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

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
......@@ -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
......
......@@ -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
......
......@@ -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
......@@ -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);
......
......@@ -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();
}
......@@ -390,7 +390,7 @@ void __init early_fixmap_init(void)
* The early fixmap range spans multiple pmds, for which
* we are not prepared:
*/
BUILD_BUG_ON((__fix_to_virt(__end_of_permanent_fixed_addresses) >> PMD_SHIFT)
BUILD_BUG_ON((__fix_to_virt(__end_of_early_ioremap_region) >> PMD_SHIFT)
!= FIXADDR_TOP >> PMD_SHIFT);
pmd = fixmap_pmd(FIXADDR_TOP);
......
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