[PATCH 4/8] ram: k3-ddrss: Add support for a partial inline ECC region

[Neha Malcom Francis]

Hi Wadim

On 28-Jan-25 10:43 AM, Wadim Egorov wrote:
> Am 27.01.25 um 21:22 schrieb Neha Malcom Francis:
>> Instead of defaulting to choosing the entire DDR region when enabling
>> inline ECC, allow picking of a range within the DDR space using DT to
>> enable.
>>
>> It expects such a node within the memory node, in the absence of which
>> we resort to enabling inline ECC for the entire DDR region:
>>
>> inline_ecc: protected at 9e780000 {
>>          device_type = "ecc";
>>          reg = <0x9e780000 0x0080000>;
>>          bootph-all;
>> };
>>
>> Signed-off-by: Neha Malcom Francis <n-francis at ti.com>
> 
> I'm not sure what went wrong, but I had difficulties applying this 
> patch. I had to use git am --reject and manually resolve a few blocks.
> 

This shouldn't have been the case, sorry about that; probably I didn't 
base it on the latest tip; will rebase and send again.
> 
>> ---
>>   drivers/ram/k3-ddrss/k3-ddrss.c | 52 +++++++++++++++++++++++++++++++--
>>   1 file changed, 49 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/ram/k3-ddrss/k3-ddrss.c 
>> b/drivers/ram/k3-ddrss/k3-ddrss.c
>> index ab46098adbf..ea2578cda58 100644
>> --- a/drivers/ram/k3-ddrss/k3-ddrss.c
>> +++ b/drivers/ram/k3-ddrss/k3-ddrss.c
>> @@ -149,6 +149,7 @@ struct k3_ddrss_desc {
>>       lpddr4_obj *driverdt;
>>       lpddr4_config config;
>>       lpddr4_privatedata pd;
>> +    struct k3_ddrss_ecc_region ecc_range;
>>       struct k3_ddrss_ecc_region ecc_regions[K3_DDRSS_MAX_ECC_REGIONS];
>>       u64 ecc_reserved_space;
>>       u64 ddr_bank_base[CONFIG_NR_DRAM_BANKS];
>> @@ -711,6 +712,30 @@ static void 
>> k3_ddrss_ddr_bank_base_size_calc(struct k3_ddrss_desc *ddrss)
>>           ddrss->ddr_ram_size += ddrss->ddr_bank_size[bank];
>>   }
>> +static void k3_ddrss_ddr_inline_ecc_base_size_calc(struct 
>> k3_ddrss_ecc_region *range)
>> +{
>> +    fdt_addr_t base;
>> +    fdt_size_t size;
>> +    ofnode node1;
>> +
>> +    node1 = ofnode_null();
>> +
>> +    do {
>> +        node1 = ofnode_by_prop_value(node1, "device_type", "ecc", 4);
>> +    } while (!ofnode_is_enabled(node1));
>> +
>> +    base = ofnode_get_addr_size(node1, "reg", &size);
>> +
>> +    if (base == FDT_ADDR_T_NONE) {
>> +        debug("%s: Failed to get ECC node reg and size\n", __func__);
>> +        range->start = 0;
>> +        range->range = 0;
>> +    } else {
>> +        range->start = base;
>> +        range->range = size;
>> +    }
>> +}
>> +
>>   static void k3_ddrss_lpddr4_ecc_calc_reserved_mem(struct 
>> k3_ddrss_desc *ddrss)
>>   {
>>       fdtdec_setup_mem_size_base_lowest();
>> @@ -759,8 +784,11 @@ static void k3_ddrss_lpddr4_ecc_init(struct 
>> k3_ddrss_desc *ddrss)
>>   static int k3_ddrss_probe(struct udevice *dev)
>>   {
>> +    u64 end;
>>       int ret;
>>       struct k3_ddrss_desc *ddrss = dev_get_priv(dev);
>> +    __maybe_unused struct k3_ddrss_data *ddrss_data = (struct 
>> k3_ddrss_data *)dev_get_driver_data(dev);
>> +    __maybe_unused struct k3_ddrss_ecc_region *range = 
>> &ddrss->ecc_range;
>>       debug("%s(dev=%p)\n", __func__, dev);
>> @@ -802,9 +830,27 @@ static int k3_ddrss_probe(struct udevice *dev)
>>           k3_ddrss_lpddr4_ecc_calc_reserved_mem(ddrss);
>> -        /* Always configure one region that covers full DDR space */
>> -        ddrss->ecc_regions[0].start = ddrss->ddr_bank_base[0] - 
>> ddrss->ddr_bank_base[0];
>> -        ddrss->ecc_regions[0].range = ddrss->ddr_ram_size - 
>> ddrss->ecc_reserved_space;
>> +        k3_ddrss_ddr_inline_ecc_base_size_calc(range);
>> +        if (!range->range) {
>> +            /* Configure entire DDR space by default */
>> +            debug("%s: Defaulting to protecting entire DDR space 
>> using inline ECC\n",
>> +                  __func__);
>> +            ddrss->ecc_range.start = ddrss->ddr_bank_base[0];
>> +            ddrss->ecc_range.range = ddrss->ddr_ram_size - 
>> ddrss->ecc_reserved_space;
>> +        } else {
>> +            ddrss->ecc_range.start = range->start;
>> +            ddrss->ecc_range.range = range->range;
>> +        }
>> +
>> +        end = ddrss->ecc_range.start + ddrss->ecc_range.range;
>> +
>> +        if (end > (ddrss->ddr_ram_size - ddrss->ecc_reserved_space))
>> +            ddrss->ecc_regions[0].range = ddrss->ddr_ram_size - 
>> ddrss->ecc_reserved_space;
>> +        else
>> +            ddrss->ecc_regions[0].range = ddrss->ecc_range.range;
>> +
>> +        ddrss->ecc_regions[0].start = ddrss->ecc_range.start - 
>> ddrss->ddr_bank_base[0];
>> +
>>           k3_ddrss_lpddr4_ecc_init(ddrss);
>>       }
> 

-- 
Thanking You
Neha Malcom Francis