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  • James Morse's avatar
    arm64: kernel: Add support for hibernate/suspend-to-disk · 82869ac5
    James Morse authored
    
    
    Add support for hibernate/suspend-to-disk.
    
    Suspend borrows code from cpu_suspend() to write cpu state onto the stack,
    before calling swsusp_save() to save the memory image.
    
    Restore creates a set of temporary page tables, covering only the
    linear map, copies the restore code to a 'safe' page, then uses the copy to
    restore the memory image. The copied code executes in the lower half of the
    address space, and once complete, restores the original kernel's page
    tables. It then calls into cpu_resume(), and follows the normal
    cpu_suspend() path back into the suspend code.
    
    To restore a kernel using KASLR, the address of the page tables, and
    cpu_resume() are stored in the hibernate arch-header and the el2
    vectors are pivotted via the 'safe' page in low memory.
    
    Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
    Tested-by: Kevin Hilman <khilman@baylibre.com> # Tested on Juno R2
    Signed-off-by: default avatarJames Morse <james.morse@arm.com>
    Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
    82869ac5