+++ /dev/null
-/*
- * arch/arm/include/asm/attrib_alloc.h
- *
- * Page allocator with custom cache attributes
- *
- * Copyright (c) 2010, NVIDIA Corporation.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- */
-
-#ifndef __ARCH_ARM_ATTRIB_ALLOC_H
-#define __ARCH_ARM_ATTRIB_ALLOC_H
-
-#include <linux/types.h>
-#include <asm/page.h>
-
-struct page *arm_attrib_alloc_pages_exact_node(int nid, gfp_t gfp,
- size_t size, pgprot_t prot);
-
-void arm_attrib_free_pages_exact(struct page *page, size_t size);
-
-static inline
-struct page *arm_attrib_alloc_pages_exact(gfp_t gfp, size_t size,
- pgprot_t prot)
-{
- return arm_attrib_alloc_pages_exact_node(-1, gfp, size, prot);
-}
-
-#define arm_attrib_alloc_page(gfp, prot) \
- arm_attrib_alloc_pages_exact((gfp), PAGE_SIZE, (prot))
-
-#define arm_attrib_free_page(page) \
- arm_attrib_free_pages_exact((page), PAGE_SIZE)
-
-#endif /* __ARCH_ARM_ATTRIB_ALLOC_H */
default 6 if ARM_L1_CACHE_SHIFT_6
default 5
-config ARM_ATTRIB_ALLOCATOR
- bool "Support custom cache attribute allocations in low memory"
- select ARCH_LOWMEM_IN_PTES if (CPU_V7)
- depends on MMU && !CPU_CACHE_VIVT
- help
- Historically, the kernel has only reserved a small region
- of physical memory for uncached access, and relied on
- explicit cache maintenance for ensuring coherency between
- the CPU and DMA.
-
- However, many recent systems support mapping discontiguous
- physical pages into contiguous DMA addresses (so-called
- system MMUs). For some DMA clients (notably graphics and
- multimedia engines), performing explict cache maintenance
- between CPU and DMA mappings can be prohibitively expensive,
- and since ARMv7, mapping the same physical page with different
- cache attributes is disallowed and has unpredictable behavior.
-
- Say 'Y' here to include page allocation support with explicit
- cache attributes; on ARMv7 systems this will also force the
- kernel's page tables to be mapped using page tables rather
- than sections.
-
config ARM_DMA_MEM_BUFFERABLE
bool "Use non-cacheable memory for DMA" if CPU_V6 && !CPU_V7
depends on !(MACH_REALVIEW_PB1176 || REALVIEW_EB_ARM11MP || \
+++ /dev/null
-/*
- * arch/arm/mm/attrib_alloc.c
- *
- * Page allocator with custom cache attributes
- *
- * Copyright (c) 2010, NVIDIA Corporation.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- */
-
-#include <linux/kernel.h>
-#include <linux/highmem.h>
-#include <linux/gfp.h>
-#include <linux/page-flags.h>
-#include <asm/tlbflush.h>
-#include <asm/cacheflush.h>
-#include <asm/pgtable.h>
-#include <asm/pgalloc.h>
-#include <asm/fixmap.h>
-#include <asm/outercache.h>
-#include <asm/attrib_alloc.h>
-#include "mm.h"
-
-static void update_kmap_pte(struct page *page, pgprot_t prot)
-{
-#ifdef CONFIG_HIGHMEM
- unsigned long addr;
- pte_t *pte;
-
- addr = (unsigned long)kmap_high_get(page);
- BUG_ON(!PageHighMem(page) || addr >= FIXADDR_START);
- if (!addr)
- return;
-
- pte = &pkmap_page_table[PKMAP_NR(addr)];
- set_pte_at(&init_mm, addr, pte, mk_pte(page, __pgprot(prot)));
- flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
- kunmap_high(page);
-#endif
-}
-
-static void update_pte(struct page *page, pgprot_t prot)
-{
-#ifdef CONFIG_ARCH_LOWMEM_IN_PTES
- unsigned long addr = (unsigned long)page_address(page);
- pgd_t *pgd = pgd_offset_k(addr);
- pmd_t *pmd = pmd_offset(pgd, addr);
- pte_t *pte;
-
- BUG_ON(pmd_none(*pmd));
- pte = pte_offset_kernel(pmd, addr);
- set_pte_at(&init_mm, addr, pte, mk_pte(page, __pgprot(prot)));
- flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
-#endif
-}
-
-void arm_attrib_free_pages_exact(struct page *page, size_t size)
-{
- struct page *p, *e;
-
- size = PAGE_ALIGN(size);
- e = page + (size >> PAGE_SHIFT);
-
- /* reset the page's mappings back to the standard kernel mappings
- * before returning it to the page allocator */
- for (p = page; p < e; p++) {
- if (PageHighMem(p))
- update_kmap_pte(p, pgprot_kernel);
- else
- update_pte(p, pgprot_kernel);
-
- __free_page(p);
- }
-}
-
-struct page *arm_attrib_alloc_pages_exact_node(int nid, gfp_t gfp,
- size_t size, pgprot_t prot)
-{
- struct page *page, *p, *e;
- unsigned int order;
- unsigned long base;
-
- size = PAGE_ALIGN(size);
- order = get_order(size);
- page = alloc_pages_node(nid, gfp, order);
-
- if (!page)
- return NULL;
-
- split_page(page, order);
-
- e = page + (1 << order);
- for (p = page + (size >> PAGE_SHIFT); p < e; p++)
- __free_page(p);
-
- e = page + (size >> PAGE_SHIFT);
-
- for (p = page; p < e; p++) {
- __flush_dcache_page(page_mapping(p), p);
-
- /* even though a freshly-allocated highmem page shouldn't
- * be mapped, because the kmaps are flushed lazily, it
- * is possible that a mapping from an old kmap_high call
- * is still present, and its cache attributes need to
- * be updated to match the new expectations */
- if (PageHighMem(p))
- update_kmap_pte(p, prot);
- else
- update_pte(p, prot);
- }
- base = page_to_phys(page);
- outer_flush_range(base, base + size);
- return page;
-}
projects / firefly-linux-kernel-4.4.55.git / commitdiff