From fb319e77a0e70b9ccfef87827d34b10d6bc2ccce Mon Sep 17 00:00:00 2001 From: Chen Zhou Date: Fri, 6 May 2022 19:44:00 +0800 Subject: of: fdt: Add memory for devices by DT property "linux,usable-memory-range" 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 = 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 Co-developed-by: Zhen Lei Signed-off-by: Zhen Lei Reviewed-by: Rob Herring Tested-by: Dave Kleikamp Acked-by: Baoquan He Link: https://lore.kernel.org/r/20220506114402.365-5-thunder.leizhen@huawei.com Signed-off-by: Catalin Marinas --- drivers/of/fdt.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) (limited to 'drivers') diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index ec315b060cd5..2f248d0acc04 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -973,16 +973,24 @@ 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 */ void __init early_init_dt_check_for_usable_mem_range(void) { - 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; unsigned long node = chosen_node_offset; if ((long)node < 0) @@ -991,16 +999,21 @@ void __init early_init_dt_check_for_usable_mem_range(void) 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 -- cgit v1.2.3 From 8af6b91f58341325bf74ecb0389ddc0039091d84 Mon Sep 17 00:00:00 2001 From: Zhen Lei Date: Fri, 6 May 2022 19:44:01 +0800 Subject: of: Support more than one crash kernel regions for kexec -s When "crashkernel=X,high" is used, there may be two crash regions: high=crashk_res and low=crashk_low_res. But now the syscall kexec_file_load() only add crashk_res into "linux,usable-memory-range", this may cause the second kernel to have no available dma memory. Fix it like kexec-tools does for option -c, add both 'high' and 'low' regions into the dtb. Signed-off-by: Zhen Lei Acked-by: Rob Herring Acked-by: Baoquan He Link: https://lore.kernel.org/r/20220506114402.365-6-thunder.leizhen@huawei.com Signed-off-by: Catalin Marinas --- drivers/of/kexec.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'drivers') diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c index b9bd1cff1793..8d374cc552be 100644 --- a/drivers/of/kexec.c +++ b/drivers/of/kexec.c @@ -386,6 +386,15 @@ void *of_kexec_alloc_and_setup_fdt(const struct kimage *image, crashk_res.end - crashk_res.start + 1); if (ret) goto out; + + if (crashk_low_res.end) { + ret = fdt_appendprop_addrrange(fdt, 0, chosen_node, + "linux,usable-memory-range", + crashk_low_res.start, + crashk_low_res.end - crashk_low_res.start + 1); + if (ret) + goto out; + } } /* add bootargs */ -- cgit v1.2.3