Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH] arm: remove dead blocks in XIP_KERNEL link script | Date | Thu, 24 Mar 2016 20:48:13 +0100 |
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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 <jonas.rabenstein@studium.uni-erlangen.de> > --- > 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 = .; > >
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