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authorMark Salter <msalter@redhat.com>2014-04-07 15:39:52 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-07 16:36:15 -0700
commitbf4b558eba920a38f91beb5ee62a8ce2628c92f7 (patch)
tree322210246d72cf0ce2a700709da443022e9dac6b /arch/arm64/kernel
parent0bf757c73d6612d3d279de3f61b35062aa9c8b1d (diff)
arm64: add early_ioremap support
Add support for early IO or memory mappings which are needed before the normal ioremap() is usable. This also adds fixmap support for permanent fixed mappings such as that used by the earlyprintk device register region. Signed-off-by: Mark Salter <msalter@redhat.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Borislav Petkov <borislav.petkov@amd.com> Cc: Dave Young <dyoung@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/arm64/kernel')
-rw-r--r--arch/arm64/kernel/early_printk.c8
-rw-r--r--arch/arm64/kernel/head.S9
-rw-r--r--arch/arm64/kernel/setup.c2
3 files changed, 11 insertions, 8 deletions
diff --git a/arch/arm64/kernel/early_printk.c b/arch/arm64/kernel/early_printk.c
index fbb6e184365..ffbbdde7aba 100644
--- a/arch/arm64/kernel/early_printk.c
+++ b/arch/arm64/kernel/early_printk.c
@@ -26,6 +26,8 @@
#include <linux/amba/serial.h>
#include <linux/serial_reg.h>
+#include <asm/fixmap.h>
+
static void __iomem *early_base;
static void (*printch)(char ch);
@@ -141,8 +143,10 @@ static int __init setup_early_printk(char *buf)
}
/* no options parsing yet */
- if (paddr)
- early_base = early_io_map(paddr, EARLYCON_IOBASE);
+ if (paddr) {
+ set_fixmap_io(FIX_EARLYCON_MEM_BASE, paddr);
+ early_base = (void __iomem *)fix_to_virt(FIX_EARLYCON_MEM_BASE);
+ }
printch = match->printch;
early_console = &early_console_dev;
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 61035d6814c..1fe5d8d2bdf 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -404,7 +404,7 @@ ENDPROC(__calc_phys_offset)
* - identity mapping to enable the MMU (low address, TTBR0)
* - first few MB of the kernel linear mapping to jump to once the MMU has
* been enabled, including the FDT blob (TTBR1)
- * - UART mapping if CONFIG_EARLY_PRINTK is enabled (TTBR1)
+ * - pgd entry for fixed mappings (TTBR1)
*/
__create_page_tables:
pgtbl x25, x26, x24 // idmap_pg_dir and swapper_pg_dir addresses
@@ -461,15 +461,12 @@ __create_page_tables:
sub x6, x6, #1 // inclusive range
create_block_map x0, x7, x3, x5, x6
1:
-#ifdef CONFIG_EARLY_PRINTK
/*
- * Create the pgd entry for the UART mapping. The full mapping is done
- * later based earlyprintk kernel parameter.
+ * Create the pgd entry for the fixed mappings.
*/
- ldr x5, =EARLYCON_IOBASE // UART virtual address
+ ldr x5, =FIXADDR_TOP // Fixed mapping virtual address
add x0, x26, #2 * PAGE_SIZE // section table address
create_pgd_entry x26, x0, x5, x6, x7
-#endif
ret
ENDPROC(__create_page_tables)
.ltorg
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 20830d1afbb..720853f70b6 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -42,6 +42,7 @@
#include <linux/of_fdt.h>
#include <linux/of_platform.h>
+#include <asm/fixmap.h>
#include <asm/cputype.h>
#include <asm/elf.h>
#include <asm/cputable.h>
@@ -361,6 +362,7 @@ void __init setup_arch(char **cmdline_p)
*cmdline_p = boot_command_line;
init_mem_pgprot();
+ early_ioremap_init();
parse_early_param();