| Message ID | 20230316131711.1284451-3-alexghiti@rivosinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | riscv: Use PUD/P4D/PGD pages for the linear mapping | expand |
Hi Alexandre, On Thu, Mar 16, 2023 at 02:17:09PM +0100, Alexandre Ghiti wrote: > This function allows to split a region in memblock.memory and will be > useful when setting up the linear mapping with STRICT_KERNEL_RWX: it > allows to isolate the kernel text/rodata and then avoid to map those > regions with a PUD/P4D/PGD. Sorry I've missed it last time. The changelog is fine in the context of this series, but if you look at it as a part of memblock changelog it doesn't provide enough background on why memblock_isolate_memory() is useful. Can you please add more context so it would be self explanatory? > Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> > Reviewed-by: Anup Patel <anup@brainfault.org> > Tested-by: Anup Patel <anup@brainfault.org> > --- > include/linux/memblock.h | 1 + > mm/memblock.c | 20 ++++++++++++++++++++ > 2 files changed, 21 insertions(+) > > diff --git a/include/linux/memblock.h b/include/linux/memblock.h > index 50ad19662a32..2f7ef97c0da7 100644 > --- a/include/linux/memblock.h > +++ b/include/linux/memblock.h > @@ -125,6 +125,7 @@ int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size); > int memblock_mark_mirror(phys_addr_t base, phys_addr_t size); > int memblock_mark_nomap(phys_addr_t base, phys_addr_t size); > int memblock_clear_nomap(phys_addr_t base, phys_addr_t size); > +int memblock_isolate_memory(phys_addr_t base, phys_addr_t size); > > void memblock_free_all(void); > void memblock_free(void *ptr, size_t size); > diff --git a/mm/memblock.c b/mm/memblock.c > index 25fd0626a9e7..e8c651a37012 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -805,6 +805,26 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type, > return 0; > } > > +/** > + * memblock_isolate_memory - isolate given range in memblock.memory > + * @base: base of range to isolate > + * @size: size of range to isolate > + * > + * Isolates the given range in memblock.memory so that it does not share any > + * region with other ranges. > + * > + * Return: > + * 0 on success, -errno on failure. > + */ > + > +int __init_memblock memblock_isolate_memory(phys_addr_t base, phys_addr_t size) > +{ > + int start_rgn, end_rgn; > + > + return memblock_isolate_range(&memblock.memory, base, size, > + &start_rgn, &end_rgn); > +} > + > static int __init_memblock memblock_remove_range(struct memblock_type *type, > phys_addr_t base, phys_addr_t size) > { > -- > 2.37.2 >
Hi Mike, On 3/16/23 21:12, Mike Rapoport wrote: > Hi Alexandre, > > On Thu, Mar 16, 2023 at 02:17:09PM +0100, Alexandre Ghiti wrote: >> This function allows to split a region in memblock.memory and will be >> useful when setting up the linear mapping with STRICT_KERNEL_RWX: it >> allows to isolate the kernel text/rodata and then avoid to map those >> regions with a PUD/P4D/PGD. > > Sorry I've missed it last time. The changelog is fine in the context of No worries :) > this series, but if you look at it as a part of memblock changelog it > doesn't provide enough background on why memblock_isolate_memory() is > useful. > > Can you please add more context so it would be self explanatory? What about: "memblock.memory contains the list of memory regions and a memory region can cover memory that will be mapped with different permissions. So to ease the mapping process, allow to isolate those regions by introducing a new function called memblock_isolate_memory. This will be used in arch specific code to isolate the kernel text/rodata regions when STRICT_KERNEL_RWX is enabled so that we avoid mapping them with PUD/P4D/PGD mappings." Thanks, Alex > >> Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> >> Reviewed-by: Anup Patel <anup@brainfault.org> >> Tested-by: Anup Patel <anup@brainfault.org> >> --- >> include/linux/memblock.h | 1 + >> mm/memblock.c | 20 ++++++++++++++++++++ >> 2 files changed, 21 insertions(+) >> >> diff --git a/include/linux/memblock.h b/include/linux/memblock.h >> index 50ad19662a32..2f7ef97c0da7 100644 >> --- a/include/linux/memblock.h >> +++ b/include/linux/memblock.h >> @@ -125,6 +125,7 @@ int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size); >> int memblock_mark_mirror(phys_addr_t base, phys_addr_t size); >> int memblock_mark_nomap(phys_addr_t base, phys_addr_t size); >> int memblock_clear_nomap(phys_addr_t base, phys_addr_t size); >> +int memblock_isolate_memory(phys_addr_t base, phys_addr_t size); >> >> void memblock_free_all(void); >> void memblock_free(void *ptr, size_t size); >> diff --git a/mm/memblock.c b/mm/memblock.c >> index 25fd0626a9e7..e8c651a37012 100644 >> --- a/mm/memblock.c >> +++ b/mm/memblock.c >> @@ -805,6 +805,26 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type, >> return 0; >> } >> >> +/** >> + * memblock_isolate_memory - isolate given range in memblock.memory >> + * @base: base of range to isolate >> + * @size: size of range to isolate >> + * >> + * Isolates the given range in memblock.memory so that it does not share any >> + * region with other ranges. >> + * >> + * Return: >> + * 0 on success, -errno on failure. >> + */ >> + >> +int __init_memblock memblock_isolate_memory(phys_addr_t base, phys_addr_t size) >> +{ >> + int start_rgn, end_rgn; >> + >> + return memblock_isolate_range(&memblock.memory, base, size, >> + &start_rgn, &end_rgn); >> +} >> + >> static int __init_memblock memblock_remove_range(struct memblock_type *type, >> phys_addr_t base, phys_addr_t size) >> { >> -- >> 2.37.2 >>
On Mon, Mar 20, 2023 at 11:54:14AM +0100, Alexandre Ghiti wrote: > Hi Mike, > > On 3/16/23 21:12, Mike Rapoport wrote: > > Hi Alexandre, > > > > On Thu, Mar 16, 2023 at 02:17:09PM +0100, Alexandre Ghiti wrote: > > > This function allows to split a region in memblock.memory and will be > > > useful when setting up the linear mapping with STRICT_KERNEL_RWX: it > > > allows to isolate the kernel text/rodata and then avoid to map those > > > regions with a PUD/P4D/PGD. > > Sorry I've missed it last time. The changelog is fine in the context of > > > No worries :) > > > > this series, but if you look at it as a part of memblock changelog it > > doesn't provide enough background on why memblock_isolate_memory() is > > useful. > > > > Can you please add more context so it would be self explanatory? > > > What about: "memblock.memory contains the list of memory regions and a > memory region can cover memory that will be mapped with different > permissions. So to ease the mapping process, allow to isolate those regions > by introducing a new function called memblock_isolate_memory. This will be > used in arch specific code to isolate the kernel text/rodata regions when > STRICT_KERNEL_RWX is enabled so that we avoid mapping them with PUD/P4D/PGD > mappings." With this change ... STRICT_KERNEL_RWX is enabled so that they can be mapped with base pages. Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> > Thanks, > > Alex > > > > > > > Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> > > > Reviewed-by: Anup Patel <anup@brainfault.org> > > > Tested-by: Anup Patel <anup@brainfault.org> > > > --- > > > include/linux/memblock.h | 1 + > > > mm/memblock.c | 20 ++++++++++++++++++++ > > > 2 files changed, 21 insertions(+) > > > > > > diff --git a/include/linux/memblock.h b/include/linux/memblock.h > > > index 50ad19662a32..2f7ef97c0da7 100644 > > > --- a/include/linux/memblock.h > > > +++ b/include/linux/memblock.h > > > @@ -125,6 +125,7 @@ int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size); > > > int memblock_mark_mirror(phys_addr_t base, phys_addr_t size); > > > int memblock_mark_nomap(phys_addr_t base, phys_addr_t size); > > > int memblock_clear_nomap(phys_addr_t base, phys_addr_t size); > > > +int memblock_isolate_memory(phys_addr_t base, phys_addr_t size); > > > void memblock_free_all(void); > > > void memblock_free(void *ptr, size_t size); > > > diff --git a/mm/memblock.c b/mm/memblock.c > > > index 25fd0626a9e7..e8c651a37012 100644 > > > --- a/mm/memblock.c > > > +++ b/mm/memblock.c > > > @@ -805,6 +805,26 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type, > > > return 0; > > > } > > > +/** > > > + * memblock_isolate_memory - isolate given range in memblock.memory > > > + * @base: base of range to isolate > > > + * @size: size of range to isolate > > > + * > > > + * Isolates the given range in memblock.memory so that it does not share any > > > + * region with other ranges. > > > + * > > > + * Return: > > > + * 0 on success, -errno on failure. > > > + */ > > > + > > > +int __init_memblock memblock_isolate_memory(phys_addr_t base, phys_addr_t size) > > > +{ > > > + int start_rgn, end_rgn; > > > + > > > + return memblock_isolate_range(&memblock.memory, base, size, > > > + &start_rgn, &end_rgn); > > > +} > > > + > > > static int __init_memblock memblock_remove_range(struct memblock_type *type, > > > phys_addr_t base, phys_addr_t size) > > > { > > > -- > > > 2.37.2 > > > >
On 3/20/23 18:44, Mike Rapoport wrote: > On Mon, Mar 20, 2023 at 11:54:14AM +0100, Alexandre Ghiti wrote: >> Hi Mike, >> >> On 3/16/23 21:12, Mike Rapoport wrote: >>> Hi Alexandre, >>> >>> On Thu, Mar 16, 2023 at 02:17:09PM +0100, Alexandre Ghiti wrote: >>>> This function allows to split a region in memblock.memory and will be >>>> useful when setting up the linear mapping with STRICT_KERNEL_RWX: it >>>> allows to isolate the kernel text/rodata and then avoid to map those >>>> regions with a PUD/P4D/PGD. >>> Sorry I've missed it last time. The changelog is fine in the context of >> >> No worries :) >> >> >>> this series, but if you look at it as a part of memblock changelog it >>> doesn't provide enough background on why memblock_isolate_memory() is >>> useful. >>> >>> Can you please add more context so it would be self explanatory? >> >> What about: "memblock.memory contains the list of memory regions and a >> memory region can cover memory that will be mapped with different >> permissions. So to ease the mapping process, allow to isolate those regions >> by introducing a new function called memblock_isolate_memory. This will be >> used in arch specific code to isolate the kernel text/rodata regions when >> STRICT_KERNEL_RWX is enabled so that we avoid mapping them with PUD/P4D/PGD >> mappings." > With this change > > ... STRICT_KERNEL_RWX is enabled so that they can be mapped with base pages. Actually they will get mapped with PMD mappings :) I'll just append: "or PMD mapping" to your sentence above if that's ok with you. > > Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Thanks for your review, Alex > >> Thanks, >> >> Alex >> >> >>>> Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> >>>> Reviewed-by: Anup Patel <anup@brainfault.org> >>>> Tested-by: Anup Patel <anup@brainfault.org> >>>> --- >>>> include/linux/memblock.h | 1 + >>>> mm/memblock.c | 20 ++++++++++++++++++++ >>>> 2 files changed, 21 insertions(+) >>>> >>>> diff --git a/include/linux/memblock.h b/include/linux/memblock.h >>>> index 50ad19662a32..2f7ef97c0da7 100644 >>>> --- a/include/linux/memblock.h >>>> +++ b/include/linux/memblock.h >>>> @@ -125,6 +125,7 @@ int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size); >>>> int memblock_mark_mirror(phys_addr_t base, phys_addr_t size); >>>> int memblock_mark_nomap(phys_addr_t base, phys_addr_t size); >>>> int memblock_clear_nomap(phys_addr_t base, phys_addr_t size); >>>> +int memblock_isolate_memory(phys_addr_t base, phys_addr_t size); >>>> void memblock_free_all(void); >>>> void memblock_free(void *ptr, size_t size); >>>> diff --git a/mm/memblock.c b/mm/memblock.c >>>> index 25fd0626a9e7..e8c651a37012 100644 >>>> --- a/mm/memblock.c >>>> +++ b/mm/memblock.c >>>> @@ -805,6 +805,26 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type, >>>> return 0; >>>> } >>>> +/** >>>> + * memblock_isolate_memory - isolate given range in memblock.memory >>>> + * @base: base of range to isolate >>>> + * @size: size of range to isolate >>>> + * >>>> + * Isolates the given range in memblock.memory so that it does not share any >>>> + * region with other ranges. >>>> + * >>>> + * Return: >>>> + * 0 on success, -errno on failure. >>>> + */ >>>> + >>>> +int __init_memblock memblock_isolate_memory(phys_addr_t base, phys_addr_t size) >>>> +{ >>>> + int start_rgn, end_rgn; >>>> + >>>> + return memblock_isolate_range(&memblock.memory, base, size, >>>> + &start_rgn, &end_rgn); >>>> +} >>>> + >>>> static int __init_memblock memblock_remove_range(struct memblock_type *type, >>>> phys_addr_t base, phys_addr_t size) >>>> { >>>> -- >>>> 2.37.2 >>>>
On Thu, Mar 23, 2023 at 12:52:36PM +0100, Alexandre Ghiti wrote: > > On 3/20/23 18:44, Mike Rapoport wrote: > > On Mon, Mar 20, 2023 at 11:54:14AM +0100, Alexandre Ghiti wrote: > > > Hi Mike, > > > > > > On 3/16/23 21:12, Mike Rapoport wrote: > > > > Hi Alexandre, > > > > > > > > On Thu, Mar 16, 2023 at 02:17:09PM +0100, Alexandre Ghiti wrote: > > > > > This function allows to split a region in memblock.memory and will be > > > > > useful when setting up the linear mapping with STRICT_KERNEL_RWX: it > > > > > allows to isolate the kernel text/rodata and then avoid to map those > > > > > regions with a PUD/P4D/PGD. > > > > Sorry I've missed it last time. The changelog is fine in the context of > > > > > > No worries :) > > > > > > > > > > this series, but if you look at it as a part of memblock changelog it > > > > doesn't provide enough background on why memblock_isolate_memory() is > > > > useful. > > > > > > > > Can you please add more context so it would be self explanatory? > > > > > > What about: "memblock.memory contains the list of memory regions and a > > > memory region can cover memory that will be mapped with different > > > permissions. So to ease the mapping process, allow to isolate those regions > > > by introducing a new function called memblock_isolate_memory. This will be > > > used in arch specific code to isolate the kernel text/rodata regions when > > > STRICT_KERNEL_RWX is enabled so that we avoid mapping them with PUD/P4D/PGD > > > mappings." > > With this change > > > > ... STRICT_KERNEL_RWX is enabled so that they can be mapped with base pages. > > > Actually they will get mapped with PMD mappings :) I'll just append: "or PMD > mapping" to your sentence above if that's ok with you. Didn't read the rest of the patches :) .. STRICT_KERNEL_RWX is enabled so that they can be mapped with differently than the rest of the memory. Does it cover the usescases? > > > > Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> > > > Thanks for your review, > > Alex > > > > > > > Thanks, > > > > > > Alex > > > > > > > > > > > Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> > > > > > Reviewed-by: Anup Patel <anup@brainfault.org> > > > > > Tested-by: Anup Patel <anup@brainfault.org> > > > > > --- > > > > > include/linux/memblock.h | 1 + > > > > > mm/memblock.c | 20 ++++++++++++++++++++ > > > > > 2 files changed, 21 insertions(+) > > > > > > > > > > diff --git a/include/linux/memblock.h b/include/linux/memblock.h > > > > > index 50ad19662a32..2f7ef97c0da7 100644 > > > > > --- a/include/linux/memblock.h > > > > > +++ b/include/linux/memblock.h > > > > > @@ -125,6 +125,7 @@ int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size); > > > > > int memblock_mark_mirror(phys_addr_t base, phys_addr_t size); > > > > > int memblock_mark_nomap(phys_addr_t base, phys_addr_t size); > > > > > int memblock_clear_nomap(phys_addr_t base, phys_addr_t size); > > > > > +int memblock_isolate_memory(phys_addr_t base, phys_addr_t size); > > > > > void memblock_free_all(void); > > > > > void memblock_free(void *ptr, size_t size); > > > > > diff --git a/mm/memblock.c b/mm/memblock.c > > > > > index 25fd0626a9e7..e8c651a37012 100644 > > > > > --- a/mm/memblock.c > > > > > +++ b/mm/memblock.c > > > > > @@ -805,6 +805,26 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type, > > > > > return 0; > > > > > } > > > > > +/** > > > > > + * memblock_isolate_memory - isolate given range in memblock.memory > > > > > + * @base: base of range to isolate > > > > > + * @size: size of range to isolate > > > > > + * > > > > > + * Isolates the given range in memblock.memory so that it does not share any > > > > > + * region with other ranges. > > > > > + * > > > > > + * Return: > > > > > + * 0 on success, -errno on failure. > > > > > + */ > > > > > + > > > > > +int __init_memblock memblock_isolate_memory(phys_addr_t base, phys_addr_t size) > > > > > +{ > > > > > + int start_rgn, end_rgn; > > > > > + > > > > > + return memblock_isolate_range(&memblock.memory, base, size, > > > > > + &start_rgn, &end_rgn); > > > > > +} > > > > > + > > > > > static int __init_memblock memblock_remove_range(struct memblock_type *type, > > > > > phys_addr_t base, phys_addr_t size) > > > > > { > > > > > -- > > > > > 2.37.2 > > > > >
On 3/23/23 13:16, Mike Rapoport wrote: > On Thu, Mar 23, 2023 at 12:52:36PM +0100, Alexandre Ghiti wrote: >> On 3/20/23 18:44, Mike Rapoport wrote: >>> On Mon, Mar 20, 2023 at 11:54:14AM +0100, Alexandre Ghiti wrote: >>>> Hi Mike, >>>> >>>> On 3/16/23 21:12, Mike Rapoport wrote: >>>>> Hi Alexandre, >>>>> >>>>> On Thu, Mar 16, 2023 at 02:17:09PM +0100, Alexandre Ghiti wrote: >>>>>> This function allows to split a region in memblock.memory and will be >>>>>> useful when setting up the linear mapping with STRICT_KERNEL_RWX: it >>>>>> allows to isolate the kernel text/rodata and then avoid to map those >>>>>> regions with a PUD/P4D/PGD. >>>>> Sorry I've missed it last time. The changelog is fine in the context of >>>> No worries :) >>>> >>>> >>>>> this series, but if you look at it as a part of memblock changelog it >>>>> doesn't provide enough background on why memblock_isolate_memory() is >>>>> useful. >>>>> >>>>> Can you please add more context so it would be self explanatory? >>>> What about: "memblock.memory contains the list of memory regions and a >>>> memory region can cover memory that will be mapped with different >>>> permissions. So to ease the mapping process, allow to isolate those regions >>>> by introducing a new function called memblock_isolate_memory. This will be >>>> used in arch specific code to isolate the kernel text/rodata regions when >>>> STRICT_KERNEL_RWX is enabled so that we avoid mapping them with PUD/P4D/PGD >>>> mappings." >>> With this change >>> >>> ... STRICT_KERNEL_RWX is enabled so that they can be mapped with base pages. >> >> Actually they will get mapped with PMD mappings :) I'll just append: "or PMD >> mapping" to your sentence above if that's ok with you. > Didn't read the rest of the patches :) > > .. STRICT_KERNEL_RWX is enabled so that they can be mapped with differently > than the rest of the memory. > > Does it cover the usescases? Yes, fine with me! Thanks again > >>> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> >> >> Thanks for your review, >> >> Alex >> >> >>>> Thanks, >>>> >>>> Alex >>>> >>>> >>>>>> Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> >>>>>> Reviewed-by: Anup Patel <anup@brainfault.org> >>>>>> Tested-by: Anup Patel <anup@brainfault.org> >>>>>> --- >>>>>> include/linux/memblock.h | 1 + >>>>>> mm/memblock.c | 20 ++++++++++++++++++++ >>>>>> 2 files changed, 21 insertions(+) >>>>>> >>>>>> diff --git a/include/linux/memblock.h b/include/linux/memblock.h >>>>>> index 50ad19662a32..2f7ef97c0da7 100644 >>>>>> --- a/include/linux/memblock.h >>>>>> +++ b/include/linux/memblock.h >>>>>> @@ -125,6 +125,7 @@ int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size); >>>>>> int memblock_mark_mirror(phys_addr_t base, phys_addr_t size); >>>>>> int memblock_mark_nomap(phys_addr_t base, phys_addr_t size); >>>>>> int memblock_clear_nomap(phys_addr_t base, phys_addr_t size); >>>>>> +int memblock_isolate_memory(phys_addr_t base, phys_addr_t size); >>>>>> void memblock_free_all(void); >>>>>> void memblock_free(void *ptr, size_t size); >>>>>> diff --git a/mm/memblock.c b/mm/memblock.c >>>>>> index 25fd0626a9e7..e8c651a37012 100644 >>>>>> --- a/mm/memblock.c >>>>>> +++ b/mm/memblock.c >>>>>> @@ -805,6 +805,26 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type, >>>>>> return 0; >>>>>> } >>>>>> +/** >>>>>> + * memblock_isolate_memory - isolate given range in memblock.memory >>>>>> + * @base: base of range to isolate >>>>>> + * @size: size of range to isolate >>>>>> + * >>>>>> + * Isolates the given range in memblock.memory so that it does not share any >>>>>> + * region with other ranges. >>>>>> + * >>>>>> + * Return: >>>>>> + * 0 on success, -errno on failure. >>>>>> + */ >>>>>> + >>>>>> +int __init_memblock memblock_isolate_memory(phys_addr_t base, phys_addr_t size) >>>>>> +{ >>>>>> + int start_rgn, end_rgn; >>>>>> + >>>>>> + return memblock_isolate_range(&memblock.memory, base, size, >>>>>> + &start_rgn, &end_rgn); >>>>>> +} >>>>>> + >>>>>> static int __init_memblock memblock_remove_range(struct memblock_type *type, >>>>>> phys_addr_t base, phys_addr_t size) >>>>>> { >>>>>> -- >>>>>> 2.37.2 >>>>>>
diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 50ad19662a32..2f7ef97c0da7 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -125,6 +125,7 @@ int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size); int memblock_mark_mirror(phys_addr_t base, phys_addr_t size); int memblock_mark_nomap(phys_addr_t base, phys_addr_t size); int memblock_clear_nomap(phys_addr_t base, phys_addr_t size); +int memblock_isolate_memory(phys_addr_t base, phys_addr_t size); void memblock_free_all(void); void memblock_free(void *ptr, size_t size); diff --git a/mm/memblock.c b/mm/memblock.c index 25fd0626a9e7..e8c651a37012 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -805,6 +805,26 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type, return 0; } +/** + * memblock_isolate_memory - isolate given range in memblock.memory + * @base: base of range to isolate + * @size: size of range to isolate + * + * Isolates the given range in memblock.memory so that it does not share any + * region with other ranges. + * + * Return: + * 0 on success, -errno on failure. + */ + +int __init_memblock memblock_isolate_memory(phys_addr_t base, phys_addr_t size) +{ + int start_rgn, end_rgn; + + return memblock_isolate_range(&memblock.memory, base, size, + &start_rgn, &end_rgn); +} + static int __init_memblock memblock_remove_range(struct memblock_type *type, phys_addr_t base, phys_addr_t size) {