Hi Thomas,
On Fri, 15 Dec 2023 at 13:26, Thomas Zimmermann <tzimmermann@xxxxxxx> wrote:
>
> The type definition of struct pci_setup_rom in <asm/pci.h> requires
> struct setup_data from <asm/bootparam.h>. Many drivers include
> <linux/pci.h>, but do not use boot parameters. Changes to bootparam.h
> or its included header files could easily trigger a large, unnecessary
> rebuild of the kernel.
>
> Moving struct setup_data and related code into its own own header file
> avoids including <asm/bootparam.h> in <asm/pci.h>. Instead include the
> new header <asm/screen_data.h> and remove the include statement for
> x86_init.h, which is unnecessary but pulls in bootparams.h.
>
> Suggested-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> ---
> arch/x86/include/asm/pci.h | 2 +-
> arch/x86/include/uapi/asm/bootparam.h | 218 +----------------------
> arch/x86/include/uapi/asm/setup_data.h | 229 +++++++++++++++++++++++++
> 3 files changed, 231 insertions(+), 218 deletions(-)
> create mode 100644 arch/x86/include/uapi/asm/setup_data.h
>
This is an improvement but not quite what I had in mind: setup_data is
a x86 specific linked list that is only referred to via a u64 in
setup_header.
So setup_data and all the specializations belong in setup_data.h.
OTOH, setup_header, the XLF load flags, efi_info, the e820 related
definitions etc are not related to setup_data at all but to
setup_header. Whether or not setup_header could live in its own header
too (along with those related definitions) is a separate question imo,
but I don't think they belong in setup_data.h
> diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
> index b40c462b4af3..f6100df3652e 100644
> --- a/arch/x86/include/asm/pci.h
> +++ b/arch/x86/include/asm/pci.h
> @@ -10,7 +10,7 @@
> #include <linux/numa.h>
> #include <asm/io.h>
> #include <asm/memtype.h>
> -#include <asm/x86_init.h>
> +#include <asm/setup_data.h>
>
> struct pci_sysdata {
> int domain; /* PCI domain */
> diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
> index 01d19fc22346..f6361eb792fd 100644
> --- a/arch/x86/include/uapi/asm/bootparam.h
> +++ b/arch/x86/include/uapi/asm/bootparam.h
> @@ -2,42 +2,7 @@
> #ifndef _ASM_X86_BOOTPARAM_H
> #define _ASM_X86_BOOTPARAM_H
>
> -/* setup_data/setup_indirect types */
> -#define SETUP_NONE 0
> -#define SETUP_E820_EXT 1
> -#define SETUP_DTB 2
> -#define SETUP_PCI 3
> -#define SETUP_EFI 4
> -#define SETUP_APPLE_PROPERTIES 5
> -#define SETUP_JAILHOUSE 6
> -#define SETUP_CC_BLOB 7
> -#define SETUP_IMA 8
> -#define SETUP_RNG_SEED 9
> -#define SETUP_ENUM_MAX SETUP_RNG_SEED
> -
> -#define SETUP_INDIRECT (1<<31)
> -#define SETUP_TYPE_MAX (SETUP_ENUM_MAX | SETUP_INDIRECT)
> -
> -/* ram_size flags */
> -#define RAMDISK_IMAGE_START_MASK 0x07FF
> -#define RAMDISK_PROMPT_FLAG 0x8000
> -#define RAMDISK_LOAD_FLAG 0x4000
> -
> -/* loadflags */
> -#define LOADED_HIGH (1<<0)
> -#define KASLR_FLAG (1<<1)
> -#define QUIET_FLAG (1<<5)
> -#define KEEP_SEGMENTS (1<<6)
> -#define CAN_USE_HEAP (1<<7)
> -
> -/* xloadflags */
> -#define XLF_KERNEL_64 (1<<0)
> -#define XLF_CAN_BE_LOADED_ABOVE_4G (1<<1)
> -#define XLF_EFI_HANDOVER_32 (1<<2)
> -#define XLF_EFI_HANDOVER_64 (1<<3)
> -#define XLF_EFI_KEXEC (1<<4)
> -#define XLF_5LEVEL (1<<5)
> -#define XLF_5LEVEL_ENABLED (1<<6)
> +#include <asm/setup_data.h>
>
> #ifndef __ASSEMBLY__
>
> @@ -48,139 +13,6 @@
> #include <asm/ist.h>
> #include <video/edid.h>
>
> -/* extensible setup data list node */
> -struct setup_data {
> - __u64 next;
> - __u32 type;
> - __u32 len;
> - __u8 data[];
> -};
> -
> -/* extensible setup indirect data node */
> -struct setup_indirect {
> - __u32 type;
> - __u32 reserved; /* Reserved, must be set to zero. */
> - __u64 len;
> - __u64 addr;
> -};
> -
> -struct setup_header {
> - __u8 setup_sects;
> - __u16 root_flags;
> - __u32 syssize;
> - __u16 ram_size;
> - __u16 vid_mode;
> - __u16 root_dev;
> - __u16 boot_flag;
> - __u16 jump;
> - __u32 header;
> - __u16 version;
> - __u32 realmode_swtch;
> - __u16 start_sys_seg;
> - __u16 kernel_version;
> - __u8 type_of_loader;
> - __u8 loadflags;
> - __u16 setup_move_size;
> - __u32 code32_start;
> - __u32 ramdisk_image;
> - __u32 ramdisk_size;
> - __u32 bootsect_kludge;
> - __u16 heap_end_ptr;
> - __u8 ext_loader_ver;
> - __u8 ext_loader_type;
> - __u32 cmd_line_ptr;
> - __u32 initrd_addr_max;
> - __u32 kernel_alignment;
> - __u8 relocatable_kernel;
> - __u8 min_alignment;
> - __u16 xloadflags;
> - __u32 cmdline_size;
> - __u32 hardware_subarch;
> - __u64 hardware_subarch_data;
> - __u32 payload_offset;
> - __u32 payload_length;
> - __u64 setup_data;
> - __u64 pref_address;
> - __u32 init_size;
> - __u32 handover_offset;
> - __u32 kernel_info_offset;
> -} __attribute__((packed));
> -
> -struct sys_desc_table {
> - __u16 length;
> - __u8 table[14];
> -};
> -
> -/* Gleaned from OFW's set-parameters in cpu/x86/pc/linux.fth */
> -struct olpc_ofw_header {
> - __u32 ofw_magic; /* OFW signature */
> - __u32 ofw_version;
> - __u32 cif_handler; /* callback into OFW */
> - __u32 irq_desc_table;
> -} __attribute__((packed));
> -
> -struct efi_info {
> - __u32 efi_loader_signature;
> - __u32 efi_systab;
> - __u32 efi_memdesc_size;
> - __u32 efi_memdesc_version;
> - __u32 efi_memmap;
> - __u32 efi_memmap_size;
> - __u32 efi_systab_hi;
> - __u32 efi_memmap_hi;
> -};
> -
> -/*
> - * This is the maximum number of entries in struct boot_params::e820_table
> - * (the zeropage), which is part of the x86 boot protocol ABI:
> - */
> -#define E820_MAX_ENTRIES_ZEROPAGE 128
> -
> -/*
> - * The E820 memory region entry of the boot protocol ABI:
> - */
> -struct boot_e820_entry {
> - __u64 addr;
> - __u64 size;
> - __u32 type;
> -} __attribute__((packed));
> -
> -/*
> - * Smallest compatible version of jailhouse_setup_data required by this kernel.
> - */
> -#define JAILHOUSE_SETUP_REQUIRED_VERSION 1
> -
> -/*
> - * The boot loader is passing platform information via this Jailhouse-specific
> - * setup data structure.
> - */
> -struct jailhouse_setup_data {
> - struct {
> - __u16 version;
> - __u16 compatible_version;
> - } __attribute__((packed)) hdr;
> - struct {
> - __u16 pm_timer_address;
> - __u16 num_cpus;
> - __u64 pci_mmconfig_base;
> - __u32 tsc_khz;
> - __u32 apic_khz;
> - __u8 standard_ioapic;
> - __u8 cpu_ids[255];
> - } __attribute__((packed)) v1;
> - struct {
> - __u32 flags;
> - } __attribute__((packed)) v2;
> -} __attribute__((packed));
> -
> -/*
> - * IMA buffer setup data information from the previous kernel during kexec
> - */
> -struct ima_setup_data {
> - __u64 addr;
> - __u64 size;
> -} __attribute__((packed));
> -
> /* The so-called "zeropage" */
> struct boot_params {
> struct screen_info screen_info; /* 0x000 */
> @@ -231,54 +63,6 @@ struct boot_params {
> __u8 _pad9[276]; /* 0xeec */
> } __attribute__((packed));
>
> -/**
> - * enum x86_hardware_subarch - x86 hardware subarchitecture
> - *
> - * The x86 hardware_subarch and hardware_subarch_data were added as of the x86
> - * boot protocol 2.07 to help distinguish and support custom x86 boot
> - * sequences. This enum represents accepted values for the x86
> - * hardware_subarch. Custom x86 boot sequences (not X86_SUBARCH_PC) do not
> - * have or simply *cannot* make use of natural stubs like BIOS or EFI, the
> - * hardware_subarch can be used on the Linux entry path to revector to a
> - * subarchitecture stub when needed. This subarchitecture stub can be used to
> - * set up Linux boot parameters or for special care to account for nonstandard
> - * handling of page tables.
> - *
> - * These enums should only ever be used by x86 code, and the code that uses
> - * it should be well contained and compartmentalized.
> - *
> - * KVM and Xen HVM do not have a subarch as these are expected to follow
> - * standard x86 boot entries. If there is a genuine need for "hypervisor" type
> - * that should be considered separately in the future. Future guest types
> - * should seriously consider working with standard x86 boot stubs such as
> - * the BIOS or EFI boot stubs.
> - *
> - * WARNING: this enum is only used for legacy hacks, for platform features that
> - * are not easily enumerated or discoverable. You should not ever use
> - * this for new features.
> - *
> - * @X86_SUBARCH_PC: Should be used if the hardware is enumerable using standard
> - * PC mechanisms (PCI, ACPI) and doesn't need a special boot flow.
> - * @X86_SUBARCH_LGUEST: Used for x86 hypervisor demo, lguest, deprecated
> - * @X86_SUBARCH_XEN: Used for Xen guest types which follow the PV boot path,
> - * which start at asm startup_xen() entry point and later jump to the C
> - * xen_start_kernel() entry point. Both domU and dom0 type of guests are
> - * currently supported through this PV boot path.
> - * @X86_SUBARCH_INTEL_MID: Used for Intel MID (Mobile Internet Device) platform
> - * systems which do not have the PCI legacy interfaces.
> - * @X86_SUBARCH_CE4100: Used for Intel CE media processor (CE4100) SoC
> - * for settop boxes and media devices, the use of a subarch for CE4100
> - * is more of a hack...
> - */
> -enum x86_hardware_subarch {
> - X86_SUBARCH_PC = 0,
> - X86_SUBARCH_LGUEST,
> - X86_SUBARCH_XEN,
> - X86_SUBARCH_INTEL_MID,
> - X86_SUBARCH_CE4100,
> - X86_NR_SUBARCHS,
> -};
> -
> #endif /* __ASSEMBLY__ */
>
> #endif /* _ASM_X86_BOOTPARAM_H */
> diff --git a/arch/x86/include/uapi/asm/setup_data.h b/arch/x86/include/uapi/asm/setup_data.h
> new file mode 100644
> index 000000000000..e1396e1bf048
> --- /dev/null
> +++ b/arch/x86/include/uapi/asm/setup_data.h
> @@ -0,0 +1,229 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +#ifndef _UAPI_ASM_X86_SETUP_DATA_H
> +#define _UAPI_ASM_X86_SETUP_DATA_H
> +
> +/* setup_data/setup_indirect types */
> +#define SETUP_NONE 0
> +#define SETUP_E820_EXT 1
> +#define SETUP_DTB 2
> +#define SETUP_PCI 3
> +#define SETUP_EFI 4
> +#define SETUP_APPLE_PROPERTIES 5
> +#define SETUP_JAILHOUSE 6
> +#define SETUP_CC_BLOB 7
> +#define SETUP_IMA 8
> +#define SETUP_RNG_SEED 9
> +#define SETUP_ENUM_MAX SETUP_RNG_SEED
> +
> +#define SETUP_INDIRECT (1<<31)
> +#define SETUP_TYPE_MAX (SETUP_ENUM_MAX | SETUP_INDIRECT)
> +
> +/* ram_size flags */
> +#define RAMDISK_IMAGE_START_MASK 0x07FF
> +#define RAMDISK_PROMPT_FLAG 0x8000
> +#define RAMDISK_LOAD_FLAG 0x4000
> +
> +/* loadflags */
> +#define LOADED_HIGH (1<<0)
> +#define KASLR_FLAG (1<<1)
> +#define QUIET_FLAG (1<<5)
> +#define KEEP_SEGMENTS (1<<6)
> +#define CAN_USE_HEAP (1<<7)
> +
> +/* xloadflags */
> +#define XLF_KERNEL_64 (1<<0)
> +#define XLF_CAN_BE_LOADED_ABOVE_4G (1<<1)
> +#define XLF_EFI_HANDOVER_32 (1<<2)
> +#define XLF_EFI_HANDOVER_64 (1<<3)
> +#define XLF_EFI_KEXEC (1<<4)
> +#define XLF_5LEVEL (1<<5)
> +#define XLF_5LEVEL_ENABLED (1<<6)
> +
> +#ifndef __ASSEMBLY__
> +
> +#include <linux/types.h>
> +
> +/* extensible setup data list node */
> +struct setup_data {
> + __u64 next;
> + __u32 type;
> + __u32 len;
> + __u8 data[];
> +};
> +
> +/* extensible setup indirect data node */
> +struct setup_indirect {
> + __u32 type;
> + __u32 reserved; /* Reserved, must be set to zero. */
> + __u64 len;
> + __u64 addr;
> +};
> +
> +struct setup_header {
> + __u8 setup_sects;
> + __u16 root_flags;
> + __u32 syssize;
> + __u16 ram_size;
> + __u16 vid_mode;
> + __u16 root_dev;
> + __u16 boot_flag;
> + __u16 jump;
> + __u32 header;
> + __u16 version;
> + __u32 realmode_swtch;
> + __u16 start_sys_seg;
> + __u16 kernel_version;
> + __u8 type_of_loader;
> + __u8 loadflags;
> + __u16 setup_move_size;
> + __u32 code32_start;
> + __u32 ramdisk_image;
> + __u32 ramdisk_size;
> + __u32 bootsect_kludge;
> + __u16 heap_end_ptr;
> + __u8 ext_loader_ver;
> + __u8 ext_loader_type;
> + __u32 cmd_line_ptr;
> + __u32 initrd_addr_max;
> + __u32 kernel_alignment;
> + __u8 relocatable_kernel;
> + __u8 min_alignment;
> + __u16 xloadflags;
> + __u32 cmdline_size;
> + __u32 hardware_subarch;
> + __u64 hardware_subarch_data;
> + __u32 payload_offset;
> + __u32 payload_length;
> + __u64 setup_data;
> + __u64 pref_address;
> + __u32 init_size;
> + __u32 handover_offset;
> + __u32 kernel_info_offset;
> +} __attribute__((packed));
> +
> +struct sys_desc_table {
> + __u16 length;
> + __u8 table[14];
> +};
> +
> +/* Gleaned from OFW's set-parameters in cpu/x86/pc/linux.fth */
> +struct olpc_ofw_header {
> + __u32 ofw_magic; /* OFW signature */
> + __u32 ofw_version;
> + __u32 cif_handler; /* callback into OFW */
> + __u32 irq_desc_table;
> +} __attribute__((packed));
> +
> +struct efi_info {
> + __u32 efi_loader_signature;
> + __u32 efi_systab;
> + __u32 efi_memdesc_size;
> + __u32 efi_memdesc_version;
> + __u32 efi_memmap;
> + __u32 efi_memmap_size;
> + __u32 efi_systab_hi;
> + __u32 efi_memmap_hi;
> +};
> +
> +/*
> + * This is the maximum number of entries in struct boot_params::e820_table
> + * (the zeropage), which is part of the x86 boot protocol ABI:
> + */
> +#define E820_MAX_ENTRIES_ZEROPAGE 128
> +
> +/*
> + * The E820 memory region entry of the boot protocol ABI:
> + */
> +struct boot_e820_entry {
> + __u64 addr;
> + __u64 size;
> + __u32 type;
> +} __attribute__((packed));
> +
> +/*
> + * Smallest compatible version of jailhouse_setup_data required by this kernel.
> + */
> +#define JAILHOUSE_SETUP_REQUIRED_VERSION 1
> +
> +/*
> + * The boot loader is passing platform information via this Jailhouse-specific
> + * setup data structure.
> + */
> +struct jailhouse_setup_data {
> + struct {
> + __u16 version;
> + __u16 compatible_version;
> + } __attribute__((packed)) hdr;
> + struct {
> + __u16 pm_timer_address;
> + __u16 num_cpus;
> + __u64 pci_mmconfig_base;
> + __u32 tsc_khz;
> + __u32 apic_khz;
> + __u8 standard_ioapic;
> + __u8 cpu_ids[255];
> + } __attribute__((packed)) v1;
> + struct {
> + __u32 flags;
> + } __attribute__((packed)) v2;
> +} __attribute__((packed));
> +
> +/*
> + * IMA buffer setup data information from the previous kernel during kexec
> + */
> +struct ima_setup_data {
> + __u64 addr;
> + __u64 size;
> +} __attribute__((packed));
> +
> +/**
> + * enum x86_hardware_subarch - x86 hardware subarchitecture
> + *
> + * The x86 hardware_subarch and hardware_subarch_data were added as of the x86
> + * boot protocol 2.07 to help distinguish and support custom x86 boot
> + * sequences. This enum represents accepted values for the x86
> + * hardware_subarch. Custom x86 boot sequences (not X86_SUBARCH_PC) do not
> + * have or simply *cannot* make use of natural stubs like BIOS or EFI, the
> + * hardware_subarch can be used on the Linux entry path to revector to a
> + * subarchitecture stub when needed. This subarchitecture stub can be used to
> + * set up Linux boot parameters or for special care to account for nonstandard
> + * handling of page tables.
> + *
> + * These enums should only ever be used by x86 code, and the code that uses
> + * it should be well contained and compartmentalized.
> + *
> + * KVM and Xen HVM do not have a subarch as these are expected to follow
> + * standard x86 boot entries. If there is a genuine need for "hypervisor" type
> + * that should be considered separately in the future. Future guest types
> + * should seriously consider working with standard x86 boot stubs such as
> + * the BIOS or EFI boot stubs.
> + *
> + * WARNING: this enum is only used for legacy hacks, for platform features that
> + * are not easily enumerated or discoverable. You should not ever use
> + * this for new features.
> + *
> + * @X86_SUBARCH_PC: Should be used if the hardware is enumerable using standard
> + * PC mechanisms (PCI, ACPI) and doesn't need a special boot flow.
> + * @X86_SUBARCH_LGUEST: Used for x86 hypervisor demo, lguest, deprecated
> + * @X86_SUBARCH_XEN: Used for Xen guest types which follow the PV boot path,
> + * which start at asm startup_xen() entry point and later jump to the C
> + * xen_start_kernel() entry point. Both domU and dom0 type of guests are
> + * currently supported through this PV boot path.
> + * @X86_SUBARCH_INTEL_MID: Used for Intel MID (Mobile Internet Device) platform
> + * systems which do not have the PCI legacy interfaces.
> + * @X86_SUBARCH_CE4100: Used for Intel CE media processor (CE4100) SoC
> + * for settop boxes and media devices, the use of a subarch for CE4100
> + * is more of a hack...
> + */
> +enum x86_hardware_subarch {
> + X86_SUBARCH_PC = 0,
> + X86_SUBARCH_LGUEST,
> + X86_SUBARCH_XEN,
> + X86_SUBARCH_INTEL_MID,
> + X86_SUBARCH_CE4100,
> + X86_NR_SUBARCHS,
> +};
> +
> +#endif /* __ASSEMBLY__ */
> +
> +#endif /* _UAPI_ASM_X86_SETUP_DATA_H */
> --
> 2.43.0
>
>
