loongarch: Add auxiliary files

Add support for manipulating architectural cache and timers, and EFI
memory maps.

Signed-off-by: Zhou Yang <zhouyang@loongson.cn>
Signed-off-by: Xiaotian Wu <wuxiaotian@loongson.cn>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

grub-core/kern/loongarch64/cache.c

@@ -0,0 +1,39 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2023 Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/cache.h>
+#include <grub/misc.h>
+
+/* Prototypes for asm functions. */
+void grub_arch_clean_dcache_range (void);
+void grub_arch_invalidate_icache_range (void);
+
+void
+grub_arch_sync_caches (void *address __attribute__((unused)),
+		       grub_size_t len __attribute__((unused)))
+{
+  grub_arch_clean_dcache_range ();
+  grub_arch_invalidate_icache_range ();
+}
+
+void
+grub_arch_sync_dma_caches (volatile void *address __attribute__((unused)),
+			   grub_size_t len __attribute__((unused)))
+{
+  /* DMA non-coherent devices not supported yet */
+}

grub-core/kern/loongarch64/cache_flush.S

@@ -0,0 +1,33 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2023 Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/symbol.h>
+
+	.file	"cache_flush.S"
+	.text
+/*
+ * No further work to do because cache consistency is maintained by hardware on
+ * LoongArch.
+ */
+FUNCTION(grub_arch_clean_dcache_range)
+	dbar 0
+	jr $ra
+
+FUNCTION(grub_arch_invalidate_icache_range)
+	ibar 0
+	jr $ra

grub-core/kern/loongarch64/efi/init.c

@@ -0,0 +1,77 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2023 Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/env.h>
+#include <grub/kernel.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+#include <grub/time.h>
+#include <grub/efi/efi.h>
+#include <grub/loader.h>
+
+#define EFI_TIMER_PERIOD_MILLISECONDS(ms) ((grub_uint64_t)(ms * 10000))
+
+static grub_uint64_t tmr;
+static grub_efi_event_t tmr_evt;
+
+static grub_uint64_t
+grub_efi_get_time_ms (void)
+{
+  return tmr;
+}
+
+static void
+grub_loongson_increment_timer (grub_efi_event_t event __attribute__ ((unused)),
+			       void *context __attribute__ ((unused)))
+{
+  tmr += 10;
+}
+
+void
+grub_machine_init (void)
+{
+  grub_efi_boot_services_t *b;
+
+  grub_efi_init ();
+
+  b = grub_efi_system_table->boot_services;
+  efi_call_5 (b->create_event, GRUB_EFI_EVT_TIMER | GRUB_EFI_EVT_NOTIFY_SIGNAL,
+	      GRUB_EFI_TPL_CALLBACK, grub_loongson_increment_timer, NULL, &tmr_evt);
+  efi_call_3 (b->set_timer, tmr_evt, GRUB_EFI_TIMER_PERIODIC, EFI_TIMER_PERIOD_MILLISECONDS(10));
+
+  grub_install_get_time_ms (grub_efi_get_time_ms);
+}
+
+void
+grub_machine_fini (int flags)
+{
+  grub_efi_boot_services_t *b;
+
+  if (!(flags & GRUB_LOADER_FLAG_NORETURN))
+    return;
+
+  b = grub_efi_system_table->boot_services;
+
+  efi_call_3 (b->set_timer, tmr_evt, GRUB_EFI_TIMER_CANCEL, 0);
+  efi_call_1 (b->close_event, tmr_evt);
+
+  grub_efi_fini ();
+
+  if (!(flags & GRUB_LOADER_FLAG_EFI_KEEP_ALLOCATED_MEMORY))
+    grub_efi_memory_fini ();
+}