pnv/xive2: Introduce macros to manipulate TIMA addresses

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>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20230601121331.487207-5-fbarrat@linux.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

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"

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 */