[PATCH v6] RISC-V: enable XIP

Alex Ghiti alex at ghiti.fr
Tue Apr 6 19:28:42 BST 2021


Le 4/6/21 à 3:54 AM, Vitaly Wool a écrit :
> On Tue, Apr 6, 2021 at 8:47 AM Alex Ghiti <alex at ghiti.fr> wrote:
>>
>> Hi Vitaly,
>>
>> Le 4/5/21 à 4:34 AM, Vitaly Wool a écrit :
>>> On Sun, Apr 4, 2021 at 10:39 AM Vitaly Wool <vitaly.wool at konsulko.com> wrote:
>>>>
>>>> On Sat, Apr 3, 2021 at 12:00 PM Alex Ghiti <alex at ghiti.fr> wrote:
>>>>>
>>>>> Hi Vitaly,
>>>>>
>>>>> Le 4/1/21 à 7:10 AM, Alex Ghiti a écrit :
>>>>>> Le 4/1/21 à 4:52 AM, Vitaly Wool a écrit :
>>>>>>> Hi Alex,
>>>>>>>
>>>>>>> On Thu, Apr 1, 2021 at 10:11 AM Alex Ghiti <alex at ghiti.fr> wrote:
>>>>>>>>
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> Le 3/30/21 à 4:04 PM, Alex Ghiti a écrit :
>>>>>>>>> Le 3/30/21 à 3:33 PM, Palmer Dabbelt a écrit :
>>>>>>>>>> On Tue, 30 Mar 2021 11:39:10 PDT (-0700), alex at 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 at google.com> wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>> On Sun, 21 Mar 2021 17:12:15 PDT (-0700), vitaly.wool at 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 at 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.
>>>>>>>>
>>>>>>>> Vitaly, can you try the branch int/alex/riscv_xip_kernel_rebase_v1 at
>>>>>>>> https://github.com/AlexGhiti/riscv-linux ? This boots fine using my
>>>>>>>> setup.
>>>>>>>>
>>>>>>>> I removed most of the pgtable.h stuff, the XIP kernel is now mapped like
>>>>>>>> any other kernel at the end of the address space, not in the vmalloc
>>>>>>>> zone as you proposed. And I fixed a few thigns along the way (pfn_base,
>>>>>>>> pfn_valid, copy_data and other stuff).
>>>>>>>>
>>>>>>>> Any comment is welcome !
>>>>>>>
>>>>>>> thanks for your efforts!
>>>>>>>
>>>>>>> I've just built your version. The build went well, but the image
>>>>>>> doesn't seem to boot for me.
>>>>>>
>>>>>> Too bad. Can you give me your config please ?
>>>>>>
>>>>>
>>>>> Apparently, as you can see below, your config works for me, at least it
>>>>> reaches userspace. Do you have traces or more info about what is wrong ?
>>>>
>>>> Console output is just the same but it stops after the following line:
>>>> [    0.003208] Console: colour dummy device 80x25
>>>>
>>>> I did some very simplistic debugging bisecting start_kernel()
>>>> execution and I could see that setup_per_cpu_pageset() was reached
>>>> while calibrate_delay() was not.
>>>>
>>>> How (and whether) this might be related to XIP I don't know :)
>>>
>>> A short update: the system would hang in sched_clock_init() if run
>>> with 'go 21000000' command.
>>
>> The output I pasted came from a boot using 'go', I can't make 'booti'
>> work in my setup.
>>
>> And you don't have this issue with your patch right ?
> 
> I don't have it with yours as well. :) However, there's a small change
> in u-boot's arch/riscv/lib/image.c that I forgot about (but sent it
> today, and you're on CC).
> Basically u-boot needs to honor force_reloc flag and not *force* the
> relocation when this flag is not set.
> 
>> Can you give me any config that could allow me to reproduce this
>> (uboot/buildroot) ? And your qemu version ?
> 
> Other than the small change mentioned above, u-boot and qemu are
> basically the latest git.
> 
> All in all, I am quite sure now that your take on XIP is working fine.
> The issue with single-core boot under QEmu seems to be  less
> reproducible on slower machines running QEmu and more reproducible on
> higher performance ones. It's not clear to me if that is a QEmu
> problem or an in-kernel race, but it's hardly a XIP problem: I was
> able to reproduce it once on a non-XIP kernel too, by copying it to
> RAM in u-boot and giving it a 'go'.

Ok then I'll post a v7 of your patch soon hoping it will go to for-next. 
I'll add my SoB to yours as I modified quite a few things and I think 
people need to know who to yell at, if you don't mind of course.

Thanks,

Alex

> 
> 
>> Thanks,
>>
>>> If I use 'booti' command it passes and goes further all the way to
>>> mounting the userspace
>>>
>>> So the problem is rather SMP related than XIP related.
>>
>>
>>
>>>
>>> Best regards,
>>>      Vitaly
>>>
>>>>> Thanks!
>>>>>
>>>>> [    0.000000] Linux version 5.12.0-rc2 (alex at debian)
>>>>> (riscv64-buildroot-linux-gnu-gcc.br_real (Buildroot 2020.11.2) 9.3.0,
>>>>> GNU ld (GNU Binutils) 2.34) #322 SMP Sat Apr 3 05:50:18 EDT 2021
>>>>> [    0.000000] Machine model: Microchip PolarFire-SoC Icicle Kit
>>>>> [    0.000000] earlycon: sbi0 at I/O port 0x0 (options '')
>>>>> [    0.000000] printk: bootconsole [sbi0] enabled
>>>>> [    0.000000] Zone ranges:
>>>>> [    0.000000]   DMA32    [mem 0x0000000080000000-0x00000000bfffffff]
>>>>> [    0.000000]   Normal   empty
>>>>> [    0.000000] Movable zone start for each node
>>>>> [    0.000000] Early memory node ranges
>>>>> [    0.000000]   node   0: [mem 0x0000000080000000-0x00000000bfffffff]
>>>>> [    0.000000] Initmem setup node 0 [mem
>>>>> 0x0000000080000000-0x00000000bfffffff]
>>>>> [    0.000000] On node 0 totalpages: 262144
>>>>> [    0.000000]   DMA32 zone: 3584 pages used for memmap
>>>>> [    0.000000]   DMA32 zone: 0 pages reserved
>>>>> [    0.000000]   DMA32 zone: 262144 pages, LIFO batch:63
>>>>> [    0.000000] SBI specification v0.2 detected
>>>>> [    0.000000] SBI implementation ID=0x1 Version=0x6
>>>>> [    0.000000] SBI v0.2 TIME extension detected
>>>>> [    0.000000] SBI v0.2 IPI extension detected
>>>>> [    0.000000] SBI v0.2 RFENCE extension detected
>>>>> [    0.000000] software IO TLB: mapped [mem
>>>>> 0x00000000b9e00000-0x00000000bde00000] (64MB)
>>>>> [    0.000000] CPU with hartid=0 is not available
>>>>> [    0.000000] CPU with hartid=0 is not available
>>>>> [    0.000000] riscv: ISA extensions acdfim
>>>>> [    0.000000] riscv: ELF capabilities acdfim
>>>>> [    0.000000] percpu: Embedded 17 pages/cpu s29856 r8192 d31584 u69632
>>>>> [    0.000000] pcpu-alloc: s29856 r8192 d31584 u69632 alloc=17*4096
>>>>> [    0.000000] pcpu-alloc: [0] 0 [0] 1 [0] 2 [0] 3
>>>>> [    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 258560
>>>>> [    0.000000] Kernel command line: earlyprintk debug earlycon=sbi
>>>>> console=ttyS0,115200n8 root=/dev/ram0 init=/sbin/init
>>>>> [    0.000000] Dentry cache hash table entries: 131072 (order: 8,
>>>>> 1048576 bytes, linear)
>>>>> [    0.000000] Inode-cache hash table entries: 65536 (order: 7, 524288
>>>>> bytes, linear)
>>>>> [    0.000000] Sorting __ex_table...
>>>>> [    0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off
>>>>> [    0.000000] Memory: 947732K/1048576K available (2999K kernel code,
>>>>> 692K rwdata, 953K rodata, 205K init, 247K bss, 100844K reserved, 0K
>>>>> cma-reserved)
>>>>> [    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1
>>>>> [    0.000000] rcu: Hierarchical RCU implementation.
>>>>> [    0.000000] rcu:     RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=4.
>>>>> [    0.000000] rcu:     RCU debug extended QS entry/exit.
>>>>> [    0.000000]  Tracing variant of Tasks RCU enabled.
>>>>> [    0.000000] rcu: RCU calculated value of scheduler-enlistment delay
>>>>> is 25 jiffies.
>>>>> [    0.000000] rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=4
>>>>> [    0.000000] NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0
>>>>> [    0.000000] CPU with hartid=0 is not available
>>>>> [    0.000000] riscv-intc: unable to find hart id for
>>>>> /cpus/cpu at 0/interrupt-controller
>>>>> [    0.000000] riscv-intc: 64 local interrupts mapped
>>>>> [    0.000000] plic: interrupt-controller at c000000: mapped 186 interrupts
>>>>> with 4 handlers for 9 contexts.
>>>>> [    0.000000] random: get_random_bytes called from
>>>>> start_kernel+0x2fe/0x49c with crng_init=0
>>>>> [    0.000000] riscv_timer_init_dt: Registering clocksource cpuid [0]
>>>>> hartid [1]
>>>>> [    0.000000] clocksource: riscv_clocksource: mask: 0xffffffffffffffff
>>>>> max_cycles: 0x1d854df40, max_idle_ns: 3526361616960 ns
>>>>> [    0.000146] sched_clock: 64 bits at 1000kHz, resolution 1000ns, wraps
>>>>> every 2199023255500ns
>>>>> [    0.006056] Console: colour dummy device 80x25
>>>>> [    0.015242] Calibrating delay loop (skipped), value calculated using
>>>>> timer frequency.. 2.00 BogoMIPS (lpj=4000)
>>>>> [    0.017130] pid_max: default: 32768 minimum: 301
>>>>> [    0.020115] Mount-cache hash table entries: 2048 (order: 2, 16384
>>>>> bytes, linear)
>>>>> [    0.021097] Mountpoint-cache hash table entries: 2048 (order: 2,
>>>>> 16384 bytes, linear)
>>>>> [    0.078755] ASID allocator using 16 bits (65536 entries)
>>>>> [    0.083669] rcu: Hierarchical SRCU implementation.
>>>>> [    0.093304] smp: Bringing up secondary CPUs ...
>>>>> [    1.149900] CPU1: failed to come online
>>>>> [    2.204183] CPU2: failed to come online
>>>>> [    3.256211] CPU3: failed to come online
>>>>> [    3.257043] smp: Brought up 1 node, 1 CPU
>>>>> [    3.269554] devtmpfs: initialized
>>>>> [    3.282015] clocksource: jiffies: mask: 0xffffffff max_cycles:
>>>>> 0xffffffff, max_idle_ns: 7645041785100000 ns
>>>>> [    3.283484] futex hash table entries: 1024 (order: 4, 65536 bytes,
>>>>> linear)
>>>>> [    3.381718] SCSI subsystem initialized
>>>>> [    3.385115] clocksource: Switched to clocksource riscv_clocksource
>>>>> [    3.602198] workingset: timestamp_bits=62 max_order=18 bucket_order=0
>>>>> [    3.624182] Block layer SCSI generic (bsg) driver version 0.4 loaded
>>>>> (major 253)
>>>>> [    3.625988] io scheduler mq-deadline registered
>>>>> [    3.626725] io scheduler kyber registered
>>>>> [    3.629047] start plist test
>>>>> [    3.641420] end plist test
>>>>> [    3.717639] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
>>>>> [    3.752315] brd: module loaded
>>>>> [    3.790207] loop: module loaded
>>>>> [    3.793943] mousedev: PS/2 mouse device common for all mice
>>>>> [    3.810511] Warning: unable to open an initial console.
>>>>> [    3.811923] Freeing unused kernel memory: 88K
>>>>> [    3.812558] This architecture does not have kernel memory protection.
>>>>> [    3.814280] Run /init as init process
>>>>> [    3.814808]   with arguments:
>>>>> [    3.815227]     /init
>>>>> [    3.815539]   with environment:
>>>>> [    3.815924]     HOME=/
>>>>> [    3.816250]     TERM=linux
>>>>> [    4.398678] random: dd: uninitialized urandom read (512 bytes read)
>>>>>
>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Alex
>>>>>>
>>>>>>> I'll take a look at the code later today.
>>>>>>>
>>>>>>> Best regards,
>>>>>>>       Vitaly
>>>>>>>
>>>>>>>> Thanks,
>>>>>>>>
>>>>>>>> Alex
>>>>>>>>
>>>>>>>>>
>>>>>>>>>> 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 at lists.infradead.org
>>>>>>>>>>>> http://lists.infradead.org/mailman/listinfo/linux-riscv
>>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> _______________________________________________
>>>>>>>>>> linux-riscv mailing list
>>>>>>>>>> linux-riscv at lists.infradead.org
>>>>>>>>>> http://lists.infradead.org/mailman/listinfo/linux-riscv
>>>>>>>>>
>>>>>>>>> _______________________________________________
>>>>>>>>> linux-riscv mailing list
>>>>>>>>> linux-riscv at lists.infradead.org
>>>>>>>>> http://lists.infradead.org/mailman/listinfo/linux-riscv
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> linux-riscv mailing list
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>>>>>>> http://lists.infradead.org/mailman/listinfo/linux-riscv
>>>>>>>
>>>
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