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/*
* 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.
*
* Portions Copyright (C) Cisco Systems, Inc.
*/
#ifndef __ASM_MACH_POWERTV_IOREMAP_H
#define __ASM_MACH_POWERTV_IOREMAP_H
#include <linux/types.h>
#include <linux/log2.h>
#include <linux/compiler.h>
#include <asm/pgtable-bits.h>
#include <asm/addrspace.h>
/* We're going to mess with bits, so get sizes */
#define IOR_BPC 8 /* Bits per char */
#define IOR_PHYS_BITS (IOR_BPC * sizeof(phys_addr_t))
#define IOR_DMA_BITS (IOR_BPC * sizeof(dma_addr_t))
/*
* Define the granularity of physical/DMA mapping in terms of the number
* of bits that defines the offset within a grain. These will be the
* least significant bits of the address. The rest of a physical or DMA
* address will be used to index into an appropriate table to find the
* offset to add to the address to yield the corresponding DMA or physical
* address, respectively.
*/
#define IOR_LSBITS 22 /* Bits in a grain */
/*
* Compute the number of most significant address bits after removing those
* used for the offset within a grain and then compute the number of table
* entries for the conversion.
*/
#define IOR_PHYS_MSBITS (IOR_PHYS_BITS - IOR_LSBITS)
#define IOR_NUM_PHYS_TO_DMA ((phys_addr_t) 1 << IOR_PHYS_MSBITS)
#define IOR_DMA_MSBITS (IOR_DMA_BITS - IOR_LSBITS)
#define IOR_NUM_DMA_TO_PHYS ((dma_addr_t) 1 << IOR_DMA_MSBITS)
/*
* Define data structures used as elements in the arrays for the conversion
* between physical and DMA addresses. We do some slightly fancy math to
* compute the width of the offset element of the conversion tables so
* that we can have the smallest conversion tables. Next, round up the
* sizes to the next higher power of two, i.e. the offset element will have
* 8, 16, 32, 64, etc. bits. This eliminates the need to mask off any
* bits. Finally, we compute a shift value that puts the most significant
* bits of the offset into the most significant bits of the offset element.
* This makes it more efficient on processors without barrel shifters and
* easier to see the values if the conversion table is dumped in binary.
*/
#define _IOR_OFFSET_WIDTH(n) (1 << order_base_2(n))
#define IOR_OFFSET_WIDTH(n) \
(_IOR_OFFSET_WIDTH(n) < 8 ? 8 : _IOR_OFFSET_WIDTH(n))
#define IOR_PHYS_OFFSET_BITS IOR_OFFSET_WIDTH(IOR_PHYS_MSBITS)
#define IOR_PHYS_SHIFT (IOR_PHYS_BITS - IOR_PHYS_OFFSET_BITS)
#define IOR_DMA_OFFSET_BITS IOR_OFFSET_WIDTH(IOR_DMA_MSBITS)
#define IOR_DMA_SHIFT (IOR_DMA_BITS - IOR_DMA_OFFSET_BITS)
struct ior_phys_to_dma {
dma_addr_t offset:IOR_DMA_OFFSET_BITS __packed
__aligned((IOR_DMA_OFFSET_BITS / IOR_BPC));
};
struct ior_dma_to_phys {
dma_addr_t offset:IOR_PHYS_OFFSET_BITS __packed
__aligned((IOR_PHYS_OFFSET_BITS / IOR_BPC));
};
extern struct ior_phys_to_dma _ior_phys_to_dma[IOR_NUM_PHYS_TO_DMA];
extern struct ior_dma_to_phys _ior_dma_to_phys[IOR_NUM_DMA_TO_PHYS];
static inline dma_addr_t _phys_to_dma_offset_raw(phys_addr_t phys)
{
return (dma_addr_t)_ior_phys_to_dma[phys >> IOR_LSBITS].offset;
}
static inline dma_addr_t _dma_to_phys_offset_raw(dma_addr_t dma)
{
return (dma_addr_t)_ior_dma_to_phys[dma >> IOR_LSBITS].offset;
}
/* These are not portable and should not be used in drivers. Drivers should
* be using ioremap() and friends to map physical addreses to virtual
* addresses and dma_map*() and friends to map virtual addresses into DMA
* addresses and back.
*/
static inline dma_addr_t phys_to_dma(phys_addr_t phys)
{
return phys + (_phys_to_dma_offset_raw(phys) << IOR_PHYS_SHIFT);
}
static inline phys_addr_t dma_to_phys(dma_addr_t dma)
{
return dma + (_dma_to_phys_offset_raw(dma) << IOR_DMA_SHIFT);
}
extern void ioremap_add_map(dma_addr_t phys, phys_addr_t alias,
dma_addr_t size);
/*
* Allow physical addresses to be fixed up to help peripherals located
* outside the low 32-bit range -- generic pass-through version.
*/
static inline phys_t fixup_bigphys_addr(phys_t phys_addr, phys_t size)
{
return phys_addr;
}
/*
* Handle the special case of addresses the area aliased into the first
* 512 MiB of the processor's physical address space. These turn into either
* kseg0 or kseg1 addresses, depending on flags.
*/
static inline void __iomem *plat_ioremap(phys_t start, unsigned long size,
unsigned long flags)
{
phys_addr_t start_offset;
void __iomem *result = NULL;
/* Start by checking to see whether this is an aliased address */
start_offset = _dma_to_phys_offset_raw(start);
/*
* If:
* o the memory is aliased into the first 512 MiB, and
* o the start and end are in the same RAM bank, and
* o we don't have a zero size or wrap around, and
* o we are supposed to create an uncached mapping,
* handle this is a kseg0 or kseg1 address
*/
if (start_offset != 0) {
phys_addr_t last;
dma_addr_t dma_to_phys_offset;
last = start + size - 1;
dma_to_phys_offset =
_dma_to_phys_offset_raw(last) << IOR_DMA_SHIFT;
if (dma_to_phys_offset == start_offset &&
size != 0 && start <= last) {
phys_t adjusted_start;
adjusted_start = start + start_offset;
if (flags == _CACHE_UNCACHED)
result = (void __iomem *) (unsigned long)
CKSEG1ADDR(adjusted_start);
else
result = (void __iomem *) (unsigned long)
CKSEG0ADDR(adjusted_start);
}
}
return result;
}
static inline int plat_iounmap(const volatile void __iomem *addr)
{
return 0;
}
#endif /* __ASM_MACH_POWERTV_IOREMAP_H */
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