| Message ID | 1552431636-31511-4-git-send-email-fenghua.yu@intel.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | x86/split_lock: Enable #AC exception for split locked accesses | expand |
Fenghua Yu <fenghua.yu@intel.com> writes: > From: Paolo Bonzini <pbonzini@redhat.com> > > Bitmaps are defined on unsigned longs, so the usage of u32[2] in the > wlcore driver is incorrect. As noted by Peter Zijlstra, casting arrays > to a bitmap is incorrect for big-endian architectures. > > When looking at it I observed that: > > - operations on reg_ch_conf_pending is always under the wl_lock mutex, > so set_bit is overkill > > - the only case where reg_ch_conf_pending is accessed a u32 at a time is > unnecessary too. > > This patch cleans up everything in this area, and changes tmp_ch_bitmap > to have the proper alignment. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> [...] > int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) > { > struct wl12xx_cmd_regdomain_dfs_config *cmd = NULL; > int ret = 0, i, b, ch_bit_idx; > - u32 tmp_ch_bitmap[2]; > + u32 tmp_ch_bitmap[2] __aligned(sizeof(unsigned long)); > struct wiphy *wiphy = wl->hw->wiphy; > struct ieee80211_supported_band *band; > bool timeout = false; [...] > @@ -1754,8 +1751,8 @@ int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) > goto out; > } > > - cmd->ch_bit_map1 = cpu_to_le32(tmp_ch_bitmap[0]); > - cmd->ch_bit_map2 = cpu_to_le32(tmp_ch_bitmap[1]); > + cmd->ch_bit_map1 = tmp_ch_bitmap[0]; > + cmd->ch_bit_map2 = tmp_ch_bitmap[1]; Will sparse still be happy? AFAICS you are now assigning u32 to __le32: struct wl12xx_cmd_regdomain_dfs_config { struct wl1271_cmd_header header; __le32 ch_bit_map1; __le32 ch_bit_map2; Also this doesn't depend on anything else from this patchset, right? So I could apply this directly?
Hi, Valo, On Thu, Mar 14, 2019 at 03:16:33PM +0200, Kalle Valo wrote: > Fenghua Yu <fenghua.yu@intel.com> writes: > > > From: Paolo Bonzini <pbonzini@redhat.com> > > > > Bitmaps are defined on unsigned longs, so the usage of u32[2] in the > > wlcore driver is incorrect. As noted by Peter Zijlstra, casting arrays > > to a bitmap is incorrect for big-endian architectures. > > > > When looking at it I observed that: > > > > - operations on reg_ch_conf_pending is always under the wl_lock mutex, > > so set_bit is overkill > > > > - the only case where reg_ch_conf_pending is accessed a u32 at a time is > > unnecessary too. > > > > This patch cleans up everything in this area, and changes tmp_ch_bitmap > > to have the proper alignment. > > > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > > Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> > > [...] > > > int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) > > { > > struct wl12xx_cmd_regdomain_dfs_config *cmd = NULL; > > int ret = 0, i, b, ch_bit_idx; > > - u32 tmp_ch_bitmap[2]; > > + u32 tmp_ch_bitmap[2] __aligned(sizeof(unsigned long)); > > struct wiphy *wiphy = wl->hw->wiphy; > > struct ieee80211_supported_band *band; > > bool timeout = false; > > [...] > > > @@ -1754,8 +1751,8 @@ int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) > > goto out; > > } > > > > - cmd->ch_bit_map1 = cpu_to_le32(tmp_ch_bitmap[0]); > > - cmd->ch_bit_map2 = cpu_to_le32(tmp_ch_bitmap[1]); > > + cmd->ch_bit_map1 = tmp_ch_bitmap[0]; > > + cmd->ch_bit_map2 = tmp_ch_bitmap[1]; > > Will sparse still be happy? AFAICS you are now assigning u32 to __le32: > > struct wl12xx_cmd_regdomain_dfs_config { > struct wl1271_cmd_header header; > > __le32 ch_bit_map1; > __le32 ch_bit_map2; Discussion between Peter and Paolo (https://lkml.org/lkml/2019/3/4/521) may answer your question. (Sorry I didn't send to you v4 patch set) > > Also this doesn't depend on anything else from this patchset, right? So > I could apply this directly? You are right. This patch doesn't rely on other patches from this patchset. This patch just fixes a split lock issue. You could apply this directly without other patches. Thanks. -Fenghua
On 15/03/19 00:16, Fenghua Yu wrote: > Hi, Valo, > > On Thu, Mar 14, 2019 at 03:16:33PM +0200, Kalle Valo wrote: >> Fenghua Yu <fenghua.yu@intel.com> writes: >> >>> From: Paolo Bonzini <pbonzini@redhat.com> >>> >>> Bitmaps are defined on unsigned longs, so the usage of u32[2] in the >>> wlcore driver is incorrect. As noted by Peter Zijlstra, casting arrays >>> to a bitmap is incorrect for big-endian architectures. >>> >>> When looking at it I observed that: >>> >>> - operations on reg_ch_conf_pending is always under the wl_lock mutex, >>> so set_bit is overkill >>> >>> - the only case where reg_ch_conf_pending is accessed a u32 at a time is >>> unnecessary too. >>> >>> This patch cleans up everything in this area, and changes tmp_ch_bitmap >>> to have the proper alignment. >>> >>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> >>> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> >> >> [...] >> >>> int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) >>> { >>> struct wl12xx_cmd_regdomain_dfs_config *cmd = NULL; >>> int ret = 0, i, b, ch_bit_idx; >>> - u32 tmp_ch_bitmap[2]; >>> + u32 tmp_ch_bitmap[2] __aligned(sizeof(unsigned long)); >>> struct wiphy *wiphy = wl->hw->wiphy; >>> struct ieee80211_supported_band *band; >>> bool timeout = false; >> >> [...] >> >>> @@ -1754,8 +1751,8 @@ int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) >>> goto out; >>> } >>> >>> - cmd->ch_bit_map1 = cpu_to_le32(tmp_ch_bitmap[0]); >>> - cmd->ch_bit_map2 = cpu_to_le32(tmp_ch_bitmap[1]); >>> + cmd->ch_bit_map1 = tmp_ch_bitmap[0]; >>> + cmd->ch_bit_map2 = tmp_ch_bitmap[1]; >> >> Will sparse still be happy? AFAICS you are now assigning u32 to __le32: >> >> struct wl12xx_cmd_regdomain_dfs_config { >> struct wl1271_cmd_header header; >> >> __le32 ch_bit_map1; >> __le32 ch_bit_map2; > > Discussion between Peter and Paolo (https://lkml.org/lkml/2019/3/4/521) > may answer your question. No, Kalle is right. You do need to change - u32 tmp_ch_bitmap[2]; + u32 tmp_ch_bitmap[2] __aligned(sizeof(unsigned long)); into - u32 tmp_ch_bitmap[2]; + __le32 tmp_ch_bitmap[2] __aligned(sizeof(unsigned long)); The assignment from wl->reg_ch_conf_pending to tmp_ch_bitmap is fine because it goes through memcpy. Paolo > (Sorry I didn't send to you v4 patch set) > >> >> Also this doesn't depend on anything else from this patchset, right? So >> I could apply this directly? > > You are right. This patch doesn't rely on other patches from this patchset. > This patch just fixes a split lock issue. You could apply this directly > without other patches. > > Thanks. > > -Fenghua >
Paolo Bonzini <pbonzini@redhat.com> writes: > On 15/03/19 00:16, Fenghua Yu wrote: >> Hi, Valo, >> >> On Thu, Mar 14, 2019 at 03:16:33PM +0200, Kalle Valo wrote: >>> Fenghua Yu <fenghua.yu@intel.com> writes: >>> >>>> From: Paolo Bonzini <pbonzini@redhat.com> >>>> >>>> Bitmaps are defined on unsigned longs, so the usage of u32[2] in the >>>> wlcore driver is incorrect. As noted by Peter Zijlstra, casting arrays >>>> to a bitmap is incorrect for big-endian architectures. >>>> >>>> When looking at it I observed that: >>>> >>>> - operations on reg_ch_conf_pending is always under the wl_lock mutex, >>>> so set_bit is overkill >>>> >>>> - the only case where reg_ch_conf_pending is accessed a u32 at a time is >>>> unnecessary too. >>>> >>>> This patch cleans up everything in this area, and changes tmp_ch_bitmap >>>> to have the proper alignment. >>>> >>>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> >>>> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> >>> >>> [...] >>> >>>> int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) >>>> { >>>> struct wl12xx_cmd_regdomain_dfs_config *cmd = NULL; >>>> int ret = 0, i, b, ch_bit_idx; >>>> - u32 tmp_ch_bitmap[2]; >>>> + u32 tmp_ch_bitmap[2] __aligned(sizeof(unsigned long)); >>>> struct wiphy *wiphy = wl->hw->wiphy; >>>> struct ieee80211_supported_band *band; >>>> bool timeout = false; >>> >>> [...] >>> >>>> @@ -1754,8 +1751,8 @@ int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) >>>> goto out; >>>> } >>>> >>>> - cmd->ch_bit_map1 = cpu_to_le32(tmp_ch_bitmap[0]); >>>> - cmd->ch_bit_map2 = cpu_to_le32(tmp_ch_bitmap[1]); >>>> + cmd->ch_bit_map1 = tmp_ch_bitmap[0]; >>>> + cmd->ch_bit_map2 = tmp_ch_bitmap[1]; >>> >>> Will sparse still be happy? AFAICS you are now assigning u32 to __le32: >>> >>> struct wl12xx_cmd_regdomain_dfs_config { >>> struct wl1271_cmd_header header; >>> >>> __le32 ch_bit_map1; >>> __le32 ch_bit_map2; >> >> Discussion between Peter and Paolo (https://lkml.org/lkml/2019/3/4/521) >> may answer your question. > > No, Kalle is right. You do need to change > > - u32 tmp_ch_bitmap[2]; > + u32 tmp_ch_bitmap[2] __aligned(sizeof(unsigned long)); > > into > > - u32 tmp_ch_bitmap[2]; > + __le32 tmp_ch_bitmap[2] __aligned(sizeof(unsigned long)); > > The assignment from wl->reg_ch_conf_pending to tmp_ch_bitmap is fine > because it goes through memcpy. Thanks for confirming, I'll then drop patch 3 and wait for a new version. IMHO it would be easier to submit this patch separately to linux-wireless, no need to have within this bigger patchset.
diff --git a/drivers/net/wireless/ti/wlcore/cmd.c b/drivers/net/wireless/ti/wlcore/cmd.c index 348be0aed97e..3b9266989afe 100644 --- a/drivers/net/wireless/ti/wlcore/cmd.c +++ b/drivers/net/wireless/ti/wlcore/cmd.c @@ -1700,14 +1700,14 @@ void wlcore_set_pending_regdomain_ch(struct wl1271 *wl, u16 channel, ch_bit_idx = wlcore_get_reg_conf_ch_idx(band, channel); if (ch_bit_idx >= 0 && ch_bit_idx <= WL1271_MAX_CHANNELS) - set_bit(ch_bit_idx, (long *)wl->reg_ch_conf_pending); + __set_bit_le(ch_bit_idx, (long *)wl->reg_ch_conf_pending); } int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) { struct wl12xx_cmd_regdomain_dfs_config *cmd = NULL; int ret = 0, i, b, ch_bit_idx; - u32 tmp_ch_bitmap[2]; + u32 tmp_ch_bitmap[2] __aligned(sizeof(unsigned long)); struct wiphy *wiphy = wl->hw->wiphy; struct ieee80211_supported_band *band; bool timeout = false; @@ -1717,7 +1717,7 @@ int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) wl1271_debug(DEBUG_CMD, "cmd reg domain config"); - memset(tmp_ch_bitmap, 0, sizeof(tmp_ch_bitmap)); + memcpy(tmp_ch_bitmap, wl->reg_ch_conf_pending, sizeof(tmp_ch_bitmap)); for (b = NL80211_BAND_2GHZ; b <= NL80211_BAND_5GHZ; b++) { band = wiphy->bands[b]; @@ -1738,13 +1738,10 @@ int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) if (ch_bit_idx < 0) continue; - set_bit(ch_bit_idx, (long *)tmp_ch_bitmap); + __set_bit_le(ch_bit_idx, (long *)tmp_ch_bitmap); } } - tmp_ch_bitmap[0] |= wl->reg_ch_conf_pending[0]; - tmp_ch_bitmap[1] |= wl->reg_ch_conf_pending[1]; - if (!memcmp(tmp_ch_bitmap, wl->reg_ch_conf_last, sizeof(tmp_ch_bitmap))) goto out; @@ -1754,8 +1751,8 @@ int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) goto out; } - cmd->ch_bit_map1 = cpu_to_le32(tmp_ch_bitmap[0]); - cmd->ch_bit_map2 = cpu_to_le32(tmp_ch_bitmap[1]); + cmd->ch_bit_map1 = tmp_ch_bitmap[0]; + cmd->ch_bit_map2 = tmp_ch_bitmap[1]; cmd->dfs_region = wl->dfs_region; wl1271_debug(DEBUG_CMD, diff --git a/drivers/net/wireless/ti/wlcore/wlcore.h b/drivers/net/wireless/ti/wlcore/wlcore.h index dd14850b0603..870eea3e7a27 100644 --- a/drivers/net/wireless/ti/wlcore/wlcore.h +++ b/drivers/net/wireless/ti/wlcore/wlcore.h @@ -320,9 +320,9 @@ struct wl1271 { bool watchdog_recovery; /* Reg domain last configuration */ - u32 reg_ch_conf_last[2] __aligned(8); + DECLARE_BITMAP(reg_ch_conf_last, 64); /* Reg domain pending configuration */ - u32 reg_ch_conf_pending[2]; + DECLARE_BITMAP(reg_ch_conf_pending, 64); /* Pointer that holds DMA-friendly block for the mailbox */ void *mbox;