iommu: Add DMA window parser, of_get_dma_window()

This code was based on:
    "arch/microblaze/kernel/prom_parse.c"
    "arch/powerpc/kernel/prom_parse.c"

Can replace "of_parse_dma_window()" in the above. This supports
different formats flexibly. "prefix" can be configured if any. "busno"
and "index" are optionally specified. Set NULL and 0 if not used.

Signed-off-by: Hiroshi DOYU <hdoyu@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
This commit is contained in:
Hiroshi Doyu 2012-06-25 14:23:54 +03:00 committed by Joerg Roedel
parent 485802a6c5
commit 4e0ee78f2a
4 changed files with 116 additions and 0 deletions

View file

@ -13,6 +13,10 @@ menuconfig IOMMU_SUPPORT
if IOMMU_SUPPORT
config OF_IOMMU
def_bool y
depends on OF
# MSM IOMMU support
config MSM_IOMMU
bool "MSM IOMMU Support"

View file

@ -1,4 +1,5 @@
obj-$(CONFIG_IOMMU_API) += iommu.o
obj-$(CONFIG_OF_IOMMU) += of_iommu.o
obj-$(CONFIG_MSM_IOMMU) += msm_iommu.o msm_iommu_dev.o
obj-$(CONFIG_AMD_IOMMU) += amd_iommu.o amd_iommu_init.o
obj-$(CONFIG_AMD_IOMMU_V2) += amd_iommu_v2.o

90
drivers/iommu/of_iommu.c Normal file
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@ -0,0 +1,90 @@
/*
* 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/limits.h>
#include <linux/of.h>
/**
* 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);

21
include/linux/of_iommu.h Normal file
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@ -0,0 +1,21 @@
#ifndef __OF_IOMMU_H
#define __OF_IOMMU_H
#ifdef CONFIG_OF_IOMMU
extern int of_get_dma_window(struct device_node *dn, const char *prefix,
int index, unsigned long *busno, dma_addr_t *addr,
size_t *size);
#else
static inline int of_get_dma_window(struct device_node *dn, const char *prefix,
int index, unsigned long *busno, dma_addr_t *addr,
size_t *size)
{
return -EINVAL;
}
#endif /* CONFIG_OF_IOMMU */
#endif /* __OF_IOMMU_H */