[PATCH] powerpc: Experimental support for new G5 Macs (#2)

This adds some very basic support for the new machines, including the
Quad G5 (tested), and other new dual core based machines and iMac G5
iSight (untested). This is still experimental !  There is no thermal
control yet, there is no proper handing of MSIs, etc.. but it
boots, I have all 4 cores up on my machine. Compared to the previous
version of this patch, this one adds DART IOMMU support for the U4
chipset and thus should work fine on setups with more than 2Gb of RAM.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 350 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/dart_iommu.c b/arch/powerpc/sysdev/dart_iommu.c
new file mode 100644
index 00000000000..df0dbdee762
--- /dev/null
+++ b/arch/powerpc/sysdev/dart_iommu.c
@@ -0,0 +1,350 @@
+/*
+ * arch/powerpc/sysdev/dart_iommu.c
+ *
+ * Copyright (C) 2004 Olof Johansson <olof@lixom.net>, IBM Corporation
+ * Copyright (C) 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>,
+ *                    IBM Corporation
+ *
+ * Based on pSeries_iommu.c:
+ * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
+ * Copyright (C) 2004 Olof Johansson <olof@lixom.net>, IBM Corporation
+ *
+ * Dynamic DMA mapping support, Apple U3, U4 & 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/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/ppc-pci.h>
+
+#include "dart.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 *__iomem dart;
+
+/* Dummy val that entries are set to when unused */
+static unsigned int dart_emptyval;
+
+static struct iommu_table iommu_table_dart;
+static int iommu_table_dart_inited;
+static int dart_dirty;
+static int dart_is_u4;
+
+#define DBG(...)
+
+static inline void dart_tlb_invalidate_all(void)
+{
+	unsigned long l = 0;
+	unsigned int reg, inv_bit;
+	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;
+
+	inv_bit = dart_is_u4 ? DART_CNTL_U4_FLUSHTLB : DART_CNTL_U3_FLUSHTLB;
+retry:
+	l = 0;
+	reg = DART_IN(DART_CNTL);
+	reg |= inv_bit;
+	DART_OUT(DART_CNTL, reg);
+
+	while ((DART_IN(DART_CNTL) & inv_bit) && l < (1L << limit))
+		l++;
+	if (l == (1L << limit)) {
+		if (limit < 4) {
+			limit++;
+		        reg = DART_IN(DART_CNTL);
+		        reg &= ~inv_bit;
+			DART_OUT(DART_CNTL, reg);
+			goto retry;
+		} else
+			panic("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 i;
+	unsigned long tmp, base, size;
+	struct resource r;
+
+	if (dart_tablebase == 0 || dart_tablesize == 0) {
+		printk(KERN_INFO "DART: table not allocated, using "
+		       "direct DMA\n");
+		return -ENODEV;
+	}
+
+	if (of_address_to_resource(dart_node, 0, &r))
+		panic("DART: can't get register base ! ");
+
+	/* 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("DART: Cannot allocate spare page!");
+	dart_emptyval = DARTMAP_VALID | ((tmp >> DART_PAGE_SHIFT) &
+					 DARTMAP_RPNMASK);
+
+	/* Map in DART registers */
+	dart = ioremap(r.start, r.end - r.start + 1);
+	if (dart == NULL)
+		panic("DART: Cannot map registers!");
+
+	/* Map in DART table */
+	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. */
+	base = dart_tablebase >> DART_PAGE_SHIFT;
+	size = dart_tablesize >> DART_PAGE_SHIFT;
+	if (dart_is_u4) {
+		BUG_ON(size & ~DART_SIZE_U4_SIZE_MASK);
+		DART_OUT(DART_BASE_U4, base);
+		DART_OUT(DART_SIZE_U4, size);
+		DART_OUT(DART_CNTL, DART_CNTL_U4_ENABLE);
+	} else {
+		BUG_ON(size & ~DART_CNTL_U3_SIZE_MASK);
+		DART_OUT(DART_CNTL,
+			 DART_CNTL_U3_ENABLE |
+			 (base << DART_CNTL_U3_BASE_SHIFT) |
+			 (size << DART_CNTL_U3_SIZE_SHIFT));
+	}
+
+	/* Invalidate DART to get rid of possible stale TLBs */
+	dart_tlb_invalidate_all();
+
+	printk(KERN_INFO "DART IOMMU initialized for %s type chipset\n",
+	       dart_is_u4 ? "U4" : "U3");
+
+	return 0;
+}
+
+static void iommu_table_dart_setup(void)
+{
+	iommu_table_dart.it_busno = 0;
+	iommu_table_dart.it_offset = 0;
+	/* it_size is in number of entries */
+	iommu_table_dart.it_size = (dart_tablesize / sizeof(u32)) >> DART_PAGE_FACTOR;
+
+	/* Initialize the common IOMMU code */
+	iommu_table_dart.it_base = (unsigned long)dart_vbase;
+	iommu_table_dart.it_index = 0;
+	iommu_table_dart.it_blocksize = 1;
+	iommu_init_table(&iommu_table_dart);
+
+	/* Reserve the last page of the DART to avoid possible prefetch
+	 * past the DART mapped area
+	 */
+	set_bit(iommu_table_dart.it_size - 1, iommu_table_dart.it_map);
+}
+
+static void iommu_dev_setup_dart(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_dart;
+}
+
+static void iommu_bus_setup_dart(struct pci_bus *bus)
+{
+	struct device_node *dn;
+
+	if (!iommu_table_dart_inited) {
+		iommu_table_dart_inited = 1;
+		iommu_table_dart_setup();
+	}
+
+	dn = pci_bus_to_OF_node(bus);
+
+	if (dn)
+		PCI_DN(dn)->iommu_table = &iommu_table_dart;
+}
+
+static void iommu_dev_setup_null(struct pci_dev *dev) { }
+static void iommu_bus_setup_null(struct pci_bus *bus) { }
+
+void iommu_init_early_dart(void)
+{
+	struct device_node *dn;
+
+	/* Find the DART in the device-tree */
+	dn = of_find_compatible_node(NULL, "dart", "u3-dart");
+	if (dn == NULL) {
+		dn = of_find_compatible_node(NULL, "dart", "u4-dart");
+		if (dn == NULL)
+			goto bail;
+		dart_is_u4 = 1;
+	}
+
+	/* 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) == 0) {
+		ppc_md.iommu_dev_setup = iommu_dev_setup_dart;
+		ppc_md.iommu_bus_setup = iommu_bus_setup_dart;
+
+		/* Setup pci_dma ops */
+		pci_iommu_init();
+
+		return;
+	}
+
+ bail:
+	/* 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();
+}
+
+
+void __init alloc_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 "DART table allocated at: %lx\n", dart_tablebase);
+}