| Message ID | 1472049366-10922-8-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
On Wed, Aug 24, 2016 at 04:36:04PM +0200, Ard Biesheuvel wrote: > Keeping __PHYS_OFFSET in x24 is actually less clear than simply taking > the value of __PHYS_OFFSET using an adrp instruction in the three places > that we need it. So change that. > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Mark. > --- > arch/arm64/kernel/head.S | 20 ++++++++++++-------- > 1 file changed, 12 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S > index c112c153821e..27f51272de68 100644 > --- a/arch/arm64/kernel/head.S > +++ b/arch/arm64/kernel/head.S > @@ -211,8 +211,8 @@ efi_header_end: > ENTRY(stext) > bl preserve_boot_args > bl el2_setup // Drop to EL1, w0=cpu_boot_mode > - adrp x24, __PHYS_OFFSET > - and x23, x24, MIN_KIMG_ALIGN - 1 // KASLR offset, defaults to 0 > + adrp x23, __PHYS_OFFSET > + and x23, x23, MIN_KIMG_ALIGN - 1 // KASLR offset, defaults to 0 > bl set_cpu_boot_mode_flag > bl __create_page_tables > /* > @@ -412,6 +412,8 @@ ENDPROC(__create_page_tables) > > /* > * The following fragment of code is executed with the MMU enabled. > + * > + * x0 = __PHYS_OFFSET > */ > .set initial_sp, init_thread_union + THREAD_START_SP > __primary_switched: > @@ -420,6 +422,12 @@ __primary_switched: > msr vbar_el1, x8 // vector table address > isb > > + str_l x21, __fdt_pointer, x5 // Save FDT pointer > + > + ldr_l x4, kimage_vaddr // Save the offset between > + sub x4, x4, x0 // the kernel virtual and > + str_l x4, kimage_voffset, x5 // physical mappings > + > // Clear BSS > adr_l x0, __bss_start > mov x1, xzr > @@ -432,12 +440,6 @@ __primary_switched: > mov x4, sp > and x4, x4, #~(THREAD_SIZE - 1) > msr sp_el0, x4 // Save thread_info > - str_l x21, __fdt_pointer, x5 // Save FDT pointer > - > - ldr_l x4, kimage_vaddr // Save the offset between > - sub x4, x4, x24 // the kernel virtual and > - str_l x4, kimage_voffset, x5 // physical mappings > - > mov x29, #0 > #ifdef CONFIG_KASAN > bl kasan_early_init > @@ -792,6 +794,7 @@ __primary_switch: > bl __relocate_kernel > #ifdef CONFIG_RANDOMIZE_BASE > ldr x8, =__primary_switched > + adrp x0, __PHYS_OFFSET > blr x8 > > /* > @@ -813,5 +816,6 @@ __primary_switch: > #endif > #endif > ldr x8, =__primary_switched > + adrp x0, __PHYS_OFFSET > br x8 > ENDPROC(__primary_switch) > -- > 2.7.4 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index c112c153821e..27f51272de68 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -211,8 +211,8 @@ efi_header_end: ENTRY(stext) bl preserve_boot_args bl el2_setup // Drop to EL1, w0=cpu_boot_mode - adrp x24, __PHYS_OFFSET - and x23, x24, MIN_KIMG_ALIGN - 1 // KASLR offset, defaults to 0 + adrp x23, __PHYS_OFFSET + and x23, x23, MIN_KIMG_ALIGN - 1 // KASLR offset, defaults to 0 bl set_cpu_boot_mode_flag bl __create_page_tables /* @@ -412,6 +412,8 @@ ENDPROC(__create_page_tables) /* * The following fragment of code is executed with the MMU enabled. + * + * x0 = __PHYS_OFFSET */ .set initial_sp, init_thread_union + THREAD_START_SP __primary_switched: @@ -420,6 +422,12 @@ __primary_switched: msr vbar_el1, x8 // vector table address isb + str_l x21, __fdt_pointer, x5 // Save FDT pointer + + ldr_l x4, kimage_vaddr // Save the offset between + sub x4, x4, x0 // the kernel virtual and + str_l x4, kimage_voffset, x5 // physical mappings + // Clear BSS adr_l x0, __bss_start mov x1, xzr @@ -432,12 +440,6 @@ __primary_switched: mov x4, sp and x4, x4, #~(THREAD_SIZE - 1) msr sp_el0, x4 // Save thread_info - str_l x21, __fdt_pointer, x5 // Save FDT pointer - - ldr_l x4, kimage_vaddr // Save the offset between - sub x4, x4, x24 // the kernel virtual and - str_l x4, kimage_voffset, x5 // physical mappings - mov x29, #0 #ifdef CONFIG_KASAN bl kasan_early_init @@ -792,6 +794,7 @@ __primary_switch: bl __relocate_kernel #ifdef CONFIG_RANDOMIZE_BASE ldr x8, =__primary_switched + adrp x0, __PHYS_OFFSET blr x8 /* @@ -813,5 +816,6 @@ __primary_switch: #endif #endif ldr x8, =__primary_switched + adrp x0, __PHYS_OFFSET br x8 ENDPROC(__primary_switch)
Keeping __PHYS_OFFSET in x24 is actually less clear than simply taking the value of __PHYS_OFFSET using an adrp instruction in the three places that we need it. So change that. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm64/kernel/head.S | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel