Messages in this thread | | | Subject | Re: [PATCH v6] RISC-V: enable XIP | From | Alex Ghiti <> | Date | Tue, 30 Mar 2021 16:04:18 -0400 |
| |
Le 3/30/21 à 3:33 PM, Palmer Dabbelt a écrit : > On Tue, 30 Mar 2021 11:39:10 PDT (-0700), alex@ghiti.fr wrote: >> >> >> Le 3/30/21 à 2:26 AM, Vitaly Wool a écrit : >>> On Tue, Mar 30, 2021 at 8:23 AM Palmer Dabbelt >>> <palmerdabbelt@google.com> wrote: >>>> >>>> On Sun, 21 Mar 2021 17:12:15 PDT (-0700), vitaly.wool@konsulko.com >>>> wrote: >>>>> Introduce XIP (eXecute In Place) support for RISC-V platforms. >>>>> It allows code to be executed directly from non-volatile storage >>>>> directly addressable by the CPU, such as QSPI NOR flash which can >>>>> be found on many RISC-V platforms. This makes way for significant >>>>> optimization of RAM footprint. The XIP kernel is not compressed >>>>> since it has to run directly from flash, so it will occupy more >>>>> space on the non-volatile storage. The physical flash address used >>>>> to link the kernel object files and for storing it has to be known >>>>> at compile time and is represented by a Kconfig option. >>>>> >>>>> XIP on RISC-V will for the time being only work on MMU-enabled >>>>> kernels. >>>>> >>>>> Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com> >>>>> >>>>> --- >>>>> >>>>> Changes in v2: >>>>> - dedicated macro for XIP address fixup when MMU is not enabled yet >>>>> o both for 32-bit and 64-bit RISC-V >>>>> - SP is explicitly set to a safe place in RAM before __copy_data call >>>>> - removed redundant alignment requirements in vmlinux-xip.lds.S >>>>> - changed long -> uintptr_t typecast in __XIP_FIXUP macro. >>>>> Changes in v3: >>>>> - rebased against latest for-next >>>>> - XIP address fixup macro now takes an argument >>>>> - SMP related fixes >>>>> Changes in v4: >>>>> - rebased against the current for-next >>>>> - less #ifdef's in C/ASM code >>>>> - dedicated XIP_FIXUP_OFFSET assembler macro in head.S >>>>> - C-specific definitions moved into #ifndef __ASSEMBLY__ >>>>> - Fixed multi-core boot >>>>> Changes in v5: >>>>> - fixed build error for non-XIP kernels >>>>> Changes in v6: >>>>> - XIP_PHYS_RAM_BASE config option renamed to PHYS_RAM_BASE >>>>> - added PHYS_RAM_BASE_FIXED config flag to allow usage of >>>>> PHYS_RAM_BASE in non-XIP configurations if needed >>>>> - XIP_FIXUP macro rewritten with a tempoarary variable to avoid side >>>>> effects >>>>> - fixed crash for non-XIP kernels that don't use built-in DTB >>>> >>>> So v5 landed on for-next, which generally means it's best to avoid >>>> re-spinning the patch and instead send along fixups. That said, the v5 >>>> is causing some testing failures for me. >>>> >>>> I'm going to drop the v5 for now as I don't have time to test this >>>> tonight. I'll try and take a look soon, as it will conflict with >>>> Alex's >>>> patches. >>> >>> I can come up with the incremental patch instead pretty much straight >>> away if that works better. >>> >>> ~Vitaly >>> >>>>> arch/riscv/Kconfig | 49 ++++++++++- >>>>> arch/riscv/Makefile | 8 +- >>>>> arch/riscv/boot/Makefile | 13 +++ >>>>> arch/riscv/include/asm/pgtable.h | 65 ++++++++++++-- >>>>> arch/riscv/kernel/cpu_ops_sbi.c | 11 ++- >>>>> arch/riscv/kernel/head.S | 49 ++++++++++- >>>>> arch/riscv/kernel/head.h | 3 + >>>>> arch/riscv/kernel/setup.c | 8 +- >>>>> arch/riscv/kernel/vmlinux-xip.lds.S | 132 >>>>> ++++++++++++++++++++++++++++ >>>>> arch/riscv/kernel/vmlinux.lds.S | 6 ++ >>>>> arch/riscv/mm/init.c | 100 +++++++++++++++++++-- >>>>> 11 files changed, 426 insertions(+), 18 deletions(-) >>>>> create mode 100644 arch/riscv/kernel/vmlinux-xip.lds.S >>>>> >>>>> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig >>>>> index 8ea60a0a19ae..bd6f82240c34 100644 >>>>> --- a/arch/riscv/Kconfig >>>>> +++ b/arch/riscv/Kconfig >>>>> @@ -441,7 +441,7 @@ config EFI_STUB >>>>> >>>>> config EFI >>>>> bool "UEFI runtime support" >>>>> - depends on OF >>>>> + depends on OF && !XIP_KERNEL >>>>> select LIBFDT >>>>> select UCS2_STRING >>>>> select EFI_PARAMS_FROM_FDT >>>>> @@ -465,11 +465,56 @@ config STACKPROTECTOR_PER_TASK >>>>> def_bool y >>>>> depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS >>>>> >>>>> +config PHYS_RAM_BASE_FIXED >>>>> + bool "Explicitly specified physical RAM address" >>>>> + default n >>>>> + >>>>> +config PHYS_RAM_BASE >>>>> + hex "Platform Physical RAM address" >>>>> + depends on PHYS_RAM_BASE_FIXED >>>>> + default "0x80000000" >>>>> + help >>>>> + This is the physical address of RAM in the system. It has >>>>> to be >>>>> + explicitly specified to run early relocations of read-write >>>>> data >>>>> + from flash to RAM. >>>>> + >>>>> +config XIP_KERNEL >>>>> + bool "Kernel Execute-In-Place from ROM" >>>>> + depends on MMU >>>>> + select PHYS_RAM_BASE_FIXED >>>>> + help >>>>> + Execute-In-Place allows the kernel to run from non-volatile >>>>> storage >>>>> + directly addressable by the CPU, such as NOR flash. This >>>>> saves RAM >>>>> + space since the text section of the kernel is not loaded >>>>> from flash >>>>> + to RAM. Read-write sections, such as the data section and >>>>> stack, >>>>> + are still copied to RAM. The XIP kernel is not compressed >>>>> since >>>>> + it has to run directly from flash, so it will take more >>>>> space to >>>>> + store it. The flash address used to link the kernel object >>>>> files, >>>>> + and for storing it, is configuration dependent. Therefore, >>>>> if you >>>>> + say Y here, you must know the proper physical address where to >>>>> + store the kernel image depending on your own flash memory >>>>> usage. >>>>> + >>>>> + Also note that the make target becomes "make xipImage" >>>>> rather than >>>>> + "make zImage" or "make Image". The final kernel binary to >>>>> put in >>>>> + ROM memory will be arch/riscv/boot/xipImage. >>>>> + >>>>> + If unsure, say N. >>>>> + >>>>> +config XIP_PHYS_ADDR >>>>> + hex "XIP Kernel Physical Location" >>>>> + depends on XIP_KERNEL >>>>> + default "0x21000000" >>>>> + help >>>>> + This is the physical address in your flash memory the >>>>> kernel will >>>>> + be linked for and stored to. This address is dependent on >>>>> your >>>>> + own flash usage. >>>>> + >>>>> endmenu >>>>> >>>>> config BUILTIN_DTB >>>>> - def_bool n >>>>> + bool >>>>> depends on OF >>>>> + default y if XIP_KERNEL >>>>> >>>>> menu "Power management options" >>>>> >>>>> diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile >>>>> index 1368d943f1f3..8fcbec03974d 100644 >>>>> --- a/arch/riscv/Makefile >>>>> +++ b/arch/riscv/Makefile >>>>> @@ -82,7 +82,11 @@ CHECKFLAGS += -D__riscv -D__riscv_xlen=$(BITS) >>>>> >>>>> # Default target when executing plain make >>>>> boot := arch/riscv/boot >>>>> +ifeq ($(CONFIG_XIP_KERNEL),y) >>>>> +KBUILD_IMAGE := $(boot)/xipImage >>>>> +else >>>>> KBUILD_IMAGE := $(boot)/Image.gz >>>>> +endif >>>>> >>>>> head-y := arch/riscv/kernel/head.o >>>>> >>>>> @@ -95,12 +99,14 @@ PHONY += vdso_install >>>>> vdso_install: >>>>> $(Q)$(MAKE) $(build)=arch/riscv/kernel/vdso $@ >>>>> >>>>> +ifneq ($(CONFIG_XIP_KERNEL),y) >>>>> ifeq ($(CONFIG_RISCV_M_MODE)$(CONFIG_SOC_CANAAN),yy) >>>>> KBUILD_IMAGE := $(boot)/loader.bin >>>>> else >>>>> KBUILD_IMAGE := $(boot)/Image.gz >>>>> endif >>>>> -BOOT_TARGETS := Image Image.gz loader loader.bin >>>>> +endif >>>>> +BOOT_TARGETS := Image Image.gz loader loader.bin xipImage >>>>> >>>>> all: $(notdir $(KBUILD_IMAGE)) >>>>> >>>>> diff --git a/arch/riscv/boot/Makefile b/arch/riscv/boot/Makefile >>>>> index 03404c84f971..6bf299f70c27 100644 >>>>> --- a/arch/riscv/boot/Makefile >>>>> +++ b/arch/riscv/boot/Makefile >>>>> @@ -17,8 +17,21 @@ >>>>> KCOV_INSTRUMENT := n >>>>> >>>>> OBJCOPYFLAGS_Image :=-O binary -R .note -R .note.gnu.build-id -R >>>>> .comment -S >>>>> +OBJCOPYFLAGS_xipImage :=-O binary -R .note -R .note.gnu.build-id >>>>> -R .comment -S >>>>> >>>>> targets := Image Image.* loader loader.o loader.lds loader.bin >>>>> +targets := Image Image.* loader loader.o loader.lds loader.bin >>>>> xipImage >>>>> + >>>>> +ifeq ($(CONFIG_XIP_KERNEL),y) >>>>> + >>>>> +quiet_cmd_mkxip = $(quiet_cmd_objcopy) >>>>> +cmd_mkxip = $(cmd_objcopy) >>>>> + >>>>> +$(obj)/xipImage: vmlinux FORCE >>>>> + $(call if_changed,mkxip) >>>>> + @$(kecho) ' Physical Address of xipImage: >>>>> $(CONFIG_XIP_PHYS_ADDR)' >>>>> + >>>>> +endif >>>>> >>>>> $(obj)/Image: vmlinux FORCE >>>>> $(call if_changed,objcopy) >>>>> diff --git a/arch/riscv/include/asm/pgtable.h >>>>> b/arch/riscv/include/asm/pgtable.h >>>>> index ebf817c1bdf4..21a9b2f8d1c7 100644 >>>>> --- a/arch/riscv/include/asm/pgtable.h >>>>> +++ b/arch/riscv/include/asm/pgtable.h >>>>> @@ -11,6 +11,33 @@ >>>>> >>>>> #include <asm/pgtable-bits.h> >>>>> >>>>> +#ifdef CONFIG_MMU >>>>> + >>>>> +#define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) >>>>> + >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> +#define VMALLOC_SIZE ((KERN_VIRT_SIZE >> 1) - SZ_16M) >>>>> +#define VMALLOC_END (PAGE_OFFSET - SZ_16M - 1) >>>>> + >>>>> +#define XIP_OFFSET SZ_8M >>>>> +#define XIP_MASK (SZ_8M - 1) >>>>> +#define XIP_VIRT_ADDR(physaddr) \ >>>>> + (PAGE_OFFSET - XIP_OFFSET + ((physaddr) & XIP_MASK)) >>>>> + >>>>> +#else >>>>> + >>>>> +#define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1) >>>>> +#define VMALLOC_END (PAGE_OFFSET - 1) >>>>> + >>>>> +#endif /* CONFIG_XIP_KERNEL */ >>>>> + >>>>> +#else >>>>> + >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> +#define XIP_VIRT_ADDR(physaddr) (physaddr) >>>>> +#endif /* CONFIG_XIP_KERNEL */ >>>>> +#endif /* CONFIG_MMU */ >>>>> + >>>>> #ifndef __ASSEMBLY__ >>>>> >>>>> /* Page Upper Directory not used in RISC-V */ >>>>> @@ -21,9 +48,25 @@ >>>>> >>>>> #ifdef CONFIG_MMU >>>>> >>>>> -#define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1) >>>>> -#define VMALLOC_END (PAGE_OFFSET - 1) >>>>> -#define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> +/* >>>>> + * Since we use sections to map it, this macro replaces the >>>>> physical address >>>>> + * with its virtual address while keeping offset from the base >>>>> section. >>>>> + */ >>>>> +#define XIP_PHYS_ADDR(va) \ >>>>> + ((uintptr_t)(va) - PAGE_OFFSET + XIP_OFFSET + >>>>> CONFIG_XIP_PHYS_ADDR) >>>>> + >>>>> +#define XIP_VIRT_ADDR_START XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR) >>>>> + >>>>> +#define XIP_FIXUP(addr) ({ \ >>>>> + uintptr_t __a = (uintptr_t)(addr); \ >>>>> + (__a >= CONFIG_XIP_PHYS_ADDR && \ >>>>> + __a < CONFIG_XIP_PHYS_ADDR + SZ_16M) ? \ >>>>> + __a - CONFIG_XIP_PHYS_ADDR + CONFIG_PHYS_RAM_BASE - >>>>> XIP_OFFSET : __a; \ >>>>> +}) >>>>> +#else >>>>> +#define XIP_FIXUP(addr) (addr) >>>>> +#endif /* CONFIG_XIP_KERNEL */ >>>>> >>>>> #define BPF_JIT_REGION_SIZE (SZ_128M) >>>>> #define BPF_JIT_REGION_START (PAGE_OFFSET - BPF_JIT_REGION_SIZE) >>>>> @@ -484,8 +527,20 @@ static inline int >>>>> ptep_clear_flush_young(struct vm_area_struct *vma, >>>>> >>>>> #define kern_addr_valid(addr) (1) /* FIXME */ >>>>> >>>>> -extern void *dtb_early_va; >>>>> -extern uintptr_t dtb_early_pa; >>>>> +extern void *_dtb_early_va; >>>>> +extern uintptr_t _dtb_early_pa; >>>>> +#if defined(CONFIG_XIP_KERNEL) && defined(CONFIG_MMU) >>>>> + >>>>> +#define dtb_early_va (*(void **)XIP_FIXUP(&_dtb_early_va)) >>>>> +#define dtb_early_pa (*(uintptr_t *)XIP_FIXUP(&_dtb_early_pa)) >>>>> + >>>>> +#else >>>>> + >>>>> +#define dtb_early_va _dtb_early_va >>>>> +#define dtb_early_pa _dtb_early_pa >>>>> + >>>>> +#endif /* CONFIG_XIP_KERNEL */ >>>>> + >>>>> void setup_bootmem(void); >>>>> void paging_init(void); >>>>> void misc_mem_init(void); >>>>> diff --git a/arch/riscv/kernel/cpu_ops_sbi.c >>>>> b/arch/riscv/kernel/cpu_ops_sbi.c >>>>> index 685fae72b7f5..2413c2997350 100644 >>>>> --- a/arch/riscv/kernel/cpu_ops_sbi.c >>>>> +++ b/arch/riscv/kernel/cpu_ops_sbi.c >>>>> @@ -53,10 +53,19 @@ static int sbi_hsm_hart_get_status(unsigned >>>>> long hartid) >>>>> } >>>>> #endif >>>>> >>>>> +static inline unsigned long get_secondary_start_phys(void) >>>>> +{ >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> + return XIP_PHYS_ADDR(secondary_start_sbi); >>>>> +#else >>>>> + return __pa_symbol(secondary_start_sbi); >>>>> +#endif >>>>> +} >>>>> + >>>>> static int sbi_cpu_start(unsigned int cpuid, struct task_struct >>>>> *tidle) >>>>> { >>>>> int rc; >>>>> - unsigned long boot_addr = __pa_symbol(secondary_start_sbi); >>>>> + unsigned long boot_addr = get_secondary_start_phys(); >>>>> int hartid = cpuid_to_hartid_map(cpuid); >>>>> >>>>> cpu_update_secondary_bootdata(cpuid, tidle); >>>>> diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S >>>>> index f5a9bad86e58..bbe74e37914f 100644 >>>>> --- a/arch/riscv/kernel/head.S >>>>> +++ b/arch/riscv/kernel/head.S >>>>> @@ -9,11 +9,23 @@ >>>>> #include <linux/linkage.h> >>>>> #include <asm/thread_info.h> >>>>> #include <asm/page.h> >>>>> +#include <asm/pgtable.h> >>>>> #include <asm/csr.h> >>>>> #include <asm/hwcap.h> >>>>> #include <asm/image.h> >>>>> #include "efi-header.S" >>>>> >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> +.macro XIP_FIXUP_OFFSET reg >>>>> + REG_L t0, _xip_fixup >>>>> + add \reg, \reg, t0 >>>>> +.endm >>>>> +_xip_fixup: .dword CONFIG_PHYS_RAM_BASE - CONFIG_XIP_PHYS_ADDR - >>>>> XIP_OFFSET >>>>> +#else >>>>> +.macro XIP_FIXUP_OFFSET reg >>>>> +.endm >>>>> +#endif /* CONFIG_XIP_KERNEL */ >>>>> + >>>>> __HEAD >>>>> ENTRY(_start) >>>>> /* >>>>> @@ -69,7 +81,11 @@ pe_head_start: >>>>> #ifdef CONFIG_MMU >>>>> relocate: >>>>> /* Relocate return address */ >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> + li a1, XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR) >>>>> +#else >>>>> li a1, PAGE_OFFSET >>>>> +#endif >>>>> la a2, _start >>>>> sub a1, a1, a2 >>>>> add ra, ra, a1 >>>>> @@ -91,6 +107,7 @@ relocate: >>>>> * to ensure the new translations are in use. >>>>> */ >>>>> la a0, trampoline_pg_dir >>>>> + XIP_FIXUP_OFFSET a0 >>>>> srl a0, a0, PAGE_SHIFT >>>>> or a0, a0, a1 >>>>> sfence.vma >>>>> @@ -144,7 +161,9 @@ secondary_start_sbi: >>>>> >>>>> slli a3, a0, LGREG >>>>> la a4, __cpu_up_stack_pointer >>>>> + XIP_FIXUP_OFFSET a4 >>>>> la a5, __cpu_up_task_pointer >>>>> + XIP_FIXUP_OFFSET a5 >>>>> add a4, a3, a4 >>>>> add a5, a3, a5 >>>>> REG_L sp, (a4) >>>>> @@ -156,6 +175,7 @@ secondary_start_common: >>>>> #ifdef CONFIG_MMU >>>>> /* Enable virtual memory and relocate to virtual address */ >>>>> la a0, swapper_pg_dir >>>>> + XIP_FIXUP_OFFSET a0 >>>>> call relocate >>>>> #endif >>>>> call setup_trap_vector >>>>> @@ -236,12 +256,33 @@ pmp_done: >>>>> .Lgood_cores: >>>>> #endif >>>>> >>>>> +#ifndef CONFIG_XIP_KERNEL >>>>> /* Pick one hart to run the main boot sequence */ >>>>> la a3, hart_lottery >>>>> li a2, 1 >>>>> amoadd.w a3, a2, (a3) >>>>> bnez a3, .Lsecondary_start >>>>> >>>>> +#else >>>>> + /* hart_lottery in flash contains a magic number */ >>>>> + la a3, hart_lottery >>>>> + mv a2, a3 >>>>> + XIP_FIXUP_OFFSET a2 >>>>> + lw t1, (a3) >>>>> + amoswap.w t0, t1, (a2) >>>>> + /* first time here if hart_lottery in RAM is not set */ >>>>> + beq t0, t1, .Lsecondary_start >>>>> + >>>>> + la sp, _end + THREAD_SIZE >>>>> + XIP_FIXUP_OFFSET sp >>>>> + mv s0, a0 >>>>> + call __copy_data >>>>> + >>>>> + /* Restore a0 copy */ >>>>> + mv a0, s0 >>>>> +#endif >>>>> + >>>>> +#ifndef CONFIG_XIP_KERNEL >>>>> /* Clear BSS for flat non-ELF images */ >>>>> la a3, __bss_start >>>>> la a4, __bss_stop >>>>> @@ -251,15 +292,18 @@ clear_bss: >>>>> add a3, a3, RISCV_SZPTR >>>>> blt a3, a4, clear_bss >>>>> clear_bss_done: >>>>> - >>>>> +#endif >>>>> /* Save hart ID and DTB physical address */ >>>>> mv s0, a0 >>>>> mv s1, a1 >>>>> + >>>>> la a2, boot_cpu_hartid >>>>> + XIP_FIXUP_OFFSET a2 >>>>> REG_S a0, (a2) >>>>> >>>>> /* Initialize page tables and relocate to virtual addresses */ >>>>> la sp, init_thread_union + THREAD_SIZE >>>>> + XIP_FIXUP_OFFSET sp >>>>> #ifdef CONFIG_BUILTIN_DTB >>>>> la a0, __dtb_start >>>>> #else >>>>> @@ -268,6 +312,7 @@ clear_bss_done: >>>>> call setup_vm >>>>> #ifdef CONFIG_MMU >>>>> la a0, early_pg_dir >>>>> + XIP_FIXUP_OFFSET a0 >>>>> call relocate >>>>> #endif /* CONFIG_MMU */ >>>>> >>>>> @@ -292,7 +337,9 @@ clear_bss_done: >>>>> >>>>> slli a3, a0, LGREG >>>>> la a1, __cpu_up_stack_pointer >>>>> + XIP_FIXUP_OFFSET a1 >>>>> la a2, __cpu_up_task_pointer >>>>> + XIP_FIXUP_OFFSET a2 >>>>> add a1, a3, a1 >>>>> add a2, a3, a2 >>>>> >>>>> diff --git a/arch/riscv/kernel/head.h b/arch/riscv/kernel/head.h >>>>> index b48dda3d04f6..aabbc3ac3e48 100644 >>>>> --- a/arch/riscv/kernel/head.h >>>>> +++ b/arch/riscv/kernel/head.h >>>>> @@ -12,6 +12,9 @@ extern atomic_t hart_lottery; >>>>> >>>>> asmlinkage void do_page_fault(struct pt_regs *regs); >>>>> asmlinkage void __init setup_vm(uintptr_t dtb_pa); >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> +asmlinkage void __init __copy_data(void); >>>>> +#endif >>>>> >>>>> extern void *__cpu_up_stack_pointer[]; >>>>> extern void *__cpu_up_task_pointer[]; >>>>> diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c >>>>> index e85bacff1b50..a0384c72c272 100644 >>>>> --- a/arch/riscv/kernel/setup.c >>>>> +++ b/arch/riscv/kernel/setup.c >>>>> @@ -50,7 +50,11 @@ struct screen_info screen_info >>>>> __section(".data") = { >>>>> * This is used before the kernel initializes the BSS so it can't >>>>> be in the >>>>> * BSS. >>>>> */ >>>>> -atomic_t hart_lottery __section(".sdata"); >>>>> +atomic_t hart_lottery __section(".sdata") >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> += ATOMIC_INIT(0xC001BEEF) >>>>> +#endif >>>>> +; >>>>> unsigned long boot_cpu_hartid; >>>>> static DEFINE_PER_CPU(struct cpu, cpu_devices); >>>>> >>>>> @@ -254,7 +258,7 @@ void __init setup_arch(char **cmdline_p) >>>>> #if IS_ENABLED(CONFIG_BUILTIN_DTB) >>>>> unflatten_and_copy_device_tree(); >>>>> #else >>>>> - if (early_init_dt_verify(__va(dtb_early_pa))) >>>>> + if (early_init_dt_verify(__va(XIP_FIXUP(dtb_early_pa)))) >>>>> unflatten_device_tree(); >>>>> else >>>>> pr_err("No DTB found in kernel mappings\n"); >>>>> diff --git a/arch/riscv/kernel/vmlinux-xip.lds.S >>>>> b/arch/riscv/kernel/vmlinux-xip.lds.S >>>>> new file mode 100644 >>>>> index 000000000000..9f0f08c34cd3 >>>>> --- /dev/null >>>>> +++ b/arch/riscv/kernel/vmlinux-xip.lds.S >>>>> @@ -0,0 +1,132 @@ >>>>> +/* SPDX-License-Identifier: GPL-2.0-only */ >>>>> +/* >>>>> + * Copyright (C) 2012 Regents of the University of California >>>>> + * Copyright (C) 2017 SiFive >>>>> + * Copyright (C) 2020 Vitaly Wool, Konsulko AB >>>>> + */ >>>>> + >>>>> +#define LOAD_OFFSET XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR) >>>>> +/* No __ro_after_init data in the .rodata section - which will >>>>> always be ro */ >>>>> +#define RO_AFTER_INIT_DATA >>>>> + >>>>> +#include <asm/vmlinux.lds.h> >>>>> +#include <asm/page.h> >>>>> +#include <asm/pgtable.h> >>>>> +#include <asm/cache.h> >>>>> +#include <asm/thread_info.h> >>>>> + >>>>> +OUTPUT_ARCH(riscv) >>>>> +ENTRY(_start) >>>>> + >>>>> +jiffies = jiffies_64; >>>>> + >>>>> +SECTIONS >>>>> +{ >>>>> + /* Beginning of code and text segment */ >>>>> + . = XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR); >>>>> + _xiprom = .; >>>>> + _start = .; >>>>> + HEAD_TEXT_SECTION >>>>> + INIT_TEXT_SECTION(PAGE_SIZE) >>>>> + /* we have to discard exit text and such at runtime, not link >>>>> time */ >>>>> + .exit.text : >>>>> + { >>>>> + EXIT_TEXT >>>>> + } >>>>> + >>>>> + .text : { >>>>> + _text = .; >>>>> + _stext = .; >>>>> + TEXT_TEXT >>>>> + SCHED_TEXT >>>>> + CPUIDLE_TEXT >>>>> + LOCK_TEXT >>>>> + KPROBES_TEXT >>>>> + ENTRY_TEXT >>>>> + IRQENTRY_TEXT >>>>> + SOFTIRQENTRY_TEXT >>>>> + *(.fixup) >>>>> + _etext = .; >>>>> + } >>>>> + RO_DATA(L1_CACHE_BYTES) >>>>> + .srodata : { >>>>> + *(.srodata*) >>>>> + } >>>>> + .init.rodata : { >>>>> + INIT_SETUP(16) >>>>> + INIT_CALLS >>>>> + CON_INITCALL >>>>> + INIT_RAM_FS >>>>> + } >>>>> + _exiprom = .; /* End of XIP ROM area */ >>>>> + >>>>> + >>>>> +/* >>>>> + * From this point, stuff is considered writable and will be >>>>> copied to RAM >>>>> + */ >>>>> + __data_loc = ALIGN(16); /* location in file */ >>>>> + . = PAGE_OFFSET; /* location in memory */ >>>>> + >>>>> + _sdata = .; /* Start of data section */ >>>>> + _data = .; >>>>> + RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE) >>>>> + _edata = .; >>>>> + __start_ro_after_init = .; >>>>> + .data.ro_after_init : AT(ADDR(.data.ro_after_init) - >>>>> LOAD_OFFSET) { >>>>> + *(.data..ro_after_init) >>>>> + } >>>>> + __end_ro_after_init = .; >>>>> + >>>>> + . = ALIGN(PAGE_SIZE); >>>>> + __init_begin = .; >>>>> + .init.data : { >>>>> + INIT_DATA >>>>> + } >>>>> + .exit.data : { >>>>> + EXIT_DATA >>>>> + } >>>>> + . = ALIGN(8); >>>>> + __soc_early_init_table : { >>>>> + __soc_early_init_table_start = .; >>>>> + KEEP(*(__soc_early_init_table)) >>>>> + __soc_early_init_table_end = .; >>>>> + } >>>>> + __soc_builtin_dtb_table : { >>>>> + __soc_builtin_dtb_table_start = .; >>>>> + KEEP(*(__soc_builtin_dtb_table)) >>>>> + __soc_builtin_dtb_table_end = .; >>>>> + } >>>>> + PERCPU_SECTION(L1_CACHE_BYTES) >>>>> + >>>>> + . = ALIGN(PAGE_SIZE); >>>>> + __init_end = .; >>>>> + >>>>> + .sdata : { >>>>> + __global_pointer$ = . + 0x800; >>>>> + *(.sdata*) >>>>> + *(.sbss*) >>>>> + } >>>>> + >>>>> + BSS_SECTION(PAGE_SIZE, PAGE_SIZE, 0) >>>>> + EXCEPTION_TABLE(0x10) >>>>> + >>>>> + .rel.dyn : AT(ADDR(.rel.dyn) - LOAD_OFFSET) { >>>>> + *(.rel.dyn*) >>>>> + } >>>>> + >>>>> + /* >>>>> + * End of copied data. We need a dummy section to get its LMA. >>>>> + * Also located before final ALIGN() as trailing padding is >>>>> not stored >>>>> + * in the resulting binary file and useless to copy. >>>>> + */ >>>>> + .data.endmark : AT(ADDR(.data.endmark) - LOAD_OFFSET) { } >>>>> + _edata_loc = LOADADDR(.data.endmark); >>>>> + >>>>> + . = ALIGN(PAGE_SIZE); >>>>> + _end = .; >>>>> + >>>>> + STABS_DEBUG >>>>> + DWARF_DEBUG >>>>> + >>>>> + DISCARDS >>>>> +} >>>>> diff --git a/arch/riscv/kernel/vmlinux.lds.S >>>>> b/arch/riscv/kernel/vmlinux.lds.S >>>>> index de03cb22d0e9..6745ec325930 100644 >>>>> --- a/arch/riscv/kernel/vmlinux.lds.S >>>>> +++ b/arch/riscv/kernel/vmlinux.lds.S >>>>> @@ -4,7 +4,12 @@ >>>>> * Copyright (C) 2017 SiFive >>>>> */ >>>>> >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> +#include "vmlinux-xip.lds.S" >>>>> +#else >>>>> + >>>>> #define LOAD_OFFSET PAGE_OFFSET >>>>> + >>>>> #include <asm/vmlinux.lds.h> >>>>> #include <asm/page.h> >>>>> #include <asm/cache.h> >>>>> @@ -132,3 +137,4 @@ SECTIONS >>>>> >>>>> DISCARDS >>>>> } >>>>> +#endif /* CONFIG_XIP_KERNEL */ >>>>> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c >>>>> index 7f5036fbee8c..efe649d41f95 100644 >>>>> --- a/arch/riscv/mm/init.c >>>>> +++ b/arch/riscv/mm/init.c >>>>> @@ -31,8 +31,8 @@ EXPORT_SYMBOL(empty_zero_page); >>>>> >>>>> extern char _start[]; >>>>> #define DTB_EARLY_BASE_VA PGDIR_SIZE >>>>> -void *dtb_early_va __initdata; >>>>> -uintptr_t dtb_early_pa __initdata; >>>>> +void *_dtb_early_va __initdata; >>>>> +uintptr_t _dtb_early_pa __initdata; >>>>> >>>>> struct pt_alloc_ops { >>>>> pte_t *(*get_pte_virt)(phys_addr_t pa); >>>>> @@ -88,6 +88,10 @@ static void print_vm_layout(void) >>>>> (unsigned long)VMALLOC_END); >>>>> print_mlm("lowmem", (unsigned long)PAGE_OFFSET, >>>>> (unsigned long)high_memory); >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> + print_mlm("xip", (unsigned long)XIP_VIRT_ADDR_START, >>>>> + (unsigned long)XIP_VIRT_ADDR_START + SZ_16M); >>>>> +#endif /* CONFIG_XIP_KERNEL */ >>>>> } >>>>> #else >>>>> static void print_vm_layout(void) { } >>>>> @@ -113,6 +117,10 @@ void __init setup_bootmem(void) >>>>> phys_addr_t dram_end = memblock_end_of_DRAM(); >>>>> phys_addr_t max_mapped_addr = __pa(~(ulong)0); >>>>> >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> + vmlinux_start = __pa_symbol(&_sdata); >>>>> +#endif >>>>> + >>>>> /* The maximal physical memory size is -PAGE_OFFSET. */ >>>>> memblock_enforce_memory_limit(-PAGE_OFFSET); >>>>> >>>>> @@ -149,11 +157,27 @@ void __init setup_bootmem(void) >>>>> memblock_allow_resize(); >>>>> } >>>>> >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> + >>>>> +extern char _xiprom[], _exiprom[]; >>>>> +extern char _sdata[], _edata[]; >>>>> + >>>>> +#endif /* CONFIG_XIP_KERNEL */ >>>>> + >>>>> #ifdef CONFIG_MMU >>>>> -static struct pt_alloc_ops pt_ops; >>>>> +static struct pt_alloc_ops _pt_ops; >>>>> + >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> +#define pt_ops (*(struct pt_alloc_ops *)XIP_FIXUP(&_pt_ops)) >>>>> +#else >>>>> +#define pt_ops _pt_ops >>>>> +#endif >>>>> >>>>> unsigned long va_pa_offset; >>>>> EXPORT_SYMBOL(va_pa_offset); >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> +#define va_pa_offset (*((unsigned long *)XIP_FIXUP(&va_pa_offset))) >>>>> +#endif >>>>> unsigned long pfn_base; >>>>> EXPORT_SYMBOL(pfn_base); >>>>> >>>>> @@ -163,6 +187,12 @@ pte_t fixmap_pte[PTRS_PER_PTE] >>>>> __page_aligned_bss; >>>>> >>>>> pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); >>>>> >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> +#define trampoline_pg_dir ((pgd_t *)XIP_FIXUP(trampoline_pg_dir)) >>>>> +#define fixmap_pte ((pte_t *)XIP_FIXUP(fixmap_pte)) >>>>> +#define early_pg_dir ((pgd_t *)XIP_FIXUP(early_pg_dir)) >>>>> +#endif /* CONFIG_XIP_KERNEL */ >>>>> + >>>>> void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, >>>>> pgprot_t prot) >>>>> { >>>>> unsigned long addr = __fix_to_virt(idx); >>>>> @@ -238,6 +268,15 @@ pmd_t fixmap_pmd[PTRS_PER_PMD] >>>>> __page_aligned_bss; >>>>> pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE); >>>>> pmd_t early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE); >>>>> >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> +pmd_t xip_pmd[PTRS_PER_PMD] __page_aligned_bss; >>>>> + >>>>> +#define trampoline_pmd ((pmd_t *)XIP_FIXUP(trampoline_pmd)) >>>>> +#define fixmap_pmd ((pmd_t *)XIP_FIXUP(fixmap_pmd)) >>>>> +#define xip_pmd ((pmd_t *)XIP_FIXUP(xip_pmd)) >>>>> +#define early_pmd ((pmd_t *)XIP_FIXUP(early_pmd)) >>>>> +#endif /* CONFIG_XIP_KERNEL */ >>>>> + >>>>> static pmd_t *__init get_pmd_virt_early(phys_addr_t pa) >>>>> { >>>>> /* Before MMU is enabled */ >>>>> @@ -354,6 +393,19 @@ static uintptr_t __init >>>>> best_map_size(phys_addr_t base, phys_addr_t size) >>>>> return PMD_SIZE; >>>>> } >>>>> >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> +/* called from head.S with MMU off */ >>>>> +asmlinkage void __init __copy_data(void) >>>>> +{ >>>>> + void *from = (void *)(&_sdata); >>>>> + void *end = (void *)(&_end); >>>>> + void *to = (void *)CONFIG_PHYS_RAM_BASE; >>>>> + size_t sz = (size_t)(end - from); >>>>> + >>>>> + memcpy(to, from, sz); >>>>> +} >>>>> +#endif >>>>> + >>>>> /* >>>>> * setup_vm() is called from head.S with MMU-off. >>>>> * >>>>> @@ -374,7 +426,8 @@ static uintptr_t __init >>>>> best_map_size(phys_addr_t base, phys_addr_t size) >>>>> >>>>> asmlinkage void __init setup_vm(uintptr_t dtb_pa) >>>>> { >>>>> - uintptr_t va, pa, end_va; >>>>> + uintptr_t va, end_va; >>>>> + uintptr_t __maybe_unused pa; >>>>> uintptr_t load_pa = (uintptr_t)(&_start); >>>>> uintptr_t load_sz = (uintptr_t)(&_end) - load_pa; >>>>> uintptr_t map_size; >>>>> @@ -382,6 +435,13 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) >>>>> pmd_t fix_bmap_spmd, fix_bmap_epmd; >>>>> #endif >>>>> >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> + uintptr_t xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR; >>>>> + uintptr_t xiprom_sz = (uintptr_t)(&_exiprom) - >>>>> (uintptr_t)(&_xiprom); >>>>> + >>>>> + load_pa = (uintptr_t)CONFIG_PHYS_RAM_BASE; >>>>> + load_sz = (uintptr_t)(&_end) - (uintptr_t)(&_sdata); >>>>> +#endif >>>>> va_pa_offset = PAGE_OFFSET - load_pa; >> >> I should have seen this before, I was too focused on having a XIP kernel >> boot. I already moved the kernel mapping in the vmalloc zone: the >> virtual to physical translations need to be handled differently now that >> the kernel mapping does not lie into linear mapping anymore, we can't >> use va_pa_offset defined above for both mappings. >> >> I was rebasing my patchset on the XIP patch but I believe that doing the >> other way around would greatly simplify the XIP patch as the kernel >> mapping would already be moved outside the linear mapping, there would >> be no need to reserve a zone in vmalloc anymore (that simplifies >> pgtable.h quite a lot). And the XIP kernel mapping could be implemented >> in a new create_kernel_page_table (that would also simplify mm/init.c). >> >> I can help to do that but I don't think we should merge this patch as is >> now. > > I think that's the right way to go for now: it's a lot harder to test > the XIP stuff, as it requires a bunch of harness changes. So let's take > the page table refactoring in now and rebase this stuff on top of it. > There's really no way to do both without making more work for someone, > it's just a headache on timing. > > Alex: if you want to sign up to spend some time there that'd be great, > otherwise I will.
I can take care of that, no problem.
> Either way, can you point me (either just indicate > the old version is OK or send a new one) to what you want me to look at > WRT the page table code? IIRC it looked pretty much fine, but I'll take > another look ASAP so we can avoid serializing everything.
The v3 is fine for me: https://patchwork.kernel.org/project/linux-riscv/list/?series=447699
> >> >> Alex >> >>>>> pfn_base = PFN_DOWN(load_pa); >>>>> >>>>> @@ -420,6 +480,21 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) >>>>> load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC); >>>>> #endif >>>>> >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> + create_pgd_mapping(trampoline_pg_dir, XIP_VIRT_ADDR_START, >>>>> + (uintptr_t)xip_pmd, PGDIR_SIZE, PAGE_TABLE); >>>>> + for (va = XIP_VIRT_ADDR_START; >>>>> + va < XIP_VIRT_ADDR_START + xiprom_sz; >>>>> + va += PMD_SIZE) { >>>>> + create_pmd_mapping(xip_pmd, va, >>>>> + xiprom + (va - XIP_VIRT_ADDR_START), >>>>> + PMD_SIZE, PAGE_KERNEL_EXEC); >>>>> + } >>>>> + >>>>> + create_pgd_mapping(early_pg_dir, XIP_VIRT_ADDR_START, >>>>> + (uintptr_t)xip_pmd, PGDIR_SIZE, PAGE_TABLE); >>>>> +#endif >>>>> + >>>>> /* >>>>> * Setup early PGD covering entire kernel which will allows >>>>> * us to reach paging_init(). We map all memory banks later >>>>> @@ -444,7 +519,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) >>>>> pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL); >>>>> dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & >>>>> (PMD_SIZE - 1)); >>>>> #else /* CONFIG_BUILTIN_DTB */ >>>>> - dtb_early_va = __va(dtb_pa); >>>>> + dtb_early_va = __va(XIP_FIXUP(dtb_pa)); >>>>> #endif /* CONFIG_BUILTIN_DTB */ >>>>> #else >>>>> #ifndef CONFIG_BUILTIN_DTB >>>>> @@ -456,7 +531,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) >>>>> pa + PGDIR_SIZE, PGDIR_SIZE, PAGE_KERNEL); >>>>> dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & >>>>> (PGDIR_SIZE - 1)); >>>>> #else /* CONFIG_BUILTIN_DTB */ >>>>> - dtb_early_va = __va(dtb_pa); >>>>> + dtb_early_va = __va(XIP_FIXUP(dtb_pa)); >>>>> #endif /* CONFIG_BUILTIN_DTB */ >>>>> #endif >>>>> dtb_early_pa = dtb_pa; >>>>> @@ -497,6 +572,9 @@ static void __init setup_vm_final(void) >>>>> uintptr_t va, map_size; >>>>> phys_addr_t pa, start, end; >>>>> u64 i; >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> + uintptr_t xiprom_sz = (uintptr_t)(&_exiprom) - >>>>> (uintptr_t)(&_xiprom); >>>>> +#endif >>>>> >>>>> /** >>>>> * MMU is enabled at this point. But page table setup is not >>>>> complete yet. >>>>> @@ -528,6 +606,16 @@ static void __init setup_vm_final(void) >>>>> map_size, PAGE_KERNEL_EXEC); >>>>> } >>>>> } >>>>> +#ifdef CONFIG_XIP_KERNEL >>>>> + map_size = best_map_size(CONFIG_XIP_PHYS_ADDR, xiprom_sz); >>>>> + for (va = XIP_VIRT_ADDR_START; >>>>> + va < XIP_VIRT_ADDR_START + xiprom_sz; >>>>> + va += map_size) >>>>> + create_pgd_mapping(swapper_pg_dir, va, >>>>> + CONFIG_XIP_PHYS_ADDR + (va - >>>>> XIP_VIRT_ADDR_START), >>>>> + map_size, PAGE_KERNEL_EXEC); >>>>> + >>>>> +#endif >>>>> >>>>> /* Clear fixmap PTE and PMD mappings */ >>>>> clear_fixmap(FIX_PTE); >>> >>> _______________________________________________ >>> linux-riscv mailing list >>> linux-riscv@lists.infradead.org >>> http://lists.infradead.org/mailman/listinfo/linux-riscv >>> > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv
| |