On 07/18/2016 10:07 AM, Sahil Mehta wrote:
> Indexed-count add for memory hotplug guarantees that a contiguous block
> of <count> lmbs beginning at a specified <index> will be assigned (NOT
> that <count> lmbs will be added). Because of Qemu's per-DIMM memory
> management, the addition of a contiguous block of memory currently
> requires a series of individual calls. Indexed-count add reduces
> this series into a single call.
>
> Signed-off-by: Sahil Mehta <sme...@linux.vnet.ibm.com>
> ---
> v2: -remove potential memory leak when parsing command
> -use u32s drc_index and count instead of u32 ic[]
> in dlpar_memory
>
> arch/powerpc/include/asm/rtas.h | 2
> arch/powerpc/platforms/pseries/dlpar.c | 34 +++++++-
> arch/powerpc/platforms/pseries/hotplug-memory.c | 100
> +++++++++++++++++++++--
> 3 files changed, 124 insertions(+), 12 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
> index 51400ba..f46b271 100644
> --- a/arch/powerpc/include/asm/rtas.h
> +++ b/arch/powerpc/include/asm/rtas.h
> @@ -307,6 +307,7 @@ struct pseries_hp_errorlog {
> union {
> __be32 drc_index;
> __be32 drc_count;
> + __be32 indexed_count[2];
> char drc_name[1];
> } _drc_u;
> };
> @@ -322,6 +323,7 @@ struct pseries_hp_errorlog {
> #define PSERIES_HP_ELOG_ID_DRC_NAME 1
> #define PSERIES_HP_ELOG_ID_DRC_INDEX 2
> #define PSERIES_HP_ELOG_ID_DRC_COUNT 3
> +#define PSERIES_HP_ELOG_ID_IC 4
>
> struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
> uint16_t section_id);
> diff --git a/arch/powerpc/platforms/pseries/dlpar.c
> b/arch/powerpc/platforms/pseries/dlpar.c
> index 2b93ae8..2a6dc9e 100644
> --- a/arch/powerpc/platforms/pseries/dlpar.c
> +++ b/arch/powerpc/platforms/pseries/dlpar.c
> @@ -345,11 +345,17 @@ static int handle_dlpar_errorlog(struct
> pseries_hp_errorlog *hp_elog)
> switch (hp_elog->id_type) {
> case PSERIES_HP_ELOG_ID_DRC_COUNT:
> hp_elog->_drc_u.drc_count =
> - be32_to_cpu(hp_elog->_drc_u.drc_count);
> + be32_to_cpu(hp_elog->_drc_u.drc_count);
> break;
> case PSERIES_HP_ELOG_ID_DRC_INDEX:
> hp_elog->_drc_u.drc_index =
> - be32_to_cpu(hp_elog->_drc_u.drc_index);
> + be32_to_cpu(hp_elog->_drc_u.drc_index);
> + break;
> + case PSERIES_HP_ELOG_ID_IC:
> + hp_elog->_drc_u.indexed_count[0] =
> + be32_to_cpu(hp_elog->_drc_u.indexed_count[0]);
> + hp_elog->_drc_u.indexed_count[1] =
> + be32_to_cpu(hp_elog->_drc_u.indexed_count[1]);
> }
>
> switch (hp_elog->resource) {
> @@ -409,7 +415,29 @@ static ssize_t dlpar_store(struct class *class, struct
> class_attribute *attr,
> goto dlpar_store_out;
> }
>
> - if (!strncmp(arg, "index", 5)) {
> + if (!strncmp(arg, "indexed-count", 13)) {
> + u32 index, count;
> + char *cstr, *istr;
> +
> + hp_elog->id_type = PSERIES_HP_ELOG_ID_IC;
> + arg += strlen("indexed-count ");
> +
> + cstr = kstrdup(arg, GFP_KERNEL);
> + istr = strchr(cstr, ' ');
> + *istr++ = '\0';
> +
> + if (kstrtou32(cstr, 0, &count) || kstrtou32(istr, 0, &index)) {
> + rc = -EINVAL;
> + pr_err("Invalid index or count : \"%s\"\n", buf);
> + kfree(cstr);
> + goto dlpar_store_out;
> + }
> +
> + kfree(cstr);
> +
> + hp_elog->_drc_u.indexed_count[0] = cpu_to_be32(count);
> + hp_elog->_drc_u.indexed_count[1] = cpu_to_be32(index);
> + } else if (!strncmp(arg, "index", 5)) {
> u32 index;
>
> hp_elog->id_type = PSERIES_HP_ELOG_ID_DRC_INDEX;
> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
> b/arch/powerpc/platforms/pseries/hotplug-memory.c
> index 2ce1385..d7942ca 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
> @@ -701,6 +701,83 @@ static int dlpar_memory_add_by_index(u32 drc_index,
> struct property *prop)
> return rc;
> }
>
> +static int dlpar_memory_add_by_ic(u32 lmbs_to_add, u32 drc_index,
> + struct property *prop)
> +{
> + struct of_drconf_cell *lmbs;
> + u32 num_lmbs, *p;
> + int i, rc;
> + int lmbs_available = 0, start_index = 0, end_index;
> +
> + pr_info("Attempting to hot-add %u LMB(s) at index %x\n",
> + lmbs_to_add, drc_index);
> +
> + if (lmbs_to_add == 0)
> + return -EINVAL;
> +
> + p = prop->value;
> + num_lmbs = *p++;
> + lmbs = (struct of_drconf_cell *)p;
> +
> + /* Navigate to drc_index */
> + while (start_index < num_lmbs) {
> + if (lmbs[start_index].drc_index == drc_index)
> + break;
> +
> + start_index++;
> + }
There should be a check here that returns -EINVAL in case the function gets a
bad drc index and/or the drc index can't be found, like in
dlpar_memory_add_by_index. Same goes for the dlpar_memory_remove_by_ic
function.
> +
> + end_index = start_index + lmbs_to_add;
> +
> + /* Validate that there are enough LMBs to satisfy the request */
> + for (i = start_index; i < end_index; i++) {
> + if (lmbs[i].flags & DRCONF_MEM_RESERVED)
> + break;
> +
> + lmbs_available++;
> + }
> +
> + if (lmbs_available < lmbs_to_add)
> + return -EINVAL;
> +
> + for (i = start_index; i < end_index; i++) {
> + if (lmbs[i].flags & DRCONF_MEM_ASSIGNED)
> + continue;
> +
> + rc = dlpar_add_lmb(&lmbs[i]);
> + if (rc)
> + break;
> +
> + lmbs[i].reserved = 1;
> + }
> +
> + if (rc) {
> + pr_err("Memory indexed-count-add failed, removing any added
> LMBs\n");
> +
> + for (i = start_index; i < end_index; i++) {
> + if (!lmbs[i].reserved)
> + continue;
> +
> + rc = dlpar_remove_lmb(&lmbs[i]);
> + if (rc)
> + pr_err("Failed to remove LMB, drc index %x\n",
> + be32_to_cpu(lmbs[i].drc_index));
> + }
> + rc = -EINVAL;
> + } else {
> + for (i = start_index; i < end_index; i++) {
> + if (!lmbs[i].reserved)
> + continue;
> +
> + pr_info("Memory at %llx (drc index %x) was hot-added\n",
> + lmbs[i].base_addr, lmbs[i].drc_index);
> + lmbs[i].reserved = 0;
> + }
> + }
> +
> + return rc;
> +}
> +
> int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
> {
> struct device_node *dn;
> @@ -708,9 +785,6 @@ int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
> u32 count, drc_index;
> int rc;
>
> - count = hp_elog->_drc_u.drc_count;
> - drc_index = hp_elog->_drc_u.drc_index;
> -
> lock_device_hotplug();
>
> dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
> @@ -727,19 +801,27 @@ int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
>
> switch (hp_elog->action) {
> case PSERIES_HP_ELOG_ACTION_ADD:
> - if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT)
> + if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT) {
> + count = hp_elog->_drc_u.drc_count;
> rc = dlpar_memory_add_by_count(count, prop);
> - else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX)
> + } else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX) {
> + drc_index = hp_elog->_drc_u.drc_index;
> rc = dlpar_memory_add_by_index(drc_index, prop);
> - else
> + } else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_IC) {
> + count = hp_elog->_drc_u.indexed_count[0];
> + drc_index = hp_elog->_drc_u.indexed_count[1];
> + rc = dlpar_memory_add_by_ic(count, drc_index, prop);
> + } else
> rc = -EINVAL;
Small point, but I think kernel style requires this last "else" have brackets.
Thanks,
Tom
> break;
> case PSERIES_HP_ELOG_ACTION_REMOVE:
> - if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT)
> + if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT) {
> + count = hp_elog->_drc_u.drc_count;
> rc = dlpar_memory_remove_by_count(count, prop);
> - else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX)
> + } else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX) {
> + drc_index = hp_elog->_drc_u.drc_index;
> rc = dlpar_memory_remove_by_index(drc_index, prop);
> - else
> + } else
> rc = -EINVAL;
> break;
> default:
>
> On 07/18/2016 10:04 AM, Sahil Mehta wrote:
>> Indexed-count memory management allows addition and removal of contiguous
>> lmb blocks with a single command. When compared to the series of calls
>> previously required to manage contiguous blocks, indexed-count decreases
>> command frequency and reduces risk of buffer overflow.
>>
>> Changes in v2:
>> --------------
>> -[PATCH 1/2]: -remove potential memory leak when parsing command
>> -use u32s drc_index and count instead of u32 ic[]
>> in dlpar_memory
>> -[PATCH 2/2]: -use u32s drc_index and count instead of u32 ic[]
>> in dlpar_memory
>>
>> -Sahil Mehta
>> ---
>> include/asm/rtas.h | 2
>> platforms/pseries/dlpar.c | 34 ++++++
>> platforms/pseries/hotplug-memory.c | 184
>> +++++++++++++++++++++++++++++++++++--
>> 3 files changed, 208 insertions(+), 12 deletions(-)
>>
>> _______________________________________________
>> Linuxppc-dev mailing list
>> Linuxppc-dev@lists.ozlabs.org
>> https://lists.ozlabs.org/listinfo/linuxppc-dev
>>
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