Re: [PATCH 2/2] of: of_reserved_mem: mark nomap memory instead of removing

On Friday 11 Jun 2021 at 11:10:36 (-0600), Rob Herring wrote:

On Fri, Jun 11, 2021 at 7:13 AM Dong Aisheng [off-list ref] wrote:

quoted

Since commit 86588296acbf ("fdt: Properly handle "no-map" field in the memory region"),
nomap memory is changed to call memblock_mark_nomap() instead of
memblock_remove(). But it only changed the reserved memory with fixed
addr and size case in early_init_dt_reserve_memory_arch(), not
including the dynamical allocation by size case in
early_init_dt_alloc_reserved_memory_arch().

Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org

Good practice is to Cc the people involved in referenced commits.
Adding them now. This code is a minefield so I'd like other eyes on
it.

Apologies for the delayed reply -- was away last week.

I've been starring at this for 15 minutes, and still can't see how it
could go wrong, so FWIW:

Reviewed-by: Quentin Perret <redacted>

Thanks,
Quentin

quoted

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
---
 drivers/of/of_reserved_mem.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 367f298a83b2..ebba88395bf8 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c

@@ -42,7 +42,7 @@ static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,

        *res_base = base;
        if (nomap)
-               return memblock_remove(base, size);
+               return memblock_mark_nomap(base, size);

        return memblock_reserve(base, size);
 }

@@ -276,7 +276,7 @@ void __init fdt_init_reserved_mem(void)
                                pr_info("node %s compatible matching fail\n",
                                        rmem->name);
                                if (nomap)
-                                       memblock_add(rmem->base, rmem->size);
+                                       memblock_clear_nomap(rmem->base, rmem->size);
                                else
                                        memblock_free(rmem->base, rmem->size);
                        }
--

2.25.1