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From: Pavel Tatashin <pasha.tatashin@soleen.com>
To: pasha.tatashin@soleen.com, jmorris@namei.org, sashal@kernel.org,
	ebiederm@xmission.com, kexec@lists.infradead.org,
	linux-kernel@vger.kernel.org, corbet@lwn.net,
	catalin.marinas@arm.com, will@kernel.org,
	linux-arm-kernel@lists.infradead.org, maz@kernel.org,
	james.morse@arm.com, vladimir.murzin@arm.com,
	matthias.bgg@gmail.com, linux-mm@kvack.org, mark.rutland@arm.com,
	steve.capper@arm.com, rfontana@redhat.com, tglx@linutronix.de,
	selindag@gmail.com, tyhicks@linux.microsoft.com,
	kernelfans@gmail.com
Subject: [PATCH v13 12/18] arm64: kexec: relocate in EL1 mode
Date: Thu,  8 Apr 2021 00:05:31 -0400	[thread overview]
Message-ID: <20210408040537.2703241-13-pasha.tatashin@soleen.com> (raw)
In-Reply-To: <20210408040537.2703241-1-pasha.tatashin@soleen.com>

Since we are going to keep MMU enabled during relocation, we need to
keep EL1 mode throughout the relocation.

Keep EL1 enabled, and switch EL2 only before enterying the new world.

Suggested-by: James Morse <james.morse@arm.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
---
 arch/arm64/kernel/cpu-reset.h       |  3 +--
 arch/arm64/kernel/machine_kexec.c   |  4 ++--
 arch/arm64/kernel/relocate_kernel.S | 13 +++++++++++--
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kernel/cpu-reset.h b/arch/arm64/kernel/cpu-reset.h
index 1922e7a690f8..f6d95512fec6 100644
--- a/arch/arm64/kernel/cpu-reset.h
+++ b/arch/arm64/kernel/cpu-reset.h
@@ -20,11 +20,10 @@ static inline void __noreturn cpu_soft_restart(unsigned long entry,
 {
 	typeof(__cpu_soft_restart) *restart;
 
-	unsigned long el2_switch = is_hyp_callable();
 	restart = (void *)__pa_symbol(__cpu_soft_restart);
 
 	cpu_install_idmap();
-	restart(el2_switch, entry, arg0, arg1, arg2);
+	restart(0, entry, arg0, arg1, arg2);
 	unreachable();
 }
 
diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index fb03b6676fb9..d5940b7889f8 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -231,8 +231,8 @@ void machine_kexec(struct kimage *kimage)
 	} else {
 		if (is_hyp_callable())
 			__hyp_set_vectors(kimage->arch.el2_vectors);
-		cpu_soft_restart(kimage->arch.kern_reloc, virt_to_phys(kimage),
-				 0, 0);
+		cpu_soft_restart(kimage->arch.kern_reloc,
+				 virt_to_phys(kimage), 0, 0);
 	}
 
 	BUG(); /* Should never get here. */
diff --git a/arch/arm64/kernel/relocate_kernel.S b/arch/arm64/kernel/relocate_kernel.S
index 36b4496524c3..df023b82544b 100644
--- a/arch/arm64/kernel/relocate_kernel.S
+++ b/arch/arm64/kernel/relocate_kernel.S
@@ -13,6 +13,7 @@
 #include <asm/kexec.h>
 #include <asm/page.h>
 #include <asm/sysreg.h>
+#include <asm/virt.h>
 
 /*
  * arm64_relocate_new_kernel - Put a 2nd stage image in place and boot it.
@@ -61,12 +62,20 @@ SYM_CODE_START(arm64_relocate_new_kernel)
 	isb
 
 	/* Start new image. */
+	ldr	x1, [x0, #KIMAGE_ARCH_EL2_VECTORS]	/* relocation start */
+	cbz	x1, .Lel1
+	ldr	x1, [x0, #KIMAGE_START]		/* relocation start */
+	ldr	x2, [x0, #KIMAGE_ARCH_DTB_MEM]	/* dtb address */
+	mov	x3, xzr
+	mov	x4, xzr
+	mov     x0, #HVC_SOFT_RESTART
+	hvc	#0				/* Jumps from el2 */
+.Lel1:
 	ldr	x4, [x0, #KIMAGE_START]		/* relocation start */
 	ldr	x0, [x0, #KIMAGE_ARCH_DTB_MEM]	/* dtb address */
-	mov	x1, xzr
 	mov	x2, xzr
 	mov	x3, xzr
-	br	x4
+	br	x4				/* Jumps from el1 */
 SYM_CODE_END(arm64_relocate_new_kernel)
 
 .align 3	/* To keep the 64-bit values below naturally aligned. */
-- 
2.25.1


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  parent reply	other threads:[~2021-04-08  4:12 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-08  4:05 [PATCH v13 00/18] arm64: MMU enabled kexec relocation Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 01/18] arm64: hyp-stub: Check the size of the HYP stub's vectors Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 02/18] arm64: hyp-stub: Move invalid vector entries into the vectors Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 03/18] arm64: hyp-stub: Move el1_sync " Pavel Tatashin
2021-04-08 10:24   ` Marc Zyngier
2021-04-08 14:45     ` Pavel Tatashin
2021-04-08 15:01       ` Marc Zyngier
2021-04-08 16:28         ` Pavel Tatashin
2021-04-26 18:10           ` Pavel Tatashin
2021-04-26 18:11             ` Pavel Tatashin
2021-04-26 18:24             ` Marc Zyngier
2021-04-08  4:05 ` [PATCH v13 04/18] arm64: kernel: add helper for booted at EL2 and not VHE Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 05/18] arm64: trans_pgd: hibernate: Add trans_pgd_copy_el2_vectors Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 06/18] arm64: hibernate: abstract ttrb0 setup function Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 07/18] arm64: kexec: flush image and lists during kexec load time Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 08/18] arm64: kexec: skip relocation code for inplace kexec Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 09/18] arm64: kexec: Use dcache ops macros instead of open-coding Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 10/18] arm64: kexec: pass kimage as the only argument to relocation function Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 11/18] arm64: kexec: kexec may require EL2 vectors Pavel Tatashin
2021-04-08  4:05 ` Pavel Tatashin [this message]
2021-04-08  4:05 ` [PATCH v13 13/18] arm64: kexec: use ld script for relocation function Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 14/18] arm64: kexec: install a copy of the linear-map Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 15/18] arm64: kexec: keep MMU enabled during kexec relocation Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 16/18] arm64: kexec: remove the pre-kexec PoC maintenance Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 17/18] arm64: kexec: Remove cpu-reset.h Pavel Tatashin
2021-04-08  4:05 ` [PATCH v13 18/18] arm64/mm: remove useless trans_pgd_map_page() Pavel Tatashin

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