[PATCH 1/1] of: of_reserved_mem: Ensure cma reserved region not cross the low/high memory

[PATCH 1/1] of: of_reserved_mem: Ensure cma reserved region not cross the low/high memory

[Jason Liu]

Need ensure the cma reserved region not cross the low/high memory boundary
when using the dynamic allocation methond through device-tree, otherwise,
kernel will fail to boot up when cma reserved region cross how/high mem.

Signed-off-by: Jason Liu <jason.hui.liu-3arQi8VN3Tc@public.gmane.org>
Cc: Laura Abbott <labbott-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Frank Rowand <frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
---
 drivers/of/of_reserved_mem.c    | 42 +++++++++++++++++++++++++++++++----------
 include/linux/of_reserved_mem.h |  3 ++-
 2 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 366d8c3..852345a 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -31,11 +31,15 @@
 
 #if defined(CONFIG_HAVE_MEMBLOCK)
 #include <linux/memblock.h>
-int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
-	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
-	phys_addr_t *res_base)
+int __init __weak early_init_dt_alloc_reserved_memory_arch(unsigned long node,
+	phys_addr_t size, phys_addr_t align, phys_addr_t start, phys_addr_t end,
+	bool nomap, phys_addr_t *res_base)
 {
 	phys_addr_t base;
+	phys_addr_t highmem_start;
+
+	highmem_start = __pa(high_memory - 1) + 1;
+
 	/*
 	 * We use __memblock_alloc_base() because memblock_alloc_base()
 	 * panic()s on allocation failure.
@@ -53,15 +57,33 @@ int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
 		return -ENOMEM;
 	}
 
+	/*
+	 * Sanity check for the cma reserved region:If the reserved region
+	 * crosses the low/high memory boundary, try to fix it up and then
+	 * fall back to allocate the cma region from the low mememory space.
+	 */
+
+	if (IS_ENABLED(CONFIG_CMA)
+	    && of_flat_dt_is_compatible(node, "shared-dma-pool")
+	    && of_get_flat_dt_prop(node, "reusable", NULL) && !nomap) {
+		if (base < highmem_start && (base + size) > highmem_start) {
+			memblock_free(base, size);
+			base = memblock_alloc_range(size, align, start,
+						highmem_start, MEMBLOCK_NONE);
+			if (!base)
+				return -ENOMEM;
+		}
+	}
+
 	*res_base = base;
 	if (nomap)
 		return memblock_remove(base, size);
 	return 0;
 }
 #else
-int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
-	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
-	phys_addr_t *res_base)
+int __init __weak early_init_dt_alloc_reserved_memory_arch(unsigned long node,
+	phys_addr_t size, phys_addr_t align, phys_addr_t start, phys_addr_t end,
+	bool nomap, phys_addr_t *res_base)
 {
 	pr_err("Reserved memory not supported, ignoring region 0x%llx%s\n",
 		  size, nomap ? " (nomap)" : "");
@@ -155,8 +177,8 @@ static int __init __reserved_mem_alloc_size(unsigned long node,
 			end = start + dt_mem_next_cell(dt_root_size_cells,
 						       &prop);
 
-			ret = early_init_dt_alloc_reserved_memory_arch(size,
-					align, start, end, nomap, &base);
+			ret = early_init_dt_alloc_reserved_memory_arch(node,
+					size, align, start, end, nomap, &base);
 			if (ret == 0) {
 				pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
 					uname, &base,
@@ -167,8 +189,8 @@ static int __init __reserved_mem_alloc_size(unsigned long node,
 		}
 
 	} else {
-		ret = early_init_dt_alloc_reserved_memory_arch(size, align,
-							0, 0, nomap, &base);
+		ret = early_init_dt_alloc_reserved_memory_arch(node,
+					size, align, 0, 0, nomap, &base);
 		if (ret == 0)
 			pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
 				uname, &base, (unsigned long)size / SZ_1M);
diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
index f8e1992..a6ee451 100644
--- a/include/linux/of_reserved_mem.h
+++ b/include/linux/of_reserved_mem.h
@@ -34,7 +34,8 @@ int of_reserved_mem_device_init_by_idx(struct device *dev,
 				       struct device_node *np, int idx);
 void of_reserved_mem_device_release(struct device *dev);
 
-int early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
+int early_init_dt_alloc_reserved_memory_arch(unsigned long node,
+					     phys_addr_t size,
 					     phys_addr_t align,
 					     phys_addr_t start,
 					     phys_addr_t end,
-- 
1.8.3.2

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Re: [PATCH 1/1] of: of_reserved_mem: Ensure cma reserved region not cross the low/high memory

[Jason Liu]

2016-11-23 19:37 GMT+08:00 Jason Liu <jason.hui.liu-3arQi8VN3Tc@public.gmane.org>:
> Need ensure the cma reserved region not cross the low/high memory boundary
> when using the dynamic allocation methond through device-tree, otherwise,
> kernel will fail to boot up when cma reserved region cross how/high mem.
>
> Signed-off-by: Jason Liu <jason.hui.liu-3arQi8VN3Tc@public.gmane.org>
> Cc: Laura Abbott <labbott-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> Cc: Frank Rowand <frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Cc: Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Cc: stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> ---
>  drivers/of/of_reserved_mem.c    | 42 +++++++++++++++++++++++++++++++----------
>  include/linux/of_reserved_mem.h |  3 ++-
>  2 files changed, 34 insertions(+), 11 deletions(-)


Rob, any comments about this patch?


Jason Liu

>
> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> index 366d8c3..852345a 100644
> --- a/drivers/of/of_reserved_mem.c
> +++ b/drivers/of/of_reserved_mem.c
> @@ -31,11 +31,15 @@
>
>  #if defined(CONFIG_HAVE_MEMBLOCK)
>  #include <linux/memblock.h>
> -int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
> -       phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
> -       phys_addr_t *res_base)
> +int __init __weak early_init_dt_alloc_reserved_memory_arch(unsigned long node,
> +       phys_addr_t size, phys_addr_t align, phys_addr_t start, phys_addr_t end,
> +       bool nomap, phys_addr_t *res_base)
>  {
>         phys_addr_t base;
> +       phys_addr_t highmem_start;
> +
> +       highmem_start = __pa(high_memory - 1) + 1;
> +
>         /*
>          * We use __memblock_alloc_base() because memblock_alloc_base()
>          * panic()s on allocation failure.
> @@ -53,15 +57,33 @@ int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
>                 return -ENOMEM;
>         }
>
> +       /*
> +        * Sanity check for the cma reserved region:If the reserved region
> +        * crosses the low/high memory boundary, try to fix it up and then
> +        * fall back to allocate the cma region from the low mememory space.
> +        */
> +
> +       if (IS_ENABLED(CONFIG_CMA)
> +           && of_flat_dt_is_compatible(node, "shared-dma-pool")
> +           && of_get_flat_dt_prop(node, "reusable", NULL) && !nomap) {
> +               if (base < highmem_start && (base + size) > highmem_start) {
> +                       memblock_free(base, size);
> +                       base = memblock_alloc_range(size, align, start,
> +                                               highmem_start, MEMBLOCK_NONE);
> +                       if (!base)
> +                               return -ENOMEM;
> +               }
> +       }
> +
>         *res_base = base;
>         if (nomap)
>                 return memblock_remove(base, size);
>         return 0;
>  }
>  #else
> -int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
> -       phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
> -       phys_addr_t *res_base)
> +int __init __weak early_init_dt_alloc_reserved_memory_arch(unsigned long node,
> +       phys_addr_t size, phys_addr_t align, phys_addr_t start, phys_addr_t end,
> +       bool nomap, phys_addr_t *res_base)
>  {
>         pr_err("Reserved memory not supported, ignoring region 0x%llx%s\n",
>                   size, nomap ? " (nomap)" : "");
> @@ -155,8 +177,8 @@ static int __init __reserved_mem_alloc_size(unsigned long node,
>                         end = start + dt_mem_next_cell(dt_root_size_cells,
>                                                        &prop);
>
> -                       ret = early_init_dt_alloc_reserved_memory_arch(size,
> -                                       align, start, end, nomap, &base);
> +                       ret = early_init_dt_alloc_reserved_memory_arch(node,
> +                                       size, align, start, end, nomap, &base);
>                         if (ret == 0) {
>                                 pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
>                                         uname, &base,
> @@ -167,8 +189,8 @@ static int __init __reserved_mem_alloc_size(unsigned long node,
>                 }
>
>         } else {
> -               ret = early_init_dt_alloc_reserved_memory_arch(size, align,
> -                                                       0, 0, nomap, &base);
> +               ret = early_init_dt_alloc_reserved_memory_arch(node,
> +                                       size, align, 0, 0, nomap, &base);
>                 if (ret == 0)
>                         pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
>                                 uname, &base, (unsigned long)size / SZ_1M);
> diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
> index f8e1992..a6ee451 100644
> --- a/include/linux/of_reserved_mem.h
> +++ b/include/linux/of_reserved_mem.h
> @@ -34,7 +34,8 @@ int of_reserved_mem_device_init_by_idx(struct device *dev,
>                                        struct device_node *np, int idx);
>  void of_reserved_mem_device_release(struct device *dev);
>
> -int early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
> +int early_init_dt_alloc_reserved_memory_arch(unsigned long node,
> +                                            phys_addr_t size,
>                                              phys_addr_t align,
>                                              phys_addr_t start,
>                                              phys_addr_t end,
> --
> 1.8.3.2
>
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Re: [PATCH 1/1] of: of_reserved_mem: Ensure cma reserved region not cross the low/high memory

[Rob Herring]

On Wed, Nov 23, 2016 at 5:37 AM, Jason Liu <jason.hui.liu-3arQi8VN3Tc@public.gmane.org> wrote:
> Need ensure the cma reserved region not cross the low/high memory boundary
> when using the dynamic allocation methond through device-tree, otherwise,
> kernel will fail to boot up when cma reserved region cross how/high mem.

The kernel command line code setting CMA already deals with this. Why
don't we just call the CMA code (cma_declare_contiguous) to deal with
this?

Rob
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Re: [PATCH 1/1] of: of_reserved_mem: Ensure cma reserved region not cross the low/high memory

[Laura Abbott]

On 12/14/2016 12:45 PM, Rob Herring wrote:
> On Wed, Nov 23, 2016 at 5:37 AM, Jason Liu <jason.hui.liu-3arQi8VN3Tc@public.gmane.org> wrote:
>> Need ensure the cma reserved region not cross the low/high memory boundary
>> when using the dynamic allocation methond through device-tree, otherwise,
>> kernel will fail to boot up when cma reserved region cross how/high mem.
> 
> The kernel command line code setting CMA already deals with this. Why
> don't we just call the CMA code (cma_declare_contiguous) to deal with
> this?
> 
> Rob
> 

That was proposed in the first version[1] but I think this is a generic
problem not specific to CMA. Even non-CMA reservations trying to span
zones could cause problems so the devicetree allocation code should
restrict reservations to a single zone.

Thanks,
Laura


[1] https://marc.info/?l=linux-kernel&m=147928325113103&w=2
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Re: [PATCH 1/1] of: of_reserved_mem: Ensure cma reserved region not cross the low/high memory

[Rob Herring]

On Wed, Dec 14, 2016 at 4:21 PM, Laura Abbott <labbott-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote:
> On 12/14/2016 12:45 PM, Rob Herring wrote:
>> On Wed, Nov 23, 2016 at 5:37 AM, Jason Liu <jason.hui.liu-3arQi8VN3Tc@public.gmane.org> wrote:
>>> Need ensure the cma reserved region not cross the low/high memory boundary
>>> when using the dynamic allocation methond through device-tree, otherwise,
>>> kernel will fail to boot up when cma reserved region cross how/high mem.
>>
>> The kernel command line code setting CMA already deals with this. Why
>> don't we just call the CMA code (cma_declare_contiguous) to deal with
>> this?
>>
>> Rob
>>
>
> That was proposed in the first version[1] but I think this is a generic
> problem not specific to CMA. Even non-CMA reservations trying to span
> zones could cause problems so the devicetree allocation code should
> restrict reservations to a single zone.

Fair enough, but that's not what this patch does. It's only for CMA.

Rob
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Re: [PATCH 1/1] of: of_reserved_mem: Ensure cma reserved region not cross the low/high memory

[Jason Liu]

2016-12-15 21:54 GMT+08:00 Rob Herring <robh+dt@kernel.org>:
> On Wed, Dec 14, 2016 at 4:21 PM, Laura Abbott <labbott@redhat.com> wrote:
>> On 12/14/2016 12:45 PM, Rob Herring wrote:
>>> On Wed, Nov 23, 2016 at 5:37 AM, Jason Liu <jason.hui.liu@nxp.com> wrote:
>>>> Need ensure the cma reserved region not cross the low/high memory boundary
>>>> when using the dynamic allocation methond through device-tree, otherwise,
>>>> kernel will fail to boot up when cma reserved region cross how/high mem.
>>>
>>> The kernel command line code setting CMA already deals with this. Why
>>> don't we just call the CMA code (cma_declare_contiguous) to deal with
>>> this?
>>>
>>> Rob
>>>
>>
>> That was proposed in the first version[1] but I think this is a generic
>> problem not specific to CMA. Even non-CMA reservations trying to span
>> zones could cause problems so the devicetree allocation code should
>> restrict reservations to a single zone.
>
> Fair enough, but that's not what this patch does. It's only for CMA.

I'm only certain that the CMA reservation from the device-tree is not
working now.
and if you guys think that this is not only the CMA but also other
non-CMA reservations
should also have this restriction on the device-tree method. I can
change the patch the patch
as the followings.


diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 366d8c3..7b8857d 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -31,11 +31,15 @@ static int reserved_mem_count;

 #if defined(CONFIG_HAVE_MEMBLOCK)
 #include <linux/memblock.h>
-int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
-       phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
-       phys_addr_t *res_base)
+int __init __weak early_init_dt_alloc_reserved_memory_arch(unsigned long node,
+       phys_addr_t size, phys_addr_t align, phys_addr_t start, phys_addr_t end,
+       bool nomap, phys_addr_t *res_base)
 {
        phys_addr_t base;
+       phys_addr_t highmem_start;
+
+       highmem_start = __pa(high_memory - 1) + 1;
+
        /*
         * We use __memblock_alloc_base() because memblock_alloc_base()
         * panic()s on allocation failure.
@@ -53,15 +57,29 @@ int __init __weak
early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
                return -ENOMEM;
        }

+       /*
+        * Sanity check for the reserved region:If the reserved region
+        * crosses the low/high memory boundary, try to fix it up and then
+        * fall back to allocate region from the low mememory space.
+        */
+
+       if (base < highmem_start && (base + size) > highmem_start) {
+               memblock_free(base, size);
+               base = memblock_alloc_range(size, align, start,
+                                       highmem_start, MEMBLOCK_NONE);
+               if (!base)
+                       return -ENOMEM;
+       }
+

if you guys have good idea, please share or post your patch. This is
really an issue
that reserve memory from the device-tree is broken.

>
> Rob