From: geoff@infradead.org (Geoff Levand) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v19 03/13] arm64/kexec: Add core kexec support Date: Mon, 20 Jun 2016 09:49:43 -0700 [thread overview] Message-ID: <1466441383.7965.15.camel@infradead.org> (raw) In-Reply-To: <57680D94.6080704@arm.com> Hi, On Mon, 2016-06-20 at 16:36 +0100, James Morse wrote: > +> > > switch (flag) { > > +> > > > > > case IND_INDIRECTION: > > +> > > > > > > > /* Set entry point just before the new list page. */ > > +> > > > > > > > entry = (kimage_entry_t *)addr - 1; > > Ah, after this restructuring we end up cleaning this page as we fall-through, > and one kimage_entry_t at a time as we walk the list. > > > > > break; > ? I added this in, but that missing break shouldn't cause any problems. > > +> > > > > > case IND_SOURCE: > > +> > > > > > > > __flush_dcache_area(addr, PAGE_SIZE); > > +> > > > > > > > break; > > +> > > > > > case IND_DESTINATION: > > +> > > > > > > > break; > > +> > > > > > default: > > +> > > > > > > > BUG(); > > +> > > > > > } > > +> > > > } > > +} > > > > diff --git a/arch/arm64/kernel/relocate_kernel.S b/arch/arm64/kernel/relocate_kernel.S > > new file mode 100644 > > index 0000000..51b73cd > > --- /dev/null > > +++ b/arch/arm64/kernel/relocate_kernel.S > > [ ... ] > > > +.ltorg > > + > > +.align 3> > > > /* To keep the 64-bit values below naturally aligned. */ > > + > > +.Lcopy_end: > > +.org> > > > KEXEC_CONTROL_PAGE_SIZE > > > On 16/06/16 23:41, Geoff Levand wrote: > > This is to check if arm64_relocate_new_kernel gets too > > big. The assembler should give an error if the location > > counter is set backwards. > > Cunning. (probably worth a comment). I thought this was the standard way to do it... > This looks like it is need because we hard-coded KEXEC_CONTROL_PAGE_SIZE in > kexec.h, so the code must be smaller than that size. > It looks like this value is only ever passed to get_order(), could we just pass > the actual size? It shouldn't matter if it grows >4K, as the core code will > allocate enough memory, and the memcpy() in machine_kexec() uses the size too. I thought 4K would be enough, but if some debugging code is added it could get too big. > Reviewed-by: James Morse <james.morse@arm.com> Thanks for your comments. -Geoff
WARNING: multiple messages have this Message-ID (diff)
From: Geoff Levand <geoff@infradead.org> To: James Morse <james.morse@arm.com> Cc: Mark Rutland <mark.rutland@arm.com>, marc.zyngier@arm.com, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will.deacon@arm.com>, AKASHI Takahiro <takahiro.akashi@linaro.org>, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v19 03/13] arm64/kexec: Add core kexec support Date: Mon, 20 Jun 2016 09:49:43 -0700 [thread overview] Message-ID: <1466441383.7965.15.camel@infradead.org> (raw) In-Reply-To: <57680D94.6080704@arm.com> Hi, On Mon, 2016-06-20 at 16:36 +0100, James Morse wrote: > +> > > switch (flag) { > > +> > > > > > case IND_INDIRECTION: > > +> > > > > > > > /* Set entry point just before the new list page. */ > > +> > > > > > > > entry = (kimage_entry_t *)addr - 1; > > Ah, after this restructuring we end up cleaning this page as we fall-through, > and one kimage_entry_t at a time as we walk the list. > > > > > break; > ? I added this in, but that missing break shouldn't cause any problems. > > +> > > > > > case IND_SOURCE: > > +> > > > > > > > __flush_dcache_area(addr, PAGE_SIZE); > > +> > > > > > > > break; > > +> > > > > > case IND_DESTINATION: > > +> > > > > > > > break; > > +> > > > > > default: > > +> > > > > > > > BUG(); > > +> > > > > > } > > +> > > > } > > +} > > > > diff --git a/arch/arm64/kernel/relocate_kernel.S b/arch/arm64/kernel/relocate_kernel.S > > new file mode 100644 > > index 0000000..51b73cd > > --- /dev/null > > +++ b/arch/arm64/kernel/relocate_kernel.S > > [ ... ] > > > +.ltorg > > + > > +.align 3> > > > /* To keep the 64-bit values below naturally aligned. */ > > + > > +.Lcopy_end: > > +.org> > > > KEXEC_CONTROL_PAGE_SIZE > > > On 16/06/16 23:41, Geoff Levand wrote: > > This is to check if arm64_relocate_new_kernel gets too > > big. The assembler should give an error if the location > > counter is set backwards. > > Cunning. (probably worth a comment). I thought this was the standard way to do it... > This looks like it is need because we hard-coded KEXEC_CONTROL_PAGE_SIZE in > kexec.h, so the code must be smaller than that size. > It looks like this value is only ever passed to get_order(), could we just pass > the actual size? It shouldn't matter if it grows >4K, as the core code will > allocate enough memory, and the memcpy() in machine_kexec() uses the size too. I thought 4K would be enough, but if some debugging code is added it could get too big. > Reviewed-by: James Morse <james.morse@arm.com> Thanks for your comments. -Geoff _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2016-06-20 16:49 UTC|newest] Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-06-16 23:48 [PATCH v19 00/13] arm64 kexec kernel patches Geoff Levand 2016-06-16 23:48 ` Geoff Levand 2016-06-16 23:48 ` [PATCH v19 05/13] arm64/kexec: Add pr_debug output Geoff Levand 2016-06-16 23:48 ` Geoff Levand 2016-06-20 16:06 ` James Morse 2016-06-20 16:06 ` James Morse 2016-06-20 16:50 ` Geoff Levand 2016-06-20 16:50 ` Geoff Levand 2016-06-16 23:48 ` [PATCH v19 02/13] arm64: Add back cpu reset routines Geoff Levand 2016-06-16 23:48 ` Geoff Levand 2016-06-16 23:48 ` [PATCH v19 04/13] arm64/kexec: Enable kexec in the arm64 defconfig Geoff Levand 2016-06-16 23:48 ` Geoff Levand 2016-06-16 23:48 ` [PATCH v19 01/13] arm64: Add cpus_are_stuck_in_kernel Geoff Levand 2016-06-16 23:48 ` Geoff Levand 2016-06-16 23:48 ` [PATCH v19 03/13] arm64/kexec: Add core kexec support Geoff Levand 2016-06-16 23:48 ` Geoff Levand 2016-06-20 15:36 ` James Morse 2016-06-20 15:36 ` James Morse 2016-06-20 16:49 ` Geoff Levand [this message] 2016-06-20 16:49 ` Geoff Levand 2016-06-16 23:48 ` [PATCH v19 11/13] arm64: kdump: enable kdump in the arm64 defconfig Geoff Levand 2016-06-16 23:48 ` Geoff Levand 2016-06-16 23:48 ` [PATCH v19 13/13] Documentation: dt: usable-memory and elfcorehdr nodes for arm64 kexec Geoff Levand 2016-06-16 23:48 ` Geoff Levand 2016-06-16 23:48 ` [PATCH v19 12/13] arm64: kdump: update a kernel doc Geoff Levand 2016-06-16 23:48 ` Geoff Levand 2016-06-16 23:48 ` [PATCH v19 10/13] arm64: kdump: add VMCOREINFO's for user-space coredump tools Geoff Levand 2016-06-16 23:48 ` Geoff Levand 2016-06-20 5:32 ` Pratyush Anand 2016-06-20 5:32 ` Pratyush Anand 2016-06-22 5:59 ` AKASHI Takahiro 2016-06-22 5:59 ` AKASHI Takahiro 2016-06-23 7:14 ` Pratyush Anand 2016-06-23 7:14 ` Pratyush Anand 2016-06-23 8:42 ` AKASHI Takahiro 2016-06-23 8:42 ` AKASHI Takahiro 2016-06-23 15:46 ` Pratyush Anand 2016-06-23 15:46 ` Pratyush Anand 2016-06-30 0:44 ` AKASHI Takahiro 2016-06-30 0:44 ` AKASHI Takahiro 2016-06-16 23:48 ` [PATCH v19 07/13] arm64: limit memory regions based on DT property, usable-memory Geoff Levand 2016-06-16 23:48 ` Geoff Levand 2016-06-16 23:48 ` [PATCH v19 08/13] arm64: kdump: implement machine_crash_shutdown() Geoff Levand 2016-06-16 23:48 ` Geoff Levand 2016-06-16 23:48 ` [PATCH v19 06/13] arm64: kdump: reserve memory for crash dump kernel Geoff Levand 2016-06-16 23:48 ` Geoff Levand 2016-06-20 16:07 ` James Morse 2016-06-20 16:07 ` James Morse 2016-06-21 1:23 ` AKASHI Takahiro 2016-06-21 1:23 ` AKASHI Takahiro 2016-06-16 23:48 ` [PATCH v19 09/13] arm64: kdump: add kdump support Geoff Levand 2016-06-16 23:48 ` Geoff Levand
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