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Date: Tue, 16 Apr 2024 13:41:41 +0000
From: Wei Yang <richard.weiyang@gmail.com>
To: skseofh@gmail.com
Cc: robh@kernel.org, saravanak@google.com, rppt@kernel.org,
	akpm@linux-foundation.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Daero Lee <daero_le.lee@samsung.com>
Subject: Re: [PATCH] memblock: add no-map alloc functions
Message-ID: <20240416134141.gnkjj223qlxk6dhr@master>
Reply-To: Wei Yang <richard.weiyang@gmail.com>
References: <20240415142448.333271-1-skseofh@gmail.com>
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On Mon, Apr 15, 2024 at 11:24:48PM +0900, skseofh@gmail.com wrote:
>From: Daero Lee <daero_le.lee@samsung.com>
>
>Like reserved-memory with the no-map property, there are memory regions
>need to be allocated in memblock.memory marked with the
>MEMBLOCK_NOMAP flag, but sholud not be allocated in memblock.reserved.
>
>So, functions were added that find the required memory area in
>memblock.memory, but do not allocate it to memblock.reserved.
>
>The early_init_dt_alloc_reserved_memory_arch function was modified
>using the no-map alloc function.
>
>Signed-off-by: Daero Lee <daero_le.lee@samsung.com>
>---
> drivers/of/of_reserved_mem.c |  9 +++--
> mm/memblock.c                | 78 ++++++++++++++++++++++++++++++++++++
> 2 files changed, 84 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
>index 8236ecae2953..504f2f60689c 100644
>--- a/drivers/of/of_reserved_mem.c
>+++ b/drivers/of/of_reserved_mem.c
>@@ -40,15 +40,18 @@ static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
> 
> 	end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
> 	align = !align ? SMP_CACHE_BYTES : align;
>-	base = memblock_phys_alloc_range(size, align, start, end);
>+	if (nomap) {
>+		base = memblock_phys_alloc_range_nomap(size, align, start, end);
>+	} else {
>+		base = memblock_phys_alloc_range(size, align, start, end);
>+	}
>+	
> 	if (!base)
> 		return -ENOMEM;
> 
> 	*res_base = base;
> 	if (nomap) {
> 		err = memblock_mark_nomap(base, size);
>-		if (err)
>-			memblock_phys_free(base, size);
> 	}
> 
> 	kmemleak_ignore_phys(base);
>diff --git a/mm/memblock.c b/mm/memblock.c
>index d09136e040d3..f103f1ecbfad 100644
>--- a/mm/memblock.c
>+++ b/mm/memblock.c
>@@ -1506,6 +1506,72 @@ phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
> 	return found;
> }
> 
>+phys_addr_t __init memblock_alloc_range_nid_nomap(phys_addr_t size,
>+                                        phys_addr_t align, phys_addr_t start,
>+                                        phys_addr_t end, int nid,
>+                                        bool exact_nid)
>+{
>+        enum memblock_flags flags = choose_memblock_flags();
>+        phys_addr_t found;
>+
>+        if (WARN_ONCE(nid == MAX_NUMNODES, "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead\n"))
>+                nid = NUMA_NO_NODE;
>+
>+        if (!align) {
>+                /* Can't use WARNs this early in boot on powerpc */
>+                dump_stack();
>+                align = SMP_CACHE_BYTES;
>+        }
>+
>+again:
>+        found = memblock_find_in_range_node(size, align, start, end, nid,
>+                                            flags);
>+        if (found)
>+                goto done;

Only find without reserve has no effect on memblock meta data. It seems run
but nothing happens.

What you want to achieve for this function?

-- 
Wei Yang
Help you, Help me