Commit 38f72f50 authored by James Morse's avatar James Morse Committed by Borislav Petkov
Browse files

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: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarJamie Iles <quic_jiles@quicinc.com>
Reviewed-by: default avatarShaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Tested-by: default avatarXin Hao <xhao@linux.alibaba.com>
Tested-by: default avatarShaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: default avatarCristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20220902154829.30399-19-james.morse@arm.com
parent 1d81d15d

arch/x86/kernel/cpu/resctrl/internal.h

+2 −2
Original line number Diff line number Diff line
@@ -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;

};

arch/x86/kernel/cpu/resctrl/monitor.c

+4 −4
Original line number Diff line number Diff line
@@ -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;

}