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Commit 2937367b authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by ard
Browse files

ARM: add support for generic early_ioremap/early_memremap 



This enables the generic early_ioremap implementation for ARM.

It uses the fixmap region reserved for kmap. Since early_ioremap
is only supported before paging_init(), and kmap is only supported
afterwards, this is guaranteed not to cause any clashes.

Tested-by: default avatarRyan Harkin <ryan.harkin@linaro.org>
Reviewed-by: default avatarMatt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
parent f7d92489

arch/arm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ config ARM 
	select GENERIC_ALLOCATOR

	select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI)

	select GENERIC_CLOCKEVENTS_BROADCAST if SMP

	select GENERIC_EARLY_IOREMAP

	select GENERIC_IDLE_POLL_SETUP

	select GENERIC_IRQ_PROBE

	select GENERIC_IRQ_SHOW

arch/arm/include/asm/Kbuild

+1 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
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

+28 −1
Original line number Diff line number Diff line
@@ -19,20 +19,47 @@ enum fixed_addresses { 
	FIX_TEXT_POKE0,

	FIX_TEXT_POKE1,



	__end_of_fixed_addresses

	__end_of_fixmap_region,



	/*

	 * Share the kmap() region with early_ioremap(): this is guaranteed

	 * not to clash since early_ioremap() is only available before

	 * paging_init(), and kmap() only after.

	 */

#define NR_FIX_BTMAPS		32

#define FIX_BTMAPS_SLOTS	7

#define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)



	FIX_BTMAP_END = __end_of_permanent_fixed_addresses,

	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,

	__end_of_early_ioremap_region

};



static const enum fixed_addresses __end_of_fixed_addresses =

	__end_of_fixmap_region > __end_of_early_ioremap_region ?

	__end_of_fixmap_region : __end_of_early_ioremap_region;



#define FIXMAP_PAGE_COMMON	(L_PTE_YOUNG | L_PTE_PRESENT | L_PTE_XN | L_PTE_DIRTY)



#define FIXMAP_PAGE_NORMAL	(FIXMAP_PAGE_COMMON | L_PTE_MT_WRITEBACK)

#define FIXMAP_PAGE_RO		(FIXMAP_PAGE_NORMAL | L_PTE_RDONLY)



/* Used by set_fixmap_(io|nocache), both meant for mapping a device */

#define FIXMAP_PAGE_IO		(FIXMAP_PAGE_COMMON | L_PTE_MT_DEV_SHARED | L_PTE_SHARED)

#define FIXMAP_PAGE_NOCACHE	FIXMAP_PAGE_IO



#define __early_set_fixmap	__set_fixmap



#ifdef CONFIG_MMU



void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);

void __init early_fixmap_init(void);



#include <asm-generic/fixmap.h>



#else



static inline void early_fixmap_init(void) { }



#endif

#endif

arch/arm/kernel/setup.c

+5 −2
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ 
#include <asm/cpu.h>

#include <asm/cputype.h>

#include <asm/elf.h>

#include <asm/early_ioremap.h>

#include <asm/fixmap.h>

#include <asm/procinfo.h>

#include <asm/psci.h>
@@ -956,8 +957,8 @@ void __init setup_arch(char **cmdline_p) 
	strlcpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);

	*cmdline_p = cmd_line;



	if (IS_ENABLED(CONFIG_FIX_EARLYCON_MEM))

	early_fixmap_init();

	early_ioremap_init();



	parse_early_param();
@@ -968,6 +969,8 @@ void __init setup_arch(char **cmdline_p) 
	sanity_check_meminfo();

	arm_memblock_init(mdesc);



	early_ioremap_reset();



	paging_init(mdesc);

	request_standard_resources(mdesc);

arch/arm/mm/ioremap.c

+9 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <asm/cp15.h>

#include <asm/cputype.h>

#include <asm/cacheflush.h>

#include <asm/early_ioremap.h>

#include <asm/mmu_context.h>

#include <asm/pgalloc.h>

#include <asm/tlbflush.h>
@@ -469,3 +470,11 @@ int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr) 
}

EXPORT_SYMBOL_GPL(pci_ioremap_io);

#endif



/*

 * Must be called after early_fixmap_init

 */

void __init early_ioremap_init(void)

{

	early_ioremap_setup();

}