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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/firmware/efi/libstub/riscv.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/firmware/efi/libstub/riscv.c')
-rw-r--r--drivers/firmware/efi/libstub/riscv.c98
1 files changed, 98 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/riscv.c b/drivers/firmware/efi/libstub/riscv.c
new file mode 100644
index 0000000000..8022b104c3
--- /dev/null
+++ b/drivers/firmware/efi/libstub/riscv.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ */
+
+#include <linux/efi.h>
+#include <linux/libfdt.h>
+
+#include <asm/efi.h>
+#include <asm/unaligned.h>
+
+#include "efistub.h"
+
+typedef void __noreturn (*jump_kernel_func)(unsigned long, unsigned long);
+
+static unsigned long hartid;
+
+static int get_boot_hartid_from_fdt(void)
+{
+ const void *fdt;
+ int chosen_node, len;
+ const void *prop;
+
+ fdt = get_efi_config_table(DEVICE_TREE_GUID);
+ if (!fdt)
+ return -EINVAL;
+
+ chosen_node = fdt_path_offset(fdt, "/chosen");
+ if (chosen_node < 0)
+ return -EINVAL;
+
+ prop = fdt_getprop((void *)fdt, chosen_node, "boot-hartid", &len);
+ if (!prop)
+ return -EINVAL;
+
+ if (len == sizeof(u32))
+ hartid = (unsigned long) fdt32_to_cpu(*(fdt32_t *)prop);
+ else if (len == sizeof(u64))
+ hartid = (unsigned long) fdt64_to_cpu(__get_unaligned_t(fdt64_t, prop));
+ else
+ return -EINVAL;
+
+ return 0;
+}
+
+static efi_status_t get_boot_hartid_from_efi(void)
+{
+ efi_guid_t boot_protocol_guid = RISCV_EFI_BOOT_PROTOCOL_GUID;
+ struct riscv_efi_boot_protocol *boot_protocol;
+ efi_status_t status;
+
+ status = efi_bs_call(locate_protocol, &boot_protocol_guid, NULL,
+ (void **)&boot_protocol);
+ if (status != EFI_SUCCESS)
+ return status;
+ return efi_call_proto(boot_protocol, get_boot_hartid, &hartid);
+}
+
+efi_status_t check_platform_features(void)
+{
+ efi_status_t status;
+ int ret;
+
+ status = get_boot_hartid_from_efi();
+ if (status != EFI_SUCCESS) {
+ ret = get_boot_hartid_from_fdt();
+ if (ret) {
+ efi_err("Failed to get boot hartid!\n");
+ return EFI_UNSUPPORTED;
+ }
+ }
+ return EFI_SUCCESS;
+}
+
+unsigned long __weak stext_offset(void)
+{
+ /*
+ * This fallback definition is used by the EFI zboot stub, which loads
+ * the entire image so it can branch via the image header at offset #0.
+ */
+ return 0;
+}
+
+void __noreturn efi_enter_kernel(unsigned long entrypoint, unsigned long fdt,
+ unsigned long fdt_size)
+{
+ unsigned long kernel_entry = entrypoint + stext_offset();
+ jump_kernel_func jump_kernel = (jump_kernel_func)kernel_entry;
+
+ /*
+ * Jump to real kernel here with following constraints.
+ * 1. MMU should be disabled.
+ * 2. a0 should contain hartid
+ * 3. a1 should DT address
+ */
+ csr_write(CSR_SATP, 0);
+ jump_kernel(hartid, fdt);
+}