From: Miles Chen <miles.chen@xxxxxxxxxxxx> Subject: mm/sparse: fix check_usemap_section_nr warnings I see a "virt_to_phys used for non-linear address" warning from check_usemap_section_nr() on arm64 platforms. In current implementation of NODE_DATA, if CONFIG_NEED_MULTIPLE_NODES=y, pglist_data is dynamically allocated and assigned to node_data[]. For example, in arch/arm64/include/asm/mmzone.h: extern struct pglist_data *node_data[]; \#define NODE_DATA(nid) (node_data[(nid)]) If CONFIG_NEED_MULTIPLE_NODES=n, pglist_data is defined as a global variable named "contig_page_data". For example, in include/linux/mmzone.h: extern struct pglist_data contig_page_data; \#define NODE_DATA(nid) (&contig_page_data) If CONFIG_DEBUG_VIRTUAL is not enabled, __pa() can handle both dynamically allocated linear addresses and symbol addresses. However, if (CONFIG_DEBUG_VIRTUAL=y && CONFIG_NEED_MULTIPLE_NODES=n) ,we can see the "virt_to_phys used for non-linear address" warning because that &contig_page_data is not a linear address on arm64. To fix it, create a small function to handle both translation. Warning message: [ 0.000000] ------------[ cut here ]------------ [ 0.000000] virt_to_phys used for non-linear address: (____ptrval____) (contig_page_data+0x0/0x1c00) [ 0.000000] WARNING: CPU: 0 PID: 0 at arch/arm64/mm/physaddr.c:15 __virt_to_phys+0x58/0x68 [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Tainted: G W 5.13.0-rc1-00074-g1140ab592e2e #3 [ 0.000000] Hardware name: linux,dummy-virt (DT) [ 0.000000] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO BTYPE=--) [ 0.000000] pc : __virt_to_phys+0x58/0x68 [ 0.000000] lr : __virt_to_phys+0x54/0x68 [ 0.000000] sp : ffff800011833e70 [ 0.000000] x29: ffff800011833e70 x28: 00000000418a0018 x27: 0000000000000000 [ 0.000000] x26: 000000000000000a x25: ffff800011b70000 x24: ffff800011b70000 [ 0.000000] x23: fffffc0001c00000 x22: ffff800011b70000 x21: 0000000047ffffb0 [ 0.000000] x20: 0000000000000008 x19: ffff800011b082c0 x18: ffffffffffffffff [ 0.000000] x17: 0000000000000000 x16: ffff800011833bf9 x15: 0000000000000004 [ 0.000000] x14: 0000000000000fff x13: ffff80001186a548 x12: 0000000000000000 [ 0.000000] x11: 0000000000000000 x10: 00000000ffffffff x9 : 0000000000000000 [ 0.000000] x8 : ffff8000115c9000 x7 : 737520737968705f x6 : ffff800011b62ef8 [ 0.000000] x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000 [ 0.000000] x2 : 0000000000000000 x1 : ffff80001159585e x0 : 0000000000000058 [ 0.000000] Call trace: [ 0.000000] __virt_to_phys+0x58/0x68 [ 0.000000] check_usemap_section_nr+0x50/0xfc [ 0.000000] sparse_init_nid+0x1ac/0x28c [ 0.000000] sparse_init+0x1c4/0x1e0 [ 0.000000] bootmem_init+0x60/0x90 [ 0.000000] setup_arch+0x184/0x1f0 [ 0.000000] start_kernel+0x78/0x488 [ 0.000000] ---[ end trace f68728a0d3053b60 ]--- Link: https://lkml.kernel.org/r/1623058729-27264-1-git-send-email-miles.chen@xxxxxxxxxxxx Signed-off-by: Miles Chen <miles.chen@xxxxxxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxx> Cc: Baoquan He <bhe@xxxxxxxxxx> Cc: Kazu <k-hagio-ab@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/sparse.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) --- a/mm/sparse.c~mm-sparse-fix-check_usemap_section_nr-warnings +++ a/mm/sparse.c @@ -344,6 +344,15 @@ size_t mem_section_usage_size(void) return sizeof(struct mem_section_usage) + usemap_size(); } +static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat) +{ +#ifndef CONFIG_NEED_MULTIPLE_NODES + return __pa_symbol(pgdat); +#else + return __pa(pgdat); +#endif +} + #ifdef CONFIG_MEMORY_HOTREMOVE static struct mem_section_usage * __init sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat, @@ -362,7 +371,7 @@ sparse_early_usemaps_alloc_pgdat_section * from the same section as the pgdat where possible to avoid * this problem. */ - goal = __pa(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT); + goal = pgdat_to_phys(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT); limit = goal + (1UL << PA_SECTION_SHIFT); nid = early_pfn_to_nid(goal >> PAGE_SHIFT); again: @@ -390,7 +399,7 @@ static void __init check_usemap_section_ } usemap_snr = pfn_to_section_nr(__pa(usage) >> PAGE_SHIFT); - pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT); + pgdat_snr = pfn_to_section_nr(pgdat_to_phys(pgdat) >> PAGE_SHIFT); if (usemap_snr == pgdat_snr) return; _
