1 files changed, 377 insertions, 0 deletions

diff --git a/arch/ppc64/kernel/bpa_iommu.c b/arch/ppc64/kernel/bpa_iommu.c
new file mode 100644
index 000000000000..f33a7bccb0d7
--- /dev/null
+++ b/arch/ppc64/kernel/bpa_iommu.c
@@ -0,0 +1,377 @@
+/*
+ * 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;
+}