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Commit 1e378098 authored by Mark Salter's avatar Mark Salter Committed by Venkatesh Yadav Abbarapu
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arm: add early_ioremap support 

This patch uses the generic early_ioremap code to implement
early_ioremap for ARM. The ARM-specific bits come mostly from
an earlier patch from Leif Lindholm <leif.lindholm@linaro.org>
here :

	 https://lkml.org/lkml/2013/10/3/279



Change-Id: I523875442caa8ecf61cc170ed3b72a612ac93427
Signed-off-by: default avatarMark Salter <msalter@redhat.com>
Tested-by: default avatarLeif Lindholm <leif.lindholm@linaro.org>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
[robh: minor re-work in prep for permanent mappings. Fix bug in page
table allocation size. Rework CONFIG_MMU dependency.]
Signed-off-by: default avatarRob Herring <robh@kernel.org>
Git-commit: 24293625537e095c2d5bcc5a63dd23dfaf062ffc
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git


[vabbar@codeaurora.org: Fixed trivial merge conflicts]
Signed-off-by: default avatarVenkatesh Yadav Abbarapu <vabbar@codeaurora.org>
parent 79704243

arch/arm/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -97,6 +97,17 @@ config ARM_DMA_USE_IOMMU 
	select ARM_HAS_SG_CHAIN

	select NEED_SG_DMA_LENGTH



config EARLY_IOREMAP

       bool "Provide early_ioremap() support for kernel initialization"

       depends on MMU

       select GENERIC_EARLY_IOREMAP

       help

         Provide a mechanism for kernel initialisation code to temporarily

         map, in a highmem-agnostic way, memory pages in before ioremap()

         and friends are available (before paging_init() has run). It uses

         the same virtual memory range as kmap so all early mappings must

         be unmapped before paging_init() is called.



if ARM_DMA_USE_IOMMU



config ARM_DMA_IOMMU_ALIGNMENT

arch/arm/include/asm/Kbuild

+1 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ generic-y += auxvec.h 
generic-y += bitsperlong.h

generic-y += cputime.h

generic-y += current.h

generic-y += early_ioremap.h

generic-y += emergency-restart.h

generic-y += errno.h

generic-y += exec.h

arch/arm/include/asm/fixmap.h

+29 −2
Original line number Diff line number Diff line 
#ifndef _ASM_FIXMAP_H

#define _ASM_FIXMAP_H



#include <linux/kernel.h>

#include <asm/pgtable.h>

#include <asm/kmap_types.h>



#define FIXADDR_START		0xffc00000UL

#define FIXADDR_END		0xfff00000UL

#define FIXADDR_TOP		(FIXADDR_END - PAGE_SIZE)



/*

 * 224 temporary boot-time mappings, used by early_ioremap(),

 * before ioremap() is functional.

 *

 * (P)re-using the FIXADDR region, which is used for highmem

 * later on, and statically aligned to 1MB.

 */

#define NR_FIX_BTMAPS          32

#define FIX_BTMAPS_SLOTS       7

#define TOTAL_FIX_BTMAPS       (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)



enum fixed_addresses {

	FIX_KMAP_BEGIN,

	FIX_EARLYCON_MEM_BASE,

	__end_of_permanent_fixed_addresses,

	FIX_BTMAP_END = __end_of_permanent_fixed_addresses,

	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,



	FIX_KMAP_BEGIN = __end_of_permanent_fixed_addresses,

	FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1,

	__end_of_fixed_addresses

	 __end_of_fixed_addresses = (FIXADDR_END - FIXADDR_START) >> PAGE_SHIFT,

};



#define FIXMAP_PAGE_COMMON (L_PTE_YOUNG | L_PTE_PRESENT | L_PTE_XN)



#define FIXMAP_PAGE_NORMAL (FIXMAP_PAGE_COMMON | L_PTE_MT_WRITEBACK)

#define FIXMAP_PAGE_IO    (FIXMAP_PAGE_COMMON | L_PTE_MT_DEV_SHARED | L_PTE_SHARED | L_PTE_DIRTY)

#define FIXMAP_PAGE_NOCACHE FIXMAP_PAGE_IO



extern void __early_set_fixmap(enum fixed_addresses idx,

					phys_addr_t phys, pgprot_t flags);



#include <asm-generic/fixmap.h>



#endif

arch/arm/include/asm/io.h

+1 −0
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <asm/byteorder.h>

#include <asm/memory.h>

#include <asm-generic/pci_iomap.h>

#include <asm/early_ioremap.h>

#include <linux/msm_rtb.h>

#include <xen/xen.h>

arch/arm/kernel/setup.c

+1 −0
Original line number Diff line number Diff line
@@ -906,6 +906,7 @@ void __init setup_arch(char **cmdline_p) 
	const struct machine_desc *mdesc;



	setup_processor();

	early_ioremap_init();

	mdesc = setup_machine_fdt(__atags_pointer);

	if (!mdesc)

		mdesc = setup_machine_tags(__atags_pointer, __machine_arch_type);