[linux-2.6-block.git] / drivers / iommu / of_iommu.c

/*
 * OF helpers for IOMMU
 *
 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <linux/export.h>
#include <linux/iommu.h>
#include <linux/limits.h>
#include <linux/of.h>
#include <linux/of_iommu.h>
#include <linux/of_pci.h>
#include <linux/slab.h>
#include <linux/fsl/mc.h>

#define NO_IOMMU	1

/**
 * of_get_dma_window - Parse *dma-window property and returns 0 if found.
 *
 * @dn: device node
 * @prefix: prefix for property name if any
 * @index: index to start to parse
 * @busno: Returns busno if supported. Otherwise pass NULL
 * @addr: Returns address that DMA starts
 * @size: Returns the range that DMA can handle
 *
 * This supports different formats flexibly. "prefix" can be
 * configured if any. "busno" and "index" are optionally
 * specified. Set 0(or NULL) if not used.
 */
int of_get_dma_window(struct device_node *dn, const char *prefix, int index,
		      unsigned long *busno, dma_addr_t *addr, size_t *size)
{
	const __be32 *dma_window, *end;
	int bytes, cur_index = 0;
	char propname[NAME_MAX], addrname[NAME_MAX], sizename[NAME_MAX];

	if (!dn || !addr || !size)
		return -EINVAL;

	if (!prefix)
		prefix = "";

	snprintf(propname, sizeof(propname), "%sdma-window", prefix);
	snprintf(addrname, sizeof(addrname), "%s#dma-address-cells", prefix);
	snprintf(sizename, sizeof(sizename), "%s#dma-size-cells", prefix);

	dma_window = of_get_property(dn, propname, &bytes);
	if (!dma_window)
		return -ENODEV;
	end = dma_window + bytes / sizeof(*dma_window);

	while (dma_window < end) {
		u32 cells;
		const void *prop;

		/* busno is one cell if supported */
		if (busno)
			*busno = be32_to_cpup(dma_window++);

		prop = of_get_property(dn, addrname, NULL);
		if (!prop)
			prop = of_get_property(dn, "#address-cells", NULL);

		cells = prop ? be32_to_cpup(prop) : of_n_addr_cells(dn);
		if (!cells)
			return -EINVAL;
		*addr = of_read_number(dma_window, cells);
		dma_window += cells;

		prop = of_get_property(dn, sizename, NULL);
		cells = prop ? be32_to_cpup(prop) : of_n_size_cells(dn);
		if (!cells)
			return -EINVAL;
		*size = of_read_number(dma_window, cells);
		dma_window += cells;

		if (cur_index++ == index)
			break;
	}
	return 0;
}
EXPORT_SYMBOL_GPL(of_get_dma_window);

static int of_iommu_xlate(struct device *dev,
			  struct of_phandle_args *iommu_spec)
{
	const struct iommu_ops *ops;
	struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
	int err;

	ops = iommu_ops_from_fwnode(fwnode);
	if ((ops && !ops->of_xlate) ||
	    !of_device_is_available(iommu_spec->np))
		return NO_IOMMU;

	err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
	if (err)
		return err;
	/*
	 * The otherwise-empty fwspec handily serves to indicate the specific
	 * IOMMU device we're waiting for, which will be useful if we ever get
	 * a proper probe-ordering dependency mechanism in future.
	 */
	if (!ops)
		return driver_deferred_probe_check_state(dev);

	return ops->of_xlate(dev, iommu_spec);
}

struct of_pci_iommu_alias_info {
	struct device *dev;
	struct device_node *np;
};

static int of_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
{
	struct of_pci_iommu_alias_info *info = data;
	struct of_phandle_args iommu_spec = { .args_count = 1 };
	int err;

	err = of_map_rid(info->np, alias, "iommu-map", "iommu-map-mask",
			 &iommu_spec.np, iommu_spec.args);
	if (err)
		return err == -ENODEV ? NO_IOMMU : err;

	err = of_iommu_xlate(info->dev, &iommu_spec);
	of_node_put(iommu_spec.np);
	return err;
}

static int of_fsl_mc_iommu_init(struct fsl_mc_device *mc_dev,
				struct device_node *master_np)
{
	struct of_phandle_args iommu_spec = { .args_count = 1 };
	int err;

	err = of_map_rid(master_np, mc_dev->icid, "iommu-map",
			 "iommu-map-mask", &iommu_spec.np,
			 iommu_spec.args);
	if (err)
		return err == -ENODEV ? NO_IOMMU : err;

	err = of_iommu_xlate(&mc_dev->dev, &iommu_spec);
	of_node_put(iommu_spec.np);
	return err;
}

const struct iommu_ops *of_iommu_configure(struct device *dev,
					   struct device_node *master_np)
{
	const struct iommu_ops *ops = NULL;
	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
	int err = NO_IOMMU;

	if (!master_np)
		return NULL;

	if (fwspec) {
		if (fwspec->ops)
			return fwspec->ops;

		/* In the deferred case, start again from scratch */
		iommu_fwspec_free(dev);
	}

	/*
	 * We don't currently walk up the tree looking for a parent IOMMU.
	 * See the `Notes:' section of
	 * Documentation/devicetree/bindings/iommu/iommu.txt
	 */
	if (dev_is_pci(dev)) {
		struct of_pci_iommu_alias_info info = {
			.dev = dev,
			.np = master_np,
		};

		err = pci_for_each_dma_alias(to_pci_dev(dev),
					     of_pci_iommu_init, &info);
	} else if (dev_is_fsl_mc(dev)) {
		err = of_fsl_mc_iommu_init(to_fsl_mc_device(dev), master_np);
	} else {
		struct of_phandle_args iommu_spec;
		int idx = 0;

		while (!of_parse_phandle_with_args(master_np, "iommus",
						   "#iommu-cells",
						   idx, &iommu_spec)) {
			err = of_iommu_xlate(dev, &iommu_spec);
			of_node_put(iommu_spec.np);
			idx++;
			if (err)
				break;
		}
	}

	/*
	 * Two success conditions can be represented by non-negative err here:
	 * >0 : there is no IOMMU, or one was unavailable for non-fatal reasons
	 *  0 : we found an IOMMU, and dev->fwspec is initialised appropriately
	 * <0 : any actual error
	 */
	if (!err)
		ops = dev->iommu_fwspec->ops;
	/*
	 * If we have reason to believe the IOMMU driver missed the initial
	 * add_device callback for dev, replay it to get things in order.
	 */
	if (ops && ops->add_device && dev->bus && !dev->iommu_group)
		err = ops->add_device(dev);

	/* Ignore all other errors apart from EPROBE_DEFER */
	if (err == -EPROBE_DEFER) {
		ops = ERR_PTR(err);
	} else if (err < 0) {
		dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
		ops = NULL;
	}

	return ops;
}
Commit	Line	Data
4e0ee78f HD	1	/*
	2	* OF helpers for IOMMU
	3	*
	4	* Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms and conditions of the GNU General Public License,
	8	* version 2, as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope it will be useful, but WITHOUT
	11	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	12	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	13	* more details.
	14	*
	15	* You should have received a copy of the GNU General Public License along with
	16	* this program; if not, write to the Free Software Foundation, Inc.,
	17	* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
	18	*/
	19
	20	#include <linux/export.h>
7eba1d51	21	#include <linux/iommu.h>
4e0ee78f HD	22	#include <linux/limits.h>
4e0ee78f HD	23	#include <linux/of.h>
cbff5634	24	#include <linux/of_iommu.h>
b996444c	25	#include <linux/of_pci.h>
a42a7a1f	26	#include <linux/slab.h>
fa0656b4	27	#include <linux/fsl/mc.h>
4e0ee78f	28
da4b0275 RM	29	#define NO_IOMMU 1
da4b0275 RM	30
4e0ee78f HD	31	/**
	32	* of_get_dma_window - Parse *dma-window property and returns 0 if found.
	33	*
	34	* @dn: device node
	35	* @prefix: prefix for property name if any
	36	* @index: index to start to parse
	37	* @busno: Returns busno if supported. Otherwise pass NULL
	38	* @addr: Returns address that DMA starts
	39	* @size: Returns the range that DMA can handle
	40	*
	41	* This supports different formats flexibly. "prefix" can be
	42	* configured if any. "busno" and "index" are optionally
	43	* specified. Set 0(or NULL) if not used.
	44	*/
	45	int of_get_dma_window(struct device_node dn, const char prefix, int index,
	46	unsigned long busno, dma_addr_t addr, size_t *size)
	47	{
	48	const __be32 dma_window, end;
	49	int bytes, cur_index = 0;
	50	char propname[NAME_MAX], addrname[NAME_MAX], sizename[NAME_MAX];
	51
	52	if (!dn \|\| !addr \|\| !size)
	53	return -EINVAL;
	54
	55	if (!prefix)
	56	prefix = "";
	57
	58	snprintf(propname, sizeof(propname), "%sdma-window", prefix);
	59	snprintf(addrname, sizeof(addrname), "%s#dma-address-cells", prefix);
	60	snprintf(sizename, sizeof(sizename), "%s#dma-size-cells", prefix);
	61
	62	dma_window = of_get_property(dn, propname, &bytes);
	63	if (!dma_window)
	64	return -ENODEV;
	65	end = dma_window + bytes / sizeof(*dma_window);
	66
	67	while (dma_window < end) {
	68	u32 cells;
	69	const void *prop;
	70
	71	/* busno is one cell if supported */
	72	if (busno)
	73	*busno = be32_to_cpup(dma_window++);
	74
	75	prop = of_get_property(dn, addrname, NULL);
	76	if (!prop)
	77	prop = of_get_property(dn, "#address-cells", NULL);
	78
	79	cells = prop ? be32_to_cpup(prop) : of_n_addr_cells(dn);
	80	if (!cells)
	81	return -EINVAL;
	82	*addr = of_read_number(dma_window, cells);
	83	dma_window += cells;
	84
	85	prop = of_get_property(dn, sizename, NULL);
	86	cells = prop ? be32_to_cpup(prop) : of_n_size_cells(dn);
	87	if (!cells)
	88	return -EINVAL;
	89	*size = of_read_number(dma_window, cells);
	90	dma_window += cells;
	91
	92	if (cur_index++ == index)
	93	break;
	94	}
95	return 0;
96	}
97	EXPORT_SYMBOL_GPL(of_get_dma_window);
1cd076bf	98
da4b0275 RM	99	static int of_iommu_xlate(struct device *dev,
da4b0275 RM	100	struct of_phandle_args *iommu_spec)
2a0c5754 RM	101	{
	102	const struct iommu_ops *ops;
	103	struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
	104	int err;
	105
	106	ops = iommu_ops_from_fwnode(fwnode);
d7b05582	107	if ((ops && !ops->of_xlate) \|\|
ac6bbf0c	108	!of_device_is_available(iommu_spec->np))
da4b0275	109	return NO_IOMMU;
2a0c5754 RM	110
	111	err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
	112	if (err)
da4b0275	113	return err;
d7b05582 RM	114	/*
	115	* The otherwise-empty fwspec handily serves to indicate the specific
	116	* IOMMU device we're waiting for, which will be useful if we ever get
	117	* a proper probe-ordering dependency mechanism in future.
	118	*/
	119	if (!ops)
78f307be	120	return driver_deferred_probe_check_state(dev);
2a0c5754	121
da4b0275	122	return ops->of_xlate(dev, iommu_spec);
2a0c5754 RM	123	}
2a0c5754 RM	124
d87beb74 RM	125	struct of_pci_iommu_alias_info {
	126	struct device *dev;
	127	struct device_node *np;
	128	};
b996444c	129
d87beb74	130	static int of_pci_iommu_init(struct pci_dev pdev, u16 alias, void data)
b996444c	131	{
d87beb74	132	struct of_pci_iommu_alias_info *info = data;
d87beb74	133	struct of_phandle_args iommu_spec = { .args_count = 1 };
2a0c5754	134	int err;
b996444c	135
2a6db719 NG	136	err = of_map_rid(info->np, alias, "iommu-map", "iommu-map-mask",
2a6db719 NG	137	&iommu_spec.np, iommu_spec.args);
2a0c5754	138	if (err)
da4b0275	139	return err == -ENODEV ? NO_IOMMU : err;
b996444c	140
da4b0275	141	err = of_iommu_xlate(info->dev, &iommu_spec);
b996444c	142	of_node_put(iommu_spec.np);
c0d05cde	143	return err;
2a0c5754 RM	144	}
2a0c5754 RM	145
fa0656b4 NG	146	static int of_fsl_mc_iommu_init(struct fsl_mc_device *mc_dev,
	147	struct device_node *master_np)
	148	{
	149	struct of_phandle_args iommu_spec = { .args_count = 1 };
	150	int err;
	151
	152	err = of_map_rid(master_np, mc_dev->icid, "iommu-map",
	153	"iommu-map-mask", &iommu_spec.np,
	154	iommu_spec.args);
	155	if (err)
	156	return err == -ENODEV ? NO_IOMMU : err;
	157
	158	err = of_iommu_xlate(&mc_dev->dev, &iommu_spec);
	159	of_node_put(iommu_spec.np);
	160	return err;
	161	}
	162
2a0c5754 RM	163	const struct iommu_ops of_iommu_configure(struct device dev,
	164	struct device_node *master_np)
	165	{
d87beb74	166	const struct iommu_ops *ops = NULL;
d7b05582	167	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
da4b0275	168	int err = NO_IOMMU;
2a0c5754 RM	169
	170	if (!master_np)
	171	return NULL;
	172
d7b05582 RM	173	if (fwspec) {
	174	if (fwspec->ops)
	175	return fwspec->ops;
	176
	177	/* In the deferred case, start again from scratch */
	178	iommu_fwspec_free(dev);
	179	}
	180
d87beb74 RM	181	/*
	182	* We don't currently walk up the tree looking for a parent IOMMU.
	183	* See the `Notes:' section of
	184	* Documentation/devicetree/bindings/iommu/iommu.txt
	185	*/
	186	if (dev_is_pci(dev)) {
	187	struct of_pci_iommu_alias_info info = {
	188	.dev = dev,
	189	.np = master_np,
	190	};
	191
	192	err = pci_for_each_dma_alias(to_pci_dev(dev),
	193	of_pci_iommu_init, &info);
fa0656b4 NG	194	} else if (dev_is_fsl_mc(dev)) {
fa0656b4 NG	195	err = of_fsl_mc_iommu_init(to_fsl_mc_device(dev), master_np);
d87beb74 RM	196	} else {
	197	struct of_phandle_args iommu_spec;
	198	int idx = 0;
	199
	200	while (!of_parse_phandle_with_args(master_np, "iommus",
	201	"#iommu-cells",
	202	idx, &iommu_spec)) {
da4b0275	203	err = of_iommu_xlate(dev, &iommu_spec);
d87beb74 RM	204	of_node_put(iommu_spec.np);
d87beb74 RM	205	idx++;
da4b0275	206	if (err)
d87beb74 RM	207	break;
	208	}
	209	}
da4b0275 RM	210
	211	/*
	212	* Two success conditions can be represented by non-negative err here:
	213	* >0 : there is no IOMMU, or one was unavailable for non-fatal reasons
	214	* 0 : we found an IOMMU, and dev->fwspec is initialised appropriately
	215	* <0 : any actual error
	216	*/
	217	if (!err)
	218	ops = dev->iommu_fwspec->ops;
d7b05582 RM	219	/*
	220	* If we have reason to believe the IOMMU driver missed the initial
	221	* add_device callback for dev, replay it to get things in order.
	222	*/
da4b0275	223	if (ops && ops->add_device && dev->bus && !dev->iommu_group)
d87beb74	224	err = ops->add_device(dev);
7eba1d51	225
a37b19a3	226	/* Ignore all other errors apart from EPROBE_DEFER */
da4b0275 RM	227	if (err == -EPROBE_DEFER) {
	228	ops = ERR_PTR(err);
	229	} else if (err < 0) {
	230	dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
a37b19a3 S	231	ops = NULL;
	232	}
	233
7b07cbef	234	return ops;
7eba1d51	235	}