[Skiboot] [PATCH 1/2] Revert "libpore: Fix incorrect mtspr instruction generation"

[Stewart Smith]

This reverts commit 65f9abea8e8cfd7f711a5c54217b5505826ff497.

Cc: stable
Fixes: 65f9abea8e8cfd7f711a5c54217b5505826ff497.
Signed-off-by: Stewart Smith <stewart at linux.vnet.ibm.com>
---
 libpore/p9_stop_api.C | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/libpore/p9_stop_api.C b/libpore/p9_stop_api.C
index cbbdfdd5de57..7242c423c652 100644
--- a/libpore/p9_stop_api.C
+++ b/libpore/p9_stop_api.C
@@ -255,10 +255,12 @@ static uint32_t getOrisInstruction( const uint16_t i_Rs, const uint16_t i_Ra,
  */
 static uint32_t getMtsprInstruction( const uint16_t i_Rs, const uint16_t i_Spr )
 {
-    uint32_t mtsprInstOpcode = MTSPR_BASE_OPCODE;
-    uint32_t temp = ((i_Spr & 0x1F) << 5) | ((i_Spr & 0x8F) >> 5);
-
-    mtsprInstOpcode |= ((i_Rs & 0x1F) << 21) | ((temp & 0x03FF) << 11);
+    uint32_t mtsprInstOpcode = 0;
+    uint32_t temp = (( i_Spr & 0x03FF ) << 11);
+    mtsprInstOpcode = (uint8_t)i_Rs << 21;
+    mtsprInstOpcode = ( temp  & 0x0000F800 ) << 5;
+    mtsprInstOpcode |= ( temp & 0x001F0000 ) >> 5;
+    mtsprInstOpcode |= MTSPR_BASE_OPCODE;
 
     return SWIZZLE_4_BYTE(mtsprInstOpcode);
 }
-- 
2.14.3