Skip over features unsupported in A7-A11 SoCs.

This includes
- GXF
- SPRR
- PAN (A7-A9)
- Atomics (A7-A10)
- FIPI (A7-A10)
- DCP

SPRR on T8030 seems to be quite different from M1 (at least according to
qemu-t8030), so keep it disabled for those CPU parts.

Signed-off-by: Nick Chan <towinchenmi@gmail.com>

src/chickens.c

@@ -69,7 +69,7 @@ void init_t6021_avalanche(int rev);
 void init_t6031_sawtooth(void);
 void init_t6031_everest(int rev);
 
-bool cpufeat_actlr_el2, cpufeat_fast_ipi;
+bool cpufeat_actlr_el2, cpufeat_fast_ipi, cpufeat_mmu_sprr;
 
 const char *init_cpu(void)
 {
@@ -230,11 +230,17 @@ const char *init_cpu(void)
         sysop("isb");
 
         msr(SYS_IMP_APL_AMX_CTX_EL1, core);
+
+        /* T8030 SPRR is different */
+        cpufeat_mmu_sprr = true;
     }
 
     if (part >= MIDR_PART_T8030_LIGHTNING)
         msr(SYS_IMP_APL_AMX_CTL_EL1, 0x100);
 
+    if (part >= MIDR_PART_T8015_MONSOON)
+        cpufeat_fast_ipi = true;
+
     /* Unmask external IRQs, set WFI mode to up (2) */
     reg_mask(SYS_IMP_APL_CYC_OVRD,
              CYC_OVRD_FIQ_MODE_MASK | CYC_OVRD_IRQ_MODE_MASK | CYC_OVRD_WFI_MODE_MASK,

src/display.c

@@ -264,6 +264,11 @@ int display_start_dcp(void)
     return 0;
 #endif
 
+    if (!has_dcp) {
+        printf("display: DCP not present\n");
+        return -1;
+    }
+
     const display_config_t *disp_cfg = display_get_config();
 
     display_is_dptx = !!disp_cfg->dptx_phy[0];
@@ -622,13 +627,14 @@ int display_init(void)
     else
         printf("display: Display is internal\n");
 
-    if (cur_boot_args.video.width == 640 && cur_boot_args.video.height == 1136) {
+    if ((cur_boot_args.video.width == 640 && cur_boot_args.video.height == 1136) &&
+        chip_id != S5L8960X) {
         printf("display: Dummy framebuffer found, initializing display\n");
         return display_configure(NULL);
-    } else if (display_is_external) {
+    } else if (display_is_external && is_mac) {
         printf("display: External display found, reconfiguring\n");
         return display_configure(NULL);
-    } else if (!(cur_boot_args.video.depth & FB_DEPTH_FLAG_RETINA)) {
+    } else if ((!(cur_boot_args.video.depth & FB_DEPTH_FLAG_RETINA)) && is_mac) {
         printf("display: Internal display with non-retina flag, assuming Sonoma bug and "
                "reconfiguring\n");
         fb_clear_direct(); // Old m1n1 stage1 ends up with an ugly logo situation, clear it.

src/exception.c

@@ -137,7 +137,6 @@ void exception_initialize(void)
         msr(CNTP_CTL_EL02, 7L);
         msr(CNTV_CTL_EL02, 7L);
     }
-
     if (cpufeat_fast_ipi) {
         reg_clr(SYS_IMP_APL_PMCR0, PMCR0_IACT | PMCR0_IMODE_MASK);
         reg_clr(SYS_IMP_APL_UPMCR0, UPMCR0_IMODE_MASK);
@@ -223,10 +222,12 @@ void print_regs(u64 *regs, int el12)
     if (is_ecore()) {
         printf("E_LSU_ERR_STS: 0x%lx\n", mrs(SYS_IMP_APL_E_LSU_ERR_STS));
         printf("E_FED_ERR_STS: 0x%lx\n", mrs(SYS_IMP_APL_E_FED_ERR_STS));
+        if (cpufeat_fast_ipi)
             printf("E_MMU_ERR_STS: 0x%lx\n", mrs(SYS_IMP_APL_E_MMU_ERR_STS));
     } else {
         printf("LSU_ERR_STS: 0x%lx\n", mrs(SYS_IMP_APL_LSU_ERR_STS));
         printf("FED_ERR_STS: 0x%lx\n", mrs(SYS_IMP_APL_FED_ERR_STS));
+        if (cpufeat_fast_ipi)
             printf("MMU_ERR_STS: 0x%lx\n", mrs(SYS_IMP_APL_MMU_ERR_STS));
     }
 }
@@ -383,8 +384,11 @@ void exc_fiq(u64 *regs)
         printf("  PMC IRQ, masking\n");
         reg_clr(SYS_IMP_APL_PMCR0, PMCR0_IACT | PMCR0_IMODE_MASK);
     }
+
+    if (cpufeat_fast_ipi) {
         reg = mrs(SYS_IMP_APL_UPMCR0);
-    if ((reg & UPMCR0_IMODE_MASK) == UPMCR0_IMODE_FIQ && (mrs(SYS_IMP_APL_UPMSR) & UPMSR_IACT)) {
+        if ((reg & UPMCR0_IMODE_MASK) == UPMCR0_IMODE_FIQ &&
+            (mrs(SYS_IMP_APL_UPMSR) & UPMSR_IACT)) {
             printf("  UPMC IRQ, masking\n");
             reg_clr(SYS_IMP_APL_UPMCR0, UPMCR0_IMODE_MASK);
         }
@@ -393,6 +397,7 @@ void exc_fiq(u64 *regs)
             printf("  Fast IPI IRQ, clearing\n");
             msr(SYS_IMP_APL_IPI_SR_EL1, IPI_SR_PENDING);
         }
+    }
 
     UNUSED(regs);
     // print_regs(regs);

src/gxf.c

@@ -30,6 +30,9 @@ void gxf_init(void)
 
 bool gxf_enabled(void)
 {
+    if (!supports_gxf())
+        return false;
+
     if (!(mrs(SYS_IMP_APL_SPRR_CONFIG_EL1) & SPRR_CONFIG_EN))
         return false;
 

src/main.c

@@ -51,6 +51,7 @@ void get_device_info(void)
         printf("  Target: %s\n", target);
 
     is_mac = !!strstr(model, "Mac");
+    has_dcp = adt_path_offset(adt, "/arm-io/dcp") > 0;
 
     int chosen = adt_path_offset(adt, "/chosen");
     if (chosen > 0) {
@@ -146,12 +147,12 @@ void m1n1_main(void)
 
     printf("Running in EL%lu\n\n", mrs(CurrentEL) >> 2);
 
-    get_device_info();
     firmware_init();
 
     heapblock_init();
 
 #ifndef BRINGUP
+    if (supports_gxf())
         gxf_init();
     mcc_init();
     mmu_init();
@@ -160,13 +161,14 @@ void m1n1_main(void)
     wdt_disable();
 #ifndef BRINGUP
     pmgr_init();
-
 #ifdef USE_FB
     display_init();
     // Kick DCP to sleep, so dodgy monitors which cause reconnect cycles don't cause us to lose the
     // framebuffer.
+    if (has_dcp)
         display_shutdown(DCP_SLEEP_IF_EXTERNAL);
-    fb_init(false);
+    // On idevice we need to always clear, because otherwise it looks scuffed on white devices
+    fb_init(!is_mac);
     fb_display_logo();
 #ifdef FB_SILENT_MODE
     fb_set_active(!cur_boot_args.video.display);

src/memory.c

@@ -503,9 +503,11 @@ void mmu_init(void)
     mmu_init_pagetables();
     mmu_add_default_mappings();
     mmu_configure();
+    if (cpufeat_mmu_sprr)
         mmu_init_sprr();
 
     // Enable EL0 memory access by EL1
+    if (supports_pan())
         msr(PAN, 0);
 
     // RES1 bits
@@ -521,9 +523,11 @@ void mmu_init(void)
 static void mmu_secondary_setup(void)
 {
     mmu_configure();
+    if (cpufeat_mmu_sprr)
         mmu_init_sprr();
 
     // Enable EL0 memory access by EL1
+    if (supports_pan())
         msr(PAN, 0);
 
     // RES1 bits

src/start.S

@@ -95,6 +95,7 @@ _start:
     bl debug_putc
     mov w0, '\n'
     bl debug_putc
+    bl pan_fixup
 
     mrs x8, CurrentEL
     cmp x8, #0xc
@@ -105,7 +106,6 @@ _start:
     bl _start_c
     b .
 
-.globl exception_initialize
 start_el3:
     bl exception_initialize
     adrp x8, _stack_bot_el3
@@ -197,6 +197,9 @@ debug_putc:
 .globl reboot
 .type reboot, @function
 reboot:
+    mrs x8, id_aa64pfr0_el1
+    tst w8, 0xf00
+    beq 1f
     mrs x0, CurrentEL
     cmp x0, #8
     beq 1f

src/startup.c

@@ -44,6 +44,21 @@ void apply_rela(uint64_t base, struct rela_entry *rela_start, struct rela_entry
     }
 }
 
+extern uint32_t _v_sp0_sync[], _v_sp0_irq[], _v_sp0_fiq[], _v_sp0_serr[];
+void pan_fixup(void)
+{
+    if (supports_pan())
+        return;
+
+    /* Patch msr pan, #0 to nop */
+    _v_sp0_sync[0] = 0xd503201f;
+    _v_sp0_irq[0] = 0xd503201f;
+    _v_sp0_fiq[0] = 0xd503201f;
+    _v_sp0_serr[0] = 0xd503201f;
+
+    sysop("isb");
+}
+
 void dump_boot_args(struct boot_args *ba)
 {
     printf("  revision:     %d\n", ba->revision);

src/utils.c

@@ -8,10 +8,11 @@
 #include "iodev.h"
 #include "smp.h"
 #include "types.h"
+#include "utils.h"
 #include "vsprintf.h"
 #include "xnuboot.h"
 
-bool is_mac = false;
+bool is_mac, has_dcp;
 
 static char ascii(char s)
 {
@@ -149,7 +150,7 @@ void spin_lock(spinlock_t *lock)
     __asm__ volatile("1:\n"
                      "mov\t%0, -1\n"
                      "2:\n"
-                     "\tcasa\t%0, %2, %1\n"
+                     "\tldaxr\t%0, %1\n"
                      "\tcmn\t%0, 1\n"
                      "\tbeq\t3f\n"
                      "\tldxr\t%0, %1\n"
@@ -158,6 +159,8 @@ void spin_lock(spinlock_t *lock)
                      "\twfe\n"
                      "\tb\t1b\n"
                      "3:"
+                     "\tstxr\t%w0, %2, %1\n"
+                     "\tcbnz\t%w0, 2b\n"
                      : "=&r"(tmp), "+m"(lock->lock)
                      : "r"(me)
                      : "cc", "memory");

src/utils.h

@@ -447,8 +447,9 @@ struct vector_args {
 };
 
 extern u32 board_id, chip_id;
-extern bool is_mac;
-extern bool cpufeat_actlr_el2, cpufeat_fast_ipi;
+
+extern bool is_mac, has_dcp;
+extern bool cpufeat_actlr_el2, cpufeat_fast_ipi, cpufeat_mmu_sprr;
 
 extern struct vector_args next_stage;