Messages in this thread Patch in this message |  | | From | Yinghai Lu <> | Subject | [PATCH v6 12/27] x86: use io_remap to access real_mode_data | Date | Thu, 13 Dec 2012 14:02:06 -0800 |
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When 64bit bootloader put real mode data above 4g, We can not access real mode data directly yet.
because in arch/x86/kernel/head_64.S, only set ident mapping for 0-1g, and kernel code/data/bss.
Move early_ioremap_init() calling as early as possible to x86_64_start_kernel.
Signed-off-by: Yinghai Lu <yinghai@kernel.org> --- arch/x86/kernel/head64.c | 26 +++++++++++++++++++++++--- arch/x86/kernel/setup.c | 2 ++ 2 files changed, 25 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 0e83fc9..16eb325 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -62,12 +62,21 @@ static void __init copy_bootdata(char *real_mode_data) { char * command_line; unsigned long cmd_line_ptr; + char *p; - memcpy(&boot_params, real_mode_data, sizeof boot_params); + /* + * for 64bit bootloader path, those data could be above 4G, + * and we do not set ident mapping for them in head_64.S. + * So need to use ioremap to access them. + */ + p = early_memremap((unsigned long)real_mode_data, sizeof(boot_params)); + memcpy(&boot_params, p, sizeof(boot_params)); + early_iounmap(p, sizeof(boot_params)); cmd_line_ptr = get_cmd_line_ptr(); if (cmd_line_ptr) { - command_line = __va(cmd_line_ptr); + command_line = early_memremap(cmd_line_ptr, COMMAND_LINE_SIZE); memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE); + early_iounmap(command_line, COMMAND_LINE_SIZE); } } @@ -92,6 +101,10 @@ void __init x86_64_start_kernel(char * real_mode_data) /* clear bss before set_intr_gate with early_idt_handler */ clear_bss(); + /* boot_params is in bss */ + early_ioremap_init(); + copy_bootdata(real_mode_data); + /* Make NULL pointers segfault */ zap_identity_mappings(); @@ -114,7 +127,14 @@ void __init x86_64_start_kernel(char * real_mode_data) void __init x86_64_start_reservations(char *real_mode_data) { - copy_bootdata(__va(real_mode_data)); + /* + * hdr.version is always not 0, so check it to see + * if boot_params is copied or not. + */ + if (!boot_params.hdr.version) { + early_ioremap_init(); + copy_bootdata(real_mode_data); + } memblock_reserve(__pa_symbol(&_text), __pa_symbol(&__bss_stop) - __pa_symbol(&_text)); diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 9546c90..e636c83 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -714,7 +714,9 @@ void __init setup_arch(char **cmdline_p) early_trap_init(); early_cpu_init(); +#ifdef CONFIG_X86_32 early_ioremap_init(); +#endif setup_olpc_ofw_pgd(); -- 1.7.10.4
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