * + * get_vm_area() would then call vmregion_alloc with an appropriate + * struct vmregion head (eg): + * + * struct vmregion vmalloc_head = { + * .vm_list = LIST_HEAD_INIT(vmalloc_head.vm_list), + * .vm_start = VMALLOC_START, + * .vm_end = VMALLOC_END, + * }; + * + * However, vmalloc_head.vm_start is variable (typically, it is dependent on + * the amount of RAM found at boot time.) I would imagine that get_vm_area() + * would have to initialise this each time prior to calling vmregion_alloc(). + */ + +struct arm_vmregion * +arm_vmregion_alloc(struct arm_vmregion_head *head, size_t align, + size_t size, gfp_t gfp) +{ + unsigned long start = head->vm_start, addr = head->vm_end; + unsigned long flags; + struct arm_vmregion *c, *new; + + if (head->vm_end - head->vm_start < size) { + printk(KERN_WARNING "%s: allocation too big (requested %#x)\n", + __func__, size); + goto out; + } + + new = kmalloc(sizeof(struct arm_vmregion), gfp); + if (!new) + goto out; + + spin_lock_irqsave(&head->vm_lock, flags); + + addr = rounddown(addr - size, align); + list_for_each_entry_reverse(c, &head->vm_list, vm_list) { + if (addr >= c->vm_end) + goto found; + addr = rounddown(c->vm_start - size, align); + if (addr < start) + goto nospc; + } + + found: + /* + * Insert this entry after the one we found. + */ + list_add(&new->vm_list, &c->vm_list); + new->vm_start = addr; + new->vm_end = addr + size; + new->vm_active = 1; + + spin_unlock_irqrestore(&head->vm_lock, flags); + return new; + + nospc: + spin_unlock_irqrestore(&head->vm_lock, flags); + kfree(new); + out: + return NULL; +} + +static struct arm_vmregion *__arm_vmregion_find(struct arm_vmregion_head *head, unsigned long addr) +{ + struct arm_vmregion *c; + + list_for_each_entry(c, &head->vm_list, vm_list) { + if (c->vm_active && c->vm_start == addr) + goto out; + } + c = NULL; + out: + return c; +} + +struct arm_vmregion *arm_vmregion_find(struct arm_vmregion_head *head, unsigned long addr) +{ + struct arm_vmregion *c; + unsigned long flags; + + spin_lock_irqsave(&head->vm_lock, flags); + c = __arm_vmregion_find(head, addr); + spin_unlock_irqrestore(&head->vm_lock, flags); + return c; +} + +struct arm_vmregion *arm_vmregion_find_remove(struct arm_vmregion_head *head, unsigned long addr) +{ + struct arm_vmregion *c; + unsigned long flags; + + spin_lock_irqsave(&head->vm_lock, flags); + c = __arm_vmregion_find(head, addr); + if (c) + c->vm_active = 0; + spin_unlock_irqrestore(&head->vm_lock, flags); + return c; +} + +void arm_vmregion_free(struct arm_vmregion_head *head, struct arm_vmregion *c) +{ + unsigned long flags; + + spin_lock_irqsave(&head->vm_lock, flags); + list_del(&c->vm_list); + spin_unlock_irqrestore(&head->vm_lock, flags); + + kfree(c); +} |