drivers/of/of_reserved_mem.c | 19 +++++++++++++++++-- include/linux/cma.h | 1 + kernel/dma/contiguous.c | 16 ++++++++++------ 3 files changed, 28 insertions(+), 8 deletions(-)
When initializing the default cma region, the "cma=" kernel parameter
takes priority over a DT defined linux,cma-default region. Hence, give
the reserved_mem framework the ability to detect this so that the DT
defined cma region can skip initialization accordingly.
Signed-off-by: Oreoluwa Babatunde <oreoluwa.babatunde@oss.qualcomm.com>
---
drivers/of/of_reserved_mem.c | 19 +++++++++++++++++--
include/linux/cma.h | 1 +
kernel/dma/contiguous.c | 16 ++++++++++------
3 files changed, 28 insertions(+), 8 deletions(-)
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 2e9ea751ed2d..bef68a4916b5 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -158,7 +158,7 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
phys_addr_t base, size;
int len;
const __be32 *prop;
- bool nomap;
+ bool nomap, default_cma;
prop = of_get_flat_dt_prop(node, "reg", &len);
if (!prop)
@@ -171,6 +171,12 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
}
nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+ default_cma = of_get_flat_dt_prop(node, "linux,cma-default", NULL);
+
+ if (default_cma && cma_skip_dt_default_reserved_mem()) {
+ pr_err("Skipping dt linux,cma-default for \"cma=\" kernel param.\n");
+ return -EINVAL;
+ }
while (len >= t_len) {
base = dt_mem_next_cell(dt_root_addr_cells, &prop);
@@ -256,12 +262,15 @@ void __init fdt_scan_reserved_mem_reg_nodes(void)
fdt_for_each_subnode(child, fdt, node) {
const char *uname;
+ bool default_cma = of_get_flat_dt_prop(child, "linux,cma-default", NULL);
prop = of_get_flat_dt_prop(child, "reg", &len);
if (!prop)
continue;
if (!of_fdt_device_is_available(fdt, child))
continue;
+ if (default_cma && cma_skip_dt_default_reserved_mem())
+ continue;
uname = fdt_get_name(fdt, child, NULL);
if (len && len % t_len != 0) {
@@ -406,7 +415,7 @@ static int __init __reserved_mem_alloc_size(unsigned long node, const char *unam
phys_addr_t base = 0, align = 0, size;
int len;
const __be32 *prop;
- bool nomap;
+ bool nomap, default_cma;
int ret;
prop = of_get_flat_dt_prop(node, "size", &len);
@@ -430,6 +439,12 @@ static int __init __reserved_mem_alloc_size(unsigned long node, const char *unam
}
nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+ default_cma = of_get_flat_dt_prop(node, "linux,cma-default", NULL);
+
+ if (default_cma && cma_skip_dt_default_reserved_mem()) {
+ pr_err("Skipping dt linux,cma-default for \"cma=\" kernel param.\n");
+ return -EINVAL;
+ }
/* Need adjust the alignment to satisfy the CMA requirement */
if (IS_ENABLED(CONFIG_CMA)
diff --git a/include/linux/cma.h b/include/linux/cma.h
index 62d9c1cf6326..3d3047029950 100644
--- a/include/linux/cma.h
+++ b/include/linux/cma.h
@@ -47,6 +47,7 @@ extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
unsigned int order_per_bit,
const char *name,
struct cma **res_cma);
+extern bool cma_skip_dt_default_reserved_mem(void);
extern struct page *cma_alloc(struct cma *cma, unsigned long count, unsigned int align,
bool no_warn);
extern bool cma_pages_valid(struct cma *cma, const struct page *pages, unsigned long count);
diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index d9b9dcba6ff7..9071c08650e3 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -90,6 +90,16 @@ static int __init early_cma(char *p)
}
early_param("cma", early_cma);
+/*
+ * cma_skip_dt_default_reserved_mem - This is called from the
+ * reserved_mem framework to detect if the default cma region is being
+ * set by the "cma=" kernel parameter.
+ */
+bool __init cma_skip_dt_default_reserved_mem(void)
+{
+ return size_cmdline != -1;
+}
+
#ifdef CONFIG_DMA_NUMA_CMA
static struct cma *dma_contiguous_numa_area[MAX_NUMNODES];
@@ -463,12 +473,6 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem)
struct cma *cma;
int err;
- if (size_cmdline != -1 && default_cma) {
- pr_info("Reserved memory: bypass %s node, using cmdline CMA params instead\n",
- rmem->name);
- return -EBUSY;
- }
-
if (!of_get_flat_dt_prop(node, "reusable", NULL) ||
of_get_flat_dt_prop(node, "no-map", NULL))
return -EINVAL;
--
2.34.1On Tue, Dec 09, 2025 at 04:20:27PM -0800, Oreoluwa Babatunde wrote: > When initializing the default cma region, the "cma=" kernel parameter > takes priority over a DT defined linux,cma-default region. Hence, give > the reserved_mem framework the ability to detect this so that the DT > defined cma region can skip initialization accordingly. > Hi Oreoluwa, Have tested i.MX6ULL 9x9, i.MX6ULL 14x14, i.MX6SLL EVK and i.MX7D SABRE-SD boards. Before this patch, i.MX6ULL 9x9 failed to allocate CMA memory when using "cma=" kernel parameter. After applying the patch, CMA allocation works correctly on all tested platforms. Tested-by: Joy Zou <joy.zou@nxp.com> BR Joy Zou > Signed-off-by: Oreoluwa Babatunde <oreoluwa.babatunde@oss.qualcomm.com> > --- > drivers/of/of_reserved_mem.c | 19 +++++++++++++++++-- > include/linux/cma.h | 1 + > kernel/dma/contiguous.c | 16 ++++++++++------ > 3 files changed, 28 insertions(+), 8 deletions(-) > 2.34.1
Hi Oreoluwa, kernel test robot noticed the following build errors: [auto build test ERROR on akpm-mm/mm-everything] [also build test ERROR on v6.18] [cannot apply to robh/for-next linus/master next-20251212] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Oreoluwa-Babatunde/of-reserved_mem-Allow-reserved_mem-framework-detect-cma-kernel-param/20251210-082127 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything patch link: https://lore.kernel.org/r/20251210002027.1171519-1-oreoluwa.babatunde%40oss.qualcomm.com patch subject: [PATCH] of: reserved_mem: Allow reserved_mem framework detect "cma=" kernel param config: arc-randconfig-001-20251212 (https://download.01.org/0day-ci/archive/20251212/202512121907.gdTOodx3-lkp@intel.com/config) compiler: arc-linux-gcc (GCC) 8.5.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251212/202512121907.gdTOodx3-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202512121907.gdTOodx3-lkp@intel.com/ All errors (new ones prefixed by >>): arc-linux-ld: drivers/of/of_reserved_mem.o: in function `fdt_scan_reserved_mem_reg_nodes': >> of_reserved_mem.c:(.init.text+0x46e): undefined reference to `cma_skip_dt_default_reserved_mem' >> arc-linux-ld: of_reserved_mem.c:(.init.text+0x46e): undefined reference to `cma_skip_dt_default_reserved_mem' arc-linux-ld: drivers/of/of_reserved_mem.o: in function `fdt_scan_reserved_mem': of_reserved_mem.c:(.init.text+0x618): undefined reference to `cma_skip_dt_default_reserved_mem' arc-linux-ld: of_reserved_mem.c:(.init.text+0x618): undefined reference to `cma_skip_dt_default_reserved_mem' arc-linux-ld: of_reserved_mem.c:(.init.text+0x77c): undefined reference to `cma_skip_dt_default_reserved_mem' arc-linux-ld: drivers/of/of_reserved_mem.o:of_reserved_mem.c:(.init.text+0x77c): more undefined references to `cma_skip_dt_default_reserved_mem' follow -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
Hi Oreoluwa,
kernel test robot noticed the following build errors:
[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on v6.18]
[cannot apply to robh/for-next linus/master next-20251212]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Oreoluwa-Babatunde/of-reserved_mem-Allow-reserved_mem-framework-detect-cma-kernel-param/20251210-082127
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20251210002027.1171519-1-oreoluwa.babatunde%40oss.qualcomm.com
patch subject: [PATCH] of: reserved_mem: Allow reserved_mem framework detect "cma=" kernel param
config: nios2-randconfig-r073-20251212 (https://download.01.org/0day-ci/archive/20251212/202512121807.G5FMUgvU-lkp@intel.com/config)
compiler: nios2-linux-gcc (GCC) 10.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251212/202512121807.G5FMUgvU-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202512121807.G5FMUgvU-lkp@intel.com/
All errors (new ones prefixed by >>):
nios2-linux-ld: drivers/of/of_reserved_mem.o: in function `__reserved_mem_reserve_reg':
>> drivers/of/of_reserved_mem.c:176: undefined reference to `cma_skip_dt_default_reserved_mem'
>> drivers/of/of_reserved_mem.c:176:(.init.text+0x5b8): relocation truncated to fit: R_NIOS2_CALL26 against `cma_skip_dt_default_reserved_mem'
nios2-linux-ld: drivers/of/of_reserved_mem.o: in function `__reserved_mem_alloc_size':
drivers/of/of_reserved_mem.c:444: undefined reference to `cma_skip_dt_default_reserved_mem'
drivers/of/of_reserved_mem.c:444:(.init.text+0x8a4): relocation truncated to fit: R_NIOS2_CALL26 against `cma_skip_dt_default_reserved_mem'
nios2-linux-ld: drivers/of/of_reserved_mem.o: in function `fdt_scan_reserved_mem_reg_nodes':
drivers/of/of_reserved_mem.c:272: undefined reference to `cma_skip_dt_default_reserved_mem'
drivers/of/of_reserved_mem.c:272:(.init.text+0xbb0): relocation truncated to fit: R_NIOS2_CALL26 against `cma_skip_dt_default_reserved_mem'
vim +176 drivers/of/of_reserved_mem.c
150
151 /*
152 * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
153 */
154 static int __init __reserved_mem_reserve_reg(unsigned long node,
155 const char *uname)
156 {
157 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
158 phys_addr_t base, size;
159 int len;
160 const __be32 *prop;
161 bool nomap, default_cma;
162
163 prop = of_get_flat_dt_prop(node, "reg", &len);
164 if (!prop)
165 return -ENOENT;
166
167 if (len && len % t_len != 0) {
168 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
169 uname);
170 return -EINVAL;
171 }
172
173 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
174 default_cma = of_get_flat_dt_prop(node, "linux,cma-default", NULL);
175
> 176 if (default_cma && cma_skip_dt_default_reserved_mem()) {
177 pr_err("Skipping dt linux,cma-default for \"cma=\" kernel param.\n");
178 return -EINVAL;
179 }
180
181 while (len >= t_len) {
182 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
183 size = dt_mem_next_cell(dt_root_size_cells, &prop);
184
185 if (size && early_init_dt_reserve_memory(base, size, nomap) == 0) {
186 /* Architecture specific contiguous memory fixup. */
187 if (of_flat_dt_is_compatible(node, "shared-dma-pool") &&
188 of_get_flat_dt_prop(node, "reusable", NULL))
189 dma_contiguous_early_fixup(base, size);
190 pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n",
191 uname, &base, (unsigned long)(size / SZ_1M));
192 } else {
193 pr_err("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
194 uname, &base, (unsigned long)(size / SZ_1M));
195 }
196
197 len -= t_len;
198 }
199 return 0;
200 }
201
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
On Tue, Dec 9, 2025 at 6:20 PM Oreoluwa Babatunde
<oreoluwa.babatunde@oss.qualcomm.com> wrote:
>
> When initializing the default cma region, the "cma=" kernel parameter
> takes priority over a DT defined linux,cma-default region. Hence, give
> the reserved_mem framework the ability to detect this so that the DT
> defined cma region can skip initialization accordingly.
Please explain here why this is a new problem. Presumably the
RESERVEDMEM_OF_DECLARE hook after commit xxxx gets called before the
early_param hook. And why is it now earlier?
I don't really like the state/ordering having to be worried about in 2 places.
> Signed-off-by: Oreoluwa Babatunde <oreoluwa.babatunde@oss.qualcomm.com>
> ---
> drivers/of/of_reserved_mem.c | 19 +++++++++++++++++--
> include/linux/cma.h | 1 +
> kernel/dma/contiguous.c | 16 ++++++++++------
> 3 files changed, 28 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> index 2e9ea751ed2d..bef68a4916b5 100644
> --- a/drivers/of/of_reserved_mem.c
> +++ b/drivers/of/of_reserved_mem.c
> @@ -158,7 +158,7 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
> phys_addr_t base, size;
> int len;
> const __be32 *prop;
> - bool nomap;
> + bool nomap, default_cma;
>
> prop = of_get_flat_dt_prop(node, "reg", &len);
> if (!prop)
> @@ -171,6 +171,12 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
> }
>
> nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
> + default_cma = of_get_flat_dt_prop(node, "linux,cma-default", NULL);
> +
> + if (default_cma && cma_skip_dt_default_reserved_mem()) {
> + pr_err("Skipping dt linux,cma-default for \"cma=\" kernel param.\n");
> + return -EINVAL;
> + }
>
> while (len >= t_len) {
> base = dt_mem_next_cell(dt_root_addr_cells, &prop);
> @@ -256,12 +262,15 @@ void __init fdt_scan_reserved_mem_reg_nodes(void)
>
> fdt_for_each_subnode(child, fdt, node) {
> const char *uname;
> + bool default_cma = of_get_flat_dt_prop(child, "linux,cma-default", NULL);
>
> prop = of_get_flat_dt_prop(child, "reg", &len);
> if (!prop)
> continue;
> if (!of_fdt_device_is_available(fdt, child))
> continue;
> + if (default_cma && cma_skip_dt_default_reserved_mem())
> + continue;
>
> uname = fdt_get_name(fdt, child, NULL);
> if (len && len % t_len != 0) {
> @@ -406,7 +415,7 @@ static int __init __reserved_mem_alloc_size(unsigned long node, const char *unam
> phys_addr_t base = 0, align = 0, size;
> int len;
> const __be32 *prop;
> - bool nomap;
> + bool nomap, default_cma;
> int ret;
>
> prop = of_get_flat_dt_prop(node, "size", &len);
> @@ -430,6 +439,12 @@ static int __init __reserved_mem_alloc_size(unsigned long node, const char *unam
> }
>
> nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
> + default_cma = of_get_flat_dt_prop(node, "linux,cma-default", NULL);
> +
> + if (default_cma && cma_skip_dt_default_reserved_mem()) {
> + pr_err("Skipping dt linux,cma-default for \"cma=\" kernel param.\n");
> + return -EINVAL;
> + }
>
> /* Need adjust the alignment to satisfy the CMA requirement */
> if (IS_ENABLED(CONFIG_CMA)
> diff --git a/include/linux/cma.h b/include/linux/cma.h
> index 62d9c1cf6326..3d3047029950 100644
> --- a/include/linux/cma.h
> +++ b/include/linux/cma.h
> @@ -47,6 +47,7 @@ extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
> unsigned int order_per_bit,
> const char *name,
> struct cma **res_cma);
> +extern bool cma_skip_dt_default_reserved_mem(void);
> extern struct page *cma_alloc(struct cma *cma, unsigned long count, unsigned int align,
> bool no_warn);
> extern bool cma_pages_valid(struct cma *cma, const struct page *pages, unsigned long count);
> diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
> index d9b9dcba6ff7..9071c08650e3 100644
> --- a/kernel/dma/contiguous.c
> +++ b/kernel/dma/contiguous.c
> @@ -90,6 +90,16 @@ static int __init early_cma(char *p)
> }
> early_param("cma", early_cma);
>
> +/*
> + * cma_skip_dt_default_reserved_mem - This is called from the
> + * reserved_mem framework to detect if the default cma region is being
> + * set by the "cma=" kernel parameter.
> + */
> +bool __init cma_skip_dt_default_reserved_mem(void)
> +{
> + return size_cmdline != -1;
> +}
> +
> #ifdef CONFIG_DMA_NUMA_CMA
>
> static struct cma *dma_contiguous_numa_area[MAX_NUMNODES];
> @@ -463,12 +473,6 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem)
> struct cma *cma;
> int err;
>
> - if (size_cmdline != -1 && default_cma) {
> - pr_info("Reserved memory: bypass %s node, using cmdline CMA params instead\n",
> - rmem->name);
> - return -EBUSY;
> - }
> -
> if (!of_get_flat_dt_prop(node, "reusable", NULL) ||
> of_get_flat_dt_prop(node, "no-map", NULL))
> return -EINVAL;
> --
> 2.34.1
>
>
Hi Rob,
On 12/10/2025 6:07 AM, Rob Herring wrote:
> On Tue, Dec 9, 2025 at 6:20 PM Oreoluwa Babatunde
> <oreoluwa.babatunde@oss.qualcomm.com> wrote:
>>
>> When initializing the default cma region, the "cma=" kernel parameter
>> takes priority over a DT defined linux,cma-default region. Hence, give
>> the reserved_mem framework the ability to detect this so that the DT
>> defined cma region can skip initialization accordingly.
>
> Please explain here why this is a new problem. Presumably the
> RESERVEDMEM_OF_DECLARE hook after commit xxxx gets called before the
> early_param hook. And why is it now earlier?
ACK. I will add more of this info in the next patch version.
>
> I don't really like the state/ordering having to be worried about in 2 places.
The advantage to having the state visible to the reserved_mem code is that
we can skip adding the DT node to the resrved_mem array since it actually
won't be used.
If this is still not preferred, another option would be to use a helper
function in contiguous.c to call dma_contiguous_early_fixup() for the
reserved_mem code. This way, "size_cmdline" can be checked internally within
the file and it can call dma_contiguous_early_fixup based on that.
>
>> Signed-off-by: Oreoluwa Babatunde <oreoluwa.babatunde@oss.qualcomm.com>
>> ---
>> drivers/of/of_reserved_mem.c | 19 +++++++++++++++++--
>> include/linux/cma.h | 1 +
>> kernel/dma/contiguous.c | 16 ++++++++++------
>> 3 files changed, 28 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
>> index 2e9ea751ed2d..bef68a4916b5 100644
>> --- a/drivers/of/of_reserved_mem.c
>> +++ b/drivers/of/of_reserved_mem.c
>> @@ -158,7 +158,7 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
>> phys_addr_t base, size;
>> int len;
>> const __be32 *prop;
>> - bool nomap;
>> + bool nomap, default_cma;
>>
>> prop = of_get_flat_dt_prop(node, "reg", &len);
>> if (!prop)
>> @@ -171,6 +171,12 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
>> }
>>
>> nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
>> + default_cma = of_get_flat_dt_prop(node, "linux,cma-default", NULL);
>> +
>> + if (default_cma && cma_skip_dt_default_reserved_mem()) {
>> + pr_err("Skipping dt linux,cma-default for \"cma=\" kernel param.\n");
>> + return -EINVAL;
>> + }
>>
>> while (len >= t_len) {
>> base = dt_mem_next_cell(dt_root_addr_cells, &prop);
>> @@ -256,12 +262,15 @@ void __init fdt_scan_reserved_mem_reg_nodes(void)
>>
>> fdt_for_each_subnode(child, fdt, node) {
>> const char *uname;
>> + bool default_cma = of_get_flat_dt_prop(child, "linux,cma-default", NULL);
>>
>> prop = of_get_flat_dt_prop(child, "reg", &len);
>> if (!prop)
>> continue;
>> if (!of_fdt_device_is_available(fdt, child))
>> continue;
>> + if (default_cma && cma_skip_dt_default_reserved_mem())
>> + continue;
>>
>> uname = fdt_get_name(fdt, child, NULL);
>> if (len && len % t_len != 0) {
>> @@ -406,7 +415,7 @@ static int __init __reserved_mem_alloc_size(unsigned long node, const char *unam
>> phys_addr_t base = 0, align = 0, size;
>> int len;
>> const __be32 *prop;
>> - bool nomap;
>> + bool nomap, default_cma;
>> int ret;
>>
>> prop = of_get_flat_dt_prop(node, "size", &len);
>> @@ -430,6 +439,12 @@ static int __init __reserved_mem_alloc_size(unsigned long node, const char *unam
>> }
>>
>> nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
>> + default_cma = of_get_flat_dt_prop(node, "linux,cma-default", NULL);
>> +
>> + if (default_cma && cma_skip_dt_default_reserved_mem()) {
>> + pr_err("Skipping dt linux,cma-default for \"cma=\" kernel param.\n");
>> + return -EINVAL;
>> + }
>>
>> /* Need adjust the alignment to satisfy the CMA requirement */
>> if (IS_ENABLED(CONFIG_CMA)
>> diff --git a/include/linux/cma.h b/include/linux/cma.h
>> index 62d9c1cf6326..3d3047029950 100644
>> --- a/include/linux/cma.h
>> +++ b/include/linux/cma.h
>> @@ -47,6 +47,7 @@ extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
>> unsigned int order_per_bit,
>> const char *name,
>> struct cma **res_cma);
>> +extern bool cma_skip_dt_default_reserved_mem(void);
>> extern struct page *cma_alloc(struct cma *cma, unsigned long count, unsigned int align,
>> bool no_warn);
>> extern bool cma_pages_valid(struct cma *cma, const struct page *pages, unsigned long count);
>> diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
>> index d9b9dcba6ff7..9071c08650e3 100644
>> --- a/kernel/dma/contiguous.c
>> +++ b/kernel/dma/contiguous.c
>> @@ -90,6 +90,16 @@ static int __init early_cma(char *p)
>> }
>> early_param("cma", early_cma);
>>
>> +/*
>> + * cma_skip_dt_default_reserved_mem - This is called from the
>> + * reserved_mem framework to detect if the default cma region is being
>> + * set by the "cma=" kernel parameter.
>> + */
>> +bool __init cma_skip_dt_default_reserved_mem(void)
>> +{
>> + return size_cmdline != -1;
>> +}
>> +
>> #ifdef CONFIG_DMA_NUMA_CMA
>>
>> static struct cma *dma_contiguous_numa_area[MAX_NUMNODES];
>> @@ -463,12 +473,6 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem)
>> struct cma *cma;
>> int err;
>>
>> - if (size_cmdline != -1 && default_cma) {
>> - pr_info("Reserved memory: bypass %s node, using cmdline CMA params instead\n",
>> - rmem->name);
>> - return -EBUSY;
>> - }
>> -
>> if (!of_get_flat_dt_prop(node, "reusable", NULL) ||
>> of_get_flat_dt_prop(node, "no-map", NULL))
>> return -EINVAL;
>> --
>> 2.34.1
>>
>>
Regards,
Oreoluwa
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