diff options
Diffstat (limited to 'arch/ppc64/kernel/u3_iommu.c')
| -rw-r--r-- | arch/ppc64/kernel/u3_iommu.c | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/u3_iommu.c b/arch/ppc64/kernel/u3_iommu.c new file mode 100644 index 00000000000..b6e3bca4102 --- /dev/null +++ b/arch/ppc64/kernel/u3_iommu.c @@ -0,0 +1,349 @@ +/* + * arch/ppc64/kernel/u3_iommu.c + * + * Copyright (C) 2004 Olof Johansson <olof@austin.ibm.com>, IBM Corporation + * + * Based on pSeries_iommu.c: + * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation + * Copyright (C) 2004 Olof Johansson <olof@austin.ibm.com>, IBM Corporation + * + * Dynamic DMA mapping support, Apple U3 & IBM CPC925 "DART" iommu. + * + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/config.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/mm.h> +#include <linux/spinlock.h> +#include <linux/string.h> +#include <linux/pci.h> +#include <linux/dma-mapping.h> +#include <linux/vmalloc.h> +#include <asm/io.h> +#include <asm/prom.h> +#include <asm/ppcdebug.h> +#include <asm/iommu.h> +#include <asm/pci-bridge.h> +#include <asm/machdep.h> +#include <asm/abs_addr.h> +#include <asm/cacheflush.h> +#include <asm/lmb.h> + +#include "pci.h" + +extern int iommu_force_on; + +/* physical base of DART registers */ +#define DART_BASE 0xf8033000UL + +/* Offset from base to control register */ +#define DARTCNTL 0 +/* Offset from base to exception register */ +#define DARTEXCP 0x10 +/* Offset from base to TLB tag registers */ +#define DARTTAG 0x1000 + + +/* Control Register fields */ + +/* base address of table (pfn) */ +#define DARTCNTL_BASE_MASK 0xfffff +#define DARTCNTL_BASE_SHIFT 12 + +#define DARTCNTL_FLUSHTLB 0x400 +#define DARTCNTL_ENABLE 0x200 + +/* size of table in pages */ +#define DARTCNTL_SIZE_MASK 0x1ff +#define DARTCNTL_SIZE_SHIFT 0 + +/* DART table fields */ +#define DARTMAP_VALID 0x80000000 +#define DARTMAP_RPNMASK 0x00ffffff + +/* Physical base address and size of the DART table */ +unsigned long dart_tablebase; /* exported to htab_initialize */ +static unsigned long dart_tablesize; + +/* Virtual base address of the DART table */ +static u32 *dart_vbase; + +/* Mapped base address for the dart */ +static unsigned int *dart; + +/* Dummy val that entries are set to when unused */ +static unsigned int dart_emptyval; + +static struct iommu_table iommu_table_u3; +static int iommu_table_u3_inited; +static int dart_dirty; + +#define DBG(...) + +static inline void dart_tlb_invalidate_all(void) +{ + unsigned long l = 0; + unsigned int reg; + unsigned long limit; + + DBG("dart: flush\n"); + + /* To invalidate the DART, set the DARTCNTL_FLUSHTLB bit in the + * control register and wait for it to clear. + * + * Gotcha: Sometimes, the DART won't detect that the bit gets + * set. If so, clear it and set it again. + */ + + limit = 0; + +retry: + reg = in_be32((unsigned int *)dart+DARTCNTL); + reg |= DARTCNTL_FLUSHTLB; + out_be32((unsigned int *)dart+DARTCNTL, reg); + + l = 0; + while ((in_be32((unsigned int *)dart+DARTCNTL) & DARTCNTL_FLUSHTLB) && + l < (1L<<limit)) { + l++; + } + if (l == (1L<<limit)) { + if (limit < 4) { + limit++; + reg = in_be32((unsigned int *)dart+DARTCNTL); + reg &= ~DARTCNTL_FLUSHTLB; + out_be32((unsigned int *)dart+DARTCNTL, reg); + goto retry; + } else + panic("U3-DART: TLB did not flush after waiting a long " + "time. Buggy U3 ?"); + } +} + +static void dart_flush(struct iommu_table *tbl) +{ + if (dart_dirty) + dart_tlb_invalidate_all(); + dart_dirty = 0; +} + +static void dart_build(struct iommu_table *tbl, long index, + long npages, unsigned long uaddr, + enum dma_data_direction direction) +{ + unsigned int *dp; + unsigned int rpn; + + DBG("dart: build at: %lx, %lx, addr: %x\n", index, npages, uaddr); + + dp = ((unsigned int*)tbl->it_base) + index; + + /* On U3, all memory is contigous, so we can move this + * out of the loop. + */ + while (npages--) { + rpn = virt_to_abs(uaddr) >> PAGE_SHIFT; + + *(dp++) = DARTMAP_VALID | (rpn & DARTMAP_RPNMASK); + + rpn++; + uaddr += PAGE_SIZE; + } + + dart_dirty = 1; +} + + +static void dart_free(struct iommu_table *tbl, long index, long npages) +{ + unsigned int *dp; + + /* We don't worry about flushing the TLB cache. The only drawback of + * not doing it is that we won't catch buggy device drivers doing + * bad DMAs, but then no 32-bit architecture ever does either. + */ + + DBG("dart: free at: %lx, %lx\n", index, npages); + + dp = ((unsigned int *)tbl->it_base) + index; + + while (npages--) + *(dp++) = dart_emptyval; +} + + +static int dart_init(struct device_node *dart_node) +{ + unsigned int regword; + unsigned int i; + unsigned long tmp; + + if (dart_tablebase == 0 || dart_tablesize == 0) { + printk(KERN_INFO "U3-DART: table not allocated, using direct DMA\n"); + return -ENODEV; + } + + /* Make sure nothing from the DART range remains in the CPU cache + * from a previous mapping that existed before the kernel took + * over + */ + flush_dcache_phys_range(dart_tablebase, dart_tablebase + dart_tablesize); + + /* Allocate a spare page to map all invalid DART pages. We need to do + * that to work around what looks like a problem with the HT bridge + * prefetching into invalid pages and corrupting data + */ + tmp = lmb_alloc(PAGE_SIZE, PAGE_SIZE); + if (!tmp) + panic("U3-DART: Cannot allocate spare page!"); + dart_emptyval = DARTMAP_VALID | ((tmp >> PAGE_SHIFT) & DARTMAP_RPNMASK); + + /* Map in DART registers. FIXME: Use device node to get base address */ + dart = ioremap(DART_BASE, 0x7000); + if (dart == NULL) + panic("U3-DART: Cannot map registers!"); + + /* Set initial control register contents: table base, + * table size and enable bit + */ + regword = DARTCNTL_ENABLE | + ((dart_tablebase >> PAGE_SHIFT) << DARTCNTL_BASE_SHIFT) | + (((dart_tablesize >> PAGE_SHIFT) & DARTCNTL_SIZE_MASK) + << DARTCNTL_SIZE_SHIFT); + dart_vbase = ioremap(virt_to_abs(dart_tablebase), dart_tablesize); + + /* Fill initial table */ + for (i = 0; i < dart_tablesize/4; i++) + dart_vbase[i] = dart_emptyval; + + /* Initialize DART with table base and enable it. */ + out_be32((unsigned int *)dart, regword); + + /* Invalidate DART to get rid of possible stale TLBs */ + dart_tlb_invalidate_all(); + + printk(KERN_INFO "U3/CPC925 DART IOMMU initialized\n"); + + return 0; +} + +static void iommu_table_u3_setup(void) +{ + iommu_table_u3.it_busno = 0; + iommu_table_u3.it_offset = 0; + /* it_size is in number of entries */ + iommu_table_u3.it_size = dart_tablesize / sizeof(u32); + + /* Initialize the common IOMMU code */ + iommu_table_u3.it_base = (unsigned long)dart_vbase; + iommu_table_u3.it_index = 0; + iommu_table_u3.it_blocksize = 1; + iommu_init_table(&iommu_table_u3); + + /* Reserve the last page of the DART to avoid possible prefetch + * past the DART mapped area + */ + set_bit(iommu_table_u3.it_size - 1, iommu_table_u3.it_map); +} + +static void iommu_dev_setup_u3(struct pci_dev *dev) +{ + struct device_node *dn; + + /* We only have one iommu table on the mac for now, which makes + * things simple. Setup all PCI devices to point to this table + * + * We must use pci_device_to_OF_node() to make sure that + * we get the real "final" pointer to the device in the + * pci_dev sysdata and not the temporary PHB one + */ + dn = pci_device_to_OF_node(dev); + + if (dn) + dn->iommu_table = &iommu_table_u3; +} + +static void iommu_bus_setup_u3(struct pci_bus *bus) +{ + struct device_node *dn; + + if (!iommu_table_u3_inited) { + iommu_table_u3_inited = 1; + iommu_table_u3_setup(); + } + + dn = pci_bus_to_OF_node(bus); + + if (dn) + dn->iommu_table = &iommu_table_u3; +} + +static void iommu_dev_setup_null(struct pci_dev *dev) { } +static void iommu_bus_setup_null(struct pci_bus *bus) { } + +void iommu_init_early_u3(void) +{ + struct device_node *dn; + + /* Find the DART in the device-tree */ + dn = of_find_compatible_node(NULL, "dart", "u3-dart"); + if (dn == NULL) + return; + + /* Setup low level TCE operations for the core IOMMU code */ + ppc_md.tce_build = dart_build; + ppc_md.tce_free = dart_free; + ppc_md.tce_flush = dart_flush; + + /* Initialize the DART HW */ + if (dart_init(dn)) { + /* If init failed, use direct iommu and null setup functions */ + ppc_md.iommu_dev_setup = iommu_dev_setup_null; + ppc_md.iommu_bus_setup = iommu_bus_setup_null; + + /* Setup pci_dma ops */ + pci_direct_iommu_init(); + } else { + ppc_md.iommu_dev_setup = iommu_dev_setup_u3; + ppc_md.iommu_bus_setup = iommu_bus_setup_u3; + + /* Setup pci_dma ops */ + pci_iommu_init(); + } +} + + +void __init alloc_u3_dart_table(void) +{ + /* Only reserve DART space if machine has more than 2GB of RAM + * or if requested with iommu=on on cmdline. + */ + if (lmb_end_of_DRAM() <= 0x80000000ull && !iommu_force_on) + return; + + /* 512 pages (2MB) is max DART tablesize. */ + dart_tablesize = 1UL << 21; + /* 16MB (1 << 24) alignment. We allocate a full 16Mb chuck since we + * will blow up an entire large page anyway in the kernel mapping + */ + dart_tablebase = (unsigned long) + abs_to_virt(lmb_alloc_base(1UL<<24, 1UL<<24, 0x80000000L)); + + printk(KERN_INFO "U3-DART allocated at: %lx\n", dart_tablebase); +} |