On 10/11/24 8:30 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>
> Acked-by: Hari Bathini <hbathini@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;
> + }
>
just minor, other prints are all "cma", any reason for "CMA" here?
> 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);
> + 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) {
