| Message ID | 20170328065130.16019-1-takahiro.akashi@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 28 March 2017 at 07:51, AKASHI Takahiro <takahiro.akashi@linaro.org> wrote: > Crash dump kernel uses only a limited range of available memory as System > RAM. On arm64 kdump, This memory range is advertised to crash dump kernel > via a device-tree property under /chosen, > linux,usable-memory-range = <BASE SIZE> > > Crash dump kernel reads this property at boot time and calls > memblock_cap_memory_range() to limit usable memory which are listed either > in UEFI memory map table or "memory" nodes of a device tree blob. > > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> > Reviewed-by: Geoff Levand <geoff@infradead.org> > Acked-by: Catalin Marinas <catalin.marinas@arm.com> > Acked-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > arch/arm64/mm/init.c | 35 +++++++++++++++++++++++++++++++++++ > 1 file changed, 35 insertions(+) > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index e19e06593e37..290794b1a0f1 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -188,10 +188,45 @@ static int __init early_mem(char *p) > } > early_param("mem", early_mem); > > +static int __init early_init_dt_scan_usablemem(unsigned long node, > + const char *uname, int depth, void *data) > +{ > + struct memblock_region *usablemem = data; > + const __be32 *reg; > + int len; > + > + if (depth != 1 || strcmp(uname, "chosen") != 0) > + return 0; > + > + reg = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); > + if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells))) > + return 1; > + > + usablemem->base = dt_mem_next_cell(dt_root_addr_cells, ®); > + usablemem->size = dt_mem_next_cell(dt_root_size_cells, ®); > + > + return 1; > +} > + > +static void __init fdt_enforce_memory_region(void) > +{ > + struct memblock_region reg = { > + .size = 0, > + }; > + > + of_scan_flat_dt(early_init_dt_scan_usablemem, ®); > + > + if (reg.size) > + memblock_cap_memory_range(reg.base, reg.size); > +} > + > void __init arm64_memblock_init(void) > { > const s64 linear_region_size = -(s64)PAGE_OFFSET; > > + /* Handle linux,usable-memory-range property */ > + fdt_enforce_memory_region(); > + > /* > * Ensure that the linear region takes up exactly half of the kernel > * virtual address space. This way, we can distinguish a linear address > -- > 2.11.1 >
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index e19e06593e37..290794b1a0f1 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -188,10 +188,45 @@ static int __init early_mem(char *p) } early_param("mem", early_mem); +static int __init early_init_dt_scan_usablemem(unsigned long node, + const char *uname, int depth, void *data) +{ + struct memblock_region *usablemem = data; + const __be32 *reg; + int len; + + if (depth != 1 || strcmp(uname, "chosen") != 0) + return 0; + + reg = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); + if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells))) + return 1; + + usablemem->base = dt_mem_next_cell(dt_root_addr_cells, ®); + usablemem->size = dt_mem_next_cell(dt_root_size_cells, ®); + + return 1; +} + +static void __init fdt_enforce_memory_region(void) +{ + struct memblock_region reg = { + .size = 0, + }; + + of_scan_flat_dt(early_init_dt_scan_usablemem, ®); + + if (reg.size) + memblock_cap_memory_range(reg.base, reg.size); +} + void __init arm64_memblock_init(void) { const s64 linear_region_size = -(s64)PAGE_OFFSET; + /* Handle linux,usable-memory-range property */ + fdt_enforce_memory_region(); + /* * Ensure that the linear region takes up exactly half of the kernel * virtual address space. This way, we can distinguish a linear address