From mboxrd@z Thu Jan 1 00:00:00 1970 From: ard.biesheuvel@linaro.org (Ard Biesheuvel) Date: Mon, 19 Mar 2018 19:19:54 +0800 Subject: [RFC PATCH 2/6] arm64/mm: create dedicated segment for pgdir mappings In-Reply-To: <20180319111958.4171-1-ard.biesheuvel@linaro.org> References: <20180319111958.4171-1-ard.biesheuvel@linaro.org> Message-ID: <20180319111958.4171-3-ard.biesheuvel@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org In order to allow the pgdir mapping to be backed by a non-adjacent physical region in a future patch, split it off from the data segment and create a dedicated pgdir segment for it. Signed-off-by: Ard Biesheuvel --- arch/arm64/include/asm/sections.h | 1 + arch/arm64/kernel/vmlinux.lds.S | 3 +++ arch/arm64/mm/mmu.c | 10 +++++++--- 3 files changed, 11 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/sections.h b/arch/arm64/include/asm/sections.h index caab039d6305..f6b70a3fb332 100644 --- a/arch/arm64/include/asm/sections.h +++ b/arch/arm64/include/asm/sections.h @@ -29,5 +29,6 @@ extern char __inittext_begin[], __inittext_end[]; extern char __irqentry_text_start[], __irqentry_text_end[]; extern char __mmuoff_data_start[], __mmuoff_data_end[]; extern char __entry_tramp_text_start[], __entry_tramp_text_end[]; +extern char __pgdir_segment_start[], __pgdir_segment_end[]; #endif /* __ASM_SECTIONS_H */ diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index 0221aca6493d..b0fa2277e8d0 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -219,6 +219,8 @@ SECTIONS idmap_pg_dir = .; . += IDMAP_DIR_SIZE; + . = ALIGN(SEGMENT_ALIGN); + __pgdir_segment_start = .; #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 tramp_pg_dir = .; . += PAGE_SIZE; @@ -229,6 +231,7 @@ SECTIONS . += RESERVED_TTBR0_SIZE; #endif swapper_pg_dir = .; + __pgdir_segment_end = . + PAGE_SIZE; . += SWAPPER_DIR_SIZE; swapper_pg_end = .; diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 007b2e32ca71..0a9c08c0948c 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -572,7 +572,7 @@ core_initcall(map_entry_trampoline); static void __init map_kernel(pgd_t *pgdp) { static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_inittext, - vmlinux_initdata, vmlinux_data; + vmlinux_initdata, vmlinux_data, vmlinux_pgdir; /* * External debuggers may need to write directly to the text @@ -596,8 +596,12 @@ static void __init map_kernel(pgd_t *pgdp) map_kernel_segment(pgdp, __initdata_begin, __initdata_end, __pa_symbol(__initdata_begin), PAGE_KERNEL, &vmlinux_initdata, 0, VM_NO_GUARD); - map_kernel_segment(pgdp, _data, _end, __pa_symbol(_data), PAGE_KERNEL, - &vmlinux_data, 0, 0); + map_kernel_segment(pgdp, _data, __pgdir_segment_start, + __pa_symbol(_data), PAGE_KERNEL, + &vmlinux_data, 0, VM_NO_GUARD); + map_kernel_segment(pgdp, __pgdir_segment_start, __pgdir_segment_end, + __pa_symbol(__pgdir_segment_start), PAGE_KERNEL, + &vmlinux_pgdir, 0, 0); if (!READ_ONCE(pgd_val(*pgd_offset_raw(pgdp, FIXADDR_START)))) { /* -- 2.11.0