From 009ed162155295311c2d53c32e9c23d02f073996 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Mon, 31 Jan 2011 13:50:46 +0000 Subject: [PATCH] ARM: LPAE: add support for ATAG_MEM64 LPAE provides support for memory banks with physical addresses of up to 40 bits. This patch adds a new atag, ATAG_MEM64, so that the Kernel can be informed about memory that exists above the 4GB boundary. Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm/include/asm/setup.h | 8 ++++++++ arch/arm/kernel/setup.c | 23 +++++++++++++++++++++++ 2 files changed, 31 insertions(+) diff --git a/arch/arm/include/asm/setup.h b/arch/arm/include/asm/setup.h index 915696dd9c7c..3842ce732dae 100644 --- a/arch/arm/include/asm/setup.h +++ b/arch/arm/include/asm/setup.h @@ -43,6 +43,13 @@ struct tag_mem32 { __u32 start; /* physical start address */ }; +#define ATAG_MEM64 0x54420002 + +struct tag_mem64 { + __u32 size; + __u64 start; /* physical start address */ +}; + /* VGA text type displays */ #define ATAG_VIDEOTEXT 0x54410003 @@ -148,6 +155,7 @@ struct tag { union { struct tag_core core; struct tag_mem32 mem; + struct tag_mem64 mem64; struct tag_videotext videotext; struct tag_ramdisk ramdisk; struct tag_initrd initrd; diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 7e7977ab994f..223af7185676 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -638,6 +638,29 @@ static int __init parse_tag_mem32(const struct tag *tag) __tagtable(ATAG_MEM, parse_tag_mem32); +static int __init parse_tag_mem64(const struct tag *tag) +{ + /* We only use 32-bits for the size. */ + unsigned long size; + phys_addr_t start, end; + + start = tag->u.mem64.start; + size = tag->u.mem64.size; + end = start + size; + + /* Ensure that the memory region is in range. */ + if (end & ~PHYS_MASK) + pr_warning("Ignoring out-of-range mem64 tag (%.8llx-%.8llx)\n", + (unsigned long long)start, + (unsigned long long)end - 1); + else + arm_add_memory(start, size); + + return 0; +} + +__tagtable(ATAG_MEM64, parse_tag_mem64); + #if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE) struct screen_info screen_info = { .orig_video_lines = 30, -- 2.39.5