[PATCH v3 0/2] powerpc/pseries: Implement indexed-count hotplug memory management

[PATCH v3 0/2] powerpc/pseries: Implement indexed-count hotplug memory management

[Sahil Mehta]

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

Changes in v3:
--------------
-[PATCH 1/2]:	-add logic to handle invalid drc_index input
		-update indexed-count trigger to follow naming convention
		-update dlpar_memory to follow kernel if-else style
-[PATCH 2/2]:	-add logic to handle invalid drc_index input

-Sahil Mehta
---
 include/asm/rtas.h                 |    2
 platforms/pseries/dlpar.c          |   34 +++++-
 platforms/pseries/hotplug-memory.c |  200 +++++++++++++++++++++++++++++++++++--
 3 files changed, 224 insertions(+), 12 deletions(-)

[PATCH v3 1/2] powerpc/pseries: Implement indexed-count hotplug memory add

[Sahil Mehta]

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 <smehta@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
v3:	-add logic to handle invalid drc_index input
	-update indexed-count trigger to follow naming convention
	-update dlpar_memory to follow kernel if-else style

 arch/powerpc/include/asm/rtas.h                 |    2
 arch/powerpc/platforms/pseries/dlpar.c          |   34 ++++++-
 arch/powerpc/platforms/pseries/hotplug-memory.c |  110 +++++++++++++++++++++--
 3 files changed, 134 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
index 51400ba..088ea75 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_DRC_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..6dbd13c 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_DRC_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_DRC_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..2d4ceb3 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -701,6 +701,89 @@ 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, start_lmb_found;
+	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;
+	start_lmb_found = 0;
+
+	/* Navigate to drc_index */
+	while (start_index < num_lmbs) {
+		if (lmbs[start_index].drc_index == drc_index) {
+			start_lmb_found = 1;
+			break;
+		}
+
+		start_index++;
+	}
+
+	if (!start_lmb_found)
+		return -EINVAL;
+
+	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 +791,6 @@ 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");
@@ -727,20 +807,32 @@ 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_DRC_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;
+		}
+
 		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:
 		pr_err("Invalid action (%d) specified\n", hp_elog->action);

Re: [PATCH v3 1/2] powerpc/pseries: Implement indexed-count hotplug memory add

[Nathan Fontenot]

On 07/25/2016 12:40 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 <smehta@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
> v3:	-add logic to handle invalid drc_index input
> 	-update indexed-count trigger to follow naming convention
> 	-update dlpar_memory to follow kernel if-else style
> 
>  arch/powerpc/include/asm/rtas.h                 |    2
>  arch/powerpc/platforms/pseries/dlpar.c          |   34 ++++++-
>  arch/powerpc/platforms/pseries/hotplug-memory.c |  110 +++++++++++++++++++++--
>  3 files changed, 134 insertions(+), 12 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
> index 51400ba..088ea75 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_DRC_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..6dbd13c 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_DRC_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_DRC_IC;
> +		arg += strlen("indexed-count ");
> +
> +		cstr = kstrdup(arg, GFP_KERNEL);
> +		istr = strchr(cstr, ' ');
> +		*istr++ = '\0';

This block should have some additional error checking. It is possible for kstrdup to return
NULL, and it is possible that the arg string does not contain a space character. Either of
these would result in dereferencing a NULL pointer.

-Nathan

> +
> +		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..2d4ceb3 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
> @@ -701,6 +701,89 @@ 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, start_lmb_found;
> +	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;
> +	start_lmb_found = 0;
> +
> +	/* Navigate to drc_index */
> +	while (start_index < num_lmbs) {
> +		if (lmbs[start_index].drc_index == drc_index) {
> +			start_lmb_found = 1;
> +			break;
> +		}
> +
> +		start_index++;
> +	}
> +
> +	if (!start_lmb_found)
> +		return -EINVAL;
> +
> +	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 +791,6 @@ 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");
> @@ -727,20 +807,32 @@ 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_DRC_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;
> +		}
> +
>  		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:
>  		pr_err("Invalid action (%d) specified\n", hp_elog->action);
> 
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev
> 

[PATCH v3 2/2] powerpc/pseries: Implement indexed-count hotplug memory remove

[Sahil Mehta]

Indexed-count remove for memory hotplug guarantees that a contiguous block
of <count> lmbs beginning at a specified <index> will be unassigned (NOT
that <count> lmbs will be removed). Because of Qemu's per-DIMM memory
management, the removal of a contiguous block of memory currently
requires a series of individual calls. Indexed-count remove reduces
this series into a single call.

Signed-off-by: Sahil Mehta <smehta@linux.vnet.ibm.com>
---
v2:	-use u32s drc_index and count instead of u32 ic[]
	 in dlpar_memory
v3:	-add logic to handle invalid drc_index input

 arch/powerpc/platforms/pseries/hotplug-memory.c |   90 +++++++++++++++++++++++
 1 file changed, 90 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 2d4ceb3..dd5eb38 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -503,6 +503,92 @@ static int dlpar_memory_remove_by_index(u32 drc_index, struct property *prop)
 	return rc;
 }

+static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index,
+				     struct property *prop)
+{
+	struct of_drconf_cell *lmbs;
+	u32 num_lmbs, *p;
+	int i, rc, start_lmb_found;
+	int lmbs_available = 0, start_index = 0, end_index;
+
+	pr_info("Attempting to hot-remove %u LMB(s) at %x\n",
+		lmbs_to_remove, drc_index);
+
+	if (lmbs_to_remove == 0)
+		return -EINVAL;
+
+	p = prop->value;
+	num_lmbs = *p++;
+	lmbs = (struct of_drconf_cell *)p;
+	start_lmb_found = 0;
+
+	/* Navigate to drc_index */
+	while (start_index < num_lmbs) {
+		if (lmbs[start_index].drc_index == drc_index) {
+			start_lmb_found = 1;
+			break;
+		}
+
+		start_index++;
+	}
+
+	if (!start_lmb_found)
+		return -EINVAL;
+
+	end_index = start_index + lmbs_to_remove;
+
+	/* 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_remove)
+		return -EINVAL;
+
+	for (i = 0; i < end_index; i++) {
+		if (!(lmbs[i].flags & DRCONF_MEM_ASSIGNED))
+			continue;
+
+		rc = dlpar_remove_lmb(&lmbs[i]);
+		if (rc)
+			break;
+
+		lmbs[i].reserved = 1;
+	}
+
+	if (rc) {
+		pr_err("Memory indexed-count-remove failed, adding any removed LMBs\n");
+
+		for (i = start_index; i < end_index; i++) {
+			if (!lmbs[i].reserved)
+				continue;
+
+			rc = dlpar_add_lmb(&lmbs[i]);
+			if (rc)
+				pr_err("Failed to add LMB, drc index %x\n",
+				       be32_to_cpu(lmbs[i].drc_index));
+
+			lmbs[i].reserved = 0;
+		}
+		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-removed\n",
+				lmbs[i].base_addr, lmbs[i].drc_index);
+
+			lmbs[i].reserved = 0;
+		}
+	}
+
+	return rc;
+}
+
 #else
 static inline int pseries_remove_memblock(unsigned long base,
 					  unsigned int memblock_size)
@@ -829,6 +915,10 @@ int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
 		} 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 if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_IC) {
+			count = hp_elog->_drc_u.indexed_count[0];
+			drc_index = hp_elog->_drc_u.indexed_count[1];
+			rc = dlpar_memory_remove_by_ic(count, drc_index, prop);
 		} else {
 			rc = -EINVAL;
 		}