/*
* ioremap.c
*
* Support for mapping between dma_addr_t values a phys_addr_t values.
*
* Copyright (C) 2005-2009 Scientific-Atlanta, Inc.
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Author: David VomLehn <dvomlehn@cisco.com>
*
* Description: Defines the platform resources for the SA settop.
*
* NOTE: The bootloader allocates persistent memory at an address which is
* 16 MiB below the end of the highest address in KSEG0. All fixed
* address memory reservations must avoid this region.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/mach-powertv/ioremap.h>
/*
* Define the sizes of and masks for grains in physical and DMA space. The
* values are the same but the types are not.
*/
#define IOR_PHYS_GRAIN ((phys_addr_t) 1 << IOR_LSBITS)
#define IOR_PHYS_GRAIN_MASK (IOR_PHYS_GRAIN - 1)
#define IOR_DMA_GRAIN ((dma_addr_t) 1 << IOR_LSBITS)
#define IOR_DMA_GRAIN_MASK (IOR_DMA_GRAIN - 1)
/*
* Values that, when accessed by an index derived from a phys_addr_t and
* added to phys_addr_t value, yield a DMA address
*/
struct ior_phys_to_dma _ior_phys_to_dma[IOR_NUM_PHYS_TO_DMA];
EXPORT_SYMBOL(_ior_phys_to_dma);
/*
* Values that, when accessed by an index derived from a dma_addr_t and
* added to that dma_addr_t value, yield a physical address
*/
struct ior_dma_to_phys _ior_dma_to_phys[IOR_NUM_DMA_TO_PHYS];
EXPORT_SYMBOL(_ior_dma_to_phys);
/**
* setup_dma_to_phys - set up conversion from DMA to physical addresses
* @dma_idx: Top IOR_LSBITS bits of the DMA address, i.e. an index
* into the array _dma_to_phys.
* @delta: Value that, when added to the DMA address, will yield the
* physical address
* @s: Number of bytes in the section of memory with the given delta
* between DMA and physical addresses.
*/
static void setup_dma_to_phys(dma_addr_t dma, phys_addr_t delta, dma_addr_t s)
{
int dma_idx, first_idx, last_idx;
phys_addr_t first, last;
/*
* Calculate the first and last indices, rounding the first up and
* the second down.
*/
first = dma & ~IOR_DMA_GRAIN_MASK;
last = (dma + s - 1) & ~IOR_DMA_GRAIN_MASK;
first_idx = first >> IOR_LSBITS; /* Convert to indices */
last_idx = last >> IOR_LSBITS;
for (dma_idx = first_idx; dma_idx <= last_idx; dma_idx++)
_ior_dma_to_phys[dma_idx].offset = delta >> IOR_DMA_SHIFT;
}
/**
* setup_phys_to_dma - set up conversion from DMA to physical addresses
* @phys_idx: Top IOR_LSBITS bits of the DMA address, i.e. an index
* into the array _phys_to_dma.
* @delta: Value that, when added to the DMA address, will yield the
* physical address
* @s: Number of bytes in the section of memory with the given delta
* between DMA and physical addresses.
*/
static void setup_phys_to_dma(phys_addr_t phys, dma_addr_t delta, phys_addr_t s)
{
int phys_idx, first_idx, last_idx;
phys_addr_t first, last;
/*
* Calculate the first and last indices, rounding the first up and
* the second down.
*/
first = phys & ~IOR_PHYS_GRAIN_MASK;
last = (phys + s - 1) & ~IOR_PHYS_GRAIN_MASK;
first_idx = first >> IOR_LSBITS; /* Convert to indices */
last_idx = last >> IOR_LSBITS;
for (phys_idx = first_idx; phys_idx <= last_idx; phys_idx++)
_ior_phys_to_dma[phys_idx].offset = delta >> IOR_PHYS_SHIFT;
}
/**
* ioremap_add_map - add to the physical and DMA address conversion arrays
* @phys: Process's view of the address of the start of the memory chunk
* @dma: DMA address of the start of the memory chunk
* @size: Size, in bytes, of the chunk of memory
*
* NOTE: It might be obvious, but the assumption is that all @size bytes have
* the same offset between the physical address and the DMA address.
*/
void ioremap_add_map(phys_addr_t phys, phys_addr_t dma, phys_addr_t size)
{
if (size == 0)
return;
if ((dma & IOR_DMA_GRAIN_MASK) != 0 ||
(phys & IOR_PHYS_GRAIN_MASK) != 0 ||
(size & IOR_PHYS_GRAIN_MASK) != 0)
pr_crit("Memory allocation must be in chunks of 0x%x bytes\n",
IOR_PHYS_GRAIN);
setup_dma_to_phys(dma, phys - dma, size);
setup_phys_to_dma(phys, dma - phys, size);
}
