Unverified Commit 07aabe8f authored by Jisheng Zhang's avatar Jisheng Zhang Committed by Palmer Dabbelt
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riscv: mm: init: try best to use IS_ENABLED(CONFIG_64BIT) instead of #ifdef 



Try our best to replace the conditional compilation using
"#ifdef CONFIG_64BIT" by a check for "IS_ENABLED(CONFIG_64BIT)", to
simplify the code and to increase compile coverage.

Now we can also remove the __maybe_unused used in max_mapped_addr
declaration.

We also remove the BUG_ON check of mapping the last 4K bytes of the
addressable memory since this is always true for every kernel actually.

Signed-off-by: default avatarJisheng Zhang <jszhang@kernel.org>
Reviewed-by: default avatarAlexandre Ghiti <alex@ghiti.fr>
Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 902d6364

arch/riscv/mm/init.c

+16 −27
Original line number Diff line number Diff line
@@ -102,10 +102,9 @@ static void __init print_vm_layout(void) 
		  (unsigned long)VMALLOC_END);

	print_mlm("lowmem", (unsigned long)PAGE_OFFSET,

		  (unsigned long)high_memory);

#ifdef CONFIG_64BIT

	if (IS_ENABLED(CONFIG_64BIT))

		print_mlm("kernel", (unsigned long)KERNEL_LINK_ADDR,

			  (unsigned long)ADDRESS_SPACE_END);

#endif

}

#else

static void print_vm_layout(void) { }
@@ -163,7 +162,7 @@ static void __init setup_bootmem(void) 
{

	phys_addr_t vmlinux_end = __pa_symbol(&_end);

	phys_addr_t vmlinux_start = __pa_symbol(&_start);

	phys_addr_t __maybe_unused max_mapped_addr;

	phys_addr_t max_mapped_addr;

	phys_addr_t phys_ram_end;



#ifdef CONFIG_XIP_KERNEL
@@ -172,17 +171,16 @@ static void __init setup_bootmem(void) 


	memblock_enforce_memory_limit(memory_limit);



	/*

	 * Reserve from the start of the kernel to the end of the kernel

	 */

#if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)

	/*

	 * Make sure we align the reservation on PMD_SIZE since we will

	 * map the kernel in the linear mapping as read-only: we do not want

	 * any allocation to happen between _end and the next pmd aligned page.

	 */

	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))

		vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK;

#endif

	/*

	 * Reserve from the start of the kernel to the end of the kernel

	 */

	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
@@ -190,7 +188,6 @@ static void __init setup_bootmem(void) 
#ifndef CONFIG_XIP_KERNEL

	phys_ram_base = memblock_start_of_DRAM();

#endif

#ifndef CONFIG_64BIT

	/*

	 * 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
@@ -200,10 +197,11 @@ static void __init setup_bootmem(void) 
	 * address space is occupied by the kernel mapping then this check must

	 * be done as soon as the kernel mapping base address is determined.

	 */

	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);

#endif

	}



	min_low_pfn = PFN_UP(phys_ram_base);

	max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end);
@@ -617,14 +615,6 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) 
	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);

	BUG_ON((kernel_map.phys_addr % PMD_SIZE) != 0);



#ifdef CONFIG_64BIT

	/*

	 * The last 4K bytes of the addressable memory can not be mapped because

	 * of IS_ERR_VALUE macro.

	 */

	BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K);

#endif



	pt_ops.alloc_pte = alloc_pte_early;

	pt_ops.get_pte_virt = get_pte_virt_early;

#ifndef __PAGETABLE_PMD_FOLDED
@@ -736,10 +726,9 @@ static void __init setup_vm_final(void) 
		}

	}



#ifdef CONFIG_64BIT

	/* Map the kernel */

	if (IS_ENABLED(CONFIG_64BIT))

		create_kernel_page_table(swapper_pg_dir, false);

#endif



	/* Clear fixmap PTE and PMD mappings */

	clear_fixmap(FIX_PTE);