// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* OpenRISC Linux
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*
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* Linux architectural port borrowing liberally from similar works of
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* others. All original copyrights apply as per the original source
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* declaration.
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*
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* Modifications for the OpenRISC architecture:
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* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
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* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
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*
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* DMA mapping callbacks...
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*/
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#include <linux/dma-map-ops.h>
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#include <linux/pagewalk.h>
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#include <asm/cpuinfo.h>
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#include <asm/spr_defs.h>
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#include <asm/tlbflush.h>
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static int
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page_set_nocache(pte_t *pte, unsigned long addr,
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unsigned long next, struct mm_walk *walk)
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{
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unsigned long cl;
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struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];
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pte_val(*pte) |= _PAGE_CI;
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/*
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* Flush the page out of the TLB so that the new page flags get
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* picked up next time there's an access
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*/
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flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
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/* Flush page out of dcache */
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for (cl = __pa(addr); cl < __pa(next); cl += cpuinfo->dcache_block_size)
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mtspr(SPR_DCBFR, cl);
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return 0;
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}
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static const struct mm_walk_ops set_nocache_walk_ops = {
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.pte_entry = page_set_nocache,
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};
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static int
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page_clear_nocache(pte_t *pte, unsigned long addr,
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unsigned long next, struct mm_walk *walk)
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{
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pte_val(*pte) &= ~_PAGE_CI;
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/*
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* Flush the page out of the TLB so that the new page flags get
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* picked up next time there's an access
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*/
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flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
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return 0;
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}
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static const struct mm_walk_ops clear_nocache_walk_ops = {
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.pte_entry = page_clear_nocache,
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};
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void *arch_dma_set_uncached(void *cpu_addr, size_t size)
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{
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unsigned long va = (unsigned long)cpu_addr;
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int error;
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/*
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* We need to iterate through the pages, clearing the dcache for
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* them and setting the cache-inhibit bit.
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*/
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mmap_read_lock(&init_mm);
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error = walk_page_range(&init_mm, va, va + size, &set_nocache_walk_ops,
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NULL);
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mmap_read_unlock(&init_mm);
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if (error)
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return ERR_PTR(error);
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return cpu_addr;
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}
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void arch_dma_clear_uncached(void *cpu_addr, size_t size)
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{
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unsigned long va = (unsigned long)cpu_addr;
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mmap_read_lock(&init_mm);
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/* walk_page_range shouldn't be able to fail here */
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WARN_ON(walk_page_range(&init_mm, va, va + size,
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&clear_nocache_walk_ops, NULL));
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mmap_read_unlock(&init_mm);
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}
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void arch_sync_dma_for_device(phys_addr_t addr, size_t size,
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enum dma_data_direction dir)
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{
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unsigned long cl;
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struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];
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switch (dir) {
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case DMA_TO_DEVICE:
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/* Flush the dcache for the requested range */
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for (cl = addr; cl < addr + size;
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cl += cpuinfo->dcache_block_size)
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mtspr(SPR_DCBFR, cl);
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break;
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case DMA_FROM_DEVICE:
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/* Invalidate the dcache for the requested range */
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for (cl = addr; cl < addr + size;
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cl += cpuinfo->dcache_block_size)
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mtspr(SPR_DCBIR, cl);
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break;
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default:
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/*
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* NOTE: If dir == DMA_BIDIRECTIONAL then there's no need to
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* flush nor invalidate the cache here as the area will need
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* to be manually synced anyway.
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*/
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break;
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}
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}
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