x86/resctrl: Move get_corrected_mbm_count() into resctrl_arch_rmid_read()

resctrl_arch_rmid_read() is intended as the function that an
architecture agnostic resctrl filesystem driver can use to
read a value in bytes from a counter. Currently the function returns
the MBM values in chunks directly from hardware. When reading a bandwidth
counter, get_corrected_mbm_count() must be used to correct the
value read.

get_corrected_mbm_count() is architecture specific, this work should be
done in resctrl_arch_rmid_read().

Move the function calls. This allows the resctrl filesystems's chunks
value to be removed in favour of the architecture private version.

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/20220902154829.30399-19-james.morse@arm.com

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 8039e8aba7de512d6acf3d63de501266ad7bd57d..bdb55c2fbdd39c065b73600a4bc0fdb42633debd 100644 (file)
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -280,14 +280,12 @@ struct rftype {
 
 /**
  * struct mbm_state - status for each MBM counter in each domain
- * @chunks:    Total data moved (multiply by rdt_group.mon_scale to get bytes)
  * @prev_bw_chunks: Previous chunks value read for bandwidth calculation
  * @prev_bw:   The most recent bandwidth in MBps
  * @delta_bw:  Difference between the current and previous bandwidth
  * @delta_comp:        Indicates whether to compute the delta_bw
  */
 struct mbm_state {
-       u64     chunks;
        u64     prev_bw_chunks;
        u32     prev_bw;
        u32     delta_bw;
@@ -297,10 +295,12 @@ struct mbm_state {
 /**
  * struct arch_mbm_state - values used to compute resctrl_arch_rmid_read()s
  *                        return value.
+ * @chunks:    Total data moved (multiply by rdt_group.mon_scale to get bytes)
  * @prev_msr:  Value of IA32_QM_CTR last time it was read for the RMID used to
  *             find this struct.
  */
 struct arch_mbm_state {
+       u64     chunks;
        u64     prev_msr;
 };
 

diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 862a4462ed60af512d0f080e6e327847da5b9635..27bb4947a176f2d7127f805f2859190358eee2cc 100644 (file)
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -204,7 +204,9 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d,
 
        am = get_arch_mbm_state(hw_dom, rmid, eventid);
        if (am) {
-               *val = mbm_overflow_count(am->prev_msr, msr_val, hw_res->mbm_width);
+               am->chunks += mbm_overflow_count(am->prev_msr, msr_val,
+                                                hw_res->mbm_width);
+               *val = get_corrected_mbm_count(rmid, am->chunks);
                am->prev_msr = msr_val;
        } else {
                *val = msr_val;
@@ -374,9 +376,7 @@ static int __mon_event_count(u32 rmid, struct rmid_read *rr)
                return 0;
        }
 
-       m->chunks += tval;
-
-       rr->val += get_corrected_mbm_count(rmid, m->chunks);
+       rr->val += tval;
 
        return 0;
 }