[mirror_ubuntu-hirsute-kernel.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>

#define NO_IOMMU	1

static const struct of_device_id __iommu_of_table_sentinel
	__used __section(__iommu_of_table_end);

/**
 * 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 bool of_iommu_driver_present(struct device_node *np)
{
	/*
	 * If the IOMMU still isn't ready by the time we reach init, assume
	 * it never will be. We don't want to defer indefinitely, nor attempt
	 * to dereference __iommu_of_table after it's been freed.
	 */
	if (system_state >= SYSTEM_RUNNING)
		return false;

	return of_match_node(&__iommu_of_table, np);
}

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) ||
	    (!ops && !of_iommu_driver_present(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_pci_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;
}

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 {
		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>
4e0ee78f	27
da4b0275 RM	28	#define NO_IOMMU 1
da4b0275 RM	29
1cd076bf WD	30	static const struct of_device_id __iommu_of_table_sentinel
	31	__used __section(__iommu_of_table_end);
	32
4e0ee78f HD	33	/**
	34	* of_get_dma_window - Parse *dma-window property and returns 0 if found.
	35	*
	36	* @dn: device node
	37	* @prefix: prefix for property name if any
	38	* @index: index to start to parse
	39	* @busno: Returns busno if supported. Otherwise pass NULL
	40	* @addr: Returns address that DMA starts
	41	* @size: Returns the range that DMA can handle
	42	*
	43	* This supports different formats flexibly. "prefix" can be
	44	* configured if any. "busno" and "index" are optionally
	45	* specified. Set 0(or NULL) if not used.
	46	*/
	47	int of_get_dma_window(struct device_node dn, const char prefix, int index,
	48	unsigned long busno, dma_addr_t addr, size_t *size)
	49	{
	50	const __be32 dma_window, end;
	51	int bytes, cur_index = 0;
	52	char propname[NAME_MAX], addrname[NAME_MAX], sizename[NAME_MAX];
	53
	54	if (!dn \|\| !addr \|\| !size)
	55	return -EINVAL;
	56
	57	if (!prefix)
	58	prefix = "";
	59
	60	snprintf(propname, sizeof(propname), "%sdma-window", prefix);
	61	snprintf(addrname, sizeof(addrname), "%s#dma-address-cells", prefix);
	62	snprintf(sizename, sizeof(sizename), "%s#dma-size-cells", prefix);
	63
	64	dma_window = of_get_property(dn, propname, &bytes);
	65	if (!dma_window)
	66	return -ENODEV;
	67	end = dma_window + bytes / sizeof(*dma_window);
	68
	69	while (dma_window < end) {
	70	u32 cells;
	71	const void *prop;
	72
	73	/* busno is one cell if supported */
	74	if (busno)
	75	*busno = be32_to_cpup(dma_window++);
	76
	77	prop = of_get_property(dn, addrname, NULL);
	78	if (!prop)
	79	prop = of_get_property(dn, "#address-cells", NULL);
	80
	81	cells = prop ? be32_to_cpup(prop) : of_n_addr_cells(dn);
	82	if (!cells)
	83	return -EINVAL;
	84	*addr = of_read_number(dma_window, cells);
	85	dma_window += cells;
	86
	87	prop = of_get_property(dn, sizename, NULL);
	88	cells = prop ? be32_to_cpup(prop) : of_n_size_cells(dn);
	89	if (!cells)
	90	return -EINVAL;
	91	*size = of_read_number(dma_window, cells);
	92	dma_window += cells;
	93
	94	if (cur_index++ == index)
	95	break;
	96	}
97	return 0;
98	}
99	EXPORT_SYMBOL_GPL(of_get_dma_window);
1cd076bf	100
d7b05582 RM	101	static bool of_iommu_driver_present(struct device_node *np)
	102	{
	103	/*
	104	* If the IOMMU still isn't ready by the time we reach init, assume
	105	* it never will be. We don't want to defer indefinitely, nor attempt
	106	* to dereference __iommu_of_table after it's been freed.
	107	*/
b903dfb2	108	if (system_state >= SYSTEM_RUNNING)
d7b05582 RM	109	return false;
	110
	111	return of_match_node(&__iommu_of_table, np);
	112	}
	113
da4b0275 RM	114	static int of_iommu_xlate(struct device *dev,
da4b0275 RM	115	struct of_phandle_args *iommu_spec)
2a0c5754 RM	116	{
	117	const struct iommu_ops *ops;
	118	struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
	119	int err;
	120
	121	ops = iommu_ops_from_fwnode(fwnode);
d7b05582	122	if ((ops && !ops->of_xlate) \|\|
573d4175	123	!of_device_is_available(iommu_spec->np) \|\|
d7b05582	124	(!ops && !of_iommu_driver_present(iommu_spec->np)))
da4b0275	125	return NO_IOMMU;
2a0c5754 RM	126
	127	err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
	128	if (err)
da4b0275	129	return err;
d7b05582 RM	130	/*
	131	* The otherwise-empty fwspec handily serves to indicate the specific
	132	* IOMMU device we're waiting for, which will be useful if we ever get
	133	* a proper probe-ordering dependency mechanism in future.
	134	*/
	135	if (!ops)
78f307be	136	return driver_deferred_probe_check_state(dev);
2a0c5754	137
da4b0275	138	return ops->of_xlate(dev, iommu_spec);
2a0c5754 RM	139	}
2a0c5754 RM	140
d87beb74 RM	141	struct of_pci_iommu_alias_info {
	142	struct device *dev;
	143	struct device_node *np;
	144	};
b996444c	145
d87beb74	146	static int of_pci_iommu_init(struct pci_dev pdev, u16 alias, void data)
b996444c	147	{
d87beb74	148	struct of_pci_iommu_alias_info *info = data;
d87beb74	149	struct of_phandle_args iommu_spec = { .args_count = 1 };
2a0c5754	150	int err;
b996444c	151
d87beb74	152	err = of_pci_map_rid(info->np, alias, "iommu-map",
2a0c5754 RM	153	"iommu-map-mask", &iommu_spec.np,
	154	iommu_spec.args);
	155	if (err)
da4b0275	156	return err == -ENODEV ? NO_IOMMU : err;
b996444c	157
da4b0275	158	err = of_iommu_xlate(info->dev, &iommu_spec);
b996444c	159	of_node_put(iommu_spec.np);
c0d05cde	160	return err;
2a0c5754 RM	161	}
	162
	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);
d87beb74 RM	194	} else {
	195	struct of_phandle_args iommu_spec;
	196	int idx = 0;
	197
	198	while (!of_parse_phandle_with_args(master_np, "iommus",
	199	"#iommu-cells",
	200	idx, &iommu_spec)) {
da4b0275	201	err = of_iommu_xlate(dev, &iommu_spec);
d87beb74 RM	202	of_node_put(iommu_spec.np);
d87beb74 RM	203	idx++;
da4b0275	204	if (err)
d87beb74 RM	205	break;
	206	}
	207	}
da4b0275 RM	208
	209	/*
	210	* Two success conditions can be represented by non-negative err here:
	211	* >0 : there is no IOMMU, or one was unavailable for non-fatal reasons
	212	* 0 : we found an IOMMU, and dev->fwspec is initialised appropriately
	213	* <0 : any actual error
	214	*/
	215	if (!err)
	216	ops = dev->iommu_fwspec->ops;
d7b05582 RM	217	/*
	218	* If we have reason to believe the IOMMU driver missed the initial
	219	* add_device callback for dev, replay it to get things in order.
	220	*/
da4b0275	221	if (ops && ops->add_device && dev->bus && !dev->iommu_group)
d87beb74	222	err = ops->add_device(dev);
7eba1d51	223
a37b19a3	224	/* Ignore all other errors apart from EPROBE_DEFER */
da4b0275 RM	225	if (err == -EPROBE_DEFER) {
	226	ops = ERR_PTR(err);
	227	} else if (err < 0) {
	228	dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
a37b19a3 S	229	ops = NULL;
	230	}
	231
7b07cbef	232	return ops;
7eba1d51	233	}