[PATCH 5/8] target/hppa: Preload I/O-space BTLB entries for LASI and the central bus

[Helge Deller <deller@kernel.org>]

From: Keith Monahan <keith@techtravels.org>

Set up the BTLB to allow operating systems to access LASI and central
bus addresses.

Signed-off-by: Keith Monahan <keith@techtravels.org>
Signed-off-by: Helge Deller <deller@gmx.de>
---
 hw/hppa/machine.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/hw/hppa/machine.c b/hw/hppa/machine.c
index 8d378385b2..e403ae5fc9 100644
--- a/hw/hppa/machine.c
+++ b/hw/hppa/machine.c
@@ -896,6 +896,38 @@ static void hppa_machine_reset(MachineState *ms, ResetType type)
         cpu[i]->env.gr[5] = CPU_HPA + i * 0x1000;
     }
 
+    /*
+     * BTLB equivalence maps for the I/O ranges HP-UX 9 uses
+     * without creating page directory entries: the LASI block and the
+     * central bus (CPU HPA, broadcast).  Must not cover other I/O space, as
+     * HP-UX probes with LPA and skips pdir setup for already mapped pages.
+     */
+    if (!hppa_is_pa20(&cpu[0]->env)) {
+        static const struct { uint32_t start, last; } io_btlb[] = {
+            { 0xf0100000, 0xf01fffff },     /* LASI */
+            { 0xfff80000, 0xffffffff },     /* central bus */
+        };
+        CPUHPPAState *env = &cpu[0]->env;
+
+        for (i = 0; i < ARRAY_SIZE(io_btlb); i++) {
+            HPPATLBEntry *ent = &env->tlb[HPPA_BTLB_ENTRIES(env) - 1 - i];
+
+            ent->itree.start = io_btlb[i].start;
+            ent->itree.last = io_btlb[i].last;
+            ent->pa = io_btlb[i].start;
+            ent->access_id = 0;
+            ent->u = 1;
+            ent->ar_pl2 = 0;
+            ent->ar_pl1 = 0;
+            ent->ar_type = 1;
+            ent->b = 0;
+            ent->d = 1;
+            ent->t = 0;
+            ent->entry_valid = 1;
+            interval_tree_insert(&ent->itree, &env->tlb_root);
+        }
+    }
+
     cpu[0]->env.gr[26] = ms->ram_size;
     cpu[0]->env.gr[25] = cpu[0]->env.kernel_entry;
     cpu[0]->env.gr[24] = cpu[0]->env.cmdline_or_bootorder;
-- 
2.54.0