diff options
| -rw-r--r-- | arch/riscv/kernel/pi/fdt_early.c | 40 | ||||
| -rw-r--r-- | arch/riscv/kernel/pi/pi.h | 1 | ||||
| -rw-r--r-- | arch/riscv/mm/init.c | 11 |
3 files changed, 49 insertions, 3 deletions
diff --git a/arch/riscv/kernel/pi/fdt_early.c b/arch/riscv/kernel/pi/fdt_early.c index 9bdee2fafe47..a12ff8090f19 100644 --- a/arch/riscv/kernel/pi/fdt_early.c +++ b/arch/riscv/kernel/pi/fdt_early.c @@ -3,6 +3,7 @@ #include <linux/init.h> #include <linux/libfdt.h> #include <linux/ctype.h> +#include <asm/csr.h> #include "pi.h" @@ -183,3 +184,42 @@ bool fdt_early_match_extension_isa(const void *fdt, const char *ext_name) return ret; } + +/** + * set_satp_mode_from_fdt - determine SATP mode based on the MMU type in fdt + * + * @dtb_pa: physical address of the device tree blob + * + * Returns the SATP mode corresponding to the MMU type of the first enabled CPU, + * 0 otherwise + */ +u64 set_satp_mode_from_fdt(uintptr_t dtb_pa) +{ + const void *fdt = (const void *)dtb_pa; + const char *mmu_type; + int node, parent; + + parent = fdt_path_offset(fdt, "/cpus"); + if (parent < 0) + return 0; + + fdt_for_each_subnode(node, fdt, parent) { + if (!fdt_node_name_eq(fdt, node, "cpu")) + continue; + + if (!fdt_device_is_available(fdt, node)) + continue; + + mmu_type = fdt_getprop(fdt, node, "mmu-type", NULL); + if (!mmu_type) + break; + + if (!strcmp(mmu_type, "riscv,sv39")) + return SATP_MODE_39; + else if (!strcmp(mmu_type, "riscv,sv48")) + return SATP_MODE_48; + break; + } + + return 0; +} diff --git a/arch/riscv/kernel/pi/pi.h b/arch/riscv/kernel/pi/pi.h index 21141d84fea6..3fee2cfddf7c 100644 --- a/arch/riscv/kernel/pi/pi.h +++ b/arch/riscv/kernel/pi/pi.h @@ -14,6 +14,7 @@ u64 get_kaslr_seed(uintptr_t dtb_pa); u64 get_kaslr_seed_zkr(const uintptr_t dtb_pa); bool set_nokaslr_from_cmdline(uintptr_t dtb_pa); u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa); +u64 set_satp_mode_from_fdt(uintptr_t dtb_pa); bool fdt_early_match_extension_isa(const void *fdt, const char *ext_name); diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 054265b3f268..85cb70b10c07 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -816,6 +816,7 @@ static __meminit pgprot_t pgprot_from_va(uintptr_t va) #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL) u64 __pi_set_satp_mode_from_cmdline(uintptr_t dtb_pa); +u64 __pi_set_satp_mode_from_fdt(uintptr_t dtb_pa); static void __init disable_pgtable_l5(void) { @@ -855,18 +856,22 @@ static void __init set_mmap_rnd_bits_max(void) * underlying hardware: establish 1:1 mapping in 4-level page table mode * then read SATP to see if the configuration was taken into account * meaning sv48 is supported. + * The maximum SATP mode is limited by both the command line and the "mmu-type" + * property in the device tree, since some platforms may hang if an unsupported + * SATP mode is attempted. */ static __init void set_satp_mode(uintptr_t dtb_pa) { u64 identity_satp, hw_satp; uintptr_t set_satp_mode_pmd = ((unsigned long)set_satp_mode) & PMD_MASK; - u64 satp_mode_cmdline = __pi_set_satp_mode_from_cmdline(dtb_pa); + u64 satp_mode_limit = min_not_zero(__pi_set_satp_mode_from_cmdline(dtb_pa), + __pi_set_satp_mode_from_fdt(dtb_pa)); kernel_map.page_offset = PAGE_OFFSET_L5; - if (satp_mode_cmdline == SATP_MODE_48) { + if (satp_mode_limit == SATP_MODE_48) { disable_pgtable_l5(); - } else if (satp_mode_cmdline == SATP_MODE_39) { + } else if (satp_mode_limit == SATP_MODE_39) { disable_pgtable_l5(); disable_pgtable_l4(); return; |