/* * IOMMU implementation for Broadband Processor Architecture * We just establish a linear mapping at boot by setting all the * IOPT cache entries in the CPU. * The mapping functions should be identical to pci_direct_iommu, * except for the handling of the high order bit that is required * by the Spider bridge. These should be split into a separate * file at the point where we get a different bridge chip. * * Copyright (C) 2005 IBM Deutschland Entwicklung GmbH, * Arnd Bergmann <arndb@de.ibm.com> * * Based on linear mapping * Copyright (C) 2003 Benjamin Herrenschmidt (benh@kernel.crashing.org) * * 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. */ #undef DEBUG #include <linux/kernel.h> #include <linux/pci.h> #include <linux/delay.h> #include <linux/string.h> #include <linux/init.h> #include <linux/bootmem.h> #include <linux/mm.h> #include <linux/dma-mapping.h> #include <asm/sections.h> #include <asm/iommu.h> #include <asm/io.h> #include <asm/prom.h> #include <asm/pci-bridge.h> #include <asm/machdep.h> #include <asm/pmac_feature.h> #include <asm/abs_addr.h> #include <asm/system.h> #include "pci.h" #include "bpa_iommu.h" static inline unsigned long get_iopt_entry(unsigned long real_address, unsigned long ioid, unsigned long prot) { return (prot & IOPT_PROT_MASK) | (IOPT_COHERENT) | (IOPT_ORDER_VC) | (real_address & IOPT_RPN_MASK) | (ioid & IOPT_IOID_MASK); } typedef struct { unsigned long val; } ioste; static inline ioste mk_ioste(unsigned long val) { ioste ioste = { .val = val, }; return ioste; } static inline ioste get_iost_entry(unsigned long iopt_base, unsigned long io_address, unsigned page_size) { unsigned long ps; unsigned long iostep; unsigned long nnpt; unsigned long shift; switch (page_size) { case 0x1000000: ps = IOST_PS_16M; nnpt = 0; /* one page per segment */ shift = 5; /* segment has 16 iopt entries */ break; case 0x100000: ps = IOST_PS_1M; nnpt = 0; /* one page per segment */ shift = 1; /* segment has 256 iopt entries */ break; case 0x10000: ps = IOST_PS_64K; nnpt = 0x07; /* 8 pages per io page table */ shift = 0; /* all entries are used */ break; case 0x1000: ps = IOST_PS_4K; nnpt = 0x7f; /* 128 pages per io page table */ shift = 0; /* all entries are used */ break; default: /* not a known compile time constant */ BUILD_BUG_ON(1); break; } iostep = iopt_base + /* need 8 bytes per iopte */ (((io_address / page_size * 8) /* align io page tables on 4k page boundaries */ << shift) /* nnpt+1 pages go into each iopt */ & ~(nnpt << 12)); nnpt++; /* this seems to work, but the documentation is not clear about wether we put nnpt or nnpt-1 into the ioste bits. In theory, this can't work for 4k pages. */ return mk_ioste(IOST_VALID_MASK | (iostep & IOST_PT_BASE_MASK) | ((nnpt << 5) & IOST_NNPT_MASK) | (ps & IOST_PS_MASK)); } /* compute the address of an io pte */ static inline unsigned long get_ioptep(ioste iost_entry, unsigned long io_address) { unsigned long iopt_base; unsigned long page_size; unsigned long page_number; unsigned long iopt_offset; iopt_base = iost_entry.val & IOST_PT_BASE_MASK; page_size = iost_entry.val & IOST_PS_MASK; /* decode page size to compute page number */ page_number = (io_address & 0x0fffffff) >> (10 + 2 * page_size); /* page number is an offset into the io page table */ iopt_offset = (page_number << 3) & 0x7fff8ul; return iopt_base + iopt_offset; } /* compute the tag field of the iopt cache entry */ static inline unsigned long get_ioc_tag(ioste iost_entry, unsigned long io_address) { unsigned long iopte = get_ioptep(iost_entry, io_address); return IOPT_VALID_MASK | ((iopte & 0x00000000000000ff8ul) >> 3) | ((iopte & 0x0000003fffffc0000ul) >> 9); } /* compute the hashed 6 bit index for the 4-way associative pte cache */ static inline unsigned long get_ioc_hash(ioste iost_entry, unsigned long io_address) { unsigned long iopte = get_ioptep(iost_entry, io_address); return ((iopte & 0x000000000000001f8ul) >> 3) ^ ((iopte & 0x00000000000020000ul) >> 17) ^ ((iopte & 0x00000000000010000ul) >> 15) ^ ((iopte & 0x00000000000008000ul) >> 13) ^ ((iopte & 0x00000000000004000ul) >> 11) ^ ((iopte & 0x00000000000002000ul) >> 9) ^ ((iopte & 0x00000000000001000ul) >> 7); } /* same as above, but pretend that we have a simpler 1-way associative pte cache with an 8 bit index */ static inline unsigned long get_ioc_hash_1way(ioste iost_entry, unsigned long io_address) { unsigned long iopte = get_ioptep(iost_entry, io_address); return ((iopte & 0x000000000000001f8ul) >> 3) ^ ((iopte & 0x00000000000020000ul) >> 17) ^ ((iopte & 0x00000000000010000ul) >> 15) ^ ((iopte & 0x00000000000008000ul) >> 13) ^ ((iopte & 0x00000000000004000ul) >> 11) ^ ((iopte & 0x00000000000002000ul) >> 9) ^ ((iopte & 0x00000000000001000ul) >> 7) ^ ((iopte & 0x0000000000000c000ul) >> 8); } static inline ioste get_iost_cache(void __iomem *base, unsigned long index) { unsigned long __iomem *p = (base + IOC_ST_CACHE_DIR); return mk_ioste(in_be64(&p[index])); } static inline void set_iost_cache(void __iomem *base, unsigned long index, ioste ste) { unsigned long __iomem *p = (base + IOC_ST_CACHE_DIR); pr_debug("ioste %02lx was %016lx, store %016lx", index, get_iost_cache(base, index).val, ste.val); out_be64(&p[index], ste.val); pr_debug(" now %016lx\n", get_iost_cache(base, index).val); } static inline unsigned long get_iopt_cache(void __iomem *base, unsigned long index, unsigned long *tag) { unsigned long __iomem *tags = (void *)(base + IOC_PT_CACHE_DIR); unsigned long __iomem *p = (void *)(base + IOC_PT_CACHE_REG); *tag = tags[index]; rmb(); return *p; } static inline void set_iopt_cache(void __iomem *base, unsigned long index, unsigned long tag, unsigned long val) { unsigned long __iomem *tags = base + IOC_PT_CACHE_DIR; unsigned long __iomem *p = base + IOC_PT_CACHE_REG; pr_debug("iopt %02lx was v%016lx/t%016lx, store v%016lx/t%016lx\n", index, get_iopt_cache(base, index, &oldtag), oldtag, val, tag); out_be64(p, val); out_be64(&tags[index], tag); } static inline void set_iost_origin(void __iomem *base) { unsigned long __iomem *p = base + IOC_ST_ORIGIN; unsigned long origin = IOSTO_ENABLE | IOSTO_SW; pr_debug("iost_origin %016lx, now %016lx\n", in_be64(p), origin); out_be64(p, origin); } static inline void set_iocmd_config(void __iomem *base) { unsigned long __iomem *p = base + 0xc00; unsigned long conf; conf = in_be64(p); pr_debug("iost_conf %016lx, now %016lx\n", conf, conf | IOCMD_CONF_TE); out_be64(p, conf | IOCMD_CONF_TE); } /* FIXME: get these from the device tree */ #define ioc_base 0x20000511000ull #define ioc_mmio_base 0x20000510000ull #define ioid 0x48a #define iopt_phys_offset (- 0x20000000) /* We have a 512MB offset from the SB */ #define io_page_size 0x1000000 static unsigned long map_iopt_entry(unsigned long address) { switch (address >> 20) { case 0x600: address = 0x24020000000ull; /* spider i/o */ break; default: address += iopt_phys_offset; break; } return get_iopt_entry(address, ioid, IOPT_PROT_RW); } static void iommu_bus_setup_null(struct pci_bus *b) { } static void iommu_dev_setup_null(struct pci_dev *d) { } /* initialize the iommu to support a simple linear mapping * for each DMA window used by any device. For now, we * happen to know that there is only one DMA window in use, * starting at iopt_phys_offset. */ static void bpa_map_iommu(void) { unsigned long address; void __iomem *base; ioste ioste; unsigned long index; base = __ioremap(ioc_base, 0x1000, _PAGE_NO_CACHE); pr_debug("%lx mapped to %p\n", ioc_base, base); set_iocmd_config(base); iounmap(base); base = __ioremap(ioc_mmio_base, 0x1000, _PAGE_NO_CACHE); pr_debug("%lx mapped to %p\n", ioc_mmio_base, base); set_iost_origin(base); for (address = 0; address < 0x100000000ul; address += io_page_size) { ioste = get_iost_entry(0x10000000000ul, address, io_page_size); if ((address & 0xfffffff) == 0) /* segment start */ set_iost_cache(base, address >> 28, ioste); index = get_ioc_hash_1way(ioste, address); pr_debug("addr %08lx, index %02lx, ioste %016lx\n", address, index, ioste.val); set_iopt_cache(base, get_ioc_hash_1way(ioste, address), get_ioc_tag(ioste, address), map_iopt_entry(address)); } iounmap(base); } static void *bpa_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, unsigned int __nocast flag) { void *ret; ret = (void *)__get_free_pages(flag, get_order(size)); if (ret != NULL) { memset(ret, 0, size); *dma_handle = virt_to_abs(ret) | BPA_DMA_VALID; } return ret; } static void bpa_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle) { free_pages((unsigned long)vaddr, get_order(size)); } static dma_addr_t bpa_map_single(struct device *hwdev, void *ptr, size_t size, enum dma_data_direction direction) { return virt_to_abs(ptr) | BPA_DMA_VALID; } static void bpa_unmap_single(struct device *hwdev, dma_addr_t dma_addr, size_t size, enum dma_data_direction direction) { } static int bpa_map_sg(struct device *hwdev, struct scatterlist *sg, int nents, enum dma_data_direction direction) { int i; for (i = 0; i < nents; i++, sg++) { sg->dma_address = (page_to_phys(sg->page) + sg->offset) | BPA_DMA_VALID; sg->dma_length = sg->length; } return nents; } static void bpa_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nents, enum dma_data_direction direction) { } static int bpa_dma_supported(struct device *dev, u64 mask) { return mask < 0x100000000ull; } void bpa_init_iommu(void) { bpa_map_iommu(); /* Direct I/O, IOMMU off */ ppc_md.iommu_dev_setup = iommu_dev_setup_null; ppc_md.iommu_bus_setup = iommu_bus_setup_null; pci_dma_ops.alloc_coherent = bpa_alloc_coherent; pci_dma_ops.free_coherent = bpa_free_coherent; pci_dma_ops.map_single = bpa_map_single; pci_dma_ops.unmap_single = bpa_unmap_single; pci_dma_ops.map_sg = bpa_map_sg; pci_dma_ops.unmap_sg = bpa_unmap_sg; pci_dma_ops.dma_supported = bpa_dma_supported; }