| Message ID | 20200603153608.30056-3-alex@ghiti.fr (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | PUD/PGDIR entries for linear mapping | expand |
On Wed, Jun 3, 2020 at 8:38 AM Alexandre Ghiti <alex@ghiti.fr> wrote: > > Improve best_map_size so that PUD or PGDIR entries are used for linear > mapping when possible as it allows better TLB utilization. > > Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> > --- > arch/riscv/mm/init.c | 45 +++++++++++++++++++++++++++++++++----------- > 1 file changed, 34 insertions(+), 11 deletions(-) > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index 9a5c97e091c1..d275f9f834cf 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -424,13 +424,29 @@ static void __init create_pgd_mapping(pgd_t *pgdp, > create_pgd_next_mapping(nextp, va, pa, sz, prot); > } > > -static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) > +static bool is_map_size_ok(uintptr_t map_size, phys_addr_t base, > + uintptr_t base_virt, phys_addr_t size) > { > - /* Upgrade to PMD_SIZE mappings whenever possible */ > - if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1))) > - return PAGE_SIZE; > + return !((base & (map_size - 1)) || (base_virt & (map_size - 1)) || > + (size < map_size)); > +} > + > +static uintptr_t __init best_map_size(phys_addr_t base, uintptr_t base_virt, > + phys_addr_t size) > +{ > +#ifndef __PAGETABLE_PMD_FOLDED > + if (is_map_size_ok(PGDIR_SIZE, base, base_virt, size)) > + return PGDIR_SIZE; > + > + if (pgtable_l4_enabled) > + if (is_map_size_ok(PUD_SIZE, base, base_virt, size)) > + return PUD_SIZE; > +#endif > + > + if (is_map_size_ok(PMD_SIZE, base, base_virt, size)) > + return PMD_SIZE; > > - return PMD_SIZE; > + return PAGE_SIZE; > } > > /* > @@ -576,7 +592,7 @@ void create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size) > asmlinkage void __init setup_vm(uintptr_t dtb_pa) > { > uintptr_t va, end_va; > - uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE); > + uintptr_t map_size; > > load_pa = (uintptr_t)(&_start); > load_sz = (uintptr_t)(&_end) - load_pa; > @@ -587,6 +603,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > > kernel_virt_addr = KERNEL_VIRT_ADDR; > > + map_size = best_map_size(load_pa, PAGE_OFFSET, MAX_EARLY_MAPPING_SIZE); > va_pa_offset = PAGE_OFFSET - load_pa; > va_kernel_pa_offset = kernel_virt_addr - load_pa; > pfn_base = PFN_DOWN(load_pa); > @@ -700,6 +717,8 @@ static void __init setup_vm_final(void) > > /* Map all memory banks */ > for_each_memblock(memory, reg) { > + uintptr_t remaining_size; > + > start = reg->base; > end = start + reg->size; > > @@ -707,15 +726,19 @@ static void __init setup_vm_final(void) > break; > if (memblock_is_nomap(reg)) > continue; > - if (start <= __pa(PAGE_OFFSET) && > - __pa(PAGE_OFFSET) < end) > - start = __pa(PAGE_OFFSET); > > - map_size = best_map_size(start, end - start); > - for (pa = start; pa < end; pa += map_size) { > + pa = start; > + remaining_size = reg->size; > + > + while (remaining_size) { > va = (uintptr_t)__va(pa); > + map_size = best_map_size(pa, va, remaining_size); > + > create_pgd_mapping(swapper_pg_dir, va, pa, > map_size, PAGE_KERNEL); > + > + pa += map_size; > + remaining_size -= map_size; > } > } > This may not work in the RV32 with 2G memory and if the map_size is determined to be a page size for the last memblock. Both pa & remaining_size will overflow and the loop will try to map memory from zero again. > -- > 2.20.1 > >
Hi Atish, Le 6/18/20 à 8:47 PM, Atish Patra a écrit : > On Wed, Jun 3, 2020 at 8:38 AM Alexandre Ghiti <alex@ghiti.fr> wrote: >> Improve best_map_size so that PUD or PGDIR entries are used for linear >> mapping when possible as it allows better TLB utilization. >> >> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> >> --- >> arch/riscv/mm/init.c | 45 +++++++++++++++++++++++++++++++++----------- >> 1 file changed, 34 insertions(+), 11 deletions(-) >> >> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c >> index 9a5c97e091c1..d275f9f834cf 100644 >> --- a/arch/riscv/mm/init.c >> +++ b/arch/riscv/mm/init.c >> @@ -424,13 +424,29 @@ static void __init create_pgd_mapping(pgd_t *pgdp, >> create_pgd_next_mapping(nextp, va, pa, sz, prot); >> } >> >> -static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) >> +static bool is_map_size_ok(uintptr_t map_size, phys_addr_t base, >> + uintptr_t base_virt, phys_addr_t size) >> { >> - /* Upgrade to PMD_SIZE mappings whenever possible */ >> - if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1))) >> - return PAGE_SIZE; >> + return !((base & (map_size - 1)) || (base_virt & (map_size - 1)) || >> + (size < map_size)); >> +} >> + >> +static uintptr_t __init best_map_size(phys_addr_t base, uintptr_t base_virt, >> + phys_addr_t size) >> +{ >> +#ifndef __PAGETABLE_PMD_FOLDED >> + if (is_map_size_ok(PGDIR_SIZE, base, base_virt, size)) >> + return PGDIR_SIZE; >> + >> + if (pgtable_l4_enabled) >> + if (is_map_size_ok(PUD_SIZE, base, base_virt, size)) >> + return PUD_SIZE; >> +#endif >> + >> + if (is_map_size_ok(PMD_SIZE, base, base_virt, size)) >> + return PMD_SIZE; >> >> - return PMD_SIZE; >> + return PAGE_SIZE; >> } >> >> /* >> @@ -576,7 +592,7 @@ void create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size) >> asmlinkage void __init setup_vm(uintptr_t dtb_pa) >> { >> uintptr_t va, end_va; >> - uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE); >> + uintptr_t map_size; >> >> load_pa = (uintptr_t)(&_start); >> load_sz = (uintptr_t)(&_end) - load_pa; >> @@ -587,6 +603,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) >> >> kernel_virt_addr = KERNEL_VIRT_ADDR; >> >> + map_size = best_map_size(load_pa, PAGE_OFFSET, MAX_EARLY_MAPPING_SIZE); >> va_pa_offset = PAGE_OFFSET - load_pa; >> va_kernel_pa_offset = kernel_virt_addr - load_pa; >> pfn_base = PFN_DOWN(load_pa); >> @@ -700,6 +717,8 @@ static void __init setup_vm_final(void) >> >> /* Map all memory banks */ >> for_each_memblock(memory, reg) { >> + uintptr_t remaining_size; >> + >> start = reg->base; >> end = start + reg->size; >> >> @@ -707,15 +726,19 @@ static void __init setup_vm_final(void) >> break; >> if (memblock_is_nomap(reg)) >> continue; >> - if (start <= __pa(PAGE_OFFSET) && >> - __pa(PAGE_OFFSET) < end) >> - start = __pa(PAGE_OFFSET); >> >> - map_size = best_map_size(start, end - start); >> - for (pa = start; pa < end; pa += map_size) { >> + pa = start; >> + remaining_size = reg->size; >> + >> + while (remaining_size) { >> va = (uintptr_t)__va(pa); >> + map_size = best_map_size(pa, va, remaining_size); >> + >> create_pgd_mapping(swapper_pg_dir, va, pa, >> map_size, PAGE_KERNEL); >> + >> + pa += map_size; >> + remaining_size -= map_size; >> } >> } >> > This may not work in the RV32 with 2G memory and if the map_size is > determined to be a page size > for the last memblock. Both pa & remaining_size will overflow and the > loop will try to map memory from zero again. I'm not sure I understand: if pa starts at 0x8000_0000 and size is 2G, then pa will overflow in the last iteration, but remaining_size will then be equal to 0 right ? And by the way, I realize that this loop only handles sizes that are aligned on map_size. Thanks, Alex > >> -- >> 2.20.1 >> >> >
On Thu, Jun 18, 2020 at 9:28 PM Alex Ghiti <alex@ghiti.fr> wrote: > > Hi Atish, > > Le 6/18/20 à 8:47 PM, Atish Patra a écrit : > > On Wed, Jun 3, 2020 at 8:38 AM Alexandre Ghiti <alex@ghiti.fr> wrote: > >> Improve best_map_size so that PUD or PGDIR entries are used for linear > >> mapping when possible as it allows better TLB utilization. > >> > >> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> > >> --- > >> arch/riscv/mm/init.c | 45 +++++++++++++++++++++++++++++++++----------- > >> 1 file changed, 34 insertions(+), 11 deletions(-) > >> > >> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > >> index 9a5c97e091c1..d275f9f834cf 100644 > >> --- a/arch/riscv/mm/init.c > >> +++ b/arch/riscv/mm/init.c > >> @@ -424,13 +424,29 @@ static void __init create_pgd_mapping(pgd_t *pgdp, > >> create_pgd_next_mapping(nextp, va, pa, sz, prot); > >> } > >> > >> -static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) > >> +static bool is_map_size_ok(uintptr_t map_size, phys_addr_t base, > >> + uintptr_t base_virt, phys_addr_t size) > >> { > >> - /* Upgrade to PMD_SIZE mappings whenever possible */ > >> - if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1))) > >> - return PAGE_SIZE; > >> + return !((base & (map_size - 1)) || (base_virt & (map_size - 1)) || > >> + (size < map_size)); > >> +} > >> + > >> +static uintptr_t __init best_map_size(phys_addr_t base, uintptr_t base_virt, > >> + phys_addr_t size) > >> +{ > >> +#ifndef __PAGETABLE_PMD_FOLDED > >> + if (is_map_size_ok(PGDIR_SIZE, base, base_virt, size)) > >> + return PGDIR_SIZE; > >> + > >> + if (pgtable_l4_enabled) > >> + if (is_map_size_ok(PUD_SIZE, base, base_virt, size)) > >> + return PUD_SIZE; > >> +#endif > >> + > >> + if (is_map_size_ok(PMD_SIZE, base, base_virt, size)) > >> + return PMD_SIZE; > >> > >> - return PMD_SIZE; > >> + return PAGE_SIZE; > >> } > >> > >> /* > >> @@ -576,7 +592,7 @@ void create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size) > >> asmlinkage void __init setup_vm(uintptr_t dtb_pa) > >> { > >> uintptr_t va, end_va; > >> - uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE); > >> + uintptr_t map_size; > >> > >> load_pa = (uintptr_t)(&_start); > >> load_sz = (uintptr_t)(&_end) - load_pa; > >> @@ -587,6 +603,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > >> > >> kernel_virt_addr = KERNEL_VIRT_ADDR; > >> > >> + map_size = best_map_size(load_pa, PAGE_OFFSET, MAX_EARLY_MAPPING_SIZE); > >> va_pa_offset = PAGE_OFFSET - load_pa; > >> va_kernel_pa_offset = kernel_virt_addr - load_pa; > >> pfn_base = PFN_DOWN(load_pa); > >> @@ -700,6 +717,8 @@ static void __init setup_vm_final(void) > >> > >> /* Map all memory banks */ > >> for_each_memblock(memory, reg) { > >> + uintptr_t remaining_size; > >> + > >> start = reg->base; > >> end = start + reg->size; > >> > >> @@ -707,15 +726,19 @@ static void __init setup_vm_final(void) > >> break; > >> if (memblock_is_nomap(reg)) > >> continue; > >> - if (start <= __pa(PAGE_OFFSET) && > >> - __pa(PAGE_OFFSET) < end) > >> - start = __pa(PAGE_OFFSET); > >> > >> - map_size = best_map_size(start, end - start); > >> - for (pa = start; pa < end; pa += map_size) { > >> + pa = start; > >> + remaining_size = reg->size; > >> + > >> + while (remaining_size) { > >> va = (uintptr_t)__va(pa); > >> + map_size = best_map_size(pa, va, remaining_size); > >> + > >> create_pgd_mapping(swapper_pg_dir, va, pa, > >> map_size, PAGE_KERNEL); > >> + > >> + pa += map_size; > >> + remaining_size -= map_size; > >> } > >> } > >> > > This may not work in the RV32 with 2G memory and if the map_size is > > determined to be a page size > > for the last memblock. Both pa & remaining_size will overflow and the > > loop will try to map memory from zero again. > > I'm not sure I understand: if pa starts at 0x8000_0000 and size is 2G, > then pa will overflow in the last iteration, but remaining_size will > then be equal to 0 right ? > Not unless the remaining_size is at least page size aligned. The last remaining size would "fff". It will overflow as well after subtracting the map_size. > And by the way, I realize that this loop only handles sizes that are > aligned on map_size. > Yeah. > Thanks, > > Alex > > > > > >> -- > >> 2.20.1 > >> > >> > >
Hi Atish, Le 6/19/20 à 2:16 PM, Atish Patra a écrit : > On Thu, Jun 18, 2020 at 9:28 PM Alex Ghiti <alex@ghiti.fr> wrote: >> Hi Atish, >> >> Le 6/18/20 à 8:47 PM, Atish Patra a écrit : >>> On Wed, Jun 3, 2020 at 8:38 AM Alexandre Ghiti <alex@ghiti.fr> wrote: >>>> Improve best_map_size so that PUD or PGDIR entries are used for linear >>>> mapping when possible as it allows better TLB utilization. >>>> >>>> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> >>>> --- >>>> arch/riscv/mm/init.c | 45 +++++++++++++++++++++++++++++++++----------- >>>> 1 file changed, 34 insertions(+), 11 deletions(-) >>>> >>>> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c >>>> index 9a5c97e091c1..d275f9f834cf 100644 >>>> --- a/arch/riscv/mm/init.c >>>> +++ b/arch/riscv/mm/init.c >>>> @@ -424,13 +424,29 @@ static void __init create_pgd_mapping(pgd_t *pgdp, >>>> create_pgd_next_mapping(nextp, va, pa, sz, prot); >>>> } >>>> >>>> -static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) >>>> +static bool is_map_size_ok(uintptr_t map_size, phys_addr_t base, >>>> + uintptr_t base_virt, phys_addr_t size) >>>> { >>>> - /* Upgrade to PMD_SIZE mappings whenever possible */ >>>> - if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1))) >>>> - return PAGE_SIZE; >>>> + return !((base & (map_size - 1)) || (base_virt & (map_size - 1)) || >>>> + (size < map_size)); >>>> +} >>>> + >>>> +static uintptr_t __init best_map_size(phys_addr_t base, uintptr_t base_virt, >>>> + phys_addr_t size) >>>> +{ >>>> +#ifndef __PAGETABLE_PMD_FOLDED >>>> + if (is_map_size_ok(PGDIR_SIZE, base, base_virt, size)) >>>> + return PGDIR_SIZE; >>>> + >>>> + if (pgtable_l4_enabled) >>>> + if (is_map_size_ok(PUD_SIZE, base, base_virt, size)) >>>> + return PUD_SIZE; >>>> +#endif >>>> + >>>> + if (is_map_size_ok(PMD_SIZE, base, base_virt, size)) >>>> + return PMD_SIZE; >>>> >>>> - return PMD_SIZE; >>>> + return PAGE_SIZE; >>>> } >>>> >>>> /* >>>> @@ -576,7 +592,7 @@ void create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size) >>>> asmlinkage void __init setup_vm(uintptr_t dtb_pa) >>>> { >>>> uintptr_t va, end_va; >>>> - uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE); >>>> + uintptr_t map_size; >>>> >>>> load_pa = (uintptr_t)(&_start); >>>> load_sz = (uintptr_t)(&_end) - load_pa; >>>> @@ -587,6 +603,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) >>>> >>>> kernel_virt_addr = KERNEL_VIRT_ADDR; >>>> >>>> + map_size = best_map_size(load_pa, PAGE_OFFSET, MAX_EARLY_MAPPING_SIZE); >>>> va_pa_offset = PAGE_OFFSET - load_pa; >>>> va_kernel_pa_offset = kernel_virt_addr - load_pa; >>>> pfn_base = PFN_DOWN(load_pa); >>>> @@ -700,6 +717,8 @@ static void __init setup_vm_final(void) >>>> >>>> /* Map all memory banks */ >>>> for_each_memblock(memory, reg) { >>>> + uintptr_t remaining_size; >>>> + >>>> start = reg->base; >>>> end = start + reg->size; >>>> >>>> @@ -707,15 +726,19 @@ static void __init setup_vm_final(void) >>>> break; >>>> if (memblock_is_nomap(reg)) >>>> continue; >>>> - if (start <= __pa(PAGE_OFFSET) && >>>> - __pa(PAGE_OFFSET) < end) >>>> - start = __pa(PAGE_OFFSET); >>>> >>>> - map_size = best_map_size(start, end - start); >>>> - for (pa = start; pa < end; pa += map_size) { >>>> + pa = start; >>>> + remaining_size = reg->size; >>>> + >>>> + while (remaining_size) { >>>> va = (uintptr_t)__va(pa); >>>> + map_size = best_map_size(pa, va, remaining_size); >>>> + >>>> create_pgd_mapping(swapper_pg_dir, va, pa, >>>> map_size, PAGE_KERNEL); >>>> + >>>> + pa += map_size; >>>> + remaining_size -= map_size; >>>> } >>>> } >>>> >>> This may not work in the RV32 with 2G memory and if the map_size is >>> determined to be a page size >>> for the last memblock. Both pa & remaining_size will overflow and the >>> loop will try to map memory from zero again. >> I'm not sure I understand: if pa starts at 0x8000_0000 and size is 2G, >> then pa will overflow in the last iteration, but remaining_size will >> then be equal to 0 right ? >> > Not unless the remaining_size is at least page size aligned. The last > remaining size would "fff". > It will overflow as well after subtracting the map_size. > >> And by the way, I realize that this loop only handles sizes that are >> aligned on map_size. >> > Yeah. Thanks for noticing, I send a v2. Alex > >> Thanks, >> >> Alex >> >> >>>> -- >>>> 2.20.1 >>>> >>>> > >
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 9a5c97e091c1..d275f9f834cf 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -424,13 +424,29 @@ static void __init create_pgd_mapping(pgd_t *pgdp, create_pgd_next_mapping(nextp, va, pa, sz, prot); } -static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) +static bool is_map_size_ok(uintptr_t map_size, phys_addr_t base, + uintptr_t base_virt, phys_addr_t size) { - /* Upgrade to PMD_SIZE mappings whenever possible */ - if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1))) - return PAGE_SIZE; + return !((base & (map_size - 1)) || (base_virt & (map_size - 1)) || + (size < map_size)); +} + +static uintptr_t __init best_map_size(phys_addr_t base, uintptr_t base_virt, + phys_addr_t size) +{ +#ifndef __PAGETABLE_PMD_FOLDED + if (is_map_size_ok(PGDIR_SIZE, base, base_virt, size)) + return PGDIR_SIZE; + + if (pgtable_l4_enabled) + if (is_map_size_ok(PUD_SIZE, base, base_virt, size)) + return PUD_SIZE; +#endif + + if (is_map_size_ok(PMD_SIZE, base, base_virt, size)) + return PMD_SIZE; - return PMD_SIZE; + return PAGE_SIZE; } /* @@ -576,7 +592,7 @@ void create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size) asmlinkage void __init setup_vm(uintptr_t dtb_pa) { uintptr_t va, end_va; - uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE); + uintptr_t map_size; load_pa = (uintptr_t)(&_start); load_sz = (uintptr_t)(&_end) - load_pa; @@ -587,6 +603,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) kernel_virt_addr = KERNEL_VIRT_ADDR; + map_size = best_map_size(load_pa, PAGE_OFFSET, MAX_EARLY_MAPPING_SIZE); va_pa_offset = PAGE_OFFSET - load_pa; va_kernel_pa_offset = kernel_virt_addr - load_pa; pfn_base = PFN_DOWN(load_pa); @@ -700,6 +717,8 @@ static void __init setup_vm_final(void) /* Map all memory banks */ for_each_memblock(memory, reg) { + uintptr_t remaining_size; + start = reg->base; end = start + reg->size; @@ -707,15 +726,19 @@ static void __init setup_vm_final(void) break; if (memblock_is_nomap(reg)) continue; - if (start <= __pa(PAGE_OFFSET) && - __pa(PAGE_OFFSET) < end) - start = __pa(PAGE_OFFSET); - map_size = best_map_size(start, end - start); - for (pa = start; pa < end; pa += map_size) { + pa = start; + remaining_size = reg->size; + + while (remaining_size) { va = (uintptr_t)__va(pa); + map_size = best_map_size(pa, va, remaining_size); + create_pgd_mapping(swapper_pg_dir, va, pa, map_size, PAGE_KERNEL); + + pa += map_size; + remaining_size -= map_size; } }
Improve best_map_size so that PUD or PGDIR entries are used for linear mapping when possible as it allows better TLB utilization. Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> --- arch/riscv/mm/init.c | 45 +++++++++++++++++++++++++++++++++----------- 1 file changed, 34 insertions(+), 11 deletions(-)