linux/drivers/iommu/of_iommu.c
Murali Karicheri ed74862103 of: iommu: Add ptr to OF node arg to of_iommu_configure()
of_iommu_configure() is called from of_dma_configure() to setup iommu ops
using DT property.  This API is currently used for platform devices for
which DMA configuration (including IOMMU ops) may come from the device's
parent.  To extend this functionality for PCI devices, this API needs to
take a parent node ptr as an argument instead of assuming device's parent.
This is needed since for PCI, the DMA configuration may be defined in the
DT node of the root bus bridge's parent device.  Currently only dma-range
is used for PCI and IOMMU is not supported.  Return error if the device is
PCI.

Add "parent" parameter (a struct device_node *) to of_iommu_configure().

Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> (AMD Seattle)
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Rob Herring <robh+dt@kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
CC: Joerg Roedel <joro@8bytes.org>
CC: Grant Likely <grant.likely@linaro.org>
CC: Russell King <linux@arm.linux.org.uk>
CC: Arnd Bergmann <arnd@arndb.de>
2015-03-03 14:42:55 -06:00

187 lines
4.8 KiB
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/slab.h>
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);
struct of_iommu_node {
struct list_head list;
struct device_node *np;
struct iommu_ops *ops;
};
static LIST_HEAD(of_iommu_list);
static DEFINE_SPINLOCK(of_iommu_lock);
void of_iommu_set_ops(struct device_node *np, struct iommu_ops *ops)
{
struct of_iommu_node *iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
if (WARN_ON(!iommu))
return;
INIT_LIST_HEAD(&iommu->list);
iommu->np = np;
iommu->ops = ops;
spin_lock(&of_iommu_lock);
list_add_tail(&iommu->list, &of_iommu_list);
spin_unlock(&of_iommu_lock);
}
struct iommu_ops *of_iommu_get_ops(struct device_node *np)
{
struct of_iommu_node *node;
struct iommu_ops *ops = NULL;
spin_lock(&of_iommu_lock);
list_for_each_entry(node, &of_iommu_list, list)
if (node->np == np) {
ops = node->ops;
break;
}
spin_unlock(&of_iommu_lock);
return ops;
}
struct iommu_ops *of_iommu_configure(struct device *dev,
struct device_node *master_np)
{
struct of_phandle_args iommu_spec;
struct device_node *np;
struct iommu_ops *ops = NULL;
int idx = 0;
if (dev_is_pci(dev)) {
dev_err(dev, "IOMMU is currently not supported for PCI\n");
return NULL;
}
/*
* We don't currently walk up the tree looking for a parent IOMMU.
* See the `Notes:' section of
* Documentation/devicetree/bindings/iommu/iommu.txt
*/
while (!of_parse_phandle_with_args(master_np, "iommus",
"#iommu-cells", idx,
&iommu_spec)) {
np = iommu_spec.np;
ops = of_iommu_get_ops(np);
if (!ops || !ops->of_xlate || ops->of_xlate(dev, &iommu_spec))
goto err_put_node;
of_node_put(np);
idx++;
}
return ops;
err_put_node:
of_node_put(np);
return NULL;
}
void __init of_iommu_init(void)
{
struct device_node *np;
const struct of_device_id *match, *matches = &__iommu_of_table;
for_each_matching_node_and_match(np, matches, &match) {
const of_iommu_init_fn init_fn = match->data;
if (init_fn(np))
pr_err("Failed to initialise IOMMU %s\n",
of_node_full_name(np));
}
}