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Diffstat (limited to 'arch/riscv/mm/init.c')
-rw-r--r--arch/riscv/mm/init.c21
1 files changed, 11 insertions, 10 deletions
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index e3218d65f21d..e3405e4b99af 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -250,18 +250,19 @@ static void __init setup_bootmem(void)
kernel_map.va_pa_offset = PAGE_OFFSET - phys_ram_base;
/*
- * memblock allocator is not aware of the fact that last 4K bytes of
- * the addressable memory can not be mapped because of IS_ERR_VALUE
- * macro. Make sure that last 4k bytes are not usable by memblock
- * if end of dram is equal to maximum addressable memory. For 64-bit
- * kernel, this problem can't happen here as the end of the virtual
- * address space is occupied by the kernel mapping then this check must
- * be done as soon as the kernel mapping base address is determined.
+ * Reserve physical address space that would be mapped to virtual
+ * addresses greater than (void *)(-PAGE_SIZE) because:
+ * - This memory would overlap with ERR_PTR
+ * - This memory belongs to high memory, which is not supported
+ *
+ * This is not applicable to 64-bit kernel, because virtual addresses
+ * after (void *)(-PAGE_SIZE) are not linearly mapped: they are
+ * occupied by kernel mapping. Also it is unrealistic for high memory
+ * to exist on 64-bit platforms.
*/
if (!IS_ENABLED(CONFIG_64BIT)) {
- max_mapped_addr = __pa(~(ulong)0);
- if (max_mapped_addr == (phys_ram_end - 1))
- memblock_set_current_limit(max_mapped_addr - 4096);
+ max_mapped_addr = __va_to_pa_nodebug(-PAGE_SIZE);
+ memblock_reserve(max_mapped_addr, (phys_addr_t)-max_mapped_addr);
}
min_low_pfn = PFN_UP(phys_ram_base);