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 <hbath...@linux.vnet.ibm.com>
Reviewed-by: Mahesh J Salgaonkar <mah...@linux.vnet.ibm.com>
> ---
> 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))
>
