Le 21/03/2015 01:47, Scott Wood a écrit :
On Tue, 2015-01-20 at 10:57 +0100, Christophe Leroy wrote:
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 <christophe.le...@c-s.fr>
---
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?
You are right, I didn't realise that PAGE_OFFSET was also configurable
and could be different from 0xC0000000.
andis. (which is what is always used in the current kernel) can be used
if CONFIG_TASK_SIZE <= 0x80000000 AND PAGE_OFFSET >= 0x80000000.
I will resubmit the patch accordingly.
Christophe
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