On 11/10/24 12:53 pm, Ritesh Harjani (IBM) wrote:
This patch refactors all CMA related initialization and alignment code
to within fadump_cma_init() which gets called in the end. This also means
that we keep [reserve_dump_area_start, boot_memory_size] page aligned
during fadump_reserve_mem(). Then later in fadump_cma_init() we extract the
aligned chunk and provide it to CMA. This inherently also fixes an issue in
the current code where the reserve_dump_area_start is not aligned
when the physical memory can have holes and the suitable chunk starts at
an unaligned boundary.
After this we should be able to call fadump_cma_init() independently
later in setup_arch() where pageblock_order is non-zero.
Suggested-by: Sourabh Jain <sourabhjain@xxxxxxxxxxxxx>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
---
arch/powerpc/kernel/fadump.c | 34 ++++++++++++++++++++++------------
1 file changed, 22 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 162327d66982..ffaec625b7a8 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -80,7 +80,7 @@ static struct cma *fadump_cma;
*/
static void __init fadump_cma_init(void)
{
- unsigned long long base, size;
+ unsigned long long base, size, end;
int rc;
if (!fw_dump.fadump_supported || !fw_dump.fadump_enabled ||
@@ -92,8 +92,24 @@ static void __init fadump_cma_init(void)
if (fw_dump.nocma || !fw_dump.boot_memory_size)
return;
+ /*
+ * [base, end) should be reserved during early init in
+ * fadump_reserve_mem(). No need to check this here as
+ * cma_init_reserved_mem() already checks for overlap.
+ * Here we give the aligned chunk of this reserved memory to CMA.
+ */
base = fw_dump.reserve_dump_area_start;
size = fw_dump.boot_memory_size;
+ end = base + size;
+
+ base = ALIGN(base, CMA_MIN_ALIGNMENT_BYTES);
+ end = ALIGN_DOWN(end, CMA_MIN_ALIGNMENT_BYTES);
+ size = end - base;
+
+ if (end <= base) {
+ pr_warn("%s: Too less memory to give to CMA\n", __func__);
+ return;
+ }
rc = cma_init_reserved_mem(base, size, 0, "fadump_cma", &fadump_cma);
if (rc) {
@@ -116,11 +132,12 @@ static void __init fadump_cma_init(void)
/*
* So we now have successfully initialized cma area for fadump.
*/
- pr_info("Initialized 0x%lx bytes cma area at %ldMB from 0x%lx "
+ pr_info("Initialized [0x%llx, %luMB] cma area from [0x%lx, %luMB] "
"bytes of memory reserved for firmware-assisted dump\n",
- cma_get_size(fadump_cma),
- (unsigned long)cma_get_base(fadump_cma) >> 20,
- fw_dump.reserve_dump_area_size);
+ cma_get_base(fadump_cma), cma_get_size(fadump_cma) >> 20,
+ fw_dump.reserve_dump_area_start,
+ fw_dump.boot_memory_size >> 20);
The changes look good. Thanks for looking into it.
For patches 2, 3 & 4
Acked-by: Hari Bathini <hbathini@xxxxxxxxxxxxx>
+ return;
}
#else
static void __init fadump_cma_init(void) { }
@@ -553,13 +570,6 @@ int __init fadump_reserve_mem(void)
if (!fw_dump.dump_active) {
fw_dump.boot_memory_size =
PAGE_ALIGN(fadump_calculate_reserve_size());
-#ifdef CONFIG_CMA
- if (!fw_dump.nocma) {
- fw_dump.boot_memory_size =
- ALIGN(fw_dump.boot_memory_size,
- CMA_MIN_ALIGNMENT_BYTES);
- }
-#endif
bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
if (fw_dump.boot_memory_size < bootmem_min) {
