[XTENSA] Add support for cache-aliasing

Add support for processors that have cache-aliasing issues, such as
the Stretch S5000 processor. Cache-aliasing means that the size of
the cache (for one way) is larger than the page size, thus, a page
can end up in several places in cache depending on the virtual to
physical translation. The method used here is to map a user page
temporarily through the auto-refill way 0 and of of the DTLB.
We probably will want to revisit this issue and use a better
approach with kmap/kunmap.

Signed-off-by: Chris Zankel <chris@zankel.net>

1 files changed, 6 insertions, 7 deletions

diff --git a/arch/xtensa/kernel/asm-offsets.c b/arch/xtensa/kernel/asm-offsets.c
index d0323cd6a2ea..d5ffe7b6443e 100644
--- a/arch/xtensa/kernel/asm-offsets.c
+++ b/arch/xtensa/kernel/asm-offsets.c
@@ -18,12 +18,13 @@
 #include <linux/stddef.h>
 #include <linux/thread_info.h>
 #include <linux/ptrace.h>
+#include <linux/mm.h>
+
 #include <asm/ptrace.h>
 #include <asm/processor.h>
 #include <asm/uaccess.h>
 
 #define DEFINE(sym, val) asm volatile("\n->" #sym " %0 " #val : : "i" (val))
-#define BLANK() asm volatile("\n->" : : )
 
 int main(void)
 {
@@ -63,7 +64,6 @@ int main(void)
         DEFINE(PT_SIZE, sizeof(struct pt_regs));
         DEFINE(PT_AREG_END, offsetof (struct pt_regs, areg[XCHAL_NUM_AREGS]));
         DEFINE(PT_USER_SIZE, offsetof(struct pt_regs, areg[XCHAL_NUM_AREGS]));
-        BLANK();
 
         /* struct task_struct */
         DEFINE(TASK_PTRACE, offsetof (struct task_struct, ptrace));
@@ -73,27 +73,26 @@ int main(void)
         DEFINE(TASK_THREAD, offsetof (struct task_struct, thread));
         DEFINE(TASK_THREAD_INFO, offsetof (struct task_struct, stack));
         DEFINE(TASK_STRUCT_SIZE, sizeof (struct task_struct));
-        BLANK();
 
         /* struct thread_info (offset from start_struct) */
         DEFINE(THREAD_RA, offsetof (struct task_struct, thread.ra));
         DEFINE(THREAD_SP, offsetof (struct task_struct, thread.sp));
         DEFINE(THREAD_CP_SAVE, offsetof (struct task_struct, thread.cp_save));
         DEFINE(THREAD_CURRENT_DS, offsetof (struct task_struct, thread.current_ds));
-        BLANK();
 
         /* struct mm_struct */
         DEFINE(MM_USERS, offsetof(struct mm_struct, mm_users));
         DEFINE(MM_PGD, offsetof (struct mm_struct, pgd));
         DEFINE(MM_CONTEXT, offsetof (struct mm_struct, context));
-        BLANK();
-        DEFINE(PT_SINGLESTEP_BIT, PT_SINGLESTEP_BIT);
+
+        /* struct page */
+        DEFINE(PAGE_FLAGS, offsetof(struct page, flags));
 
         /* constants */
         DEFINE(_CLONE_VM, CLONE_VM);
         DEFINE(_CLONE_UNTRACED, CLONE_UNTRACED);
+        DEFINE(PG_ARCH_1, PG_arch_1);
 
         return 0;
 }
 
-