[SPARC64]: Eliminate NR_CPUS limitations.

Cheetah systems can have cpuids as large as 1023, although physical
systems don't have that many cpus.

Only three limitations existed in the kernel preventing arbitrary
NR_CPUS values:

1) dcache dirty cpu state stored in page->flags on
   D-cache aliasing platforms.  With some build time
   calculations and some build-time BUG checks on
   page->flags layout, this one was easily solved.

2) The cheetah XCALL delivery code could only handle
   a cpumask with up to 32 cpus set.  Some simple looping
   logic clears that up too.

3) thread_info->cpu was a u8, easily changed to a u16.

There are a few spots in the kernel that still put NR_CPUS
sized arrays on the kernel stack, but that's not a sparc64
specific problem.

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 5 insertions, 5 deletions

diff --git a/include/asm-sparc64/cpudata.h b/include/asm-sparc64/cpudata.h
index f321b1d21227..03c385de7619 100644
--- a/include/asm-sparc64/cpudata.h
+++ b/include/asm-sparc64/cpudata.h
@@ -202,7 +202,7 @@ extern struct sun4v_2insn_patch_entry __sun4v_2insn_patch,
  * the calculations done by the macro mid-stream.
  */
 #define LOAD_PER_CPU_BASE(DEST, THR, REG1, REG2, REG3)  \
-        ldub    [THR + TI_CPU], REG1;                   \
+        lduh    [THR + TI_CPU], REG1;                   \
         sethi   %hi(__per_cpu_shift), REG3;             \
         sethi   %hi(__per_cpu_base), REG2;              \
         ldx     [REG3 + %lo(__per_cpu_shift)], REG3;    \
diff --git a/include/asm-sparc64/thread_info.h b/include/asm-sparc64/thread_info.h
index 2ebf7f27bf91..98252cd44dd6 100644
--- a/include/asm-sparc64/thread_info.h
+++ b/include/asm-sparc64/thread_info.h
@@ -38,8 +38,8 @@ struct thread_info {
         /* D$ line 1 */
         struct task_struct      *task;
         unsigned long           flags;
-        __u8                    cpu;
         __u8                    fpsaved[7];
+        __u8                    pad;
         unsigned long           ksp;
 
         /* D$ line 2 */
@@ -49,7 +49,7 @@ struct thread_info {
         int                     preempt_count;  /* 0 => preemptable, <0 => BUG */
         __u8                    new_child;
         __u8                    syscall_noerror;
-        __u16                   __pad;
+        __u16                   cpu;
 
         unsigned long           *utraps;
 
@@ -83,8 +83,7 @@ struct thread_info {
 #define TI_CURRENT_DS   (TI_FLAGS + TI_FLAG_BYTE_CURRENT_DS)
 #define TI_FPDEPTH      (TI_FLAGS + TI_FLAG_BYTE_FPDEPTH)
 #define TI_WSAVED       (TI_FLAGS + TI_FLAG_BYTE_WSAVED)
-#define TI_CPU          0x00000010
-#define TI_FPSAVED      0x00000011
+#define TI_FPSAVED      0x00000010
 #define TI_KSP          0x00000018
 #define TI_FAULT_ADDR   0x00000020
 #define TI_KREGS        0x00000028
@@ -92,6 +91,7 @@ struct thread_info {
 #define TI_PRE_COUNT    0x00000038
 #define TI_NEW_CHILD    0x0000003c
 #define TI_SYS_NOERROR  0x0000003d
+#define TI_CPU          0x0000003e
 #define TI_UTRAPS       0x00000040
 #define TI_REG_WINDOW   0x00000048
 #define TI_RWIN_SPTRS   0x000003c8