Unverified Commit c09dc9e1 authored by Alexandre Ghiti's avatar Alexandre Ghiti Committed by Palmer Dabbelt
Browse files

riscv: Fix memory_limit for 64-bit kernel 



As described in Documentation/riscv/vm-layout.rst, the end of the
virtual address space for 64-bit kernel is occupied by the modules/BPF/
kernel mappings so this actually reduces the amount of memory we are able
to map and then use in the linear mapping. So make sure this limit is
correctly set.

Signed-off-by: default avatarAlexandre Ghiti <alex@ghiti.fr>
Fixes: 2bfc6cd8 ("riscv: Move kernel mapping outside of linear mapping")
Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent c79e89ec

arch/riscv/mm/init.c

+9 −2
Original line number Diff line number Diff line
@@ -127,10 +127,17 @@ void __init mem_init(void) 
}



/*

 * The default maximal physical memory size is -PAGE_OFFSET,

 * limit the memory size via mem.

 * The default maximal physical memory size is -PAGE_OFFSET for 32-bit kernel,

 * whereas for 64-bit kernel, the end of the virtual address space is occupied

 * by the modules/BPF/kernel mappings which reduces the available size of the

 * linear mapping.

 * Limit the memory size via mem.

 */

#ifdef CONFIG_64BIT

static phys_addr_t memory_limit = -PAGE_OFFSET - SZ_4G;

#else

static phys_addr_t memory_limit = -PAGE_OFFSET;

#endif



static int __init early_mem(char *p)

{