[PATCH v2 4/5] pnv/xive2: Introduce macros to manipulate TIMA addresses

[Frederic Barrat <fbarrat@linux.ibm.com>]

TIMA addresses are somewhat special and are split in several bit
fields with different meanings. This patch describes it and introduce
macros to more easily access the various fields.

Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
---
 hw/intc/xive.c             | 14 +++++++-------
 include/hw/ppc/xive_regs.h | 16 ++++++++++++++++
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/hw/intc/xive.c b/hw/intc/xive.c
index a986b96843..ebe399bc09 100644
--- a/hw/intc/xive.c
+++ b/hw/intc/xive.c
@@ -249,7 +249,7 @@ static const uint8_t *xive_tm_views[] = {
 static uint64_t xive_tm_mask(hwaddr offset, unsigned size, bool write)
 {
     uint8_t page_offset = (offset >> TM_SHIFT) & 0x3;
-    uint8_t reg_offset = offset & 0x3F;
+    uint8_t reg_offset = offset & TM_REG_OFFSET;
     uint8_t reg_mask = write ? 0x1 : 0x2;
     uint64_t mask = 0x0;
     int i;
@@ -266,8 +266,8 @@ static uint64_t xive_tm_mask(hwaddr offset, unsigned size, bool write)
 static void xive_tm_raw_write(XiveTCTX *tctx, hwaddr offset, uint64_t value,
                               unsigned size)
 {
-    uint8_t ring_offset = offset & 0x30;
-    uint8_t reg_offset = offset & 0x3F;
+    uint8_t ring_offset = offset & TM_RING_OFFSET;
+    uint8_t reg_offset = offset & TM_REG_OFFSET;
     uint64_t mask = xive_tm_mask(offset, size, true);
     int i;
 
@@ -296,8 +296,8 @@ static void xive_tm_raw_write(XiveTCTX *tctx, hwaddr offset, uint64_t value,
 
 static uint64_t xive_tm_raw_read(XiveTCTX *tctx, hwaddr offset, unsigned size)
 {
-    uint8_t ring_offset = offset & 0x30;
-    uint8_t reg_offset = offset & 0x3F;
+    uint8_t ring_offset = offset & TM_RING_OFFSET;
+    uint8_t reg_offset = offset & TM_REG_OFFSET;
     uint64_t mask = xive_tm_mask(offset, size, false);
     uint64_t ret;
     int i;
@@ -534,7 +534,7 @@ void xive_tctx_tm_write(XivePresenter *xptr, XiveTCTX *tctx, hwaddr offset,
     /*
      * First, check for special operations in the 2K region
      */
-    if (offset & 0x800) {
+    if (offset & TM_SPECIAL_OP) {
         xto = xive_tm_find_op(offset, size, true);
         if (!xto) {
             qemu_log_mask(LOG_GUEST_ERROR, "XIVE: invalid write access at TIMA "
@@ -573,7 +573,7 @@ uint64_t xive_tctx_tm_read(XivePresenter *xptr, XiveTCTX *tctx, hwaddr offset,
     /*
      * First, check for special operations in the 2K region
      */
-    if (offset & 0x800) {
+    if (offset & TM_SPECIAL_OP) {
         xto = xive_tm_find_op(offset, size, false);
         if (!xto) {
             qemu_log_mask(LOG_GUEST_ERROR, "XIVE: invalid read access to TIMA"
diff --git a/include/hw/ppc/xive_regs.h b/include/hw/ppc/xive_regs.h
index b7fde2354e..4a3c9badd3 100644
--- a/include/hw/ppc/xive_regs.h
+++ b/include/hw/ppc/xive_regs.h
@@ -48,6 +48,22 @@
 
 #define TM_SHIFT                16
 
+/*
+ * TIMA addresses are 12-bits (4k page).
+ * The MSB indicates a special op with side effect, which can be
+ * refined with bit 10 (see below).
+ * The registers, logically grouped in 4 rings (a quad-word each), are
+ * defined on the 6 LSBs (offset below 0x40)
+ * In between, we can add a cache line index from 0...3 (ie, 0, 0x80,
+ * 0x100, 0x180) to select a specific snooper. Those 'snoop port
+ * address' bits should be dropped when processing the operations as
+ * they are all equivalent.
+ */
+#define TM_ADDRESS_MASK         0xC3F
+#define TM_SPECIAL_OP           0x800
+#define TM_RING_OFFSET          0x30
+#define TM_REG_OFFSET           0x3F
+
 /* TM register offsets */
 #define TM_QW0_USER             0x000 /* All rings */
 #define TM_QW1_OS               0x010 /* Ring 0..2 */
-- 
2.40.1