tunables_static: New module to set up static tunables

This is for things that xnu hard-codes. This first one for AGX is
required to make coprocessor TLB coherency work properly...

Signed-off-by: Asahi Lina <lina@asahilina.net>

Makefile

@@ -116,7 +116,7 @@ OBJECTS := \
 	start.o \
 	startup.o \
 	string.o \
-	tunables.o \
+	tunables.o tunables_static.o \
 	tps6598x.o \
 	uart.o \
 	uartproxy.o \

src/kboot.c

@@ -10,6 +10,7 @@
 #include "pcie.h"
 #include "sep.h"
 #include "smp.h"
+#include "tunables.h"
 #include "types.h"
 #include "usb.h"
 #include "utils.h"
@@ -1149,6 +1150,7 @@ int kboot_boot(void *kernel)
     usb_init();
     pcie_init();
     dapf_init_all();
+    tunables_apply_static();
 
     printf("Setting SMP mode to WFE...\n");
     smp_set_wfe_mode(true);

src/tunables.h

@@ -37,4 +37,6 @@ int tunables_apply_local(const char *path, const char *prop, u32 reg_idx);
  */
 int tunables_apply_local_addr(const char *path, const char *prop, uintptr_t base);
 
+int tunables_apply_static(void);
+
 #endif

src/tunables_static.c

@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: MIT */
+
+#include "tunables.h"
+#include "adt.h"
+#include "pmgr.h"
+#include "soc.h"
+#include "types.h"
+#include "utils.h"
+
+/*
+ * These magic tunable sequences are hardcoded in various places in XNU, and are required for
+ * proper operation of various fabric features and other miscellanea. Without them, things tend
+ * to subtly break...
+ */
+
+struct entry {
+    u32 offset;
+    u32 clear;
+    u32 set;
+};
+
+struct entry t8103_agx_tunables[] = {
+    {0x30, 0xffffffff, 0x50014},     {0x34, 0xffffffff, 0xa003c},
+    {0x400, 0x400103ff, 0x40010001}, {0x600, 0x1ffffff, 0x1ffffff},
+    {0x738, 0x1ff01ff, 0x140034},    {0x798, 0x1ff01ff, 0x14003c},
+    {0x800, 0x100, 0x100},           {-1, 0, 0},
+};
+
+static void tunables_apply(u64 base, struct entry *entry)
+{
+    while (entry->offset != UINT32_MAX) {
+        mask32(base + entry->offset, entry->clear, entry->set);
+        entry++;
+    }
+}
+
+int power_and_apply(const char *path, u64 base, struct entry *entries)
+{
+    if (pmgr_adt_power_enable(path) < 0) {
+        printf("tunables: Failed to enable power: %s\n", path);
+        return -1;
+    }
+
+    tunables_apply(base, entries);
+
+    if (pmgr_adt_power_disable(path) < 0) {
+        printf("tunables: Failed to disable power: %s\n", path);
+        return -1;
+    }
+
+    return 0;
+}
+
+int tunables_apply_static(void)
+{
+    int ret = 0;
+
+    switch (chip_id) {
+        case T8103:
+            ret |= power_and_apply("/arm-io/sgx", 0x205000000, t8103_agx_tunables);
+            break;
+        default:
+            break;
+    }
+
+    return ret ? -1 : 0;
+}