ppc/xive2: Fix calculation of END queue sizes

The queue size of an Event Notification Descriptor (END)
is determined by the 'cl' and QsZ fields of the END.
If the cl field is 1, then the queue size (in bytes) will
be the size of a cache line 128B * 2^QsZ and QsZ is limited
to 4.  Otherwise, it will be 4096B * 2^QsZ with QsZ limited
to 12.

Fixes: f8a233dedf2 ("ppc/xive2: Introduce a XIVE2 core framework")
Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Michael Kowal <kowal@linux.ibm.com>
Reviewed-by: Caleb Schlossin <calebs@linux.ibm.com>
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Link: https://lore.kernel.org/qemu-devel/20250512031100.439842-4-npiggin@gmail.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

diff --git a/hw/intc/xive2.c b/hw/intc/xive2.c
index a08cf906d0e65353a066554d7858d6b1919927af..cb75ca8798534f4f0760984532e35f9d722c5927 100644 (file)
--- a/hw/intc/xive2.c
+++ b/hw/intc/xive2.c
@@ -188,12 +188,27 @@ void xive2_eas_pic_print_info(Xive2Eas *eas, uint32_t lisn, GString *buf)
                            (uint32_t) xive_get_field64(EAS2_END_DATA, eas->w));
 }
 
+#define XIVE2_QSIZE_CHUNK_CL    128
+#define XIVE2_QSIZE_CHUNK_4k   4096
+/* Calculate max number of queue entries for an END */
+static uint32_t xive2_end_get_qentries(Xive2End *end)
+{
+    uint32_t w3 = end->w3;
+    uint32_t qsize = xive_get_field32(END2_W3_QSIZE, w3);
+    if (xive_get_field32(END2_W3_CL, w3)) {
+        g_assert(qsize <= 4);
+        return (XIVE2_QSIZE_CHUNK_CL << qsize) / sizeof(uint32_t);
+    } else {
+        g_assert(qsize <= 12);
+        return (XIVE2_QSIZE_CHUNK_4k << qsize) / sizeof(uint32_t);
+    }
+}
+
 void xive2_end_queue_pic_print_info(Xive2End *end, uint32_t width, GString *buf)
 {
     uint64_t qaddr_base = xive2_end_qaddr(end);
-    uint32_t qsize = xive_get_field32(END2_W3_QSIZE, end->w3);
     uint32_t qindex = xive_get_field32(END2_W1_PAGE_OFF, end->w1);
-    uint32_t qentries = 1 << (qsize + 10);
+    uint32_t qentries = xive2_end_get_qentries(end);
     int i;
 
     /*
@@ -223,8 +238,7 @@ void xive2_end_pic_print_info(Xive2End *end, uint32_t end_idx, GString *buf)
     uint64_t qaddr_base = xive2_end_qaddr(end);
     uint32_t qindex = xive_get_field32(END2_W1_PAGE_OFF, end->w1);
     uint32_t qgen = xive_get_field32(END2_W1_GENERATION, end->w1);
-    uint32_t qsize = xive_get_field32(END2_W3_QSIZE, end->w3);
-    uint32_t qentries = 1 << (qsize + 10);
+    uint32_t qentries = xive2_end_get_qentries(end);
 
     uint32_t nvx_blk = xive_get_field32(END2_W6_VP_BLOCK, end->w6);
     uint32_t nvx_idx = xive_get_field32(END2_W6_VP_OFFSET, end->w6);
@@ -341,13 +355,12 @@ void xive2_nvgc_pic_print_info(Xive2Nvgc *nvgc, uint32_t nvgc_idx, GString *buf)
 static void xive2_end_enqueue(Xive2End *end, uint32_t data)
 {
     uint64_t qaddr_base = xive2_end_qaddr(end);
-    uint32_t qsize = xive_get_field32(END2_W3_QSIZE, end->w3);
     uint32_t qindex = xive_get_field32(END2_W1_PAGE_OFF, end->w1);
     uint32_t qgen = xive_get_field32(END2_W1_GENERATION, end->w1);
 
     uint64_t qaddr = qaddr_base + (qindex << 2);
     uint32_t qdata = cpu_to_be32((qgen << 31) | (data & 0x7fffffff));
-    uint32_t qentries = 1 << (qsize + 10);
+    uint32_t qentries = xive2_end_get_qentries(end);
 
     if (dma_memory_write(&address_space_memory, qaddr, &qdata, sizeof(qdata),
                          MEMTXATTRS_UNSPECIFIED)) {

diff --git a/include/hw/ppc/xive2_regs.h b/include/hw/ppc/xive2_regs.h
index b11395c563504c384faaf071c4c5951a0427b005..3c28de8a304da60f5f93e35bc3cac29bfbba5914 100644 (file)
--- a/include/hw/ppc/xive2_regs.h
+++ b/include/hw/ppc/xive2_regs.h
@@ -87,6 +87,7 @@ typedef struct Xive2End {
 #define END2_W2_EQ_ADDR_HI         PPC_BITMASK32(8, 31)
         uint32_t       w3;
 #define END2_W3_EQ_ADDR_LO         PPC_BITMASK32(0, 24)
+#define END2_W3_CL                 PPC_BIT32(27)
 #define END2_W3_QSIZE              PPC_BITMASK32(28, 31)
         uint32_t       w4;
 #define END2_W4_END_BLOCK          PPC_BITMASK32(4, 7)