On 06/30/2016 12:22 PM, 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>
> ---
> arch/powerpc/include/asm/rtas.h | 2
> arch/powerpc/platforms/pseries/dlpar.c | 32 ++++++-
> arch/powerpc/platforms/pseries/hotplug-memory.c | 109
> ++++++++++++++++++++---
> 3 files changed, 126 insertions(+), 17 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
Probably should continue the naming convention of prefixing
PSERIES_HP_ELOG_ID_DRC_XXX for consistency.
-Tyrel
>
> 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..a3d5f20 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 +415,27 @@ 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);
> + 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..cf359bf 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
> @@ -458,8 +458,8 @@ static int dlpar_memory_remove_by_count(u32
> lmbs_to_remove,
> if (!lmbs[i].reserved)
> continue;
>
> - pr_info("Memory at %llx was hot-removed\n",
> - lmbs[i].base_addr);
> + pr_info("Memory at %llx (drc index %x) was
> hot-removed\n",
> + lmbs[i].base_addr, lmbs[i].drc_index);
>
> lmbs[i].reserved = 0;
> }
> @@ -618,7 +618,6 @@ static int dlpar_memory_add_by_count(u32 lmbs_to_add,
> struct property *prop)
> num_lmbs = *p++;
> lmbs = (struct of_drconf_cell *)p;
>
> - /* Validate that there are enough LMBs to satisfy the request */
> for (i = 0; i < num_lmbs; i++) {
> if (!(lmbs[i].flags & DRCONF_MEM_ASSIGNED))
> lmbs_available++;
> @@ -634,7 +633,7 @@ static int dlpar_memory_add_by_count(u32 lmbs_to_add,
> struct property *prop)
>
> lmbs_added++;
>
> - /* Mark this lmb so we can remove it later if all of the
> + /* Mark this LMB so we can remove it later if all of the
> * requested LMBs cannot be added.
> */
> lmbs[i].reserved = 1;
> @@ -701,16 +700,90 @@ 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++;
> + }
> +
> + 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;
> struct property *prop;
> - u32 count, drc_index;
> + u32 count, drc_index, ic[2];
> 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 +800,27 @@ 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) {
> + ic[0] = hp_elog->_drc_u.indexed_count[0];
> + ic[1] = hp_elog->_drc_u.indexed_count[1];
> + rc = dlpar_memory_add_by_ic(ic[0], ic[1], prop);
> + } else
> rc = -EINVAL;
> 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 06/30/2016 02:21 PM, Sahil Mehta wrote:
>> Indexed-count memory management allows addition and removal of contiguous
>> lmb blocks to be added and removed with a single command. When compared
>> to the series of calls previously required to manage contiguous blocks,
>> indexed-count decreases command frequency and complexity, consequently
>> preventing buffer overflow.
>>
>> -Sahil Mehta
>> ---
>> include/asm/rtas.h | 2
>> platforms/pseries/dlpar.c | 32 +++++-
>> platforms/pseries/hotplug-memory.c | 194
>> ++++++++++++++++++++++++++++++++++---
>> 3 files changed, 210 insertions(+), 18 deletions(-)
>>
>> _______________________________________________
>> Linuxppc-dev mailing list
>> Linuxppc-dev@lists.ozlabs.org
>> https://lists.ozlabs.org/listinfo/linuxppc-dev
>>
>
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev
>
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