137 lines
4.6 KiB
C
137 lines
4.6 KiB
C
/*
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* ioremap.c
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*
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* Support for mapping between dma_addr_t values a phys_addr_t values.
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*
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* Copyright (C) 2005-2009 Scientific-Atlanta, Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Author: David VomLehn <dvomlehn@cisco.com>
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*
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* Description: Defines the platform resources for the SA settop.
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*
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* NOTE: The bootloader allocates persistent memory at an address which is
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* 16 MiB below the end of the highest address in KSEG0. All fixed
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* address memory reservations must avoid this region.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <asm/mach-powertv/ioremap.h>
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/*
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* Define the sizes of and masks for grains in physical and DMA space. The
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* values are the same but the types are not.
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*/
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#define IOR_PHYS_GRAIN ((phys_addr_t) 1 << IOR_LSBITS)
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#define IOR_PHYS_GRAIN_MASK (IOR_PHYS_GRAIN - 1)
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#define IOR_DMA_GRAIN ((dma_addr_t) 1 << IOR_LSBITS)
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#define IOR_DMA_GRAIN_MASK (IOR_DMA_GRAIN - 1)
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/*
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* Values that, when accessed by an index derived from a phys_addr_t and
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* added to phys_addr_t value, yield a DMA address
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*/
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struct ior_phys_to_dma _ior_phys_to_dma[IOR_NUM_PHYS_TO_DMA];
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EXPORT_SYMBOL(_ior_phys_to_dma);
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/*
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* Values that, when accessed by an index derived from a dma_addr_t and
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* added to that dma_addr_t value, yield a physical address
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*/
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struct ior_dma_to_phys _ior_dma_to_phys[IOR_NUM_DMA_TO_PHYS];
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EXPORT_SYMBOL(_ior_dma_to_phys);
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/**
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* setup_dma_to_phys - set up conversion from DMA to physical addresses
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* @dma_idx: Top IOR_LSBITS bits of the DMA address, i.e. an index
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* into the array _dma_to_phys.
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* @delta: Value that, when added to the DMA address, will yield the
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* physical address
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* @s: Number of bytes in the section of memory with the given delta
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* between DMA and physical addresses.
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*/
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static void setup_dma_to_phys(dma_addr_t dma, phys_addr_t delta, dma_addr_t s)
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{
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int dma_idx, first_idx, last_idx;
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phys_addr_t first, last;
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/*
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* Calculate the first and last indices, rounding the first up and
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* the second down.
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*/
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first = dma & ~IOR_DMA_GRAIN_MASK;
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last = (dma + s - 1) & ~IOR_DMA_GRAIN_MASK;
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first_idx = first >> IOR_LSBITS; /* Convert to indices */
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last_idx = last >> IOR_LSBITS;
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for (dma_idx = first_idx; dma_idx <= last_idx; dma_idx++)
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_ior_dma_to_phys[dma_idx].offset = delta >> IOR_DMA_SHIFT;
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}
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/**
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* setup_phys_to_dma - set up conversion from DMA to physical addresses
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* @phys_idx: Top IOR_LSBITS bits of the DMA address, i.e. an index
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* into the array _phys_to_dma.
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* @delta: Value that, when added to the DMA address, will yield the
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* physical address
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* @s: Number of bytes in the section of memory with the given delta
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* between DMA and physical addresses.
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*/
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static void setup_phys_to_dma(phys_addr_t phys, dma_addr_t delta, phys_addr_t s)
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{
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int phys_idx, first_idx, last_idx;
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phys_addr_t first, last;
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/*
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* Calculate the first and last indices, rounding the first up and
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* the second down.
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*/
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first = phys & ~IOR_PHYS_GRAIN_MASK;
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last = (phys + s - 1) & ~IOR_PHYS_GRAIN_MASK;
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first_idx = first >> IOR_LSBITS; /* Convert to indices */
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last_idx = last >> IOR_LSBITS;
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for (phys_idx = first_idx; phys_idx <= last_idx; phys_idx++)
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_ior_phys_to_dma[phys_idx].offset = delta >> IOR_PHYS_SHIFT;
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}
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/**
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* ioremap_add_map - add to the physical and DMA address conversion arrays
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* @phys: Process's view of the address of the start of the memory chunk
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* @dma: DMA address of the start of the memory chunk
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* @size: Size, in bytes, of the chunk of memory
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*
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* NOTE: It might be obvious, but the assumption is that all @size bytes have
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* the same offset between the physical address and the DMA address.
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*/
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void ioremap_add_map(phys_addr_t phys, phys_addr_t dma, phys_addr_t size)
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{
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if (size == 0)
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return;
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if ((dma & IOR_DMA_GRAIN_MASK) != 0 ||
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(phys & IOR_PHYS_GRAIN_MASK) != 0 ||
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(size & IOR_PHYS_GRAIN_MASK) != 0)
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pr_crit("Memory allocation must be in chunks of 0x%x bytes\n",
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IOR_PHYS_GRAIN);
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setup_dma_to_phys(dma, phys - dma, size);
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setup_phys_to_dma(phys, dma - phys, size);
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}
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