linux-kernel - [tip: x86/cache] x86/resctrl: Move get_corrected_mbm_count() into resctrl_arch_rmid

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Date:   Fri, 23 Sep 2022 18:01:43 -0000
From:   "tip-bot2 for James Morse" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     James Morse <james.morse@....com>, Borislav Petkov <bp@...e.de>,
        Jamie Iles <quic_jiles@...cinc.com>,
        Shaopeng Tan <tan.shaopeng@...itsu.com>,
        Reinette Chatre <reinette.chatre@...el.com>,
        Xin Hao <xhao@...ux.alibaba.com>,
        Cristian Marussi <cristian.marussi@....com>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: x86/cache] x86/resctrl: Move get_corrected_mbm_count() into
 resctrl_arch_rmid_read()

The following commit has been merged into the x86/cache branch of tip:

Commit-ID:     38f72f50d6498ee60ac89deff3686e34ce0c2a32
Gitweb:        https://git.kernel.org/tip/38f72f50d6498ee60ac89deff3686e34ce0c2a32
Author:        James Morse <james.morse@....com>
AuthorDate:    Fri, 02 Sep 2022 15:48:26 
Committer:     Borislav Petkov <bp@...e.de>
CommitterDate: Fri, 23 Sep 2022 14:22:53 +02:00

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@....com>
Signed-off-by: Borislav Petkov <bp@...e.de>
Reviewed-by: Jamie Iles <quic_jiles@...cinc.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@...itsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@...el.com>
Tested-by: Xin Hao <xhao@...ux.alibaba.com>
Tested-by: Shaopeng Tan <tan.shaopeng@...itsu.com>
Tested-by: Cristian Marussi <cristian.marussi@....com>
Link: https://lore.kernel.org/r/20220902154829.30399-19-james.morse@arm.com
---
 arch/x86/kernel/cpu/resctrl/internal.h | 4 ++--
 arch/x86/kernel/cpu/resctrl/monitor.c  | 8 ++++----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 8039e8a..bdb55c2 100644
--- 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 862a446..27bb494 100644
--- 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;
 }