On Thursday 24 March 2016 19:58:40 Jonas Rabenstein wrote:
> Commit 538bf4694898 ("ARM: 8513/1: xip: Move XIP linking to a separate
> file") separated all CONFIG_XIP_KERNEL related portions of the linker
> script into a separate file. The copied parts depending on CONFIG_SMP
> may be removed, as CONFIG_SMP (and related options) can never be
> selected together with CONFIG_XIP_KERNEL. CONFIG_SMP_ON_UP has a direct
> dependency on !CONFIG_XIP_KERNEL. CONFIG_XIP_KERNEL itself depends on
> !ARCH_MULTIPLATFORM, but all devices specifying HAVE_SMP are also some
> kind of multiplatform devices. Finally, HAVE_TCM is also only selected
> by multiplatform devices and may not selected for the same reasons.
>
> Signed-off-by: Jonas Rabenstein <[email protected]>
> ---
> I detected the issue with chimaera, a tool I currently develop for my
> bachelor
> thesis extending the undertaker tool suite (https://undertaker.cs.fau.de).
Your analysis of the existing dependencies sounds correct to me. We clearly
cannot have SMP_ON_UP, and it may make sense to drop the TCM section
as it is very unlikely to get used here (it's already basically unused
on the non-XIP kernel, but should remain there).
Regarding SMP and HOTPLUG_CPU, I think it makes sense to leave the support
in this file, because it's possible that we will need that in the foreseeable
future.
Arnd
> arch/arm/kernel/vmlinux-xip.lds.S | 75
> ---------------------------------------
> 1 file changed, 75 deletions(-)
>
> diff --git a/arch/arm/kernel/vmlinux-xip.lds.S
> b/arch/arm/kernel/vmlinux-xip.lds.S
> index cba1ec8..7da95f8 100644
> --- a/arch/arm/kernel/vmlinux-xip.lds.S
> +++ b/arch/arm/kernel/vmlinux-xip.lds.S
> @@ -25,13 +25,8 @@
> *(.hyp.idmap.text) \
> VMLINUX_SYMBOL(__hyp_idmap_text_end) = .;
>
> -#ifdef CONFIG_HOTPLUG_CPU
> -#define ARM_CPU_DISCARD(x)
> -#define ARM_CPU_KEEP(x) x
> -#else
> #define ARM_CPU_DISCARD(x) x
> #define ARM_CPU_KEEP(x)
> -#endif
>
> #if (defined(CONFIG_SMP_ON_UP) && !defined(CONFIG_DEBUG_SPINLOCK)) || \
> defined(CONFIG_GENERIC_BUG)
> @@ -74,9 +69,7 @@ SECTIONS
> *(.text.fixup)
> *(__ex_table)
> #endif
> -#ifndef CONFIG_SMP_ON_UP
> *(.alt.smp.init)
> -#endif
> *(.discard)
> *(.discard.*)
> }
> @@ -177,13 +170,6 @@ SECTIONS
> *(.taglist.init)
> __tagtable_end = .;
> }
> -#ifdef CONFIG_SMP_ON_UP
> - .init.smpalt : {
> - __smpalt_begin = .;
> - *(.alt.smp.init)
> - __smpalt_end = .;
> - }
> -#endif
> .init.pv_table : {
> __pv_table_begin = .;
> *(.pv_table)
> @@ -197,10 +183,6 @@ SECTIONS
> INIT_RAM_FS
> }
>
> -#ifdef CONFIG_SMP
> - PERCPU_SECTION(L1_CACHE_BYTES)
> -#endif
> -
> _exiprom = .; /* End of XIP ROM area */
> __data_loc = ALIGN(4); /* location in binary */
> . = PAGE_OFFSET + TEXT_OFFSET;
> @@ -236,63 +218,6 @@ SECTIONS
> }
> _edata_loc = __data_loc + SIZEOF(.data);
>
> -#ifdef CONFIG_HAVE_TCM
> - /*
> - * We align everything to a page boundary so we can
> - * free it after init has commenced and TCM contents have
> - * been copied to its destination.
> - */
> - .tcm_start : {
> - . = ALIGN(PAGE_SIZE);
> - __tcm_start = .;
> - __itcm_start = .;
> - }
> -
> - /*
> - * Link these to the ITCM RAM
> - * Put VMA to the TCM address and LMA to the common RAM
> - * and we'll upload the contents from RAM to TCM and free
> - * the used RAM after that.
> - */
> - .text_itcm ITCM_OFFSET : AT(__itcm_start)
> - {
> - __sitcm_text = .;
> - *(.tcm.text)
> - *(.tcm.rodata)
> - . = ALIGN(4);
> - __eitcm_text = .;
> - }
> -
> - /*
> - * Reset the dot pointer, this is needed to create the
> - * relative __dtcm_start below (to be used as extern in code).
> - */
> - . = ADDR(.tcm_start) + SIZEOF(.tcm_start) + SIZEOF(.text_itcm);
> -
> - .dtcm_start : {
> - __dtcm_start = .;
> - }
> -
> - /* TODO: add remainder of ITCM as well, that can be used for data! */
> - .data_dtcm DTCM_OFFSET : AT(__dtcm_start)
> - {
> - . = ALIGN(4);
> - __sdtcm_data = .;
> - *(.tcm.data)
> - . = ALIGN(4);
> - __edtcm_data = .;
> - }
> -
> - /* Reset the dot pointer or the linker gets confused */
> - . = ADDR(.dtcm_start) + SIZEOF(.data_dtcm);
> -
> - /* End marker for freeing TCM copy in linked object */
> - .tcm_end : AT(ADDR(.dtcm_start) + SIZEOF(.data_dtcm)){
> - . = ALIGN(PAGE_SIZE);
> - __tcm_end = .;
> - }
> -#endif
> -
> BSS_SECTION(0, 0, 0)
> _end = .;
>
>
