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-rw-r--r--arch/arm64/kernel/head.S12
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 368ad1f7c36c..0a0a49756826 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -82,10 +82,8 @@
#ifdef CONFIG_ARM64_64K_PAGES
#define MM_MMUFLAGS PTE_ATTRINDX(MT_NORMAL) | PTE_FLAGS
-#define IO_MMUFLAGS PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_XN | PTE_FLAGS
#else
#define MM_MMUFLAGS PMD_ATTRINDX(MT_NORMAL) | PMD_FLAGS
-#define IO_MMUFLAGS PMD_ATTRINDX(MT_DEVICE_nGnRE) | PMD_SECT_XN | PMD_FLAGS
#endif
/*
@@ -368,6 +366,7 @@ 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)
*/
__create_page_tables:
pgtbl x25, x26, x24 // idmap_pg_dir and swapper_pg_dir addresses
@@ -420,6 +419,15 @@ __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.
+ */
+ ldr x5, =EARLYCON_IOBASE // UART 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