powerpc: Move U3 IOMMU driver to arch/powerpc/sysdev

Signed-off-by: Paul Mackerras <paulus@samba.org>

2 files changed, 328 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index d071ae875e25..8acd21dee05d 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_PPC_I8259)		+= i8259.o
 obj-$(CONFIG_PPC_MPC106)        += grackle.o
 obj-$(CONFIG_BOOKE)             += dcr.o
 obj-$(CONFIG_40x)               += dcr.o
+obj-$(CONFIG_U3_DART)           += u3_iommu.o
diff --git a/arch/powerpc/sysdev/u3_iommu.c b/arch/powerpc/sysdev/u3_iommu.c
new file mode 100644
index 000000000000..fba871a1bda5
--- /dev/null
+++ b/arch/powerpc/sysdev/u3_iommu.c
@@ -0,0 +1,327 @@
+/*
+ * 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 <asm/dart.h>
+#include <asm/ppc-pci.h>
+
+extern int iommu_force_on;
+
+/* 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);
+
+        index <<= DART_PAGE_FACTOR;
+        npages <<= DART_PAGE_FACTOR;
+
+        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) >> DART_PAGE_SHIFT;
+
+                *(dp++) = DARTMAP_VALID | (rpn & DARTMAP_RPNMASK);
+
+                rpn++;
+                uaddr += DART_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);
+
+        index <<= DART_PAGE_FACTOR;
+        npages <<= DART_PAGE_FACTOR;
+
+        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(DART_PAGE_SIZE, DART_PAGE_SIZE);
+        if (!tmp)
+                panic("U3-DART: Cannot allocate spare page!");
+        dart_emptyval = DARTMAP_VALID | ((tmp >> DART_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 >> DART_PAGE_SHIFT) << DARTCNTL_BASE_SHIFT) |
+                (((dart_tablesize >> DART_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)
+                PCI_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)
+                PCI_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);
+}