[Stable-7.2.15 27/33] hw/intc/riscv_aplic: Fix in_clrip[x] read emulation

[Michael Tokarev]

From: Anup Patel <apatel@ventanamicro.com>

The reads to in_clrip[x] registers return rectified input values of the
interrupt sources.

A rectified input value of an interrupt source is defined by the section
"4.5.2 Source configurations (sourcecfg[1]–sourcecfg[1023])" of the RISC-V
AIA specification as:
"rectified input value = (incoming wire value) XOR (source is inverted)"

Update the riscv_aplic_read_input_word() implementation to match the above.

Fixes: e8f79343cfc8 ("hw/intc: Add RISC-V AIA APLIC device emulation")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20240306095722.463296-3-apatel@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
(cherry picked from commit 0678e9f29c2301d0a1afc8d01a78cdfa7ad2ddbd)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/hw/intc/riscv_aplic.c b/hw/intc/riscv_aplic.c
index 961caff7b6..c95f822525 100644
--- a/hw/intc/riscv_aplic.c
+++ b/hw/intc/riscv_aplic.c
@@ -151,7 +151,7 @@
 static uint32_t riscv_aplic_read_input_word(RISCVAPLICState *aplic,
                                             uint32_t word)
 {
-    uint32_t i, irq, ret = 0;
+    uint32_t i, irq, sourcecfg, sm, raw_input, irq_inverted, ret = 0;
 
     for (i = 0; i < 32; i++) {
         irq = word * 32 + i;
@@ -159,7 +159,20 @@ static uint32_t 
riscv_aplic_read_input_word(RISCVAPLICState *aplic,
             continue;
         }
 
-        ret |= ((aplic->state[irq] & APLIC_ISTATE_INPUT) ? 1 : 0) << i;
+        sourcecfg = aplic->sourcecfg[irq];
+        if (sourcecfg & APLIC_SOURCECFG_D) {
+            continue;
+        }
+
+        sm = sourcecfg & APLIC_SOURCECFG_SM_MASK;
+        if (sm == APLIC_SOURCECFG_SM_INACTIVE) {
+            continue;
+        }
+
+        raw_input = (aplic->state[irq] & APLIC_ISTATE_INPUT) ? 1 : 0;
+        irq_inverted = (sm == APLIC_SOURCECFG_SM_LEVEL_LOW ||
+                        sm == APLIC_SOURCECFG_SM_EDGE_FALL) ? 1 : 0;
+        ret |= (raw_input ^ irq_inverted) << i;
     }
 
     return ret;
-- 
2.39.5