| Message ID | 20230726164620.717288-2-charlie@rivosinc.com |
|---|---|
| State | New |
| Headers | show |
| Series | RISC-V: mm: Make SV48 the default address space | expand |
On Thu, Jul 27, 2023 at 01:33:41PM +0100, Conor Dooley wrote: > Hey Charlie, > > On Wed, Jul 26, 2023 at 09:45:55AM -0700, Charlie Jenkins wrote: > > Make sv48 the default address space for mmap as some applications > > currently depend on this assumption. A hint address passed to mmap will > > cause the largest address space that fits entirely into the hint to be > > used. If the hint is less than or equal to 1<<38, an sv39 address will > > be used. An exception is that if the hint address is 0, then a sv48 > > address will be used. After an address space is completely full, the next > > smallest address space will be used. > > > > Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> > > --- > > arch/riscv/include/asm/elf.h | 2 +- > > arch/riscv/include/asm/pgtable.h | 13 ++++++++- > > arch/riscv/include/asm/processor.h | 47 +++++++++++++++++++++++++----- > > 3 files changed, 53 insertions(+), 9 deletions(-) > > > > diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h > > index c24280774caf..5d3368d5585c 100644 > > --- a/arch/riscv/include/asm/elf.h > > +++ b/arch/riscv/include/asm/elf.h > > @@ -49,7 +49,7 @@ extern bool compat_elf_check_arch(Elf32_Ehdr *hdr); > > * the loader. We need to make sure that it is out of the way of the program > > * that it will "exec", and that there is sufficient room for the brk. > > */ > > -#define ELF_ET_DYN_BASE ((TASK_SIZE / 3) * 2) > > +#define ELF_ET_DYN_BASE ((DEFAULT_MAP_WINDOW / 3) * 2) > > > > #ifdef CONFIG_64BIT > > #ifdef CONFIG_COMPAT > > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > > index 75970ee2bda2..530f6a171a2b 100644 > > --- a/arch/riscv/include/asm/pgtable.h > > +++ b/arch/riscv/include/asm/pgtable.h > > @@ -63,12 +63,23 @@ > > * position vmemmap directly below the VMALLOC region. > > */ > > #ifdef CONFIG_64BIT > > +#define VA_BITS_SV39 39 > > +#define VA_BITS_SV48 48 > > +#define VA_BITS_SV57 57 > > + > > +#define VA_USER_SV39 (UL(1) << (VA_BITS_SV39 - 1)) > > +#define VA_USER_SV48 (UL(1) << (VA_BITS_SV48 - 1)) > > +#define VA_USER_SV57 (UL(1) << (VA_BITS_SV57 - 1)) > > + > > #define VA_BITS (pgtable_l5_enabled ? \ > > - 57 : (pgtable_l4_enabled ? 48 : 39)) > > + VA_BITS_SV57 : (pgtable_l4_enabled ? VA_BITS_SV48 : VA_BITS_SV39)) > > #else > > #define VA_BITS 32 > > #endif > > Please, at the very least, build test things for rv32 if you are going > to change things in mm: > io_uring/io_uring.c:3457:20: error: use of undeclared identifier 'VA_BITS_SV39' > io_uring/io_uring.c:3457:20: error: use of undeclared identifier 'VA_BITS_SV39' > io_uring/io_uring.c:3457:20: error: use of undeclared identifier 'VA_BITS_SV39' > io_uring/io_uring.c:3457:20: error: use of undeclared identifier 'VA_BITS_SV39' > io_uring/io_uring.c:3457:20: error: use of undeclared identifier 'VA_BITS_SV39' > io_uring/io_uring.c:3457:20: error: use of undeclared identifier 'VA_BITS_SV39' > mm/util.c:441:19: error: use of undeclared identifier 'VA_BITS_SV39' > mm/util.c:441:19: error: use of undeclared identifier 'VA_BITS_SV39' > mm/util.c:441:19: error: use of undeclared identifier 'VA_BITS_SV39' > mm/util.c:441:19: error: use of undeclared identifier 'VA_BITS_SV39' > mm/util.c:441:19: error: use of undeclared identifier 'VA_BITS_SV39' > mm/util.c:441:19: error: use of undeclared identifier 'VA_BITS_SV39' > mm/mmap.c:1770:20: error: use of undeclared identifier 'VA_BITS_SV39' > mm/mmap.c:1770:20: error: use of undeclared identifier 'VA_BITS_SV39' > mm/mmap.c:1770:20: error: use of undeclared identifier 'VA_BITS_SV39' > mm/mmap.c:1770:20: error: use of undeclared identifier 'VA_BITS_SV39' > mm/mmap.c:1770:20: error: use of undeclared identifier 'VA_BITS_SV39' > mm/mmap.c:1770:20: error: use of undeclared identifier 'VA_BITS_SV39' > > Thanks, > Conor. Thanks for that catch, I sent out a new patch to fix that up. There were also some problems with 32-bit compat support that I resolved.
diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h index c24280774caf..5d3368d5585c 100644 --- a/arch/riscv/include/asm/elf.h +++ b/arch/riscv/include/asm/elf.h @@ -49,7 +49,7 @@ extern bool compat_elf_check_arch(Elf32_Ehdr *hdr); * the loader. We need to make sure that it is out of the way of the program * that it will "exec", and that there is sufficient room for the brk. */ -#define ELF_ET_DYN_BASE ((TASK_SIZE / 3) * 2) +#define ELF_ET_DYN_BASE ((DEFAULT_MAP_WINDOW / 3) * 2) #ifdef CONFIG_64BIT #ifdef CONFIG_COMPAT diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 75970ee2bda2..530f6a171a2b 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -63,12 +63,23 @@ * position vmemmap directly below the VMALLOC region. */ #ifdef CONFIG_64BIT +#define VA_BITS_SV39 39 +#define VA_BITS_SV48 48 +#define VA_BITS_SV57 57 + +#define VA_USER_SV39 (UL(1) << (VA_BITS_SV39 - 1)) +#define VA_USER_SV48 (UL(1) << (VA_BITS_SV48 - 1)) +#define VA_USER_SV57 (UL(1) << (VA_BITS_SV57 - 1)) + #define VA_BITS (pgtable_l5_enabled ? \ - 57 : (pgtable_l4_enabled ? 48 : 39)) + VA_BITS_SV57 : (pgtable_l4_enabled ? VA_BITS_SV48 : VA_BITS_SV39)) #else #define VA_BITS 32 #endif +#define MMAP_VA_BITS ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS) +#define MMAP_MIN_VA_BITS ((VA_BITS >= VA_BITS_SV39) ? VA_BITS_SV39 : VA_BITS) + #define VMEMMAP_SHIFT \ (VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT) #define VMEMMAP_SIZE BIT(VMEMMAP_SHIFT) diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index c950a8d9edef..050e27577419 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -13,20 +13,53 @@ #include <asm/ptrace.h> -/* - * This decides where the kernel will search for a free chunk of vm - * space during mmap's. - */ -#define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3) - -#define STACK_TOP TASK_SIZE #ifdef CONFIG_64BIT +#define DEFAULT_MAP_WINDOW (UL(1) << (MMAP_VA_BITS - 1)) #define STACK_TOP_MAX TASK_SIZE_64 + +#define arch_get_mmap_end(addr, len, flags) \ +({ \ + unsigned long mmap_end; \ + if ((addr) == 0) \ + mmap_end = DEFAULT_MAP_WINDOW; \ + else if ((addr) >= VA_USER_SV57) \ + mmap_end = STACK_TOP_MAX; \ + else if ((((addr) >= VA_USER_SV48)) && (VA_BITS >= VA_BITS_SV48)) \ + mmap_end = VA_USER_SV48; \ + else \ + mmap_end = VA_USER_SV39; \ + mmap_end; \ +}) + +#define arch_get_mmap_base(addr, base) \ +({ \ + unsigned long mmap_base; \ + unsigned long rnd_gap = (base) - DEFAULT_MAP_WINDOW; \ + if ((addr) == 0) \ + mmap_base = (base); \ + else if (((addr) >= VA_USER_SV57) && (VA_BITS >= VA_BITS_SV57)) \ + mmap_base = VA_USER_SV57 + rnd_gap; \ + else if ((((addr) >= VA_USER_SV48)) && (VA_BITS >= VA_BITS_SV48)) \ + mmap_base = VA_USER_SV48 + rnd_gap; \ + else \ + mmap_base = VA_USER_SV39 + rnd_gap; \ + mmap_base; \ +}) + #else +#define DEFAULT_MAP_WINDOW TASK_SIZE #define STACK_TOP_MAX TASK_SIZE #endif #define STACK_ALIGN 16 +#define STACK_TOP DEFAULT_MAP_WINDOW + +/* + * This decides where the kernel will search for a free chunk of vm + * space during mmap's. + */ +#define TASK_UNMAPPED_BASE PAGE_ALIGN(MMAP_MIN_VA_BITS / 3) + #ifndef __ASSEMBLY__ struct task_struct;
Make sv48 the default address space for mmap as some applications currently depend on this assumption. A hint address passed to mmap will cause the largest address space that fits entirely into the hint to be used. If the hint is less than or equal to 1<<38, an sv39 address will be used. An exception is that if the hint address is 0, then a sv48 address will be used. After an address space is completely full, the next smallest address space will be used. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> --- arch/riscv/include/asm/elf.h | 2 +- arch/riscv/include/asm/pgtable.h | 13 ++++++++- arch/riscv/include/asm/processor.h | 47 +++++++++++++++++++++++++----- 3 files changed, 53 insertions(+), 9 deletions(-)