x86/resctrl: Add resctrl_rmid_realloc_limit to abstract x86's boot_cpu_data

resctrl_rmid_realloc_threshold can be set by user-space. The maximum
value is specified by the architecture.

Currently max_threshold_occ_write() reads the maximum value from
boot_cpu_data.x86_cache_size, which is not portable to another
architecture.

Add resctrl_rmid_realloc_limit to describe the maximum size in bytes
that user-space can set the threshold to.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jamie Iles <quic_jiles@quicinc.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Xin Hao <xhao@linux.alibaba.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20220902154829.30399-21-james.morse@arm.com
This commit is contained in:
James Morse 2022-09-02 15:48:28 +00:00 committed by Borislav Petkov
parent ae2328b529
commit d80975e264
3 changed files with 9 additions and 3 deletions

View file

@ -67,6 +67,11 @@ unsigned int rdt_mon_features;
*/
unsigned int resctrl_rmid_realloc_threshold;
/*
* This is the maximum value for the reallocation threshold, in bytes.
*/
unsigned int resctrl_rmid_realloc_limit;
#define CF(cf) ((unsigned long)(1048576 * (cf) + 0.5))
/*
@ -747,10 +752,10 @@ int rdt_get_mon_l3_config(struct rdt_resource *r)
{
unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset;
struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
unsigned int cl_size = boot_cpu_data.x86_cache_size;
unsigned int threshold;
int ret;
resctrl_rmid_realloc_limit = boot_cpu_data.x86_cache_size * 1024;
hw_res->mon_scale = boot_cpu_data.x86_cache_occ_scale;
r->num_rmid = boot_cpu_data.x86_cache_max_rmid + 1;
hw_res->mbm_width = MBM_CNTR_WIDTH_BASE;
@ -767,7 +772,7 @@ int rdt_get_mon_l3_config(struct rdt_resource *r)
*
* For a 35MB LLC and 56 RMIDs, this is ~1.8% of the LLC.
*/
threshold = cl_size * 1024 / r->num_rmid;
threshold = resctrl_rmid_realloc_limit / r->num_rmid;
/*
* Because num_rmid may not be a power of two, round the value

View file

@ -1059,7 +1059,7 @@ static ssize_t max_threshold_occ_write(struct kernfs_open_file *of,
if (ret)
return ret;
if (bytes > (boot_cpu_data.x86_cache_size * 1024))
if (bytes > resctrl_rmid_realloc_limit)
return -EINVAL;
resctrl_rmid_realloc_threshold = resctrl_arch_round_mon_val(bytes);

View file

@ -251,5 +251,6 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d,
u32 rmid, enum resctrl_event_id eventid);
extern unsigned int resctrl_rmid_realloc_threshold;
extern unsigned int resctrl_rmid_realloc_limit;
#endif /* _RESCTRL_H */