On 26/12/2025 11:51, Sumit Garg wrote:
> On Wed, Nov 12, 2025 at 10:28:51PM +0530, Aswin Murugan wrote:
>> The SMEM driver was failing to resolve memory regions on some boards
>> because `dev_of_offset()` + `fdtdec_lookup_phandle()` did not yield a
>> valid DT node. Modernize the code to use driver-model/ofnode accessors
>> and make the probe robust for both DT styles (direct `reg` vs
>> `memory-region` phandle).
>>
>> - qcom_smem_map_memory():
>> * Drop fdtdec path; use dev_read_phandle_with_args() +
>> ofnode_read_resource().
>> * Use dev_read_phandle_with_args() +
>> fnode_read_resource().
>>
>> - qcom_smem_probe():
>> * Try dev_read_addr_size() first (map via <reg>), else fall back to
>> qcom_smem_map_memory() with "memory-region".
>> * Check "qcom,rpm-msg-ram" presence to add second region.
>>
>> - Additionally, SMEM_HOST_COUNT is increased to support newer SMEM
>> versions that include more remote processors. This avoids failures
>> during processor ID checks.
>>
>> Signed-off-by: Aswin Murugan <[email protected]>
>> ---
>> drivers/smem/msm_smem.c | 56 +++++++++++++++++++++++++++++------------
>> 1 file changed, 40 insertions(+), 16 deletions(-)
>
> There was an earlier effort from Casey to import SMEM driver here [1]
> from Linux kernel. But unfortunately that patch-set didn't got reworked
> to make into U-Boot mainline.
>
> Casey, do you have any plans to respin the patch-set? Or it's fine for
> others to take over that patch-set?
If any of you guys would be willing to take it over that would be a huge
help! I'm not sure when I'd get around to it myself. I'm very much
looking forward to getting the memory map from smem at long last :D
I'd appreciate it if you could fixup the authorship/sob on my old
patches if you do resend them.
Thanks and kind regards,
>
> [1] https://patchwork.ozlabs.org/project/uboot/list/?series=433987&state=*
>
> -Sumit
>
>>
>> diff --git a/drivers/smem/msm_smem.c b/drivers/smem/msm_smem.c
>> index ccd145f9afb..b6b92d3530d 100644
>> --- a/drivers/smem/msm_smem.c
>> +++ b/drivers/smem/msm_smem.c
>> @@ -88,7 +88,7 @@ DECLARE_GLOBAL_DATA_PTR;
>> #define SMEM_GLOBAL_HOST 0xfffe
>>
>> /* Max number of processors/hosts in a system */
>> -#define SMEM_HOST_COUNT 10
>> +#define SMEM_HOST_COUNT 25
>>
>> /**
>> * struct smem_proc_comm - proc_comm communication struct (legacy)
>> @@ -821,23 +821,34 @@ static int qcom_smem_enumerate_partitions(struct
>> qcom_smem *smem,
>> static int qcom_smem_map_memory(struct qcom_smem *smem, struct udevice *dev,
>> const char *name, int i)
>> {
>> - struct fdt_resource r;
>> int ret;
>> - int node = dev_of_offset(dev);
>> + struct ofnode_phandle_args args;
>> + struct resource r;
>>
>> - ret = fdtdec_lookup_phandle(gd->fdt_blob, node, name);
>> - if (ret < 0) {
>> - dev_err(dev, "No %s specified\n", name);
>> + if (!dev_read_prop(dev, name, NULL)) {
>> + dev_err(dev, "%s prop not found\n", name);
>> return -EINVAL;
>> }
>>
>> - ret = fdt_get_resource(gd->fdt_blob, ret, "reg", 0, &r);
>> - if (ret)
>> - return ret;
>> + ret = dev_read_phandle_with_args(dev, name, NULL, 0, 0, &args);
>> + if (ret) {
>> + dev_err(dev, "%s phandle read failed\n", name);
>> + return -EINVAL;
>> + }
>>
>> + if (!ofnode_valid(args.node)) {
>> + dev_err(dev, "Invalid node from phandle args\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = ofnode_read_resource(args.node, 0, &r);
>> + if (ret) {
>> + dev_err(dev, "Can't get mmap base address(%d)\n", ret);
>> + return ret;
>> + }
>> smem->regions[i].aux_base = (u32)r.start;
>> - smem->regions[i].size = fdt_resource_size(&r);
>> - smem->regions[i].virt_base = devm_ioremap(dev, r.start,
>> fdt_resource_size(&r));
>> + smem->regions[i].size = resource_size(&r);
>> + smem->regions[i].virt_base = devm_ioremap(dev, r.start,
>> resource_size(&r));
>> if (!smem->regions[i].virt_base)
>> return -ENOMEM;
>>
>> @@ -852,10 +863,14 @@ static int qcom_smem_probe(struct udevice *dev)
>> int num_regions;
>> u32 version;
>> int ret;
>> - int node = dev_of_offset(dev);
>> + fdt_addr_t addr;
>> + fdt_size_t size;
>> +
>> + if (__smem)
>> + return 0;
>>
>> num_regions = 1;
>> - if (fdtdec_lookup_phandle(gd->fdt_blob, node, "qcomrpm-msg-ram") >= 0)
>> + if (dev_read_prop(dev, "qcom,rpm-msg-ram", NULL))
>> num_regions++;
>>
>> array_size = num_regions * sizeof(struct smem_region);
>> @@ -866,9 +881,18 @@ static int qcom_smem_probe(struct udevice *dev)
>> smem->dev = dev;
>> smem->num_regions = num_regions;
>>
>> - ret = qcom_smem_map_memory(smem, dev, "memory-region", 0);
>> - if (ret)
>> - return ret;
>> + addr = dev_read_addr_size(dev, &size);
>> + if (addr == FDT_ADDR_T_NONE) {
>> + ret = qcom_smem_map_memory(smem, dev, "memory-region", 0);
>> + if (ret)
>> + return ret;
>> + } else {
>> + smem->regions[0].aux_base = (u32)addr;
>> + smem->regions[0].size = size;
>> + smem->regions[0].virt_base = devm_ioremap(dev, addr, size);
>> + if (!smem->regions[0].virt_base)
>> + return -ENOMEM;
>> + }
>>
>> if (num_regions > 1) {
>> ret = qcom_smem_map_memory(smem, dev,
>> --
>> 2.34.1
>>
--
// Casey (she/her)
