arm64: Fix cache enable/disable during bootload

* Fix crash in arch_mmu_generate_post_efi_page_tables due to MMU being
  disabled too early. Fixed by only disabling the cache/MMU while TTBRx
  is being written.
* Disable I-cache while TTBRx is being written. This mirrors the
  behavior in u-boot.
* With these fixes, UEFI boot now reaches ExitBootServices before
  crashing.

Change-Id: Iea04765cdf914791b93b3da378b0df56e46a1d9d
Reviewed-on: https://review.haiku-os.org/c/haiku/+/8079
Haiku-Format: Haiku-format Bot <[email protected]>
Reviewed-by: David Karoly <[email protected]>
Tested-by: Commit checker robot <[email protected]>
Reviewed-by: waddlesplash <[email protected]>

src/system/boot/platform/efi/arch/arm64/arch_cache.cpp

@@ -13,10 +13,9 @@ arch_cache_disable()
 {
 	if (arch_mmu_cache_enabled()) {
 		uint64 sctlr = _arch_mmu_get_sctlr();
-		sctlr &= ~(SCTLR_M | SCTLR_C);
+		sctlr &= ~(SCTLR_M | SCTLR_C | SCTLR_I);
 		_arch_mmu_set_sctlr(sctlr);
 
-// 		_arch_cache_flush_invalidate_all();
 		_arch_cache_clean_poc();
 		_arch_mmu_invalidate_tlb_all(arch_exception_level());
 	}
@@ -28,7 +27,7 @@ arch_cache_enable()
 {
 	if (!arch_mmu_cache_enabled()) {
 		uint64 sctlr = _arch_mmu_get_sctlr();
-		sctlr |= (SCTLR_M | SCTLR_C);
+		sctlr |= (SCTLR_M | SCTLR_C | SCTLR_I);
 		_arch_mmu_set_sctlr(sctlr);
 	}
 }

src/system/boot/platform/efi/arch/arm64/arch_mmu.cpp

@@ -348,7 +348,9 @@ arch_mmu_allocate_kernel_page_tables(void)
 	if (page == NULL) {
 		page = CurrentRegime.AllocatePage();
 		if (page != NULL) {
+			arch_cache_disable();
 			WRITE_SPECIALREG(TTBR1_EL1, page);
+			arch_cache_enable();
 		} else {
 			panic("Not enough memory for kernel initial page\n");
 		}

src/system/boot/platform/efi/arch/arm64/arch_start.cpp

@@ -115,11 +115,6 @@ arch_start_kernel(addr_t kernelEntry)
 
 		dprintf("Kernel entry accessibility W: %x R: %x\n", arch_mmu_write_access(kernelEntry),
 			arch_mmu_read_access(kernelEntry));
-
-		if (el == 1) {
-			// Disable CACHE & MMU before dealing with TTBRx
-			arch_cache_disable();
-		}
 	}
 
 	// Generate page tables for use after ExitBootServices.