March 2025 - Linux-stable-mirror

[PATCH AUTOSEL 6.1 1/9] ASoC: tas2770: Fix volume scale

by Sasha Levin

From: Hector Martin <marcan(a)marcan.st> [ Upstream commit 579cd64b9df8a60284ec3422be919c362de40e41 ] The scale starts at -100dB, not -128dB. Signed-off-by: Hector Martin <marcan(a)marcan.st> Signed-off-by: Mark Brown <broonie(a)kernel.org> Link: https://patch.msgid.link/20250208-asoc-tas2770-v1-1-cf50ff1d59a3@kernel.org Signed-off-by: Mark Brown <broonie(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- sound/soc/codecs/tas2770.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sound/soc/codecs/tas2770.c b/sound/soc/codecs/tas2770.c index 8557759acb1f2..e284a3a854591 100644 --- a/sound/soc/codecs/tas2770.c +++ b/sound/soc/codecs/tas2770.c @@ -508,7 +508,7 @@ static int tas2770_codec_probe(struct snd_soc_component *component) } static DECLARE_TLV_DB_SCALE(tas2770_digital_tlv, 1100, 50, 0); -static DECLARE_TLV_DB_SCALE(tas2770_playback_volume, -12750, 50, 0); +static DECLARE_TLV_DB_SCALE(tas2770_playback_volume, -10050, 50, 0); static const struct snd_kcontrol_new tas2770_snd_controls[] = { SOC_SINGLE_TLV("Speaker Playback Volume", TAS2770_PLAY_CFG_REG2, -- 2.39.5

3 months, 1 week

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[PATCH AUTOSEL 6.6 01/11] ASoC: tas2770: Fix volume scale

by Sasha Levin

From: Hector Martin <marcan(a)marcan.st> [ Upstream commit 579cd64b9df8a60284ec3422be919c362de40e41 ] The scale starts at -100dB, not -128dB. Signed-off-by: Hector Martin <marcan(a)marcan.st> Signed-off-by: Mark Brown <broonie(a)kernel.org> Link: https://patch.msgid.link/20250208-asoc-tas2770-v1-1-cf50ff1d59a3@kernel.org Signed-off-by: Mark Brown <broonie(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- sound/soc/codecs/tas2770.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sound/soc/codecs/tas2770.c b/sound/soc/codecs/tas2770.c index 99bf402eb5667..5c6b825c757b3 100644 --- a/sound/soc/codecs/tas2770.c +++ b/sound/soc/codecs/tas2770.c @@ -508,7 +508,7 @@ static int tas2770_codec_probe(struct snd_soc_component *component) } static DECLARE_TLV_DB_SCALE(tas2770_digital_tlv, 1100, 50, 0); -static DECLARE_TLV_DB_SCALE(tas2770_playback_volume, -12750, 50, 0); +static DECLARE_TLV_DB_SCALE(tas2770_playback_volume, -10050, 50, 0); static const struct snd_kcontrol_new tas2770_snd_controls[] = { SOC_SINGLE_TLV("Speaker Playback Volume", TAS2770_PLAY_CFG_REG2, -- 2.39.5

3 months, 1 week

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[PATCH AUTOSEL 6.12 01/17] phy: ti: gmii-sel: Do not use syscon helper to build regmap

by Sasha Levin

From: Andrew Davis <afd(a)ti.com> [ Upstream commit 5ab90f40121a9f6a9b368274cd92d0f435dc7cfa ] The syscon helper device_node_to_regmap() is used to fetch a regmap registered to a device node. It also currently creates this regmap if the node did not already have a regmap associated with it. This should only be used on "syscon" nodes. This driver is not such a device and instead uses device_node_to_regmap() on its own node as a hacky way to create a regmap for itself. This will not work going forward and so we should create our regmap the normal way by defining our regmap_config, fetching our memory resource, then using the normal regmap_init_mmio() function. Signed-off-by: Andrew Davis <afd(a)ti.com> Tested-by: Nishanth Menon <nm(a)ti.com> Link: https://lore.kernel.org/r/20250123182234.597665-1-afd@ti.com Signed-off-by: Vinod Koul <vkoul(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- drivers/phy/ti/phy-gmii-sel.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/phy/ti/phy-gmii-sel.c b/drivers/phy/ti/phy-gmii-sel.c index 103b266fec771..2c2256fe5a3b6 100644 --- a/drivers/phy/ti/phy-gmii-sel.c +++ b/drivers/phy/ti/phy-gmii-sel.c @@ -423,6 +423,12 @@ static int phy_gmii_sel_init_ports(struct phy_gmii_sel_priv *priv) return 0; } +static const struct regmap_config phy_gmii_sel_regmap_cfg = { + .reg_bits = 32, + .val_bits = 32, + .reg_stride = 4, +}; + static int phy_gmii_sel_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -467,7 +473,14 @@ static int phy_gmii_sel_probe(struct platform_device *pdev) priv->regmap = syscon_node_to_regmap(node->parent); if (IS_ERR(priv->regmap)) { - priv->regmap = device_node_to_regmap(node); + void __iomem *base; + + base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(base)) + return dev_err_probe(dev, PTR_ERR(base), + "failed to get base memory resource\n"); + + priv->regmap = regmap_init_mmio(dev, base, &phy_gmii_sel_regmap_cfg); if (IS_ERR(priv->regmap)) return dev_err_probe(dev, PTR_ERR(priv->regmap), "Failed to get syscon\n"); -- 2.39.5

3 months, 1 week

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[RESEND PATCH] ASoC: tegra: Fix ADX S24_LE audio format

by Thorsten Blum

Commit 4204eccc7b2a ("ASoC: tegra: Add support for S24_LE audio format") added support for the S24_LE audio format, but duplicated S16_LE in OUT_DAI() for ADX instead. Fix this by adding support for the S24_LE audio format. Compile-tested only. Cc: stable(a)vger.kernel.org Fixes: 4204eccc7b2a ("ASoC: tegra: Add support for S24_LE audio format") Signed-off-by: Thorsten Blum <thorsten.blum(a)linux.dev> --- sound/soc/tegra/tegra210_adx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/sound/soc/tegra/tegra210_adx.c b/sound/soc/tegra/tegra210_adx.c index 3e6e8f51f380..0aa93b948378 100644 --- a/sound/soc/tegra/tegra210_adx.c +++ b/sound/soc/tegra/tegra210_adx.c @@ -264,7 +264,7 @@ static const struct snd_soc_dai_ops tegra210_adx_out_dai_ops = { .rates = SNDRV_PCM_RATE_8000_192000, \ .formats = SNDRV_PCM_FMTBIT_S8 | \ SNDRV_PCM_FMTBIT_S16_LE | \ - SNDRV_PCM_FMTBIT_S16_LE | \ + SNDRV_PCM_FMTBIT_S24_LE | \ SNDRV_PCM_FMTBIT_S32_LE, \ }, \ .capture = { \ @@ -274,7 +274,7 @@ static const struct snd_soc_dai_ops tegra210_adx_out_dai_ops = { .rates = SNDRV_PCM_RATE_8000_192000, \ .formats = SNDRV_PCM_FMTBIT_S8 | \ SNDRV_PCM_FMTBIT_S16_LE | \ - SNDRV_PCM_FMTBIT_S16_LE | \ + SNDRV_PCM_FMTBIT_S24_LE | \ SNDRV_PCM_FMTBIT_S32_LE, \ }, \ .ops = &tegra210_adx_out_dai_ops, \ -- 2.48.1

3 months, 1 week

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[PATCH] mailbox: tegra-hsp: Add check for devm_kstrdup_const()

by Haoxiang Li

Add check for the return value of devm_kstrdup_const() in tegra_hsp_doorbell_create() to catch potential exception. Fixes: a54d03ed01b4 ("mailbox: tegra-hsp: use devm_kstrdup_const()") Cc: stable(a)vger.kernel.org Signed-off-by: Haoxiang Li <haoxiang_li2024(a)163.com> --- drivers/mailbox/tegra-hsp.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c index c1981f091bd1..773a1cf6d93d 100644 --- a/drivers/mailbox/tegra-hsp.c +++ b/drivers/mailbox/tegra-hsp.c @@ -285,6 +285,8 @@ tegra_hsp_doorbell_create(struct tegra_hsp *hsp, const char *name, db->channel.hsp = hsp; db->name = devm_kstrdup_const(hsp->dev, name, GFP_KERNEL); + if (!db->name) + return ERR_PTR(-ENOMEM); db->master = master; db->index = index; -- 2.25.1

3 months, 1 week

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[PATCH] media: uvcvideo: Fix deferred probing error

by Ricardo Ribalda

uvc_gpio_parse() can return -EPROBE_DEFER when the GPIOs it depends on have not yet been probed. This return code should be propagated to the caller of uvc_probe() to ensure that probing is retried when the required GPIOs become available. Currently, this error code is incorrectly converted to -ENODEV, causing some internal cameras to be ignored. This commit fixes this issue by propagating the -EPROBE_DEFER error. Cc: stable(a)vger.kernel.org Fixes: 2886477ff987 ("media: uvcvideo: Implement UVC_EXT_GPIO_UNIT") Signed-off-by: Ricardo Ribalda <ribalda(a)chromium.org> --- drivers/media/usb/uvc/uvc_driver.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c index a10d4f4d9f95..73a7f23b616c 100644 --- a/drivers/media/usb/uvc/uvc_driver.c +++ b/drivers/media/usb/uvc/uvc_driver.c @@ -2253,9 +2253,10 @@ static int uvc_probe(struct usb_interface *intf, } /* Parse the associated GPIOs. */ - if (uvc_gpio_parse(dev) < 0) { + ret = uvc_gpio_parse(dev); + if (ret < 0) { uvc_dbg(dev, PROBE, "Unable to parse UVC GPIOs\n"); - goto error; + goto error_retcode; } dev_info(&dev->udev->dev, "Found UVC %u.%02x device %s (%04x:%04x)\n", @@ -2328,9 +2329,11 @@ static int uvc_probe(struct usb_interface *intf, return 0; error: + ret = -ENODEV; +error_retcode: uvc_unregister_video(dev); kref_put(&dev->ref, uvc_delete); - return -ENODEV; + return ret; } static void uvc_disconnect(struct usb_interface *intf) --- base-commit: c4b7779abc6633677e6edb79e2809f4f61fde157 change-id: 20250129-uvc-eprobedefer-b5ebb4db63cc Best regards, -- Ricardo Ribalda <ribalda(a)chromium.org>

3 months, 1 week

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[PATCH v4 1/6] Revert "wifi: mt76: mt7925: Update mt7925_mcu_uni_[tx,rx]_ba for MLO"

by sean.wang＠kernel.org

From: Sean Wang <sean.wang(a)mediatek.com> For MLO, mac80211 will send the BA action for each link to the driver, so the driver does not need to handle it itself. Therefore, revert this patch. Fixes: e38a82d25b08 ("wifi: mt76: connac: Extend mt76_connac_mcu_uni_add_dev for MLO") Cc: stable(a)vger.kernel.org Signed-off-by: Ming Yen Hsieh <mingyen.hsieh(a)mediatek.com> Tested-by: Caleb Jorden <cjorden(a)gmail.com> Signed-off-by: Sean Wang <sean.wang(a)mediatek.com> --- v2: 1) generate the patch based on the latest mt76 tree 2) update the commit message v3: 1) fixed the merge conflict v4: 1) added tested-by tag --- .../net/wireless/mediatek/mt76/mt7925/main.c | 10 ++-- .../net/wireless/mediatek/mt76/mt7925/mcu.c | 50 ++++--------------- .../wireless/mediatek/mt76/mt7925/mt7925.h | 2 - 3 files changed, 15 insertions(+), 47 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/main.c b/drivers/net/wireless/mediatek/mt76/mt7925/main.c index 98daf80ac131..8dba17c8697c 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7925/main.c +++ b/drivers/net/wireless/mediatek/mt76/mt7925/main.c @@ -1289,22 +1289,22 @@ mt7925_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif, case IEEE80211_AMPDU_RX_START: mt76_rx_aggr_start(&dev->mt76, &msta->deflink.wcid, tid, ssn, params->buf_size); - mt7925_mcu_uni_rx_ba(dev, vif, params, true); + mt7925_mcu_uni_rx_ba(dev, params, true); break; case IEEE80211_AMPDU_RX_STOP: mt76_rx_aggr_stop(&dev->mt76, &msta->deflink.wcid, tid); - mt7925_mcu_uni_rx_ba(dev, vif, params, false); + mt7925_mcu_uni_rx_ba(dev, params, false); break; case IEEE80211_AMPDU_TX_OPERATIONAL: mtxq->aggr = true; mtxq->send_bar = false; - mt7925_mcu_uni_tx_ba(dev, vif, params, true); + mt7925_mcu_uni_tx_ba(dev, params, true); break; case IEEE80211_AMPDU_TX_STOP_FLUSH: case IEEE80211_AMPDU_TX_STOP_FLUSH_CONT: mtxq->aggr = false; clear_bit(tid, &msta->deflink.wcid.ampdu_state); - mt7925_mcu_uni_tx_ba(dev, vif, params, false); + mt7925_mcu_uni_tx_ba(dev, params, false); break; case IEEE80211_AMPDU_TX_START: set_bit(tid, &msta->deflink.wcid.ampdu_state); @@ -1313,7 +1313,7 @@ mt7925_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif, case IEEE80211_AMPDU_TX_STOP_CONT: mtxq->aggr = false; clear_bit(tid, &msta->deflink.wcid.ampdu_state); - mt7925_mcu_uni_tx_ba(dev, vif, params, false); + mt7925_mcu_uni_tx_ba(dev, params, false); ieee80211_stop_tx_ba_cb_irqsafe(vif, sta->addr, tid); break; } diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7925/mcu.c index 15815ad84713..4c133200c70b 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7925/mcu.c +++ b/drivers/net/wireless/mediatek/mt76/mt7925/mcu.c @@ -607,60 +607,30 @@ mt7925_mcu_sta_ba(struct mt76_dev *dev, struct mt76_vif_link *mvif, /** starec & wtbl **/ int mt7925_mcu_uni_tx_ba(struct mt792x_dev *dev, - struct ieee80211_vif *vif, struct ieee80211_ampdu_params *params, bool enable) { struct mt792x_sta *msta = (struct mt792x_sta *)params->sta->drv_priv; - struct mt792x_vif *mvif = (struct mt792x_vif *)vif->drv_priv; - struct mt792x_link_sta *mlink; - struct mt792x_bss_conf *mconf; - unsigned long usable_links = ieee80211_vif_usable_links(vif); - struct mt76_wcid *wcid; - u8 link_id, ret; - - for_each_set_bit(link_id, &usable_links, IEEE80211_MLD_MAX_NUM_LINKS) { - mconf = mt792x_vif_to_link(mvif, link_id); - mlink = mt792x_sta_to_link(msta, link_id); - wcid = &mlink->wcid; - - if (enable && !params->amsdu) - mlink->wcid.amsdu = false; + struct mt792x_vif *mvif = msta->vif; + struct mt76_wcid *wcid = &mvif->sta.deflink.wcid; - ret = mt7925_mcu_sta_ba(&dev->mt76, &mconf->mt76, wcid, params, - enable, true); - if (ret < 0) - break; - } + if (enable && !params->amsdu) + msta->deflink.wcid.amsdu = false; - return ret; + return mt7925_mcu_sta_ba(&dev->mt76, &mvif->bss_conf.mt76, wcid, + params, enable, true); } int mt7925_mcu_uni_rx_ba(struct mt792x_dev *dev, - struct ieee80211_vif *vif, struct ieee80211_ampdu_params *params, bool enable) { struct mt792x_sta *msta = (struct mt792x_sta *)params->sta->drv_priv; - struct mt792x_vif *mvif = (struct mt792x_vif *)vif->drv_priv; - struct mt792x_link_sta *mlink; - struct mt792x_bss_conf *mconf; - unsigned long usable_links = ieee80211_vif_usable_links(vif); - struct mt76_wcid *wcid; - u8 link_id, ret; - - for_each_set_bit(link_id, &usable_links, IEEE80211_MLD_MAX_NUM_LINKS) { - mconf = mt792x_vif_to_link(mvif, link_id); - mlink = mt792x_sta_to_link(msta, link_id); - wcid = &mlink->wcid; - - ret = mt7925_mcu_sta_ba(&dev->mt76, &mconf->mt76, wcid, params, - enable, false); - if (ret < 0) - break; - } + struct mt792x_vif *mvif = msta->vif; + struct mt76_wcid *wcid = &mvif->sta.deflink.wcid; - return ret; + return mt7925_mcu_sta_ba(&dev->mt76, &mvif->bss_conf.mt76, wcid, + params, enable, false); } static int mt7925_load_clc(struct mt792x_dev *dev, const char *fw_name) diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/mt7925.h b/drivers/net/wireless/mediatek/mt76/mt7925/mt7925.h index 8707b5d04743..fd5f9d4ea4a7 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7925/mt7925.h +++ b/drivers/net/wireless/mediatek/mt76/mt7925/mt7925.h @@ -263,11 +263,9 @@ int mt7925_mcu_set_beacon_filter(struct mt792x_dev *dev, struct ieee80211_vif *vif, bool enable); int mt7925_mcu_uni_tx_ba(struct mt792x_dev *dev, - struct ieee80211_vif *vif, struct ieee80211_ampdu_params *params, bool enable); int mt7925_mcu_uni_rx_ba(struct mt792x_dev *dev, - struct ieee80211_vif *vif, struct ieee80211_ampdu_params *params, bool enable); void mt7925_scan_work(struct work_struct *work); -- 2.25.1

3 months, 1 week

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[PATCH v2 4/5] sparc/mm: Avoid calling arch_enter/leave_lazy_mmu() in set_ptes

by Ryan Roberts

With commit 1a10a44dfc1d ("sparc64: implement the new page table range API") set_ptes was added to the sparc architecture. The implementation included calling arch_enter/leave_lazy_mmu() calls. The patch removes the usage of arch_enter/leave_lazy_mmu() since this implies nesting of lazy mmu regions which is not supported. Without this fix, lazy mmu mode is effectively disabled because we exit the mode after the first set_ptes: remap_pte_range() -> arch_enter_lazy_mmu() -> set_ptes() -> arch_enter_lazy_mmu() -> arch_leave_lazy_mmu() -> arch_leave_lazy_mmu() Powerpc suffered the same problem and fixed it in a corresponding way with commit 47b8def9358c ("powerpc/mm: Avoid calling arch_enter/leave_lazy_mmu() in set_ptes"). Cc: <stable(a)vger.kernel.org> Fixes: 1a10a44dfc1d ("sparc64: implement the new page table range API") Acked-by: David Hildenbrand <david(a)redhat.com> Acked-by: Andreas Larsson <andreas(a)gaisler.com> Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com> --- arch/sparc/include/asm/pgtable_64.h | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h index 2b7f358762c1..dc28f2c4eee3 100644 --- a/arch/sparc/include/asm/pgtable_64.h +++ b/arch/sparc/include/asm/pgtable_64.h @@ -936,7 +936,6 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, static inline void set_ptes(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte, unsigned int nr) { - arch_enter_lazy_mmu_mode(); for (;;) { __set_pte_at(mm, addr, ptep, pte, 0); if (--nr == 0) @@ -945,7 +944,6 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr, pte_val(pte) += PAGE_SIZE; addr += PAGE_SIZE; } - arch_leave_lazy_mmu_mode(); } #define set_ptes set_ptes -- 2.43.0

3 months, 1 week

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[PATCH v2 3/5] sparc/mm: Disable preemption in lazy mmu mode

by Ryan Roberts

Since commit 38e0edb15bd0 ("mm/apply_to_range: call pte function with lazy updates") it's been possible for arch_[enter|leave]_lazy_mmu_mode() to be called without holding a page table lock (for the kernel mappings case), and therefore it is possible that preemption may occur while in the lazy mmu mode. The Sparc lazy mmu implementation is not robust to preemption since it stores the lazy mode state in a per-cpu structure and does not attempt to manage that state on task switch. Powerpc had the same issue and fixed it by explicitly disabling preemption in arch_enter_lazy_mmu_mode() and re-enabling in arch_leave_lazy_mmu_mode(). See commit b9ef323ea168 ("powerpc/64s: Disable preemption in hash lazy mmu mode"). Given Sparc's lazy mmu mode is based on powerpc's, let's fix it in the same way here. Cc: <stable(a)vger.kernel.org> Fixes: 38e0edb15bd0 ("mm/apply_to_range: call pte function with lazy updates") Acked-by: David Hildenbrand <david(a)redhat.com> Acked-by: Andreas Larsson <andreas(a)gaisler.com> Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com> --- arch/sparc/mm/tlb.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c index 8648a50afe88..a35ddcca5e76 100644 --- a/arch/sparc/mm/tlb.c +++ b/arch/sparc/mm/tlb.c @@ -52,8 +52,10 @@ void flush_tlb_pending(void) void arch_enter_lazy_mmu_mode(void) { - struct tlb_batch *tb = this_cpu_ptr(&tlb_batch); + struct tlb_batch *tb; + preempt_disable(); + tb = this_cpu_ptr(&tlb_batch); tb->active = 1; } @@ -64,6 +66,7 @@ void arch_leave_lazy_mmu_mode(void) if (tb->tlb_nr) flush_tlb_pending(); tb->active = 0; + preempt_enable(); } static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr, -- 2.43.0

3 months, 1 week

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[PATCH v2 1/5] mm: Fix lazy mmu docs and usage

by Ryan Roberts

The docs, implementations and use of arch_[enter|leave]_lazy_mmu_mode() is a bit of a mess (to put it politely). There are a number of issues related to nesting of lazy mmu regions and confusion over whether the task, when in a lazy mmu region, is preemptible or not. Fix all the issues relating to the core-mm. Follow up commits will fix the arch-specific implementations. 3 arches implement lazy mmu; powerpc, sparc and x86. When arch_[enter|leave]_lazy_mmu_mode() was first introduced by commit 6606c3e0da53 ("[PATCH] paravirt: lazy mmu mode hooks.patch"), it was expected that lazy mmu regions would never nest and that the appropriate page table lock(s) would be held while in the region, thus ensuring the region is non-preemptible. Additionally lazy mmu regions were only used during manipulation of user mappings. Commit 38e0edb15bd0 ("mm/apply_to_range: call pte function with lazy updates") started invoking the lazy mmu mode in apply_to_pte_range(), which is used for both user and kernel mappings. For kernel mappings the region is no longer protected by any lock so there is no longer any guarantee about non-preemptibility. Additionally, for RT configs, the holding the PTL only implies no CPU migration, it doesn't prevent preemption. Commit bcc6cc832573 ("mm: add default definition of set_ptes()") added arch_[enter|leave]_lazy_mmu_mode() to the default implementation of set_ptes(), used by x86. So after this commit, lazy mmu regions can be nested. Additionally commit 1a10a44dfc1d ("sparc64: implement the new page table range API") and commit 9fee28baa601 ("powerpc: implement the new page table range API") did the same for the sparc and powerpc set_ptes() overrides. powerpc couldn't deal with preemption so avoids it in commit b9ef323ea168 ("powerpc/64s: Disable preemption in hash lazy mmu mode"), which explicitly disables preemption for the whole region in its implementation. x86 can support preemption (or at least it could until it tried to add support nesting; more on this below). Sparc looks to be totally broken in the face of preemption, as far as I can tell. powerpc can't deal with nesting, so avoids it in commit 47b8def9358c ("powerpc/mm: Avoid calling arch_enter/leave_lazy_mmu() in set_ptes"), which removes the lazy mmu calls from its implementation of set_ptes(). x86 attempted to support nesting in commit 49147beb0ccb ("x86/xen: allow nesting of same lazy mode") but as far as I can tell, this breaks its support for preemption. In short, it's all a mess; the semantics for arch_[enter|leave]_lazy_mmu_mode() are not clearly defined and as a result the implementations all have different expectations, sticking plasters and bugs. arm64 is aiming to start using these hooks, so let's clean everything up before adding an arm64 implementation. Update the documentation to state that lazy mmu regions can never be nested, must not be called in interrupt context and preemption may or may not be enabled for the duration of the region. And fix the generic implementation of set_ptes() to avoid nesting. arch-specific fixes to conform to the new spec will proceed this one. These issues were spotted by code review and I have no evidence of issues being reported in the wild. Cc: <stable(a)vger.kernel.org> Fixes: bcc6cc832573 ("mm: add default definition of set_ptes()") Acked-by: David Hildenbrand <david(a)redhat.com> Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com> --- include/linux/pgtable.h | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 94d267d02372..787c632ee2c9 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -222,10 +222,14 @@ static inline int pmd_dirty(pmd_t pmd) * hazard could result in the direct mode hypervisor case, since the actual * write to the page tables may not yet have taken place, so reads though * a raw PTE pointer after it has been modified are not guaranteed to be - * up to date. This mode can only be entered and left under the protection of - * the page table locks for all page tables which may be modified. In the UP - * case, this is required so that preemption is disabled, and in the SMP case, - * it must synchronize the delayed page table writes properly on other CPUs. + * up to date. + * + * In the general case, no lock is guaranteed to be held between entry and exit + * of the lazy mode. So the implementation must assume preemption may be enabled + * and cpu migration is possible; it must take steps to be robust against this. + * (In practice, for user PTE updates, the appropriate page table lock(s) are + * held, but for kernel PTE updates, no lock is held). Nesting is not permitted + * and the mode cannot be used in interrupt context. */ #ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE #define arch_enter_lazy_mmu_mode() do {} while (0) @@ -287,7 +291,6 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr, { page_table_check_ptes_set(mm, ptep, pte, nr); - arch_enter_lazy_mmu_mode(); for (;;) { set_pte(ptep, pte); if (--nr == 0) @@ -295,7 +298,6 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr, ptep++; pte = pte_next_pfn(pte); } - arch_leave_lazy_mmu_mode(); } #endif #define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1) -- 2.43.0

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Linux-stable-mirror March 2025