[RFT PATCH v2] efi: map memreserve table before first use
From: Ard Biesheuvel <hidden>
Date: 2018-11-20 19:16:34
Also in:
linux-efi
Subsystem:
extensible firmware interface (efi), the rest · Maintainers:
Ard Biesheuvel, Linus Torvalds
Mapping the MEMRESERVE EFI configuration table from an early initcall is too late: the GICv3 ITS code that creates persistent reservations for the boot CPU's LPI tables is invoked from init_IRQ(), which runs much earlier than the handling of the initcalls. So instead, move the initialization performed by the initcall into efi_mem_reserve_persistent() itself, but keep the initcall as well so that the init is guaranteed to have been called before SMP boot. Signed-off-by: Ard Biesheuvel <redacted> --- drivers/firmware/efi/efi.c | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index fad7c62cfc0e..0e2d52a0c50e 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c@@ -969,13 +969,33 @@ bool efi_is_table_address(unsigned long phys_addr) static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock); static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init; -int efi_mem_reserve_persistent(phys_addr_t addr, u64 size) +static int __init efi_memreserve_map_root(void) +{ + if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR) + return -ENODEV; + + efi_memreserve_root = memremap(efi.mem_reserve, + sizeof(*efi_memreserve_root), + MEMREMAP_WB); + if (WARN_ON_ONCE(!efi_memreserve_root)) + return -ENOMEM; + return 0; +} + +int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size) { struct linux_efi_memreserve *rsv; + int rc; - if (!efi_memreserve_root) + if (efi_memreserve_root == (void *)ULONG_MAX) return -ENODEV; + if (!efi_memreserve_root) { + rc = efi_memreserve_map_root(); + if (rc) + return rc; + } + rsv = kmalloc(sizeof(*rsv), GFP_ATOMIC); if (!rsv) return -ENOMEM;
@@ -993,14 +1013,12 @@ int efi_mem_reserve_persistent(phys_addr_t addr, u64 size) static int __init efi_memreserve_root_init(void) { - if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR) - return -ENODEV; + if (efi_memreserve_root) + return 0; - efi_memreserve_root = memremap(efi.mem_reserve, - sizeof(*efi_memreserve_root), - MEMREMAP_WB); + efi_memreserve_map_root(); if (!efi_memreserve_root) - return -ENOMEM; + efi_memreserve_root = (void *)ULONG_MAX; return 0; } early_initcall(efi_memreserve_root_init);
--
2.17.1