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.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/arm/Kconfig | 1 +
arch/arm/include/asm/Kbuild | 1 +
arch/arm/include/asm/fixmap.h | 28 +++++++++++++++++++-
arch/arm/kernel/setup.c | 7 +++--
arch/arm/mm/ioremap.c | 9 +++++++
arch/arm/mm/mmu.c | 2 +-
6 files changed, 44 insertions(+), 4 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 72ad724c67ae..e4b7d6cfd8eb 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -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
diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild
index be648eb47cd9..4ea9642af500 100644
--- a/arch/arm/include/asm/Kbuild
+++ b/arch/arm/include/asm/Kbuild
@@ -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
diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h
index 58cfe9f1a687..defac13e161a 100644
--- a/arch/arm/include/asm/fixmap.h
+++ b/arch/arm/include/asm/fixmap.h
@@ -19,9 +19,26 @@ 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)
@@ -30,9 +47,18 @@ enum fixed_addresses {
#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
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 20edd349d379..5df2bca57c42 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -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_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);
diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 0c81056c1dd7..66a978d05958 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -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();
+}
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 7cd15143a507..b74686be6272 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -389,7 +389,7 @@ 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);
--
1.9.1
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