From: Sven Schnelle <svens@stackframe.org>
To: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org, Sven Schnelle <svens@stackframe.org>
Subject: [PATCH 2/4] parisc: add kexec syscall support
Date: Sun, 8 Sep 2019 11:33:04 +0200 [thread overview]
Message-ID: <20190908093306.31455-3-svens@stackframe.org> (raw)
In-Reply-To: <20190908093306.31455-1-svens@stackframe.org>
---
arch/parisc/Kconfig | 13 +++
arch/parisc/include/asm/fixmap.h | 1 +
arch/parisc/include/asm/kexec.h | 37 +++++++
arch/parisc/kernel/Makefile | 1 +
arch/parisc/kernel/kexec.c | 102 ++++++++++++++++++
arch/parisc/kernel/relocate_kernel.S | 149 +++++++++++++++++++++++++++
include/uapi/linux/kexec.h | 1 +
7 files changed, 304 insertions(+)
create mode 100644 arch/parisc/include/asm/kexec.h
create mode 100644 arch/parisc/kernel/kexec.c
create mode 100644 arch/parisc/kernel/relocate_kernel.S
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index ee59171edffe..548c767f4358 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -346,6 +346,19 @@ config NR_CPUS
depends on SMP
default "4"
+config KEXEC
+ bool "Kexec system call"
+ select KEXEC_CORE
+ help
+ kexec is a system call that implements the ability to shutdown your
+ current kernel, and to start another kernel. It is like a reboot
+ but it is independent of the system firmware. And like a reboot
+ you can start any kernel with it, not just Linux.
+
+ It is an ongoing process to be certain the hardware in a machine
+ shutdown, so do not be surprised if this code does not
+ initially work for you.
+
endmenu
diff --git a/arch/parisc/include/asm/fixmap.h b/arch/parisc/include/asm/fixmap.h
index 288da73d4cc0..e480b2c05407 100644
--- a/arch/parisc/include/asm/fixmap.h
+++ b/arch/parisc/include/asm/fixmap.h
@@ -30,6 +30,7 @@
enum fixed_addresses {
/* Support writing RO kernel text via kprobes, jump labels, etc. */
FIX_TEXT_POKE0,
+ FIX_TEXT_KEXEC,
FIX_BITMAP_COUNT
};
diff --git a/arch/parisc/include/asm/kexec.h b/arch/parisc/include/asm/kexec.h
new file mode 100644
index 000000000000..a99ea747d7ed
--- /dev/null
+++ b/arch/parisc/include/asm/kexec.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_PARISC_KEXEC_H
+#define _ASM_PARISC_KEXEC_H
+
+#ifdef CONFIG_KEXEC
+
+/* Maximum physical address we can use pages from */
+#define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
+/* Maximum address we can reach in physical address mode */
+#define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
+/* Maximum address we can use for the control code buffer */
+#define KEXEC_CONTROL_MEMORY_LIMIT (-1UL)
+
+#define KEXEC_CONTROL_PAGE_SIZE 4096
+
+#define KEXEC_ARCH KEXEC_ARCH_PARISC
+#define ARCH_HAS_KIMAGE_ARCH
+
+#ifndef __ASSEMBLY__
+
+struct kimage_arch {
+ unsigned long initrd_start;
+ unsigned long initrd_end;
+ unsigned long cmdline;
+};
+
+static inline void crash_setup_regs(struct pt_regs *newregs,
+ struct pt_regs *oldregs)
+{
+ /* Dummy implementation for now */
+}
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* CONFIG_KEXEC */
+
+#endif /* _ASM_PARISC_KEXEC_H */
diff --git a/arch/parisc/kernel/Makefile b/arch/parisc/kernel/Makefile
index c232266b517c..487cf88866a8 100644
--- a/arch/parisc/kernel/Makefile
+++ b/arch/parisc/kernel/Makefile
@@ -37,3 +37,4 @@ obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_KPROBES) += kprobes.o
+obj-$(CONFIG_KEXEC) += kexec.o relocate_kernel.o
diff --git a/arch/parisc/kernel/kexec.c b/arch/parisc/kernel/kexec.c
new file mode 100644
index 000000000000..deeb0466d359
--- /dev/null
+++ b/arch/parisc/kernel/kexec.c
@@ -0,0 +1,102 @@
+#include <linux/kernel.h>
+#include <linux/console.h>
+#include <linux/kexec.h>
+#include <linux/delay.h>
+#include <asm/cacheflush.h>
+#include <asm/sections.h>
+
+extern void relocate_new_kernel(unsigned long head,
+ unsigned long start,
+ unsigned long phys);
+
+extern const unsigned int relocate_new_kernel_size;
+extern unsigned int kexec_initrd_start_offset;
+extern unsigned int kexec_initrd_end_offset;
+extern unsigned int kexec_cmdline_offset;
+extern unsigned int kexec_free_mem_offset;
+
+static void kexec_show_segment_info(const struct kimage *kimage, unsigned long n)
+{
+ pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
+ n,
+ kimage->segment[n].mem,
+ kimage->segment[n].mem + kimage->segment[n].memsz,
+ (unsigned long)kimage->segment[n].memsz,
+ (unsigned long)kimage->segment[n].memsz / PAGE_SIZE);
+}
+
+static void kexec_image_info(const struct kimage *kimage)
+{
+ unsigned long i;
+
+ pr_debug("kexec kimage info:\n");
+ pr_debug(" type: %d\n", kimage->type);
+ pr_debug(" start: %lx\n", kimage->start);
+ pr_debug(" head: %lx\n", kimage->head);
+ pr_debug(" nr_segments: %lu\n", kimage->nr_segments);
+
+ for (i = 0; i < kimage->nr_segments; i++)
+ kexec_show_segment_info(kimage, i);
+}
+
+void machine_kexec_cleanup(struct kimage *kimage)
+{
+}
+
+void machine_crash_shutdown(struct pt_regs *regs)
+{
+}
+
+void machine_shutdown(void)
+{
+ smp_send_stop();
+ while(num_online_cpus() > 1) {
+ cpu_relax();
+ mdelay(1);
+ }
+}
+
+void machine_kexec(struct kimage *image)
+{
+#ifdef CONFIG_64BIT
+ Elf64_Fdesc desc;
+#endif
+ void (*reloc)(unsigned long head,
+ unsigned long start,
+ unsigned long phys);
+
+ unsigned long phys = page_to_phys(image->control_code_page);
+ void *virt = (void *)__fix_to_virt(FIX_TEXT_KEXEC);
+ struct kimage_arch *arch = &image->arch;
+
+ set_fixmap(FIX_TEXT_KEXEC, phys);
+
+ flush_cache_all();
+
+#ifdef CONFIG_64BIT
+ reloc = (void *)&desc;
+ desc.addr = (long long)virt;
+#else
+ reloc = (void *)virt;
+#endif
+
+ memcpy(virt, dereference_function_descriptor(relocate_new_kernel),
+ relocate_new_kernel_size);
+
+ *(unsigned long *)(virt + kexec_cmdline_offset) = arch->cmdline;
+ *(unsigned long *)(virt + kexec_initrd_start_offset) = arch->initrd_start;
+ *(unsigned long *)(virt + kexec_initrd_end_offset) = arch->initrd_end;
+ *(unsigned long *)(virt + kexec_free_mem_offset) = PAGE0->mem_free;
+
+ flush_cache_all();
+ flush_tlb_all();
+ local_irq_disable();
+
+ reloc(image->head & PAGE_MASK, image->start, phys);
+}
+
+int machine_kexec_prepare(struct kimage *image)
+{
+ kexec_image_info(image);
+ return 0;
+}
diff --git a/arch/parisc/kernel/relocate_kernel.S b/arch/parisc/kernel/relocate_kernel.S
new file mode 100644
index 000000000000..2561e52b8d9b
--- /dev/null
+++ b/arch/parisc/kernel/relocate_kernel.S
@@ -0,0 +1,149 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/linkage.h>
+#include <linux/kexec.h>
+
+#include <asm/assembly.h>
+#include <asm/asm-offsets.h>
+#include <asm/page.h>
+#include <asm/setup.h>
+#include <asm/psw.h>
+
+.level PA_ASM_LEVEL
+
+.macro kexec_param name
+.align 8
+ENTRY(kexec\()_\name)
+#ifdef CONFIG_64BIT
+ .dword 0
+#else
+ .word 0
+#endif
+
+ENTRY(kexec\()_\name\()_offset)
+ .word kexec\()_\name - relocate_new_kernel
+.endm
+
+.text
+
+/* args:
+ * r26 - kimage->head
+ * r25 - start address of kernel
+ * r24 - physical address of relocate code
+ */
+
+ENTRY_CFI(relocate_new_kernel)
+0: copy %arg1, %rp
+ /* disable I and Q bit, so we are allowed to execute RFI */
+ rsm PSW_SM_I, %r0
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+
+ rsm PSW_SM_Q, %r0
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+
+ /*
+ * After return-from-interrupt, we want to run without Code/Data
+ * translation enabled just like on a normal boot.
+ */
+
+ /* calculate new physical execution address */
+ ldo 1f-0b(%arg2), %r1
+ mtctl %r0, %cr17 /* IIASQ */
+ mtctl %r0, %cr17 /* IIASQ */
+ mtctl %r1, %cr18 /* IIAOQ */
+ ldo 4(%r1),%r1
+ mtctl %r1, %cr18 /* IIAOQ */
+#ifdef CONFIG_64BIT
+ depdi,z 1, PSW_W_BIT, 1, %r1
+ mtctl %r1, %cr22 /* IPSW */
+#else
+ mtctl %r0, %cr22 /* IPSW */
+#endif
+ /* lets go... */
+ rfi
+1: nop
+ nop
+
+.Lloop:
+ LDREG,ma REG_SZ(%arg0), %r3
+ /* If crash kernel, no copy needed */
+ cmpib,COND(=),n 0,%r3,boot
+
+ bb,<,n %r3, 31 - IND_DONE_BIT, boot
+ bb,>=,n %r3, 31 - IND_INDIRECTION_BIT, .Lnotind
+ /* indirection, load and restart */
+ movb %r3, %arg0, .Lloop
+ depi 0, 31, PAGE_SHIFT, %arg0
+
+.Lnotind:
+ bb,>=,n %r3, 31 - IND_DESTINATION_BIT, .Lnotdest
+ b .Lloop
+ copy %r3, %r20
+
+.Lnotdest:
+ bb,>= %r3, 31 - IND_SOURCE_BIT, .Lloop
+ depi 0, 31, PAGE_SHIFT, %r3
+ copy %r3, %r21
+
+ /* copy page */
+ copy %r0, %r18
+ zdepi 1, 31 - PAGE_SHIFT, 1, %r18
+ add %r20, %r18, %r17
+
+ depi 0, 31, PAGE_SHIFT, %r20
+.Lcopy:
+ copy %r20, %r12
+ LDREG,ma REG_SZ(%r21), %r8
+ LDREG,ma REG_SZ(%r21), %r9
+ LDREG,ma REG_SZ(%r21), %r10
+ LDREG,ma REG_SZ(%r21), %r11
+ STREG,ma %r8, REG_SZ(%r20)
+ STREG,ma %r9, REG_SZ(%r20)
+ STREG,ma %r10, REG_SZ(%r20)
+ STREG,ma %r11, REG_SZ(%r20)
+
+#ifndef CONFIG_64BIT
+ LDREG,ma REG_SZ(%r21), %r8
+ LDREG,ma REG_SZ(%r21), %r9
+ LDREG,ma REG_SZ(%r21), %r10
+ LDREG,ma REG_SZ(%r21), %r11
+ STREG,ma %r8, REG_SZ(%r20)
+ STREG,ma %r9, REG_SZ(%r20)
+ STREG,ma %r10, REG_SZ(%r20)
+ STREG,ma %r11, REG_SZ(%r20)
+#endif
+
+ fdc %r0(%r12)
+ cmpb,COND(<<) %r20,%r17,.Lcopy
+ fic (%sr4, %r12)
+ b,n .Lloop
+
+boot:
+ mtctl %r0, %cr15
+
+ LDREG kexec_free_mem-0b(%arg2), %arg0
+ LDREG kexec_cmdline-0b(%arg2), %arg1
+ LDREG kexec_initrd_end-0b(%arg2), %arg3
+ LDREG kexec_initrd_start-0b(%arg2), %arg2
+ bv,n %r0(%rp)
+
+ENDPROC_CFI(relocate_new_kernel);
+
+ENTRY(relocate_new_kernel_size)
+ .word relocate_new_kernel_size - relocate_new_kernel
+
+kexec_param cmdline
+kexec_param initrd_start
+kexec_param initrd_end
+kexec_param free_mem
diff --git a/include/uapi/linux/kexec.h b/include/uapi/linux/kexec.h
index 6d112868272d..05669c87a0af 100644
--- a/include/uapi/linux/kexec.h
+++ b/include/uapi/linux/kexec.h
@@ -31,6 +31,7 @@
#define KEXEC_ARCH_DEFAULT ( 0 << 16)
#define KEXEC_ARCH_386 ( 3 << 16)
#define KEXEC_ARCH_68K ( 4 << 16)
+#define KEXEC_ARCH_PARISC (15 << 16)
#define KEXEC_ARCH_X86_64 (62 << 16)
#define KEXEC_ARCH_PPC (20 << 16)
#define KEXEC_ARCH_PPC64 (21 << 16)
--
2.23.0.rc1
next prev parent reply other threads:[~2019-09-08 9:33 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-08 9:33 [PATCH 0/4] kexec support for PARISC Sven Schnelle
2019-09-08 9:33 ` [PATCH 1/4] parisc: add __pdc_cpu_rendezvous() Sven Schnelle
2019-09-08 9:33 ` Sven Schnelle [this message]
2019-09-08 9:33 ` [PATCH 3/4] parisc: wire up kexec_file_load syscall Sven Schnelle
2019-09-08 9:33 ` [PATCH 4/4] parisc: add support for kexec_file_load() syscall Sven Schnelle
2019-09-08 13:45 ` [PATCH 0/4] kexec support for PARISC Helge Deller
2019-09-17 14:39 ` Helge Deller
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