arch/powerpc/sysdev/dart_iommu.c - linux - Git at Google

 /*
  * 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) {
 		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 {
 		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);
 }
	/*
	* 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) {
	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 {
	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);
	}