| Message ID | 20210629091349.3802690-3-alex@ghiti.fr (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/3] riscv: Fix memory_limit for 64-bit kernel | expand |
On Tue, 29 Jun 2021 02:13:48 PDT (-0700), alex@ghiti.fr wrote: > The check that is done in setup_bootmem currently only works for 32-bit > kernel since the kernel mapping has been moved outside of the linear > mapping for 64-bit kernel. So make sure that for 64-bit kernel, the kernel > mapping does not overlap with the last 4K of the addressable memory. > > Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> > --- > arch/riscv/mm/init.c | 18 ++++++++++++++++-- > 1 file changed, 16 insertions(+), 2 deletions(-) > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index a1a0c4afa80f..a90c41bc9485 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -156,7 +156,7 @@ 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 max_mapped_addr = __pa(~(ulong)0); > + phys_addr_t __maybe_unused max_mapped_addr; > phys_addr_t dram_end; > > #ifdef CONFIG_XIP_KERNEL > @@ -179,14 +179,20 @@ static void __init setup_bootmem(void) > memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); > > dram_end = memblock_end_of_DRAM(); > +#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 > * macro. Make sure that last 4k bytes are not usable by memblock > - * if end of dram is equal to maximum addressable memory. > + * 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 in create_kernel_page_table. > */ > + max_mapped_addr = __pa(~(ulong)0); > if (max_mapped_addr == (dram_end - 1)) > memblock_set_current_limit(max_mapped_addr - 4096); > +#endif > > min_low_pfn = PFN_UP(memblock_start_of_DRAM()); > max_low_pfn = max_pfn = PFN_DOWN(dram_end); > @@ -556,6 +562,7 @@ static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size, > uintptr_t va, end_va; > > end_va = kernel_virt_addr + load_sz; > + > for (va = kernel_virt_addr; va < end_va; va += map_size) > create_pgd_mapping(pgdir, va, > load_pa + (va - kernel_virt_addr), > @@ -602,6 +609,13 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > /* Sanity check alignment and size */ > BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); > BUG_ON((load_pa % map_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_virt_addr + load_sz) > ADDRESS_SPACE_END - SZ_4K); > +#endif > > pt_ops.alloc_pte = alloc_pte_early; > pt_ops.get_pte_virt = get_pte_virt_early; Thanks. These are on fixes, with some fixes tags added. This one had some merge conflicts that I had to fix up, LMK if something went wrong.
Hi Palmer, Le 29/06/2021 à 11:13, Alexandre Ghiti a écrit : > The check that is done in setup_bootmem currently only works for 32-bit > kernel since the kernel mapping has been moved outside of the linear > mapping for 64-bit kernel. So make sure that for 64-bit kernel, the kernel > mapping does not overlap with the last 4K of the addressable memory. > > Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> > --- > arch/riscv/mm/init.c | 18 ++++++++++++++++-- > 1 file changed, 16 insertions(+), 2 deletions(-) > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index a1a0c4afa80f..a90c41bc9485 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -156,7 +156,7 @@ 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 max_mapped_addr = __pa(~(ulong)0); > + phys_addr_t __maybe_unused max_mapped_addr; > phys_addr_t dram_end; > > #ifdef CONFIG_XIP_KERNEL > @@ -179,14 +179,20 @@ static void __init setup_bootmem(void) > memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); > > dram_end = memblock_end_of_DRAM(); > +#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 > * macro. Make sure that last 4k bytes are not usable by memblock > - * if end of dram is equal to maximum addressable memory. > + * 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 in create_kernel_page_table. This comment is wrong, I have just sent a patch fixing this: "riscv: Fix comment regarding kernel mapping overlapping with IS_ERR_VALUE" > */ > + max_mapped_addr = __pa(~(ulong)0); > if (max_mapped_addr == (dram_end - 1)) > memblock_set_current_limit(max_mapped_addr - 4096); > +#endif > > min_low_pfn = PFN_UP(memblock_start_of_DRAM()); > max_low_pfn = max_pfn = PFN_DOWN(dram_end); > @@ -556,6 +562,7 @@ static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size, > uintptr_t va, end_va; > > end_va = kernel_virt_addr + load_sz; > + I saw that you removed this useless new line, thanks. > for (va = kernel_virt_addr; va < end_va; va += map_size) > create_pgd_mapping(pgdir, va, > load_pa + (va - kernel_virt_addr), > @@ -602,6 +609,13 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > /* Sanity check alignment and size */ > BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); > BUG_ON((load_pa % map_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_virt_addr + load_sz) > ADDRESS_SPACE_END - SZ_4K); > +#endif > > pt_ops.alloc_pte = alloc_pte_early; > pt_ops.get_pte_virt = get_pte_virt_early; > The merge you have done is correct to me. Sorry about the above mistakes, should have caught those before. Thanks, Alex
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index a1a0c4afa80f..a90c41bc9485 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -156,7 +156,7 @@ 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 max_mapped_addr = __pa(~(ulong)0); + phys_addr_t __maybe_unused max_mapped_addr; phys_addr_t dram_end; #ifdef CONFIG_XIP_KERNEL @@ -179,14 +179,20 @@ static void __init setup_bootmem(void) memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); dram_end = memblock_end_of_DRAM(); +#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 * macro. Make sure that last 4k bytes are not usable by memblock - * if end of dram is equal to maximum addressable memory. + * 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 in create_kernel_page_table. */ + max_mapped_addr = __pa(~(ulong)0); if (max_mapped_addr == (dram_end - 1)) memblock_set_current_limit(max_mapped_addr - 4096); +#endif min_low_pfn = PFN_UP(memblock_start_of_DRAM()); max_low_pfn = max_pfn = PFN_DOWN(dram_end); @@ -556,6 +562,7 @@ static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size, uintptr_t va, end_va; end_va = kernel_virt_addr + load_sz; + for (va = kernel_virt_addr; va < end_va; va += map_size) create_pgd_mapping(pgdir, va, load_pa + (va - kernel_virt_addr), @@ -602,6 +609,13 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) /* Sanity check alignment and size */ BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); BUG_ON((load_pa % map_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_virt_addr + load_sz) > ADDRESS_SPACE_END - SZ_4K); +#endif pt_ops.alloc_pte = alloc_pte_early; pt_ops.get_pte_virt = get_pte_virt_early;
The check that is done in setup_bootmem currently only works for 32-bit kernel since the kernel mapping has been moved outside of the linear mapping for 64-bit kernel. So make sure that for 64-bit kernel, the kernel mapping does not overlap with the last 4K of the addressable memory. Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> --- arch/riscv/mm/init.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)