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-rw-r--r--arch/powerpc/platforms/cell/iommu.c381
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 000000000000..74f999b4ac9e
--- /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;
+}

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