mm/cma: report base address of single range correctly

The cma_declare_contiguous_nid code was refactored by commit c009da4258f9
("mm, cma: support multiple contiguous ranges, if requested"), so that it
could use an internal function to attempt a single range area first, and
then try a multi-range one.

However, that meant that the actual base address used for the !fixed case
(base == 0) wasn't available one level up to be printed in the
informational message, and it would always end up printing a base address
of 0 in the boot message.

Make the internal function take a phys_addr_t pointer to the base address,
so that the value is available to the caller.

[fvdl@google.com: v2]
Link: https://lkml.kernel.org/r/20250408164000.3215690-1-fvdl@google.com
Link: https://lkml.kernel.org/r/20250407165435.2567898-1-fvdl@google.com
Fixes: c009da4258f9 ("mm, cma: support multiple contiguous ranges, if requested")
Signed-off-by: Frank van der Linden <fvdl@google.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Closes: https://lore.kernel.org/linux-mm/CAMuHMdVWviQ7O9yBFE3f=ev0eVb1CnsQvR6SKtEROBbM6z7g3w@mail.gmail.com/
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/cma.c b/mm/cma.c
index b06d5fe73399f2a9232c55fd0fc7b2207b990c48..15632939f20a1e548910d2e626e97e6e8cdb8ee3 100644 (file)
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -35,7 +35,7 @@
 struct cma cma_areas[MAX_CMA_AREAS];
 unsigned int cma_area_count;
 
-static int __init __cma_declare_contiguous_nid(phys_addr_t base,
+static int __init __cma_declare_contiguous_nid(phys_addr_t *basep,
                        phys_addr_t size, phys_addr_t limit,
                        phys_addr_t alignment, unsigned int order_per_bit,
                        bool fixed, const char *name, struct cma **res_cma,
@@ -370,7 +370,7 @@ int __init cma_declare_contiguous_multi(phys_addr_t total_size,
                        phys_addr_t align, unsigned int order_per_bit,
                        const char *name, struct cma **res_cma, int nid)
 {
-       phys_addr_t start, end;
+       phys_addr_t start = 0, end;
        phys_addr_t size, sizesum, sizeleft;
        struct cma_init_memrange *mrp, *mlp, *failed;
        struct cma_memrange *cmrp;
@@ -384,7 +384,7 @@ int __init cma_declare_contiguous_multi(phys_addr_t total_size,
        /*
         * First, try it the normal way, producing just one range.
         */
-       ret = __cma_declare_contiguous_nid(0, total_size, 0, align,
+       ret = __cma_declare_contiguous_nid(&start, total_size, 0, align,
                        order_per_bit, false, name, res_cma, nid);
        if (ret != -ENOMEM)
                goto out;
@@ -580,7 +580,7 @@ int __init cma_declare_contiguous_nid(phys_addr_t base,
 {
        int ret;
 
-       ret = __cma_declare_contiguous_nid(base, size, limit, alignment,
+       ret = __cma_declare_contiguous_nid(&base, size, limit, alignment,
                        order_per_bit, fixed, name, res_cma, nid);
        if (ret != 0)
                pr_err("Failed to reserve %ld MiB\n",
@@ -592,14 +592,14 @@ int __init cma_declare_contiguous_nid(phys_addr_t base,
        return ret;
 }
 
-static int __init __cma_declare_contiguous_nid(phys_addr_t base,
+static int __init __cma_declare_contiguous_nid(phys_addr_t *basep,
                        phys_addr_t size, phys_addr_t limit,
                        phys_addr_t alignment, unsigned int order_per_bit,
                        bool fixed, const char *name, struct cma **res_cma,
                        int nid)
 {
        phys_addr_t memblock_end = memblock_end_of_DRAM();
-       phys_addr_t highmem_start;
+       phys_addr_t highmem_start, base = *basep;
        int ret;
 
        /*
@@ -722,12 +722,15 @@ static int __init __cma_declare_contiguous_nid(phys_addr_t base,
        }
 
        ret = cma_init_reserved_mem(base, size, order_per_bit, name, res_cma);
-       if (ret)
+       if (ret) {
                memblock_phys_free(base, size);
+               return ret;
+       }
 
        (*res_cma)->nid = nid;
+       *basep = base;
 
-       return ret;
+       return 0;
 }
 
 static void cma_debug_show_areas(struct cma *cma)