Re: [PATCH 2/2] powerpc/fadump: avoid holes in boot memory area when fadump is registered
From: Mahesh Jagannath Salgaonkar <hidden>
Date: 2017-05-05 06:56:33
On 05/04/2017 11:24 PM, Hari Bathini wrote:
To register fadump, boot memory area - the size of low memory chunk that is required for a kernel to boot successfully when booted with restricted memory, is assumed to have no holes. But this memory area is currently not protected from hot-remove operations. So, fadump could fail to re-register after a memory hot-remove operation, if memory is removed from boot memory area. To avoid this, ensure that memory from boot memory area is not hot-removed when fadump is registered. Signed-off-by: Hari Bathini <redacted>
Reviewed-by: Mahesh J Salgaonkar <redacted>
quoted hunk ↗ jump to hunk
--- arch/powerpc/include/asm/fadump.h | 1 + arch/powerpc/kernel/fadump.c | 12 ++++++++++++ arch/powerpc/platforms/pseries/hotplug-memory.c | 7 +++++++ 3 files changed, 20 insertions(+)diff --git a/arch/powerpc/include/asm/fadump.h b/arch/powerpc/include/asm/fadump.h index 0031806..609fccc 100644 --- a/arch/powerpc/include/asm/fadump.h +++ b/arch/powerpc/include/asm/fadump.h@@ -198,6 +198,7 @@ struct fad_crash_memory_ranges { unsigned long long size; }; +extern int is_fadump_boot_memory_area(u64 addr, ulong size); extern int early_init_dt_scan_fw_dump(unsigned long node, const char *uname, int depth, void *data); extern int fadump_reserve_mem(void);diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c index 03563c6..ea7dfdc 100644 --- a/arch/powerpc/kernel/fadump.c +++ b/arch/powerpc/kernel/fadump.c@@ -114,6 +114,18 @@ int __init early_init_dt_scan_fw_dump(unsigned long node, return 1; } +/* + * If fadump is registered, check if the memory provided + * falls within boot memory area. + */ +int is_fadump_boot_memory_area(u64 addr, ulong size) +{ + if (!fw_dump.dump_registered) + return 0; + + return (addr + size) > RMA_START && addr <= fw_dump.boot_memory_size; +} + int is_fadump_active(void) { return fw_dump.dump_active;diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c index e104c71..a186b8e 100644 --- a/arch/powerpc/platforms/pseries/hotplug-memory.c +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c@@ -22,6 +22,7 @@ #include <asm/machdep.h> #include <asm/prom.h> #include <asm/sparsemem.h> +#include <asm/fadump.h> #include "pseries.h" static bool rtas_hp_event;@@ -406,6 +407,12 @@ static bool lmb_is_removable(struct of_drconf_cell *lmb) scns_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE; phys_addr = lmb->base_addr; +#ifdef CONFIG_FA_DUMP + /* Don't hot-remove memory that falls in fadump boot memory area */ + if (is_fadump_boot_memory_area(phys_addr, block_sz)) + return false; +#endif + for (i = 0; i < scns_per_block; i++) { pfn = PFN_DOWN(phys_addr); if (!pfn_present(pfn))