c790950928
This patch adds support for CMA to dma-mapping subsystem for ARM architecture. By default a global CMA area is used, but specific devices are allowed to have their private memory areas if required (they can be created with dma_declare_contiguous() function during board initialisation). Contiguous memory areas reserved for DMA are remapped with 2-level page tables on boot. Once a buffer is requested, a low memory kernel mapping is updated to to match requested memory access type. GFP_ATOMIC allocations are performed from special pool which is created early during boot. This way remapping page attributes is not needed on allocation time. CMA has been enabled unconditionally for ARMv6+ systems. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> CC: Michal Nazarewicz <mina86@mina86.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
74 lines
1.8 KiB
C
74 lines
1.8 KiB
C
#ifdef CONFIG_MMU
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/* the upper-most page table pointer */
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extern pmd_t *top_pmd;
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/*
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* 0xffff8000 to 0xffffffff is reserved for any ARM architecture
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* specific hacks for copying pages efficiently, while 0xffff4000
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* is reserved for VIPT aliasing flushing by generic code.
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*
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* Note that we don't allow VIPT aliasing caches with SMP.
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*/
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#define COPYPAGE_MINICACHE 0xffff8000
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#define COPYPAGE_V6_FROM 0xffff8000
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#define COPYPAGE_V6_TO 0xffffc000
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/* PFN alias flushing, for VIPT caches */
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#define FLUSH_ALIAS_START 0xffff4000
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static inline void set_top_pte(unsigned long va, pte_t pte)
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{
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pte_t *ptep = pte_offset_kernel(top_pmd, va);
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set_pte_ext(ptep, pte, 0);
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local_flush_tlb_kernel_page(va);
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}
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static inline pte_t get_top_pte(unsigned long va)
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{
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pte_t *ptep = pte_offset_kernel(top_pmd, va);
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return *ptep;
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}
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static inline pmd_t *pmd_off_k(unsigned long virt)
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{
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return pmd_offset(pud_offset(pgd_offset_k(virt), virt), virt);
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}
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struct mem_type {
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pteval_t prot_pte;
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pmdval_t prot_l1;
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pmdval_t prot_sect;
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unsigned int domain;
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};
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const struct mem_type *get_mem_type(unsigned int type);
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extern void __flush_dcache_page(struct address_space *mapping, struct page *page);
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/*
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* ARM specific vm_struct->flags bits.
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*/
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/* (super)section-mapped I/O regions used by ioremap()/iounmap() */
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#define VM_ARM_SECTION_MAPPING 0x80000000
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/* permanent static mappings from iotable_init() */
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#define VM_ARM_STATIC_MAPPING 0x40000000
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/* mapping type (attributes) for permanent static mappings */
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#define VM_ARM_MTYPE(mt) ((mt) << 20)
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#define VM_ARM_MTYPE_MASK (0x1f << 20)
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#endif
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#ifdef CONFIG_ZONE_DMA
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extern u32 arm_dma_limit;
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#else
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#define arm_dma_limit ((u32)~0)
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#endif
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extern phys_addr_t arm_lowmem_limit;
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void __init bootmem_init(void);
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void arm_mm_memblock_reserve(void);
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void dma_contiguous_remap(void);
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