LoongArch: add kernel setvirtmap for runtime

LoongArch inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5OHOB

--------------------------------
Signed-off-by: Nliuyun <liuyun@loongson.cn>
Change-Id: I6bca1ca0a6881ef497c97ed86aeb2fd5e6088157

arch/loongarch/kernel/efi.c

@@ -22,6 +22,7 @@
 
 #include <asm/early_ioremap.h>
 #include <asm/efi.h>
+#include <asm/tlb.h>
 #include <asm/loongson.h>
 
 static unsigned long efi_nr_tables;
@@ -30,8 +31,99 @@ static unsigned long efi_config_table;
 static efi_system_table_t *efi_systab;
 static efi_config_table_type_t arch_tables[] __initdata = {{},};
 
+static void __init create_tlb(u32 index, u64 vppn, u32 ps, u32 mat)
+{
+	unsigned long tlblo0, tlblo1;
+
+	write_csr_pagesize(ps);
+
+	tlblo0 = vppn | CSR_TLBLO0_V | CSR_TLBLO0_WE |
+		CSR_TLBLO0_GLOBAL | (mat << CSR_TLBLO0_CCA_SHIFT);
+	tlblo1 = tlblo0 + (1 << ps);
+
+	csr_write64(vppn, LOONGARCH_CSR_TLBEHI);
+	csr_write64(tlblo0, LOONGARCH_CSR_TLBELO0);
+	csr_write64(tlblo1, LOONGARCH_CSR_TLBELO1);
+	csr_xchg32(0, CSR_TLBIDX_EHINV, LOONGARCH_CSR_TLBIDX);
+	csr_xchg32(index, CSR_TLBIDX_IDX, LOONGARCH_CSR_TLBIDX);
+
+	tlb_write_indexed();
+}
+
+#define MTLB_ENTRY_INDEX	0x800
+
+/* Create VA == PA mapping as UEFI */
+static void __init fix_efi_mapping(void)
+{
+	unsigned int index = MTLB_ENTRY_INDEX;
+	unsigned int tlbnr = boot_cpu_data.tlbsizemtlb - 2;
+	unsigned long i, vppn;
+
+	/* Low Memory, Cached */
+	create_tlb(index++, 0x00000000, PS_128M, 1);
+	/* MMIO Registers, Uncached */
+	create_tlb(index++, 0x10000000, PS_128M, 0);
+
+	/* High Memory, Cached */
+	for (i = 0; i < tlbnr; i++) {
+		vppn = 0x80000000ULL + (i * SZ_2G);
+		create_tlb(index++, vppn, PS_1G, 1);
+	}
+}
+
+/*
+ * set_virtual_map() - create a virtual mapping for the EFI memory map and call
+ * efi_set_virtual_address_map enter virtual for runtime service
+ *
+ * This function populates the virt_addr fields of all memory region descriptors
+ * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors
+ * are also copied to @runtime_map, and their total count is returned in @count.
+ */
+static int __init set_virtual_map(void)
+{
+	efi_status_t status;
+	int count = 0;
+	unsigned int size;
+	unsigned long attr;
+	efi_runtime_services_t *rt;
+	efi_set_virtual_address_map_t *svam;
+	efi_memory_desc_t *in, runtime_map[32];
+
+	size = sizeof(efi_memory_desc_t);
+
+	for_each_efi_memory_desc(in) {
+		attr = in->attribute;
+		if (!(attr & EFI_MEMORY_RUNTIME))
+			continue;
+
+		if (attr & (EFI_MEMORY_WB | EFI_MEMORY_WT))
+			in->virt_addr = TO_CACHE(in->phys_addr);
+		else
+			in->virt_addr = TO_UNCACHE(in->phys_addr);
+
+		memcpy(&runtime_map[count++], in, size);
+	}
+
+	rt = early_memremap_ro((unsigned long)efi_systab->runtime, sizeof(*rt));
+
+	/* Install the new virtual address map */
+	svam = rt->set_virtual_address_map;
+
+	fix_efi_mapping();
+
+	status = svam(size * count, size, efi.memmap.desc_version,
+			(efi_memory_desc_t *)TO_PHYS((unsigned long)runtime_map));
+
+	local_flush_tlb_all();
+	write_csr_pagesize(PS_DEFAULT_SIZE);
+
+	return 0;
+}
+
 void __init efi_runtime_init(void)
 {
+	efi_status_t status;
+
 	if (!efi_enabled(EFI_BOOT))
 		return;
 
@@ -40,6 +132,13 @@ void __init efi_runtime_init(void)
 		return;
 	}
 
+	if (!efi_systab->runtime)
+		return;
+
+	status = set_virtual_map();
+	if (status < 0)
+		return;
+
 	efi.runtime = (efi_runtime_services_t *)efi_systab->runtime;
 	efi.runtime_version = (unsigned int)efi.runtime->hdr.revision;
 

drivers/firmware/efi/libstub/efi-stub-helper.c

@@ -22,7 +22,7 @@ bool efi_nochunk;
 bool efi_nokaslr = !IS_ENABLED(CONFIG_RANDOMIZE_BASE);
 bool efi_noinitrd;
 int efi_loglevel = CONSOLE_LOGLEVEL_DEFAULT;
-bool efi_novamap;
+bool efi_novamap = IS_ENABLED(CONFIG_LOONGARCH); /* LoongArch call svam() in kernel */;
 
 static bool efi_nosoftreserve;
 static bool efi_disable_pci_dma = IS_ENABLED(CONFIG_EFI_DISABLE_PCI_DMA);

drivers/firmware/efi/libstub/loongarch-stub.c

@@ -52,8 +52,5 @@ void __noreturn efi_enter_kernel(unsigned long entrypoint, unsigned long fdt, un
 	real_kernel_entry = (kernel_entry_t)
 		((unsigned long)&kernel_entry - entrypoint + VMLINUX_LOAD_ADDRESS);
 
-	if (!efi_novamap)
 	real_kernel_entry(true, fdt);
-	else
-		real_kernel_entry(false, fdt);
 }