| Message ID | 20211210065533.2023-10-thunder.leizhen@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | support reserving crashkernel above 4G on arm64 kdump | expand |
On Fri, 10 Dec 2021 14:55:32 +0800, Zhen Lei wrote: > From: Chen Zhou <chenzhou10@huawei.com> > > When reserving crashkernel in high memory, some low memory is reserved > for crash dump kernel devices and never mapped by the first kernel. > This memory range is advertised to crash dump kernel via DT property > under /chosen, > linux,usable-memory-range = <BASE1 SIZE1 [BASE2 SIZE2]> > > We reused the DT property linux,usable-memory-range and made the low > memory region as the second range "BASE2 SIZE2", which keeps compatibility > with existing user-space and older kdump kernels. > > Crash dump kernel reads this property at boot time and call memblock_add() > to add the low memory region after memblock_cap_memory_range() has been > called. > > Signed-off-by: Chen Zhou <chenzhou10@huawei.com> > Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> > Tested-by: Dave Kleikamp <dave.kleikamp@oracle.com> > --- > drivers/of/fdt.c | 33 +++++++++++++++++++++++---------- > 1 file changed, 23 insertions(+), 10 deletions(-) > Reviewed-by: Rob Herring <robh@kernel.org>
On 12/10/21 12:55 AM, Zhen Lei wrote: > From: Chen Zhou <chenzhou10@huawei.com> > > When reserving crashkernel in high memory, some low memory is reserved > for crash dump kernel devices and never mapped by the first kernel. > This memory range is advertised to crash dump kernel via DT property > under /chosen, > linux,usable-memory-range = <BASE1 SIZE1 [BASE2 SIZE2]> > > We reused the DT property linux,usable-memory-range and made the low > memory region as the second range "BASE2 SIZE2", which keeps compatibility > with existing user-space and older kdump kernels. > > Crash dump kernel reads this property at boot time and call memblock_add() > to add the low memory region after memblock_cap_memory_range() has been > called. > > Signed-off-by: Chen Zhou <chenzhou10@huawei.com> > Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> > Tested-by: Dave Kleikamp <dave.kleikamp@oracle.com> Acked-by: John Donnelly <john.p.donnelly@oracle.com> > --- > drivers/of/fdt.c | 33 +++++++++++++++++++++++---------- > 1 file changed, 23 insertions(+), 10 deletions(-) > > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index 37b477a51175359..f7b72fa773250ad 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -967,6 +967,15 @@ static void __init early_init_dt_check_for_elfcorehdr(unsigned long node) > > static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; > > +/* > + * The main usage of linux,usable-memory-range is for crash dump kernel. > + * Originally, the number of usable-memory regions is one. Now there may > + * be two regions, low region and high region. > + * To make compatibility with existing user-space and older kdump, the low > + * region is always the last range of linux,usable-memory-range if exist. > + */ > +#define MAX_USABLE_RANGES 2 > + > /** > * early_init_dt_check_for_usable_mem_range - Decode usable memory range > * location from flat tree > @@ -974,10 +983,9 @@ static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; > */ > static void __init early_init_dt_check_for_usable_mem_range(unsigned long node) > { > - const __be32 *prop; > - int len; > - phys_addr_t cap_mem_addr; > - phys_addr_t cap_mem_size; > + struct memblock_region rgn[MAX_USABLE_RANGES] = {0}; > + const __be32 *prop, *endp; > + int len, i; > > if ((long)node < 0) > return; > @@ -985,16 +993,21 @@ static void __init early_init_dt_check_for_usable_mem_range(unsigned long node) > pr_debug("Looking for usable-memory-range property... "); > > prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); > - if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells))) > + if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells))) > return; > > - cap_mem_addr = dt_mem_next_cell(dt_root_addr_cells, &prop); > - cap_mem_size = dt_mem_next_cell(dt_root_size_cells, &prop); > + endp = prop + (len / sizeof(__be32)); > + for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) { > + rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop); > + rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop); > > - pr_debug("cap_mem_start=%pa cap_mem_size=%pa\n", &cap_mem_addr, > - &cap_mem_size); > + pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n", > + i, &rgn[i].base, &rgn[i].size); > + } > > - memblock_cap_memory_range(cap_mem_addr, cap_mem_size); > + memblock_cap_memory_range(rgn[0].base, rgn[0].size); > + for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++) > + memblock_add(rgn[i].base, rgn[i].size); > } > > #ifdef CONFIG_SERIAL_EARLYCON
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 37b477a51175359..f7b72fa773250ad 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -967,6 +967,15 @@ static void __init early_init_dt_check_for_elfcorehdr(unsigned long node) static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; +/* + * The main usage of linux,usable-memory-range is for crash dump kernel. + * Originally, the number of usable-memory regions is one. Now there may + * be two regions, low region and high region. + * To make compatibility with existing user-space and older kdump, the low + * region is always the last range of linux,usable-memory-range if exist. + */ +#define MAX_USABLE_RANGES 2 + /** * early_init_dt_check_for_usable_mem_range - Decode usable memory range * location from flat tree @@ -974,10 +983,9 @@ static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; */ static void __init early_init_dt_check_for_usable_mem_range(unsigned long node) { - const __be32 *prop; - int len; - phys_addr_t cap_mem_addr; - phys_addr_t cap_mem_size; + struct memblock_region rgn[MAX_USABLE_RANGES] = {0}; + const __be32 *prop, *endp; + int len, i; if ((long)node < 0) return; @@ -985,16 +993,21 @@ static void __init early_init_dt_check_for_usable_mem_range(unsigned long node) pr_debug("Looking for usable-memory-range property... "); prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); - if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells))) + if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells))) return; - cap_mem_addr = dt_mem_next_cell(dt_root_addr_cells, &prop); - cap_mem_size = dt_mem_next_cell(dt_root_size_cells, &prop); + endp = prop + (len / sizeof(__be32)); + for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) { + rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop); + rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop); - pr_debug("cap_mem_start=%pa cap_mem_size=%pa\n", &cap_mem_addr, - &cap_mem_size); + pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n", + i, &rgn[i].base, &rgn[i].size); + } - memblock_cap_memory_range(cap_mem_addr, cap_mem_size); + memblock_cap_memory_range(rgn[0].base, rgn[0].size); + for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++) + memblock_add(rgn[i].base, rgn[i].size); } #ifdef CONFIG_SERIAL_EARLYCON