On 10/02/2018 03:56 PM, Tyrel Datwyler wrote:
> On 10/01/2018 05:59 AM, Michael Bringmann wrote:
>> powerpc/drmem: Export many of the functions of DRMEM to parse
>> "ibm,dynamic-memory" and "ibm,dynamic-memory-v2" during hotplug
>> operations and for Post Migration events.
>>
>> Also modify the DRMEM initialization code to allow it to,
>>
>> * Be called after system initialization
>> * Provide a separate user copy of the LMB array that is produces
>> * Free the user copy upon request
>>
>> In addition, a couple of changes were made to make the creation
>> of additional copies of the LMB array more useful including,
>>
>> * Add new iterator to work through a pair of drmem_info arrays.
>> * Modify DRMEM code to replace usages of dt_root_addr_cells, and
>> dt_mem_next_cell, as these are only available at first boot.
>>
>> Signed-off-by: Michael Bringmann <m...@linux.vnet.ibm.com>
>> ---
>> arch/powerpc/include/asm/drmem.h | 15 ++++++++
>> arch/powerpc/mm/drmem.c | 75
>> ++++++++++++++++++++++++++++----------
>> 2 files changed, 70 insertions(+), 20 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/drmem.h
>> b/arch/powerpc/include/asm/drmem.h
>> index ce242b9..b0e70fd 100644
>> --- a/arch/powerpc/include/asm/drmem.h
>> +++ b/arch/powerpc/include/asm/drmem.h
>> @@ -35,6 +35,18 @@ struct drmem_lmb_info {
>> &drmem_info->lmbs[0], \
>> &drmem_info->lmbs[drmem_info->n_lmbs - 1])
>>
>> +#define for_each_dinfo_lmb(dinfo, lmb) \
>> + for_each_drmem_lmb_in_range((lmb), \
>> + &dinfo->lmbs[0], \
>> + &dinfo->lmbs[dinfo->n_lmbs - 1])
>> +
>> +#define for_each_pair_dinfo_lmb(dinfo1, lmb1, dinfo2, lmb2) \
>> + for ((lmb1) = (&dinfo1->lmbs[0]), \
>> + (lmb2) = (&dinfo2->lmbs[0]); \
>> + ((lmb1) <= (&dinfo1->lmbs[dinfo1->n_lmbs - 1])) && \
>> + ((lmb2) <= (&dinfo2->lmbs[dinfo2->n_lmbs - 1])); \
>> + (lmb1)++, (lmb2)++)
>> +
>> /*
>> * The of_drconf_cell_v1 struct defines the layout of the LMB data
>> * specified in the ibm,dynamic-memory device tree property.
>> @@ -94,6 +106,9 @@ void __init walk_drmem_lmbs(struct device_node *dn,
>> void (*func)(struct drmem_lmb *, const __be32 **));
>> int drmem_update_dt(void);
>>
>> +struct drmem_lmb_info *drmem_lmbs_init(struct property *prop);
>> +void drmem_lmbs_free(struct drmem_lmb_info *dinfo);
>> +
>> #ifdef CONFIG_PPC_PSERIES
>> void __init walk_drmem_lmbs_early(unsigned long node,
>> void (*func)(struct drmem_lmb *, const __be32 **));
>> diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
>> index 3f18036..13d2abb 100644
>> --- a/arch/powerpc/mm/drmem.c
>> +++ b/arch/powerpc/mm/drmem.c
>> @@ -20,6 +20,7 @@
>>
>> static struct drmem_lmb_info __drmem_info;
>> struct drmem_lmb_info *drmem_info = &__drmem_info;
>> +static int n_root_addr_cells;
>
> What is the point of this new global? I see two places were it gets
> initialized if it is null, and both those initializers simply set it to
> "dt_root_addr_cells". I also checked the rest of the patches in the series
> and none of those even reference this variable.
The point of these changes is to introduce code that can be used after
an LPAR migration. The variable dt_root_addr_cells was observed to be
zero (0) after migration on powerpc. As it is defined as,
./drivers/of/fdt.c:int __initdata dt_root_addr_cells;
its definition may be replaced by other code/variables after initial boot.
We needed the value to persist, and it was cheaper to cache it.
>
>>
>> u64 drmem_lmb_memory_max(void)
>> {
>> @@ -193,12 +194,13 @@ int drmem_update_dt(void)
>> return rc;
>> }
>>
>> -static void __init read_drconf_v1_cell(struct drmem_lmb *lmb,
>> +static void read_drconf_v1_cell(struct drmem_lmb *lmb,
>> const __be32 **prop)
>> {
>> const __be32 *p = *prop;
>>
>> - lmb->base_addr = dt_mem_next_cell(dt_root_addr_cells, &p);
>> + lmb->base_addr = of_read_number(p, n_root_addr_cells);
>> + p += n_root_addr_cells;
>
> Unnecessary code churn do to the introduction of "n_root_addr_cells".'
See note above.
>
>> lmb->drc_index = of_read_number(p++, 1);
>>
>> p++; /* skip reserved field */
>> @@ -209,7 +211,7 @@ static void __init read_drconf_v1_cell(struct drmem_lmb
>> *lmb,
>> *prop = p;
>> }
>>
>> -static void __init __walk_drmem_v1_lmbs(const __be32 *prop, const __be32
>> *usm,
>> +static void __walk_drmem_v1_lmbs(const __be32 *prop, const __be32 *usm,
>> void (*func)(struct drmem_lmb *, const __be32 **))
>> {
>> struct drmem_lmb lmb;
>> @@ -225,13 +227,14 @@ static void __init __walk_drmem_v1_lmbs(const __be32
>> *prop, const __be32 *usm,
>> }
>> }
>>
>> -static void __init read_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
>> +static void read_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
>> const __be32 **prop)
>> {
>> const __be32 *p = *prop;
>>
>> dr_cell->seq_lmbs = of_read_number(p++, 1);
>> - dr_cell->base_addr = dt_mem_next_cell(dt_root_addr_cells, &p);
>> + dr_cell->base_addr = of_read_number(p, n_root_addr_cells);
>> + p += n_root_addr_cells;
>
> Same comment as above.
See note above.
>
>> dr_cell->drc_index = of_read_number(p++, 1);
>> dr_cell->aa_index = of_read_number(p++, 1);
>> dr_cell->flags = of_read_number(p++, 1);
>> @@ -239,7 +242,7 @@ static void __init read_drconf_v2_cell(struct
>> of_drconf_cell_v2 *dr_cell,
>> *prop = p;
>> }
>>
>> -static void __init __walk_drmem_v2_lmbs(const __be32 *prop, const __be32
>> *usm,
>> +static void __walk_drmem_v2_lmbs(const __be32 *prop, const __be32 *usm,
>> void (*func)(struct drmem_lmb *, const __be32 **))
>> {
>> struct of_drconf_cell_v2 dr_cell;
>> @@ -275,6 +278,9 @@ void __init walk_drmem_lmbs_early(unsigned long node,
>> const __be32 *prop, *usm;
>> int len;
>>
>> + if (n_root_addr_cells == 0)
>> + n_root_addr_cells = dt_root_addr_cells;
>> +
>
> As I mentioned initially whats the point? Why not just use
> "dt_root_addr_cells"?
See note above.
>
>> prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &len);
>> if (!prop || len < dt_root_size_cells * sizeof(__be32))
>> return;
>> @@ -353,24 +359,26 @@ void __init walk_drmem_lmbs(struct device_node *dn,
>> }
>> }
>>
>> -static void __init init_drmem_v1_lmbs(const __be32 *prop)
>> +static void init_drmem_v1_lmbs(const __be32 *prop,
>> + struct drmem_lmb_info *dinfo)
>> {
>> struct drmem_lmb *lmb;
>>
>> - drmem_info->n_lmbs = of_read_number(prop++, 1);
>> - if (drmem_info->n_lmbs == 0)
>> + dinfo->n_lmbs = of_read_number(prop++, 1);
>> + if (dinfo->n_lmbs == 0)
>> return;
>>
>> - drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
>> + dinfo->lmbs = kcalloc(dinfo->n_lmbs, sizeof(*lmb),
>> GFP_KERNEL);
>> - if (!drmem_info->lmbs)
>> + if (!dinfo->lmbs)
>> return;
>>
>> - for_each_drmem_lmb(lmb)
>> + for_each_dinfo_lmb(dinfo, lmb)
>> read_drconf_v1_cell(lmb, &prop);
>> }
>>
>> -static void __init init_drmem_v2_lmbs(const __be32 *prop)
>> +static void init_drmem_v2_lmbs(const __be32 *prop,
>> + struct drmem_lmb_info *dinfo)
>> {
>> struct drmem_lmb *lmb;
>> struct of_drconf_cell_v2 dr_cell;
>> @@ -386,12 +394,12 @@ static void __init init_drmem_v2_lmbs(const __be32
>> *prop)
>> p = prop;
>> for (i = 0; i < lmb_sets; i++) {
>> read_drconf_v2_cell(&dr_cell, &p);
>> - drmem_info->n_lmbs += dr_cell.seq_lmbs;
>> + dinfo->n_lmbs += dr_cell.seq_lmbs;
>> }
>>
>> - drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
>> + dinfo->lmbs = kcalloc(dinfo->n_lmbs, sizeof(*lmb),
>> GFP_KERNEL);
>> - if (!drmem_info->lmbs)
>> + if (!dinfo->lmbs)
>> return;
>>
>> /* second pass, read in the LMB information */
>> @@ -402,10 +410,10 @@ static void __init init_drmem_v2_lmbs(const __be32
>> *prop)
>> read_drconf_v2_cell(&dr_cell, &p);
>>
>> for (j = 0; j < dr_cell.seq_lmbs; j++) {
>> - lmb = &drmem_info->lmbs[lmb_index++];
>> + lmb = &dinfo->lmbs[lmb_index++];
>>
>> lmb->base_addr = dr_cell.base_addr;
>> - dr_cell.base_addr += drmem_info->lmb_size;
>> + dr_cell.base_addr += dinfo->lmb_size;
>>
>> lmb->drc_index = dr_cell.drc_index;
>> dr_cell.drc_index++;
>> @@ -416,11 +424,38 @@ static void __init init_drmem_v2_lmbs(const __be32
>> *prop)
>> }
>> }
>>
>> +void drmem_lmbs_free(struct drmem_lmb_info *dinfo)
>> +{
>> + if (dinfo) {
>> + kfree(dinfo->lmbs);
>> + kfree(dinfo);
>> + }
>> +}
>> +
>> +struct drmem_lmb_info *drmem_lmbs_init(struct property *prop)
>> +{
>> + struct drmem_lmb_info *dinfo;
>> +
>> + dinfo = kzalloc(sizeof(*dinfo), GFP_KERNEL);
>> + if (!dinfo)
>> + return NULL;
>> +
>> + if (!strcmp("ibm,dynamic-memory", prop->name))
>> + init_drmem_v1_lmbs(prop->value, dinfo);
>> + else if (!strcmp("ibm,dynamic-memory-v2", prop->name))
>> + init_drmem_v2_lmbs(prop->value, dinfo);
>> +
>> + return dinfo;
>> +}
>> +
>> static int __init drmem_init(void)
>> {
>> struct device_node *dn;
>> const __be32 *prop;
>>
>> + if (n_root_addr_cells == 0)
>> + n_root_addr_cells = dt_root_addr_cells;
>> +
>
> See previous comment.
See note above.
>
> -Tyrel
Michael
>
>> dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
>> if (!dn) {
>> pr_info("No dynamic reconfiguration memory found\n");
>> @@ -434,11 +469,11 @@ static int __init drmem_init(void)
>>
>> prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
>> if (prop) {
>> - init_drmem_v1_lmbs(prop);
>> + init_drmem_v1_lmbs(prop, drmem_info);
>> } else {
>> prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
>> if (prop)
>> - init_drmem_v2_lmbs(prop);
>> + init_drmem_v2_lmbs(prop, drmem_info);
>> }
>>
>> of_node_put(dn);
>>
>
>
--
Michael W. Bringmann
Linux Technology Center
IBM Corporation
Tie-Line 363-5196
External: (512) 286-5196
Cell: (512) 466-0650
m...@linux.vnet.ibm.com
