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-rw-r--r--arch/riscv/include/asm/elf.h6
-rw-r--r--arch/riscv/include/asm/kexec.h19
-rw-r--r--arch/riscv/kernel/Makefile2
-rw-r--r--arch/riscv/kernel/crash_save_regs.S56
-rw-r--r--arch/riscv/kernel/kexec_relocate.S68
-rw-r--r--arch/riscv/kernel/machine_kexec.c43
-rw-r--r--arch/riscv/kernel/setup.c11
-rw-r--r--arch/riscv/mm/init.c71
8 files changed, 249 insertions, 27 deletions
diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
index 5c725e1df58b..f4b490cd0e5d 100644
--- a/arch/riscv/include/asm/elf.h
+++ b/arch/riscv/include/asm/elf.h
@@ -81,4 +81,10 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm,
int uses_interp);
#endif /* CONFIG_MMU */
+#define ELF_CORE_COPY_REGS(dest, regs) \
+do { \
+ *(struct user_regs_struct *)&(dest) = \
+ *(struct user_regs_struct *)regs; \
+} while (0);
+
#endif /* _ASM_RISCV_ELF_H */
diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
index 86e6e4922d1f..1e954101906a 100644
--- a/arch/riscv/include/asm/kexec.h
+++ b/arch/riscv/include/asm/kexec.h
@@ -23,11 +23,16 @@
#define KEXEC_ARCH KEXEC_ARCH_RISCV
+extern void riscv_crash_save_regs(struct pt_regs *newregs);
+
static inline void
crash_setup_regs(struct pt_regs *newregs,
struct pt_regs *oldregs)
{
- /* Dummy implementation for now */
+ if (oldregs)
+ memcpy(newregs, oldregs, sizeof(struct pt_regs));
+ else
+ riscv_crash_save_regs(newregs);
}
@@ -40,10 +45,12 @@ struct kimage_arch {
const extern unsigned char riscv_kexec_relocate[];
const extern unsigned int riscv_kexec_relocate_size;
-typedef void (*riscv_kexec_do_relocate)(unsigned long first_ind_entry,
- unsigned long jump_addr,
- unsigned long fdt_addr,
- unsigned long hartid,
- unsigned long va_pa_off);
+typedef void (*riscv_kexec_method)(unsigned long first_ind_entry,
+ unsigned long jump_addr,
+ unsigned long fdt_addr,
+ unsigned long hartid,
+ unsigned long va_pa_off);
+
+extern riscv_kexec_method riscv_kexec_norelocate;
#endif
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 96650aaed5eb..3ee07bf0cea7 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -58,7 +58,7 @@ obj-$(CONFIG_SMP) += cpu_ops_sbi.o
endif
obj-$(CONFIG_HOTPLUG_CPU) += cpu-hotplug.o
obj-$(CONFIG_KGDB) += kgdb.o
-obj-$(CONFIG_KEXEC) += kexec_relocate.o machine_kexec.o
+obj-$(CONFIG_KEXEC) += kexec_relocate.o crash_save_regs.o machine_kexec.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
diff --git a/arch/riscv/kernel/crash_save_regs.S b/arch/riscv/kernel/crash_save_regs.S
new file mode 100644
index 000000000000..7832fb763aba
--- /dev/null
+++ b/arch/riscv/kernel/crash_save_regs.S
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 FORTH-ICS/CARV
+ * Nick Kossifidis <mick@ics.forth.gr>
+ */
+
+#include <asm/asm.h> /* For RISCV_* and REG_* macros */
+#include <asm/csr.h> /* For CSR_* macros */
+#include <asm/asm-offsets.h> /* For offsets on pt_regs */
+#include <linux/linkage.h> /* For SYM_* macros */
+
+.section ".text"
+SYM_CODE_START(riscv_crash_save_regs)
+ REG_S ra, PT_RA(a0) /* x1 */
+ REG_S sp, PT_SP(a0) /* x2 */
+ REG_S gp, PT_GP(a0) /* x3 */
+ REG_S tp, PT_TP(a0) /* x4 */
+ REG_S t0, PT_T0(a0) /* x5 */
+ REG_S t1, PT_T1(a0) /* x6 */
+ REG_S t2, PT_T2(a0) /* x7 */
+ REG_S s0, PT_S0(a0) /* x8/fp */
+ REG_S s1, PT_S1(a0) /* x9 */
+ REG_S a0, PT_A0(a0) /* x10 */
+ REG_S a1, PT_A1(a0) /* x11 */
+ REG_S a2, PT_A2(a0) /* x12 */
+ REG_S a3, PT_A3(a0) /* x13 */
+ REG_S a4, PT_A4(a0) /* x14 */
+ REG_S a5, PT_A5(a0) /* x15 */
+ REG_S a6, PT_A6(a0) /* x16 */
+ REG_S a7, PT_A7(a0) /* x17 */
+ REG_S s2, PT_S2(a0) /* x18 */
+ REG_S s3, PT_S3(a0) /* x19 */
+ REG_S s4, PT_S4(a0) /* x20 */
+ REG_S s5, PT_S5(a0) /* x21 */
+ REG_S s6, PT_S6(a0) /* x22 */
+ REG_S s7, PT_S7(a0) /* x23 */
+ REG_S s8, PT_S8(a0) /* x24 */
+ REG_S s9, PT_S9(a0) /* x25 */
+ REG_S s10, PT_S10(a0) /* x26 */
+ REG_S s11, PT_S11(a0) /* x27 */
+ REG_S t3, PT_T3(a0) /* x28 */
+ REG_S t4, PT_T4(a0) /* x29 */
+ REG_S t5, PT_T5(a0) /* x30 */
+ REG_S t6, PT_T6(a0) /* x31 */
+
+ csrr t1, CSR_STATUS
+ csrr t2, CSR_EPC
+ csrr t3, CSR_TVAL
+ csrr t4, CSR_CAUSE
+
+ REG_S t1, PT_STATUS(a0)
+ REG_S t2, PT_EPC(a0)
+ REG_S t3, PT_BADADDR(a0)
+ REG_S t4, PT_CAUSE(a0)
+ ret
+SYM_CODE_END(riscv_crash_save_regs)
diff --git a/arch/riscv/kernel/kexec_relocate.S b/arch/riscv/kernel/kexec_relocate.S
index 84101d0a23ef..88c3beabe9b4 100644
--- a/arch/riscv/kernel/kexec_relocate.S
+++ b/arch/riscv/kernel/kexec_relocate.S
@@ -151,7 +151,73 @@ SYM_CODE_START(riscv_kexec_relocate)
SYM_CODE_END(riscv_kexec_relocate)
riscv_kexec_relocate_end:
- .section ".rodata"
+
+/* Used for jumping to crashkernel */
+.section ".text"
+SYM_CODE_START(riscv_kexec_norelocate)
+ /*
+ * s0: (const) Phys address to jump to
+ * s1: (const) Phys address of the FDT image
+ * s2: (const) The hartid of the current hart
+ * s3: (const) va_pa_offset, used when switching MMU off
+ */
+ mv s0, a1
+ mv s1, a2
+ mv s2, a3
+ mv s3, a4
+
+ /* Disable / cleanup interrupts */
+ csrw CSR_SIE, zero
+ csrw CSR_SIP, zero
+
+ /* Switch to physical addressing */
+ la s4, 1f
+ sub s4, s4, s3
+ csrw CSR_STVEC, s4
+ csrw CSR_SATP, zero
+
+.align 2
+1:
+ /* Pass the arguments to the next kernel / Cleanup*/
+ mv a0, s2
+ mv a1, s1
+ mv a2, s0
+
+ /* Cleanup */
+ mv a3, zero
+ mv a4, zero
+ mv a5, zero
+ mv a6, zero
+ mv a7, zero
+
+ mv s0, zero
+ mv s1, zero
+ mv s2, zero
+ mv s3, zero
+ mv s4, zero
+ mv s5, zero
+ mv s6, zero
+ mv s7, zero
+ mv s8, zero
+ mv s9, zero
+ mv s10, zero
+ mv s11, zero
+
+ mv t0, zero
+ mv t1, zero
+ mv t2, zero
+ mv t3, zero
+ mv t4, zero
+ mv t5, zero
+ mv t6, zero
+ csrw CSR_SEPC, zero
+ csrw CSR_SCAUSE, zero
+ csrw CSR_SSCRATCH, zero
+
+ jalr zero, a2, 0
+SYM_CODE_END(riscv_kexec_norelocate)
+
+.section ".rodata"
SYM_DATA(riscv_kexec_relocate_size,
.long riscv_kexec_relocate_end - riscv_kexec_relocate)
diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_kexec.c
index e165c7874740..cc048143fba5 100644
--- a/arch/riscv/kernel/machine_kexec.c
+++ b/arch/riscv/kernel/machine_kexec.c
@@ -59,11 +59,6 @@ machine_kexec_prepare(struct kimage *image)
kexec_image_info(image);
- if (image->type == KEXEC_TYPE_CRASH) {
- pr_warn("Loading a crash kernel is unsupported for now.\n");
- return -EINVAL;
- }
-
/* Find the Flattened Device Tree and save its physical address */
for (i = 0; i < image->nr_segments; i++) {
if (image->segment[i].memsz <= sizeof(fdt))
@@ -85,17 +80,21 @@ machine_kexec_prepare(struct kimage *image)
}
/* Copy the assembler code for relocation to the control page */
- control_code_buffer = page_address(image->control_code_page);
- control_code_buffer_sz = page_size(image->control_code_page);
- if (unlikely(riscv_kexec_relocate_size > control_code_buffer_sz)) {
- pr_err("Relocation code doesn't fit within a control page\n");
- return -EINVAL;
- }
- memcpy(control_code_buffer, riscv_kexec_relocate,
- riscv_kexec_relocate_size);
+ if (image->type != KEXEC_TYPE_CRASH) {
+ control_code_buffer = page_address(image->control_code_page);
+ control_code_buffer_sz = page_size(image->control_code_page);
- /* Mark the control page executable */
- set_memory_x((unsigned long) control_code_buffer, 1);
+ if (unlikely(riscv_kexec_relocate_size > control_code_buffer_sz)) {
+ pr_err("Relocation code doesn't fit within a control page\n");
+ return -EINVAL;
+ }
+
+ memcpy(control_code_buffer, riscv_kexec_relocate,
+ riscv_kexec_relocate_size);
+
+ /* Mark the control page executable */
+ set_memory_x((unsigned long) control_code_buffer, 1);
+ }
return 0;
}
@@ -147,6 +146,9 @@ void machine_shutdown(void)
void
machine_crash_shutdown(struct pt_regs *regs)
{
+ crash_save_cpu(regs, smp_processor_id());
+ machine_shutdown();
+ pr_info("Starting crashdump kernel...\n");
}
/**
@@ -169,7 +171,12 @@ machine_kexec(struct kimage *image)
unsigned long this_hart_id = raw_smp_processor_id();
unsigned long fdt_addr = internal->fdt_addr;
void *control_code_buffer = page_address(image->control_code_page);
- riscv_kexec_do_relocate do_relocate = control_code_buffer;
+ riscv_kexec_method kexec_method = NULL;
+
+ if (image->type != KEXEC_TYPE_CRASH)
+ kexec_method = control_code_buffer;
+ else
+ kexec_method = (riscv_kexec_method) &riscv_kexec_norelocate;
pr_notice("Will call new kernel at %08lx from hart id %lx\n",
jump_addr, this_hart_id);
@@ -180,7 +187,7 @@ machine_kexec(struct kimage *image)
/* Jump to the relocation code */
pr_notice("Bye...\n");
- do_relocate(first_ind_entry, jump_addr, fdt_addr,
- this_hart_id, va_pa_offset);
+ kexec_method(first_ind_entry, jump_addr, fdt_addr,
+ this_hart_id, va_pa_offset);
unreachable();
}
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 9193ba3a006b..0aa9f8340115 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -20,6 +20,7 @@
#include <linux/swiotlb.h>
#include <linux/smp.h>
#include <linux/efi.h>
+#include <linux/crash_dump.h>
#include <asm/cpu_ops.h>
#include <asm/early_ioremap.h>
@@ -160,6 +161,14 @@ static void __init init_resources(void)
if (ret < 0)
goto error;
+#ifdef CONFIG_KEXEC_CORE
+ if (crashk_res.start != crashk_res.end) {
+ ret = add_resource(&iomem_resource, &crashk_res);
+ if (ret < 0)
+ goto error;
+ }
+#endif
+
for_each_reserved_mem_region(region) {
res = &mem_res[res_idx--];
@@ -252,7 +261,6 @@ void __init setup_arch(char **cmdline_p)
efi_init();
setup_bootmem();
paging_init();
- init_resources();
#if IS_ENABLED(CONFIG_BUILTIN_DTB)
unflatten_and_copy_device_tree();
#else
@@ -263,6 +271,7 @@ void __init setup_arch(char **cmdline_p)
#endif
misc_mem_init();
+ init_resources();
sbi_init();
if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index a2f4c148f02e..63c94d33e18a 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -2,6 +2,8 @@
/*
* Copyright (C) 2012 Regents of the University of California
* Copyright (C) 2019 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2020 FORTH-ICS/CARV
+ * Nick Kossifidis <mick@ics.forth.gr>
*/
#include <linux/init.h>
@@ -14,6 +16,7 @@
#include <linux/libfdt.h>
#include <linux/set_memory.h>
#include <linux/dma-map-ops.h>
+#include <linux/crash_dump.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
@@ -658,6 +661,71 @@ void mark_rodata_ro(void)
}
#endif
+#ifdef CONFIG_KEXEC_CORE
+/*
+ * reserve_crashkernel() - reserves memory for crash kernel
+ *
+ * This function reserves memory area given in "crashkernel=" kernel command
+ * line parameter. The memory reserved is used by dump capture kernel when
+ * primary kernel is crashing.
+ */
+static void __init reserve_crashkernel(void)
+{
+ unsigned long long crash_base = 0;
+ unsigned long long crash_size = 0;
+ unsigned long search_start = memblock_start_of_DRAM();
+ unsigned long search_end = memblock_end_of_DRAM();
+
+ int ret = 0;
+
+ ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
+ &crash_size, &crash_base);
+ if (ret || !crash_size)
+ return;
+
+ crash_size = PAGE_ALIGN(crash_size);
+
+ if (crash_base == 0) {
+ /*
+ * Current riscv boot protocol requires 2MB alignment for
+ * RV64 and 4MB alignment for RV32 (hugepage size)
+ */
+ crash_base = memblock_find_in_range(search_start, search_end,
+ crash_size, PMD_SIZE);
+
+ if (crash_base == 0) {
+ pr_warn("crashkernel: couldn't allocate %lldKB\n",
+ crash_size >> 10);
+ return;
+ }
+ } else {
+ /* User specifies base address explicitly. */
+ if (!memblock_is_region_memory(crash_base, crash_size)) {
+ pr_warn("crashkernel: requested region is not memory\n");
+ return;
+ }
+
+ if (memblock_is_region_reserved(crash_base, crash_size)) {
+ pr_warn("crashkernel: requested region is reserved\n");
+ return;
+ }
+
+
+ if (!IS_ALIGNED(crash_base, PMD_SIZE)) {
+ pr_warn("crashkernel: requested region is misaligned\n");
+ return;
+ }
+ }
+ memblock_reserve(crash_base, crash_size);
+
+ pr_info("crashkernel: reserved 0x%016llx - 0x%016llx (%lld MB)\n",
+ crash_base, crash_base + crash_size, crash_size >> 20);
+
+ crashk_res.start = crash_base;
+ crashk_res.end = crash_base + crash_size - 1;
+}
+#endif /* CONFIG_KEXEC_CORE */
+
void __init paging_init(void)
{
setup_vm_final();
@@ -670,6 +738,9 @@ void __init misc_mem_init(void)
arch_numa_init();
sparse_init();
zone_sizes_init();
+#ifdef CONFIG_KEXEC_CORE
+ reserve_crashkernel();
+#endif
memblock_dump_all();
}