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authorAlexandre Ghiti <alexandre.ghiti@canonical.com>2021-12-06 13:46:51 +0300
committerPalmer Dabbelt <palmer@rivosinc.com>2022-01-20 04:54:09 +0300
commite8a62cc26ddf53a3c6ba2a8d33036cf7b84f3923 (patch)
tree15b9020880a651c756268a4560b8c6c720fc1031 /drivers/firmware
parent60639f74c2f4fcc3ffa2ac0b120eaa874ccc713f (diff)
downloadlinux-e8a62cc26ddf53a3c6ba2a8d33036cf7b84f3923.tar.xz
riscv: Implement sv48 support
By adding a new 4th level of page table, give the possibility to 64bit kernel to address 2^48 bytes of virtual address: in practice, that offers 128TB of virtual address space to userspace and allows up to 64TB of physical memory. If the underlying hardware does not support sv48, we will automatically fallback to a standard 3-level page table by folding the new PUD level into PGDIR level. In order to detect HW capabilities at runtime, we use SATP feature that ignores writes with an unsupported mode. Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/efi/libstub/efi-stub.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index 26e69788f27a..b3db5d91ed38 100644
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -40,6 +40,8 @@
#ifdef CONFIG_ARM64
# define EFI_RT_VIRTUAL_LIMIT DEFAULT_MAP_WINDOW_64
+#elif defined(CONFIG_RISCV)
+# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE_MIN
#else
# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE
#endif