linux/arch/x86/include/asm/realmode.h
Thomas Gleixner f6f1ae9128 x86/smpboot: Implement a bit spinlock to protect the realmode stack
Parallel AP bringup requires that the APs can run fully parallel through
the early startup code including the real mode trampoline.

To prepare for this implement a bit-spinlock to serialize access to the
real mode stack so that parallel upcoming APs are not going to corrupt each
others stack while going through the real mode startup code.

Co-developed-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck
Link: https://lore.kernel.org/r/20230512205257.355425551@linutronix.de
2023-05-15 13:45:03 +02:00

101 lines
2.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ARCH_X86_REALMODE_H
#define _ARCH_X86_REALMODE_H
/*
* Flag bit definitions for use with the flags field of the trampoline header
* in the CONFIG_X86_64 variant.
*/
#define TH_FLAGS_SME_ACTIVE_BIT 0
#define TH_FLAGS_SME_ACTIVE BIT(TH_FLAGS_SME_ACTIVE_BIT)
#ifndef __ASSEMBLY__
#include <linux/types.h>
#include <asm/io.h>
/* This must match data at realmode/rm/header.S */
struct real_mode_header {
u32 text_start;
u32 ro_end;
/* SMP trampoline */
u32 trampoline_start;
u32 trampoline_header;
#ifdef CONFIG_AMD_MEM_ENCRYPT
u32 sev_es_trampoline_start;
#endif
#ifdef CONFIG_X86_64
u32 trampoline_start64;
u32 trampoline_pgd;
#endif
/* ACPI S3 wakeup */
#ifdef CONFIG_ACPI_SLEEP
u32 wakeup_start;
u32 wakeup_header;
#endif
/* APM/BIOS reboot */
u32 machine_real_restart_asm;
#ifdef CONFIG_X86_64
u32 machine_real_restart_seg;
#endif
};
/* This must match data at realmode/rm/trampoline_{32,64}.S */
struct trampoline_header {
#ifdef CONFIG_X86_32
u32 start;
u16 gdt_pad;
u16 gdt_limit;
u32 gdt_base;
#else
u64 start;
u64 efer;
u32 cr4;
u32 flags;
u32 lock;
#endif
};
extern struct real_mode_header *real_mode_header;
extern unsigned char real_mode_blob_end[];
extern unsigned long initial_code;
extern unsigned long initial_stack;
#ifdef CONFIG_AMD_MEM_ENCRYPT
extern unsigned long initial_vc_handler;
#endif
extern u32 *trampoline_lock;
extern unsigned char real_mode_blob[];
extern unsigned char real_mode_relocs[];
#ifdef CONFIG_X86_32
extern unsigned char startup_32_smp[];
extern unsigned char boot_gdt[];
#else
extern unsigned char secondary_startup_64[];
extern unsigned char secondary_startup_64_no_verify[];
#endif
static inline size_t real_mode_size_needed(void)
{
if (real_mode_header)
return 0; /* already allocated. */
return ALIGN(real_mode_blob_end - real_mode_blob, PAGE_SIZE);
}
static inline void set_real_mode_mem(phys_addr_t mem)
{
real_mode_header = (struct real_mode_header *) __va(mem);
}
void reserve_real_mode(void);
void load_trampoline_pgtable(void);
void init_real_mode(void);
#endif /* __ASSEMBLY__ */
#endif /* _ARCH_X86_REALMODE_H */