/*
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* Generic page table allocator for IOMMUs.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* Copyright (C) 2014 ARM Limited
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*
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* Author: Will Deacon <will.deacon@arm.com>
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*/
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#define pr_fmt(fmt) "io-pgtable: " fmt
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#include <linux/bug.h>
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#include <linux/io-pgtable.h>
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/iommu.h>
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#include <linux/debugfs.h>
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#include <linux/atomic.h>
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#include <linux/module.h>
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static const struct io_pgtable_init_fns *
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io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] = {
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#ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE
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[ARM_32_LPAE_S1] = &io_pgtable_arm_32_lpae_s1_init_fns,
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[ARM_32_LPAE_S2] = &io_pgtable_arm_32_lpae_s2_init_fns,
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[ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns,
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[ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns,
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#endif
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#ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S
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[ARM_V7S] = &io_pgtable_arm_v7s_init_fns,
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#endif
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#ifdef CONFIG_IOMMU_IO_PGTABLE_FAST
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[ARM_V8L_FAST] = &io_pgtable_av8l_fast_init_fns,
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#endif
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};
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static struct dentry *io_pgtable_top;
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struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
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struct io_pgtable_cfg *cfg,
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void *cookie)
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{
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struct io_pgtable *iop;
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const struct io_pgtable_init_fns *fns;
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if (fmt >= IO_PGTABLE_NUM_FMTS)
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return NULL;
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fns = io_pgtable_init_table[fmt];
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if (!fns)
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return NULL;
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iop = fns->alloc(cfg, cookie);
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if (!iop)
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return NULL;
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iop->fmt = fmt;
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iop->cookie = cookie;
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iop->cfg = *cfg;
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return &iop->ops;
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}
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EXPORT_SYMBOL_GPL(alloc_io_pgtable_ops);
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/*
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* It is the IOMMU driver's responsibility to ensure that the page table
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* is no longer accessible to the walker by this point.
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*/
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void free_io_pgtable_ops(struct io_pgtable_ops *ops)
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{
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struct io_pgtable *iop;
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if (!ops)
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return;
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iop = container_of(ops, struct io_pgtable, ops);
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io_pgtable_tlb_flush_all(iop);
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io_pgtable_init_table[iop->fmt]->free(iop);
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}
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EXPORT_SYMBOL_GPL(free_io_pgtable_ops);
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static atomic_t pages_allocated;
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void *io_pgtable_alloc_pages_exact(struct io_pgtable_cfg *cfg, void *cookie,
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size_t size, gfp_t gfp_mask)
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{
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void *ret;
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if (cfg->tlb->alloc_pages_exact)
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ret = cfg->tlb->alloc_pages_exact(cookie, size, gfp_mask);
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else
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ret = alloc_pages_exact(size, gfp_mask);
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if (likely(ret))
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atomic_add(1 << get_order(size), &pages_allocated);
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return ret;
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}
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void io_pgtable_free_pages_exact(struct io_pgtable_cfg *cfg, void *cookie,
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void *virt, size_t size)
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{
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if (cfg->tlb->free_pages_exact)
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cfg->tlb->free_pages_exact(cookie, virt, size);
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else
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free_pages_exact(virt, size);
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atomic_sub(1 << get_order(size), &pages_allocated);
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}
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static int __init io_pgtable_init(void)
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{
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static const char io_pgtable_str[] __initconst = "io-pgtable";
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static const char pages_str[] __initconst = "pages";
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io_pgtable_top = debugfs_create_dir(io_pgtable_str, iommu_debugfs_top);
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debugfs_create_atomic_t(pages_str, 0600, io_pgtable_top,
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&pages_allocated);
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return 0;
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}
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static void __exit io_pgtable_exit(void)
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{
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debugfs_remove_recursive(io_pgtable_top);
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}
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module_init(io_pgtable_init);
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module_exit(io_pgtable_exit);
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