On 04/17/2017 08:04 AM, Michael Bringmann wrote:
> hotplug_init: Simplify the code needed for runtime memory hotplug and
> maintenance with a conversion routine that transforms the compressed
> property "ibm,dynamic-memory-v2" to the form of "ibm,dynamic-memory"
> within the "ibm,dynamic-reconfiguration-memory" node. Thus only
> a single set of routines should be required at runtime to parse, edit,
> and manipulate the memory representation in the device tree. Similarly,
> any userspace applications that need this information will only need
> to recognize the older format to be able to continue to operate.
>
> Signed-off-by: Michael Bringmann <m...@linux.vnet.ibm.com>
> ---
> Changes in V2:
> -- Add missing of_node_put() calls.
> -- Correct description of change.
> ---
> arch/powerpc/platforms/pseries/Makefile | 4 -
> arch/powerpc/platforms/pseries/hotplug-memory.c | 104
> +++++++++++++++++++++++
> 2 files changed, 104 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/Makefile
> b/arch/powerpc/platforms/pseries/Makefile
> index 8f4ba08..87eb665 100644
> --- a/arch/powerpc/platforms/pseries/Makefile
> +++ b/arch/powerpc/platforms/pseries/Makefile
> @@ -5,14 +5,14 @@ obj-y := lpar.o hvCall.o nvram.o
> reconfig.o \
> of_helpers.o \
> setup.o iommu.o event_sources.o ras.o \
> firmware.o power.o dlpar.o mobility.o rng.o \
> - pci.o pci_dlpar.o eeh_pseries.o msi.o
> + pci.o pci_dlpar.o eeh_pseries.o msi.o \
> + hotplug-memory.o
> obj-$(CONFIG_SMP) += smp.o
> obj-$(CONFIG_SCANLOG) += scanlog.o
> obj-$(CONFIG_KEXEC_CORE) += kexec.o
> obj-$(CONFIG_PSERIES_ENERGY) += pseries_energy.o
>
> obj-$(CONFIG_HOTPLUG_CPU) += hotplug-cpu.o
> -obj-$(CONFIG_MEMORY_HOTPLUG) += hotplug-memory.o
>
> obj-$(CONFIG_HVC_CONSOLE) += hvconsole.o
> obj-$(CONFIG_HVCS) += hvcserver.o
> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
> b/arch/powerpc/platforms/pseries/hotplug-memory.c
> index e104c71..f948505 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
> @@ -24,8 +24,6 @@
> #include <asm/sparsemem.h>
> #include "pseries.h"
>
> -static bool rtas_hp_event;
> -
> unsigned long pseries_memory_block_size(void)
> {
> struct device_node *np;
> @@ -69,6 +67,10 @@ unsigned long pseries_memory_block_size(void)
> return memblock_size;
> }
>
> +#ifdef CONFIG_MEMORY_HOTPLUG
> +
> +static bool rtas_hp_event;
> +
> static void dlpar_free_property(struct property *prop)
> {
> kfree(prop->name);
> @@ -1165,11 +1167,109 @@ static int pseries_memory_notifier(struct
> notifier_block *nb,
> static struct notifier_block pseries_mem_nb = {
> .notifier_call = pseries_memory_notifier,
> };
> +#endif /* CONFIG_MEMORY_HOTPLUG */
> +
> +static int pseries_rewrite_dynamic_memory_v2(void)
> +{
> + unsigned long memblock_size;
> + struct device_node *dn;
> + struct property *prop, *prop_v2;
> + __be32 *p;
> + struct of_drconf_cell *lmbs;
> + u32 num_lmb_desc_sets, num_lmbs;
> + int i, j, k;
> +
> + dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
> + if (!dn)
> + return -EINVAL;
> +
> + prop_v2 = of_find_property(dn, "ibm,dynamic-memory-v2", NULL);
> + if (!prop_v2) {
> + of_node_put(dn);
> + return -EINVAL;
> + }
> +
> + memblock_size = pseries_memory_block_size();
> + if (!memblock_size) {
> + of_node_put(dn);
> + return -EINVAL;
> + }
> +
> + /* The first int of the property is the number of lmb sets
> + * described by the property.
> + */
> + p = (__be32 *)prop_v2->value;
> + num_lmb_desc_sets = be32_to_cpu(*p++);
> +
> + /* Count the number of LMBs for generating the alternate format
> + */
> + for (i = 0, num_lmbs = 0; i < num_lmb_desc_sets; i++) {
> + struct of_drconf_cell_v2 drmem;
> +
> + read_drconf_cell_v2(&drmem, (const __be32 **)&p);
> + num_lmbs += drmem.num_seq_lmbs;
> + }
> +
> + /* Create an empty copy of the new 'ibm,dynamic-memory' property
> + */
> + prop = kzalloc(sizeof(*prop), GFP_KERNEL);
> + if (!prop) {
> + of_node_put(dn);
> + return -ENOMEM;
> + }
> + prop->name = kstrdup("ibm,dynamic-memory", GFP_KERNEL);
> + prop->length = dyn_mem_v2_len(num_lmbs);
> + prop->value = kzalloc(prop->length, GFP_KERNEL);
> +
> + /* Copy/expand the ibm,dynamic-memory-v2 format to produce the
> + * ibm,dynamic-memory format.
> + */
> + p = (__be32 *)prop->value;
> + *p = cpu_to_be32(num_lmbs);
> + p++;
> + lmbs = (struct of_drconf_cell *)p;
> +
> + p = (__be32 *)prop_v2->value;
> + p++;
> +
> + for (i = 0, k = 0; i < num_lmb_desc_sets; i++) {
> + struct of_drconf_cell_v2 drmem;
> +
> + read_drconf_cell_v2(&drmem, (const __be32 **)&p);
> +
> + for (j = 0; j < drmem.num_seq_lmbs; j++) {
> + lmbs[k+j].base_addr = be64_to_cpu(drmem.base_addr);
> + lmbs[k+j].drc_index = be32_to_cpu(drmem.drc_index);
> + lmbs[k+j].aa_index = be32_to_cpu(drmem.aa_index);
> + lmbs[k+i].flags = be32_to_cpu(drmem.flags);
> +
> + drmem.base_addr += memblock_size;
> + drmem.drc_index++;
> + }
> +
> + k += drmem.num_seq_lmbs;
> + }
> +
> + of_node_put(dn);
You don't want to release your reference of a device node until you are
done using it. So, this of_node_put() really should go below the
of_remove_property() and of_add_property() calls seeing as those both
act upon the device_node "dn".
-Tyrel
> +
> + of_remove_property(dn, prop_v2);
> +
> + of_add_property(dn, prop);
> +
> + /* And disable feature flag since the property has gone away */
> + powerpc_firmware_features &= ~FW_FEATURE_DYN_MEM_V2;
> +
> + return 0;
> +}
>
> static int __init pseries_memory_hotplug_init(void)
> {
> + if (firmware_has_feature(FW_FEATURE_DYN_MEM_V2))
> + pseries_rewrite_dynamic_memory_v2();
> +#ifdef CONFIG_MEMORY_HOTPLUG
> if (firmware_has_feature(FW_FEATURE_LPAR))
> of_reconfig_notifier_register(&pseries_mem_nb);
> +#endif /* CONFIG_MEMORY_HOTPLUG */
>
> return 0;
> }
>
