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>
---
* No changes since v1.
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 60b9108..d3e1e18 100644
--- a/arch/powerpc/include/asm/fadump.h
+++ b/arch/powerpc/include/asm/fadump.h
@@ -200,6 +200,7 @@ 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 e4e1a14..4ba7db9 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -113,6 +113,18 @@ 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))
