| /* |
| * 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); |
| } |