From 9f935a4a4372657e43b25fe2f4022fdeb3ca2387 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Mon, 7 Sep 2020 19:16:27 +0530 Subject: [PATCH] lib: utils: Improve fdt_cpu_fixup() implementation The fdt_cpu_fixup() should work fine even if HARTs without MMU are not marked invalid by platform support code. In future, we plan to treat HARTs without MMU as valid in the generic platform support so that we can hold these HARTs in HSM STOPPED state. Signed-off-by: Anup Patel Reviewed-by: Atish Patra --- lib/utils/fdt/fdt_fixup.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/lib/utils/fdt/fdt_fixup.c b/lib/utils/fdt/fdt_fixup.c index 4da7397..8f554e1 100644 --- a/lib/utils/fdt/fdt_fixup.c +++ b/lib/utils/fdt/fdt_fixup.c @@ -21,7 +21,8 @@ void fdt_cpu_fixup(void *fdt) { struct sbi_scratch *scratch = sbi_scratch_thishart_ptr(); const struct sbi_platform *plat = sbi_platform_ptr(scratch); - int err, cpu_offset, cpus_offset; + int err, cpu_offset, cpus_offset, len; + const char *mmu_type; u32 hartid; err = fdt_open_into(fdt, fdt, fdt_totalsize(fdt) + 32); @@ -37,7 +38,15 @@ void fdt_cpu_fixup(void *fdt) if (err) continue; - if (sbi_platform_hart_invalid(plat, hartid)) + /* + * Disable a HART DT node if one of the following is true: + * 1. The HART is marked invalid by platform support + * 2. MMU is not available for the HART + */ + + mmu_type = fdt_getprop(fdt, cpu_offset, "mmu-type", &len); + if (sbi_platform_hart_invalid(plat, hartid) || + !mmu_type || !len) fdt_setprop_string(fdt, cpu_offset, "status", "disabled"); }