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Message-Id: <20210125191923.1060122-10-pasha.tatashin@soleen.com>
Date: Mon, 25 Jan 2021 14:19:14 -0500
From: Pavel Tatashin <pasha.tatashin@...een.com>
To: pasha.tatashin@...een.com, jmorris@...ei.org, sashal@...nel.org,
ebiederm@...ssion.com, kexec@...ts.infradead.org,
linux-kernel@...r.kernel.org, corbet@....net,
catalin.marinas@....com, will@...nel.org,
linux-arm-kernel@...ts.infradead.org, maz@...nel.org,
james.morse@....com, vladimir.murzin@....com,
matthias.bgg@...il.com, linux-mm@...ck.org, mark.rutland@....com,
steve.capper@....com, rfontana@...hat.com, tglx@...utronix.de,
selindag@...il.com, tyhicks@...ux.microsoft.com
Subject: [PATCH v10 09/18] arm64: kexec: move relocation function setup
Currently, kernel relocation function is configured in machine_kexec()
at the time of kexec reboot by using control_code_page.
This operation, however, is more logical to be done during kexec_load,
and thus remove from reboot time. Move, setup of this function to
newly added machine_kexec_post_load().
Because once MMU is enabled, kexec control page will contain more than
relocation kernel, but also vector table, add pointer to the actual
function within this page arch.kern_reloc. Currently, it equals to the
beginning of page, we will add offsets later, when vector table is
added.
Signed-off-by: Pavel Tatashin <pasha.tatashin@...een.com>
Reviewed-by: James Morse <james.morse@....com>
---
arch/arm64/include/asm/kexec.h | 1 +
arch/arm64/kernel/machine_kexec.c | 46 +++++++++++++------------------
2 files changed, 20 insertions(+), 27 deletions(-)
diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
index 61530ec3a9b1..9befcd87e9a8 100644
--- a/arch/arm64/include/asm/kexec.h
+++ b/arch/arm64/include/asm/kexec.h
@@ -95,6 +95,7 @@ static inline void crash_post_resume(void) {}
struct kimage_arch {
void *dtb;
phys_addr_t dtb_mem;
+ phys_addr_t kern_reloc;
/* Core ELF header buffer */
void *elf_headers;
unsigned long elf_headers_mem;
diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index 8096a6aa1d49..a8aaa6562429 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -42,6 +42,7 @@ static void _kexec_image_info(const char *func, int line,
pr_debug(" start: %lx\n", kimage->start);
pr_debug(" head: %lx\n", kimage->head);
pr_debug(" nr_segments: %lu\n", kimage->nr_segments);
+ pr_debug(" kern_reloc: %pa\n", &kimage->arch.kern_reloc);
for (i = 0; i < kimage->nr_segments; i++) {
pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
@@ -58,6 +59,22 @@ void machine_kexec_cleanup(struct kimage *kimage)
/* Empty routine needed to avoid build errors. */
}
+int machine_kexec_post_load(struct kimage *kimage)
+{
+ void *reloc_code = page_to_virt(kimage->control_code_page);
+
+ memcpy(reloc_code, arm64_relocate_new_kernel,
+ arm64_relocate_new_kernel_size);
+ kimage->arch.kern_reloc = __pa(reloc_code);
+
+ /* Flush the reloc_code in preparation for its execution. */
+ __flush_dcache_area(reloc_code, arm64_relocate_new_kernel_size);
+ flush_icache_range((uintptr_t)reloc_code, (uintptr_t)reloc_code +
+ arm64_relocate_new_kernel_size);
+
+ return 0;
+}
+
/**
* machine_kexec_prepare - Prepare for a kexec reboot.
*
@@ -143,8 +160,6 @@ static void kexec_segment_flush(const struct kimage *kimage)
*/
void machine_kexec(struct kimage *kimage)
{
- phys_addr_t reboot_code_buffer_phys;
- void *reboot_code_buffer;
bool in_kexec_crash = (kimage == kexec_crash_image);
bool stuck_cpus = cpus_are_stuck_in_kernel();
@@ -155,31 +170,8 @@ void machine_kexec(struct kimage *kimage)
WARN(in_kexec_crash && (stuck_cpus || smp_crash_stop_failed()),
"Some CPUs may be stale, kdump will be unreliable.\n");
- reboot_code_buffer_phys = page_to_phys(kimage->control_code_page);
- reboot_code_buffer = phys_to_virt(reboot_code_buffer_phys);
-
kexec_image_info(kimage);
- /*
- * Copy arm64_relocate_new_kernel to the reboot_code_buffer for use
- * after the kernel is shut down.
- */
- memcpy(reboot_code_buffer, arm64_relocate_new_kernel,
- arm64_relocate_new_kernel_size);
-
- /* Flush the reboot_code_buffer in preparation for its execution. */
- __flush_dcache_area(reboot_code_buffer, arm64_relocate_new_kernel_size);
-
- /*
- * Although we've killed off the secondary CPUs, we don't update
- * the online mask if we're handling a crash kernel and consequently
- * need to avoid flush_icache_range(), which will attempt to IPI
- * the offline CPUs. Therefore, we must use the __* variant here.
- */
- __flush_icache_range((uintptr_t)reboot_code_buffer,
- (uintptr_t)reboot_code_buffer +
- arm64_relocate_new_kernel_size);
-
/* Flush the kimage list and its buffers. */
kexec_list_flush(kimage);
@@ -193,7 +185,7 @@ void machine_kexec(struct kimage *kimage)
/*
* cpu_soft_restart will shutdown the MMU, disable data caches, then
- * transfer control to the reboot_code_buffer which contains a copy of
+ * transfer control to the kern_reloc which contains a copy of
* the arm64_relocate_new_kernel routine. arm64_relocate_new_kernel
* uses physical addressing to relocate the new image to its final
* position and transfers control to the image entry point when the
@@ -203,7 +195,7 @@ void machine_kexec(struct kimage *kimage)
* userspace (kexec-tools).
* In kexec_file case, the kernel starts directly without purgatory.
*/
- cpu_soft_restart(reboot_code_buffer_phys, kimage->head, kimage->start,
+ cpu_soft_restart(kimage->arch.kern_reloc, kimage->head, kimage->start,
kimage->arch.dtb_mem);
BUG(); /* Should never get here. */
--
2.25.1
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