diff options
Diffstat (limited to 'arch/powerpc/platforms/cell/iommu.c')
| -rw-r--r-- | arch/powerpc/platforms/cell/iommu.c | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c new file mode 100644 index 0000000..74f999b --- /dev/null +++ b/arch/powerpc/platforms/cell/iommu.c @@ -0,0 +1,381 @@ +/* + * IOMMU implementation for Cell 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 <asm/ppc-pci.h> + +#include "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() is not usable here */ + extern void __get_iost_entry_bad_page_size(void); + __get_iost_entry_bad_page_size(); + } + 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 cell_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 *cell_alloc_coherent(struct device *hwdev, size_t size, + dma_addr_t *dma_handle, gfp_t 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) | CELL_DMA_VALID; + } + return ret; +} + +static void cell_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 cell_map_single(struct device *hwdev, void *ptr, + size_t size, enum dma_data_direction direction) +{ + return virt_to_abs(ptr) | CELL_DMA_VALID; +} + +static void cell_unmap_single(struct device *hwdev, dma_addr_t dma_addr, + size_t size, enum dma_data_direction direction) +{ +} + +static int cell_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) + | CELL_DMA_VALID; + sg->dma_length = sg->length; + } + + return nents; +} + +static void cell_unmap_sg(struct device *hwdev, struct scatterlist *sg, + int nents, enum dma_data_direction direction) +{ +} + +static int cell_dma_supported(struct device *dev, u64 mask) +{ + return mask < 0x100000000ull; +} + +void cell_init_iommu(void) +{ + cell_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 = cell_alloc_coherent; + pci_dma_ops.free_coherent = cell_free_coherent; + pci_dma_ops.map_single = cell_map_single; + pci_dma_ops.unmap_single = cell_unmap_single; + pci_dma_ops.map_sg = cell_map_sg; + pci_dma_ops.unmap_sg = cell_unmap_sg; + pci_dma_ops.dma_supported = cell_dma_supported; +} |
