Page MenuHomeFreeBSD
Differential D22431

Add x86 msr tweak KPI.
ClosedPublic
Actions

Authored by kib on Nov 17 2019, 4:09 PM.
Tags
None
Referenced Files
Unknown Object (File)
Mon, Mar 17, 12:36 AM
Unknown Object (File)
Sun, Mar 16, 11:41 PM
Unknown Object (File)
Sun, Mar 16, 11:35 PM
Unknown Object (File)
Sun, Mar 16, 11:30 PM
Unknown Object (File)
Sun, Mar 16, 11:15 PM
Unknown Object (File)
Feb 10 2025, 5:02 PM
Unknown Object (File)
Feb 5 2025, 1:48 AM
Unknown Object (File)
Feb 5 2025, 1:36 AM
View All 81 Files
Subscribers
gnn
imp

Details

Reviewers
markj
emaste
scottl
scottph
Commits
rS354828: Add x86 msr tweak KPI.
Summary

It is consistently uses rendezvouz IPI instead of binding current thread to all CPUs.

Use the KPI to tweak MSRs in mitigation code.

Diff Detail

Repository
rS FreeBSD src repository - subversion
Lint
Lint Not Applicable
Unit
Tests Not Applicable

Event Timeline

kib created this revision.Nov 17 2019, 4:09 PM
Herald added subscribers: gnn, imp. · View Herald TranscriptNov 17 2019, 4:09 PM
Harbormaster completed remote builds in B27606: Diff 64496.Nov 17 2019, 4:09 PM
scottl added a comment.Nov 18 2019, 6:24 AM

This looks great. My only complaint is using the name "tweak", I think it's too casual and poorly descriptive. Maybe x86_program_msr_smp()?

kib updated this revision to Diff 64519.Nov 18 2019, 1:21 PM

Rename to x86_msr_op().
Restore sched_bind() mode of broadcast to keep the ssb toggle algorithm unchanged. I do think that my switch to smp_rendezvous for ssb is actually fine because our use of mwait does not re-enable interrupts, but let do that as separate change.

Harbormaster completed remote builds in B27615: Diff 64519.Nov 18 2019, 1:21 PM
markj added inline comments.Nov 18 2019, 3:42 PM
sys/x86/x86/cpu_machdep.c
153 ↗(On Diff #64519)

Should we also assert that OP_LOCAL and OP_SCHED are not both specified?

172 ↗(On Diff #64519)

I think it would be nicer to have an explicit name for this case, to make it easier to read the calling code. Maybe MSR_OP_RENDEZVOUS.

kib updated this revision to Diff 64529.Nov 18 2019, 4:20 PM
kib marked 2 inline comments as done.

Add MSR_OP_RENDEZVOUS. Assert that exactly one command mode flag is passed.

Harbormaster completed remote builds in B27619: Diff 64529.Nov 18 2019, 4:20 PM
markj accepted this revision.Nov 18 2019, 4:25 PM
This revision is now accepted and ready to land.Nov 18 2019, 4:25 PM
scottl added a comment.Nov 18 2019, 4:33 PM

Minor request, if the MSR_OP_LOCAL/SCHED/RENDEVOUS opcodes are mutually exclusive from each other then don't make them be bitfield definitions, just have them be sequential numbers.

kib updated this revision to Diff 64538.Nov 18 2019, 7:27 PM

Make execution submode numeric.

This revision now requires review to proceed.Nov 18 2019, 7:27 PM
Harbormaster completed remote builds in B27624: Diff 64538.Nov 18 2019, 7:27 PM
kib updated this revision to Diff 64539.Nov 18 2019, 7:52 PM

x86_var.h was missed.

Harbormaster completed remote builds in B27625: Diff 64539.Nov 18 2019, 7:52 PM
markj accepted this revision.Nov 18 2019, 7:56 PM
This revision is now accepted and ready to land.Nov 18 2019, 7:56 PM
scottl accepted this revision.Nov 18 2019, 7:59 PM
Closed by commit rS354828: Add x86 msr tweak KPI. (authored by kib). · Explain WhyNov 18 2019, 8:54 PM
This revision was automatically updated to reflect the committed changes.
kib added a commit: rS354828: Add x86 msr tweak KPI..

Revision Contents
Changeset List

PathSize
head/
sys/
dev/
hwpmc/
15 lines
x86/
include/
8 lines
x86/
161 lines

Diff 64543

View Options

head/sys/dev/hwpmc/hwpmc_core.c

Show First 20 Lines • Show All 701 Lines • ▼ Show 20 Linesieee80211_phy_vht_validate_mcs(enum ieee80211_sta_rx_bw bw, uint8_t nss,
uint16_t mask; uint16_t mask;
mask = ieee80211_phy_vht_get_mcs_mask(bw, nss); mask = ieee80211_phy_vht_get_mcs_mask(bw, nss);
if (mask == 0) if (mask == 0)
return (false); return (false);
return ((mask & (1 << mcs)) != 0); return ((mask & (1 << mcs)) != 0);
} }
struct mcs_entry {
int n_sym; /* Number of bits per symbol */
int cod_n; /* Coding rate numerator */
int cod_d; /* Coding rate denominator */
};
/*
* These parameters are taken from 802.11-2020 Table 21-29
* (VHT-MCSs for Mandatory 20 MHZ, Nss=1).
*
* n_sym corresponds to "Nbpscs", cod_n/cod_d corresponds to
* "R".
*/
static struct mcs_entry mcs_entries[] = {
{ 1, 1, 2 }, /* MCS0 */
{ 2, 1, 2 },
{ 2, 3, 4 },
{ 4, 1, 2 },
{ 4, 3, 4 },
{ 6, 2, 3 },
{ 6, 3, 4 },
{ 6, 5, 6 },
{ 8, 3, 4 },
{ 8, 5, 6 }, /* MCS9 */
};
/**
* @brief Calculate the bitrate of the given VHT MCS rate.
*
* @param bw Channel bandwidth (enum ieee80211_sta_rx_bw)
* @param nss Number of spatial streams, 1..8
* @param mcs MCS, 0..9
* @param is_shortgi True if short guard-interval (400nS)
* false otherwise (800nS)
*
* @returns The bitrate in kbit/sec.
*/
uint32_t
ieee80211_phy_vht_get_mcs_kbit(enum ieee80211_sta_rx_bw bw,
uint8_t nss, uint8_t mcs, bool is_shortgi)
{
uint32_t sym_len, n_carriers;
/* Validate MCS 0..9, NSS 1..8 */
if (mcs > 9)
return (0);
if (nss == 0 || nss > 8)
return (0);
/*
* Short-GI - 3.6uS symbol time, long-GI - 4.0uS symbol time
*
* See 802.11-2020 Table 21-5 (Timing-related constraints.)
*/
if (is_shortgi)
sym_len = 36;
else
sym_len = 40;
/*
* Calculate the number of carriers for the given channel bandwidth
*
* See 802.11-2020 Table 21-5 (Timing-related constraints.)
*/
switch (bw) {
case IEEE80211_STA_RX_BW_20:
n_carriers = 52;
break;
case IEEE80211_STA_RX_BW_40:
n_carriers = 108;
break;
case IEEE80211_STA_RX_BW_80:
n_carriers = 234;
break;
case IEEE80211_STA_RX_BW_160:
n_carriers = 468;
break;
default:
return (0);
}
return ((n_carriers * mcs_entries[mcs].n_sym * mcs_entries[mcs].cod_n *
nss * 10000) / (mcs_entries[mcs].cod_d * sym_len));
}
View Options

head/sys/x86/include/x86_var.h

Show First 20 Lines • Show All 701 Lines • ▼ Show 20 Linesieee80211_phy_vht_validate_mcs(enum ieee80211_sta_rx_bw bw, uint8_t nss,
uint16_t mask; uint16_t mask;
mask = ieee80211_phy_vht_get_mcs_mask(bw, nss); mask = ieee80211_phy_vht_get_mcs_mask(bw, nss);
if (mask == 0) if (mask == 0)
return (false); return (false);
return ((mask & (1 << mcs)) != 0); return ((mask & (1 << mcs)) != 0);
} }
struct mcs_entry {
int n_sym; /* Number of bits per symbol */
int cod_n; /* Coding rate numerator */
int cod_d; /* Coding rate denominator */
};
/*
* These parameters are taken from 802.11-2020 Table 21-29
* (VHT-MCSs for Mandatory 20 MHZ, Nss=1).
*
* n_sym corresponds to "Nbpscs", cod_n/cod_d corresponds to
* "R".
*/
static struct mcs_entry mcs_entries[] = {
{ 1, 1, 2 }, /* MCS0 */
{ 2, 1, 2 },
{ 2, 3, 4 },
{ 4, 1, 2 },
{ 4, 3, 4 },
{ 6, 2, 3 },
{ 6, 3, 4 },
{ 6, 5, 6 },
{ 8, 3, 4 },
{ 8, 5, 6 }, /* MCS9 */
};
/**
* @brief Calculate the bitrate of the given VHT MCS rate.
*
* @param bw Channel bandwidth (enum ieee80211_sta_rx_bw)
* @param nss Number of spatial streams, 1..8
* @param mcs MCS, 0..9
* @param is_shortgi True if short guard-interval (400nS)
* false otherwise (800nS)
*
* @returns The bitrate in kbit/sec.
*/
uint32_t
ieee80211_phy_vht_get_mcs_kbit(enum ieee80211_sta_rx_bw bw,
uint8_t nss, uint8_t mcs, bool is_shortgi)
{
uint32_t sym_len, n_carriers;
/* Validate MCS 0..9, NSS 1..8 */
if (mcs > 9)
return (0);
if (nss == 0 || nss > 8)
return (0);
/*
* Short-GI - 3.6uS symbol time, long-GI - 4.0uS symbol time
*
* See 802.11-2020 Table 21-5 (Timing-related constraints.)
*/
if (is_shortgi)
sym_len = 36;
else
sym_len = 40;
/*
* Calculate the number of carriers for the given channel bandwidth
*
* See 802.11-2020 Table 21-5 (Timing-related constraints.)
*/
switch (bw) {
case IEEE80211_STA_RX_BW_20:
n_carriers = 52;
break;
case IEEE80211_STA_RX_BW_40:
n_carriers = 108;
break;
case IEEE80211_STA_RX_BW_80:
n_carriers = 234;
break;
case IEEE80211_STA_RX_BW_160:
n_carriers = 468;
break;
default:
return (0);
}
return ((n_carriers * mcs_entries[mcs].n_sym * mcs_entries[mcs].cod_n *
nss * 10000) / (mcs_entries[mcs].cod_d * sym_len));
}
View Options

head/sys/x86/x86/cpu_machdep.c

Show First 20 Lines • Show All 701 Lines • ▼ Show 20 Linesieee80211_phy_vht_validate_mcs(enum ieee80211_sta_rx_bw bw, uint8_t nss,
uint16_t mask; uint16_t mask;
mask = ieee80211_phy_vht_get_mcs_mask(bw, nss); mask = ieee80211_phy_vht_get_mcs_mask(bw, nss);
if (mask == 0) if (mask == 0)
return (false); return (false);
return ((mask & (1 << mcs)) != 0); return ((mask & (1 << mcs)) != 0);
} }
struct mcs_entry {
int n_sym; /* Number of bits per symbol */
int cod_n; /* Coding rate numerator */
int cod_d; /* Coding rate denominator */
};
/*
* These parameters are taken from 802.11-2020 Table 21-29
* (VHT-MCSs for Mandatory 20 MHZ, Nss=1).
*
* n_sym corresponds to "Nbpscs", cod_n/cod_d corresponds to
* "R".
*/
static struct mcs_entry mcs_entries[] = {
{ 1, 1, 2 }, /* MCS0 */
{ 2, 1, 2 },
{ 2, 3, 4 },
{ 4, 1, 2 },
{ 4, 3, 4 },
{ 6, 2, 3 },
{ 6, 3, 4 },
{ 6, 5, 6 },
{ 8, 3, 4 },
{ 8, 5, 6 }, /* MCS9 */
};
/**
* @brief Calculate the bitrate of the given VHT MCS rate.
*
* @param bw Channel bandwidth (enum ieee80211_sta_rx_bw)
* @param nss Number of spatial streams, 1..8
* @param mcs MCS, 0..9
* @param is_shortgi True if short guard-interval (400nS)
* false otherwise (800nS)
*
* @returns The bitrate in kbit/sec.
*/
uint32_t
ieee80211_phy_vht_get_mcs_kbit(enum ieee80211_sta_rx_bw bw,
uint8_t nss, uint8_t mcs, bool is_shortgi)
{
uint32_t sym_len, n_carriers;
/* Validate MCS 0..9, NSS 1..8 */
if (mcs > 9)
return (0);
if (nss == 0 || nss > 8)
return (0);
/*
* Short-GI - 3.6uS symbol time, long-GI - 4.0uS symbol time
*
* See 802.11-2020 Table 21-5 (Timing-related constraints.)
*/
if (is_shortgi)
sym_len = 36;
else
sym_len = 40;
/*
* Calculate the number of carriers for the given channel bandwidth
*
* See 802.11-2020 Table 21-5 (Timing-related constraints.)
*/
switch (bw) {
case IEEE80211_STA_RX_BW_20:
n_carriers = 52;
break;
case IEEE80211_STA_RX_BW_40:
n_carriers = 108;
break;
case IEEE80211_STA_RX_BW_80:
n_carriers = 234;
break;
case IEEE80211_STA_RX_BW_160:
n_carriers = 468;
break;
default:
return (0);
}
return ((n_carriers * mcs_entries[mcs].n_sym * mcs_entries[mcs].cod_n *
nss * 10000) / (mcs_entries[mcs].cod_d * sym_len));
}