Re: [PATCH v2 11/11] powerpc/8xx: Add support for TASK_SIZE greater than 0x80000000
From: Scott Wood <hidden>
Date: 2015-03-21 00:47:21
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On Tue, 2015-01-20 at 10:57 +0100, Christophe Leroy wrote:
quoted hunk ↗ jump to hunk
By default, TASK_SIZE is set to 0x80000000 for PPC_8xx, which is most likely sufficient for most cases. However, kernel configuration allows to set TASK_SIZE to another value, so the 8xx shall handle it. Signed-off-by: Christophe Leroy <redacted> --- v2: no change arch/powerpc/kernel/head_8xx.S | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-)diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index ead6448..92a6456 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S@@ -48,6 +48,19 @@ mtspr spr, reg #endif +/* Macro to test if an address is a kernel address */ +#if CONFIG_TASK_SIZE <= 0x80000000 +#define IS_KERNEL(tmp, addr) \ + andis. tmp, addr, 0x8000 /* Address >= 0x80000000 */ +#define BRANCH_UNLESS_KERNEL(label) beq label +#else
This works if CONFIG_TASK_SIZE == 0x80000000, but what if it's less, and you have a kernel address < 0x80000000? -Scott