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[PATCH v2 4/6] Revert "PCI: qcom: Enable MSI interrupts together with Link up if 'Global IRQ' is supported"

by Niklas Cassel

This reverts commit ba4a2e2317b9faeca9193ed6d3193ddc3cf2aba3. While this fake hotplugging was a nice idea, it has shown that this feature does not handle PCIe switches correctly: pci_bus 0004:43: busn_res: can not insert [bus 43-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:43: busn_res: [bus 43-41] end is updated to 43 pci_bus 0004:43: busn_res: can not insert [bus 43] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:00.0: devices behind bridge are unusable because [bus 43] cannot be assigned for them pci_bus 0004:44: busn_res: can not insert [bus 44-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:44: busn_res: [bus 44-41] end is updated to 44 pci_bus 0004:44: busn_res: can not insert [bus 44] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:02.0: devices behind bridge are unusable because [bus 44] cannot be assigned for them pci_bus 0004:45: busn_res: can not insert [bus 45-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:45: busn_res: [bus 45-41] end is updated to 45 pci_bus 0004:45: busn_res: can not insert [bus 45] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:06.0: devices behind bridge are unusable because [bus 45] cannot be assigned for them pci_bus 0004:46: busn_res: can not insert [bus 46-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:46: busn_res: [bus 46-41] end is updated to 46 pci_bus 0004:46: busn_res: can not insert [bus 46] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:0e.0: devices behind bridge are unusable because [bus 46] cannot be assigned for them pci_bus 0004:42: busn_res: [bus 42-41] end is updated to 46 pci_bus 0004:42: busn_res: can not insert [bus 42-46] under [bus 41] (conflicts with (null) [bus 41]) pci 0004:41:00.0: devices behind bridge are unusable because [bus 42-46] cannot be assigned for them pcieport 0004:40:00.0: bridge has subordinate 41 but max busn 46 During the initial scan, PCI core doesn't see the switch and since the Root Port is not hot plug capable, the secondary bus number gets assigned as the subordinate bus number. This means, the PCI core assumes that only one bus will appear behind the Root Port since the Root Port is not hot plug capable. This works perfectly fine for PCIe endpoints connected to the Root Port, since they don't extend the bus. However, if a PCIe switch is connected, then there is a problem when the downstream busses starts showing up and the PCI core doesn't extend the subordinate bus number after initial scan during boot. The long term plan is to migrate this driver to the pwrctrl framework, once it adds proper support for powering up and enumerating PCIe switches. Cc: stable(a)vger.kernel.org Suggested-by: Manivannan Sadhasivam <mani(a)kernel.org> Acked-by: Shawn Lin <shawn.lin(a)rock-chips.com> Tested-by: Shawn Lin <shawn.lin(a)rock-chips.com> Signed-off-by: Niklas Cassel <cassel(a)kernel.org> --- drivers/pci/controller/dwc/pcie-qcom.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index e87ec6779d44..c5fcb87972e9 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -136,7 +136,6 @@ /* PARF_INT_ALL_{STATUS/CLEAR/MASK} register fields */ #define PARF_INT_ALL_LINK_UP BIT(13) -#define PARF_INT_MSI_DEV_0_7 GENMASK(30, 23) /* PARF_NO_SNOOP_OVERRIDE register fields */ #define WR_NO_SNOOP_OVERRIDE_EN BIT(1) @@ -1982,8 +1981,7 @@ static int qcom_pcie_probe(struct platform_device *pdev) goto err_host_deinit; } - writel_relaxed(PARF_INT_ALL_LINK_UP | PARF_INT_MSI_DEV_0_7, - pcie->parf + PARF_INT_ALL_MASK); + writel_relaxed(PARF_INT_ALL_LINK_UP, pcie->parf + PARF_INT_ALL_MASK); } qcom_pcie_icc_opp_update(pcie); -- 2.52.0

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[PATCH v2 5/6] Revert "PCI: qcom: Enumerate endpoints based on Link up event in 'global_irq' interrupt"

by Niklas Cassel

This reverts commit 4581403f67929d02c197cb187c4e1e811c9e762a. While this fake hotplugging was a nice idea, it has shown that this feature does not handle PCIe switches correctly: pci_bus 0004:43: busn_res: can not insert [bus 43-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:43: busn_res: [bus 43-41] end is updated to 43 pci_bus 0004:43: busn_res: can not insert [bus 43] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:00.0: devices behind bridge are unusable because [bus 43] cannot be assigned for them pci_bus 0004:44: busn_res: can not insert [bus 44-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:44: busn_res: [bus 44-41] end is updated to 44 pci_bus 0004:44: busn_res: can not insert [bus 44] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:02.0: devices behind bridge are unusable because [bus 44] cannot be assigned for them pci_bus 0004:45: busn_res: can not insert [bus 45-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:45: busn_res: [bus 45-41] end is updated to 45 pci_bus 0004:45: busn_res: can not insert [bus 45] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:06.0: devices behind bridge are unusable because [bus 45] cannot be assigned for them pci_bus 0004:46: busn_res: can not insert [bus 46-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:46: busn_res: [bus 46-41] end is updated to 46 pci_bus 0004:46: busn_res: can not insert [bus 46] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:0e.0: devices behind bridge are unusable because [bus 46] cannot be assigned for them pci_bus 0004:42: busn_res: [bus 42-41] end is updated to 46 pci_bus 0004:42: busn_res: can not insert [bus 42-46] under [bus 41] (conflicts with (null) [bus 41]) pci 0004:41:00.0: devices behind bridge are unusable because [bus 42-46] cannot be assigned for them pcieport 0004:40:00.0: bridge has subordinate 41 but max busn 46 During the initial scan, PCI core doesn't see the switch and since the Root Port is not hot plug capable, the secondary bus number gets assigned as the subordinate bus number. This means, the PCI core assumes that only one bus will appear behind the Root Port since the Root Port is not hot plug capable. This works perfectly fine for PCIe endpoints connected to the Root Port, since they don't extend the bus. However, if a PCIe switch is connected, then there is a problem when the downstream busses starts showing up and the PCI core doesn't extend the subordinate bus number after initial scan during boot. The long term plan is to migrate this driver to the pwrctrl framework, once it adds proper support for powering up and enumerating PCIe switches. Cc: stable(a)vger.kernel.org Suggested-by: Manivannan Sadhasivam <mani(a)kernel.org> Acked-by: Shawn Lin <shawn.lin(a)rock-chips.com> Tested-by: Shawn Lin <shawn.lin(a)rock-chips.com> Signed-off-by: Niklas Cassel <cassel(a)kernel.org> --- drivers/pci/controller/dwc/pcie-qcom.c | 58 +------------------------- 1 file changed, 1 insertion(+), 57 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index c5fcb87972e9..13e6c334e10d 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -55,9 +55,6 @@ #define PARF_AXI_MSTR_WR_ADDR_HALT_V2 0x1a8 #define PARF_Q2A_FLUSH 0x1ac #define PARF_LTSSM 0x1b0 -#define PARF_INT_ALL_STATUS 0x224 -#define PARF_INT_ALL_CLEAR 0x228 -#define PARF_INT_ALL_MASK 0x22c #define PARF_SID_OFFSET 0x234 #define PARF_BDF_TRANSLATE_CFG 0x24c #define PARF_DBI_BASE_ADDR_V2 0x350 @@ -134,9 +131,6 @@ /* PARF_LTSSM register fields */ #define LTSSM_EN BIT(8) -/* PARF_INT_ALL_{STATUS/CLEAR/MASK} register fields */ -#define PARF_INT_ALL_LINK_UP BIT(13) - /* PARF_NO_SNOOP_OVERRIDE register fields */ #define WR_NO_SNOOP_OVERRIDE_EN BIT(1) #define RD_NO_SNOOP_OVERRIDE_EN BIT(3) @@ -1635,32 +1629,6 @@ static void qcom_pcie_init_debugfs(struct qcom_pcie *pcie) qcom_pcie_link_transition_count); } -static irqreturn_t qcom_pcie_global_irq_thread(int irq, void *data) -{ - struct qcom_pcie *pcie = data; - struct dw_pcie_rp *pp = &pcie->pci->pp; - struct device *dev = pcie->pci->dev; - u32 status = readl_relaxed(pcie->parf + PARF_INT_ALL_STATUS); - - writel_relaxed(status, pcie->parf + PARF_INT_ALL_CLEAR); - - if (FIELD_GET(PARF_INT_ALL_LINK_UP, status)) { - msleep(PCIE_RESET_CONFIG_WAIT_MS); - dev_dbg(dev, "Received Link up event. Starting enumeration!\n"); - /* Rescan the bus to enumerate endpoint devices */ - pci_lock_rescan_remove(); - pci_rescan_bus(pp->bridge->bus); - pci_unlock_rescan_remove(); - - qcom_pcie_icc_opp_update(pcie); - } else { - dev_WARN_ONCE(dev, 1, "Received unknown event. INT_STATUS: 0x%08x\n", - status); - } - - return IRQ_HANDLED; -} - static void qcom_pci_free_msi(void *ptr) { struct dw_pcie_rp *pp = (struct dw_pcie_rp *)ptr; @@ -1805,8 +1773,7 @@ static int qcom_pcie_probe(struct platform_device *pdev) struct dw_pcie_rp *pp; struct resource *res; struct dw_pcie *pci; - int ret, irq; - char *name; + int ret; pcie_cfg = of_device_get_match_data(dev); if (!pcie_cfg) { @@ -1963,27 +1930,6 @@ static int qcom_pcie_probe(struct platform_device *pdev) goto err_phy_exit; } - name = devm_kasprintf(dev, GFP_KERNEL, "qcom_pcie_global_irq%d", - pci_domain_nr(pp->bridge->bus)); - if (!name) { - ret = -ENOMEM; - goto err_host_deinit; - } - - irq = platform_get_irq_byname_optional(pdev, "global"); - if (irq > 0) { - ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, - qcom_pcie_global_irq_thread, - IRQF_ONESHOT, name, pcie); - if (ret) { - dev_err_probe(&pdev->dev, ret, - "Failed to request Global IRQ\n"); - goto err_host_deinit; - } - - writel_relaxed(PARF_INT_ALL_LINK_UP, pcie->parf + PARF_INT_ALL_MASK); - } - qcom_pcie_icc_opp_update(pcie); if (pcie->mhi) @@ -1991,8 +1937,6 @@ static int qcom_pcie_probe(struct platform_device *pdev) return 0; -err_host_deinit: - dw_pcie_host_deinit(pp); err_phy_exit: list_for_each_entry_safe(port, tmp, &pcie->ports, list) { phy_exit(port->phy); -- 2.52.0

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[PATCH V4 1/8] mm/slab: use unsigned long for orig_size to ensure proper metadata align

by Harry Yoo

When both KASAN and SLAB_STORE_USER are enabled, accesses to struct kasan_alloc_meta fields can be misaligned on 64-bit architectures. This occurs because orig_size is currently defined as unsigned int, which only guarantees 4-byte alignment. When struct kasan_alloc_meta is placed after orig_size, it may end up at a 4-byte boundary rather than the required 8-byte boundary on 64-bit systems. Note that 64-bit architectures without HAVE_EFFICIENT_UNALIGNED_ACCESS are assumed to require 64-bit accesses to be 64-bit aligned. See HAVE_64BIT_ALIGNED_ACCESS and commit adab66b71abf ("Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"") for more details. Change orig_size from unsigned int to unsigned long to ensure proper alignment for any subsequent metadata. This should not waste additional memory because kmalloc objects are already aligned to at least ARCH_KMALLOC_MINALIGN. Suggested-by: Andrey Ryabinin <ryabinin.a.a(a)gmail.com> Cc: stable(a)vger.kernel.org Fixes: 6edf2576a6cc ("mm/slub: enable debugging memory wasting of kmalloc") Signed-off-by: Harry Yoo <harry.yoo(a)oracle.com> --- mm/slub.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index ad71f01571f0..1c747435a6ab 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -857,7 +857,7 @@ static inline bool slab_update_freelist(struct kmem_cache *s, struct slab *slab, * request size in the meta data area, for better debug and sanity check. */ static inline void set_orig_size(struct kmem_cache *s, - void *object, unsigned int orig_size) + void *object, unsigned long orig_size) { void *p = kasan_reset_tag(object); @@ -867,10 +867,10 @@ static inline void set_orig_size(struct kmem_cache *s, p += get_info_end(s); p += sizeof(struct track) * 2; - *(unsigned int *)p = orig_size; + *(unsigned long *)p = orig_size; } -static inline unsigned int get_orig_size(struct kmem_cache *s, void *object) +static inline unsigned long get_orig_size(struct kmem_cache *s, void *object) { void *p = kasan_reset_tag(object); @@ -883,7 +883,7 @@ static inline unsigned int get_orig_size(struct kmem_cache *s, void *object) p += get_info_end(s); p += sizeof(struct track) * 2; - return *(unsigned int *)p; + return *(unsigned long *)p; } #ifdef CONFIG_SLUB_DEBUG @@ -1198,7 +1198,7 @@ static void print_trailer(struct kmem_cache *s, struct slab *slab, u8 *p) off += 2 * sizeof(struct track); if (slub_debug_orig_size(s)) - off += sizeof(unsigned int); + off += sizeof(unsigned long); off += kasan_metadata_size(s, false); @@ -1394,7 +1394,7 @@ static int check_pad_bytes(struct kmem_cache *s, struct slab *slab, u8 *p) off += 2 * sizeof(struct track); if (s->flags & SLAB_KMALLOC) - off += sizeof(unsigned int); + off += sizeof(unsigned long); } off += kasan_metadata_size(s, false); @@ -7949,7 +7949,7 @@ static int calculate_sizes(struct kmem_cache_args *args, struct kmem_cache *s) /* Save the original kmalloc request size */ if (flags & SLAB_KMALLOC) - size += sizeof(unsigned int); + size += sizeof(unsigned long); } #endif -- 2.43.0

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[PATCH v2 4/4] mm/hugetlb: fix excessive IPI broadcasts when unsharing PMD tables using mmu_gather

by David Hildenbrand (Red Hat)

As reported, ever since commit 1013af4f585f ("mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race") we can end up in some situations where we perform so many IPI broadcasts when unsharing hugetlb PMD page tables that it severely regresses some workloads. In particular, when we fork()+exit(), or when we munmap() a large area backed by many shared PMD tables, we perform one IPI broadcast per unshared PMD table. There are two optimizations to be had: (1) When we process (unshare) multiple such PMD tables, such as during exit(), it is sufficient to send a single IPI broadcast (as long as we respect locking rules) instead of one per PMD table. Locking prevents that any of these PMD tables could get reuse before we drop the lock. (2) When we are not the last sharer (> 2 users including us), there is no need to send the IPI broadcast. The shared PMD tables cannot become exclusive (fully unshared) before an IPI will be broadcasted by the last sharer. Concurrent GUP-fast could walk into a PMD table just before we unshared it. It could then succeed in grabbing a page from the shared page table even after munmap() etc succeeded (and supressed an IPI). But there is not difference compared to GUP-fast just sleeping for a while after grabbing the page and re-enabling IRQs. Most importantly, GUP-fast will never walk into page tables that are no-longer shared, because the last sharer will issue an IPI broadcast. (if ever required, checking whether the PUD changed in GUP-fast after grabbing the page like we do in the PTE case could handle this) So let's rework PMD sharing TLB flushing + IPI sync to use the mmu_gather infrastructure so we can implement these optimizations and demystify the code at least a bit. Extend the mmu_gather infrastructure to be able to deal with our special hugetlb PMD table sharing implementation. We'll consolidate the handling for (full) unsharing of PMD tables in tlb_unshare_pmd_ptdesc() and tlb_flush_unshared_tables(), and track in "struct mmu_gather" whether we had (full) unsharing of PMD tables. Because locking is very special (concurrent unsharing+reuse must be prevented), we disallow deferring flushing to tlb_finish_mmu() and instead require an explicit earlier call to tlb_flush_unshared_tables(). From hugetlb code, we call huge_pmd_unshare_flush() where we make sure that the expected lock protecting us from concurrent unsharing+reuse is still held. Check with a VM_WARN_ON_ONCE() in tlb_finish_mmu() that tlb_flush_unshared_tables() was properly called earlier. Document it all properly. Notes about tlb_remove_table_sync_one() interaction with unsharing: There are two fairly tricky things: (1) tlb_remove_table_sync_one() is a NOP on architectures without CONFIG_MMU_GATHER_RCU_TABLE_FREE. Here, the assumption is that the previous TLB flush would send an IPI to all relevant CPUs. Careful: some architectures like x86 only send IPIs to all relevant CPUs when tlb->freed_tables is set. The relevant architectures should be selecting MMU_GATHER_RCU_TABLE_FREE, but x86 might not do that in stable kernels and it might have been problematic before this patch. Also, the arch flushing behavior (independent of IPIs) is different when tlb->freed_tables is set. Do we have to enlighten them to also take care of tlb->unshared_tables? So far we didn't care, so hopefully we are fine. Of course, we could be setting tlb->freed_tables as well, but that might then unnecessarily flush too much, because the semantics of tlb->freed_tables are a bit fuzzy. This patch changes nothing in this regard. (2) tlb_remove_table_sync_one() is not a NOP on architectures with CONFIG_MMU_GATHER_RCU_TABLE_FREE that actually don't need a sync. Take x86 as an example: in the common case (!pv, !X86_FEATURE_INVLPGB) we still issue IPIs during TLB flushes and don't actually need the second tlb_remove_table_sync_one(). This optimized can be implemented on top of this, by checking e.g., in tlb_remove_table_sync_one() whether we really need IPIs. But as described in (1), it really must honor tlb->freed_tables then to send IPIs to all relevant CPUs. Further note that the ptdesc_pmd_pts_dec() in huge_pmd_share() is not a concern, as we are holding the i_mmap_lock the whole time, preventing concurrent unsharing. That ptdesc_pmd_pts_dec() usage will be removed separately as a cleanup later. There are plenty more cleanups to be had, but they have to wait until this is fixed. Fixes: 1013af4f585f ("mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race") Reported-by: Uschakow, Stanislav" <suschako(a)amazon.de> Closes: https://lore.kernel.org/all/4d3878531c76479d9f8ca9789dc6485d@amazon.de/ Tested-by: Laurence Oberman <loberman(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: David Hildenbrand (Red Hat) <david(a)kernel.org> --- include/asm-generic/tlb.h | 74 ++++++++++++++++++++++- include/linux/hugetlb.h | 19 +++--- mm/hugetlb.c | 121 ++++++++++++++++++++++---------------- mm/mmu_gather.c | 7 +++ mm/mprotect.c | 2 +- mm/rmap.c | 25 +++++--- 6 files changed, 179 insertions(+), 69 deletions(-) diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 1fff717cae510..706416babb3d6 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -364,6 +364,20 @@ struct mmu_gather { unsigned int vma_huge : 1; unsigned int vma_pfn : 1; + /* + * Did we unshare (unmap) any shared page tables? For now only + * used for hugetlb PMD table sharing. + */ + unsigned int unshared_tables : 1; + + /* + * Did we unshare any page tables such that they are now exclusive + * and could get reused+modified by the new owner? When setting this + * flag, "unshared_tables" will be set as well. For now only used + * for hugetlb PMD table sharing. + */ + unsigned int fully_unshared_tables : 1; + unsigned int batch_count; #ifndef CONFIG_MMU_GATHER_NO_GATHER @@ -400,6 +414,7 @@ static inline void __tlb_reset_range(struct mmu_gather *tlb) tlb->cleared_pmds = 0; tlb->cleared_puds = 0; tlb->cleared_p4ds = 0; + tlb->unshared_tables = 0; /* * Do not reset mmu_gather::vma_* fields here, we do not * call into tlb_start_vma() again to set them if there is an @@ -484,7 +499,7 @@ static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb) * these bits. */ if (!(tlb->freed_tables || tlb->cleared_ptes || tlb->cleared_pmds || - tlb->cleared_puds || tlb->cleared_p4ds)) + tlb->cleared_puds || tlb->cleared_p4ds || tlb->unshared_tables)) return; tlb_flush(tlb); @@ -773,6 +788,63 @@ static inline bool huge_pmd_needs_flush(pmd_t oldpmd, pmd_t newpmd) } #endif +#ifdef CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING +static inline void tlb_unshare_pmd_ptdesc(struct mmu_gather *tlb, struct ptdesc *pt, + unsigned long addr) +{ + /* + * The caller must make sure that concurrent unsharing + exclusive + * reuse is impossible until tlb_flush_unshared_tables() was called. + */ + VM_WARN_ON_ONCE(!ptdesc_pmd_is_shared(pt)); + ptdesc_pmd_pts_dec(pt); + + /* Clearing a PUD pointing at a PMD table with PMD leaves. */ + tlb_flush_pmd_range(tlb, addr & PUD_MASK, PUD_SIZE); + + /* + * If the page table is now exclusively owned, we fully unshared + * a page table. + */ + if (!ptdesc_pmd_is_shared(pt)) + tlb->fully_unshared_tables = true; + tlb->unshared_tables = true; +} + +static inline void tlb_flush_unshared_tables(struct mmu_gather *tlb) +{ + /* + * As soon as the caller drops locks to allow for reuse of + * previously-shared tables, these tables could get modified and + * even reused outside of hugetlb context, so we have to make sure that + * any page table walkers (incl. TLB, GUP-fast) are aware of that + * change. + * + * Even if we are not fully unsharing a PMD table, we must + * flush the TLB for the unsharer now. + */ + if (tlb->unshared_tables) + tlb_flush_mmu_tlbonly(tlb); + + /* + * Similarly, we must make sure that concurrent GUP-fast will not + * walk previously-shared page tables that are getting modified+reused + * elsewhere. So broadcast an IPI to wait for any concurrent GUP-fast. + * + * We only perform this when we are the last sharer of a page table, + * as the IPI will reach all CPUs: any GUP-fast. + * + * Note that on configs where tlb_remove_table_sync_one() is a NOP, + * the expectation is that the tlb_flush_mmu_tlbonly() would have issued + * required IPIs already for us. + */ + if (tlb->fully_unshared_tables) { + tlb_remove_table_sync_one(); + tlb->fully_unshared_tables = false; + } +} +#endif /* CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING */ + #endif /* CONFIG_MMU */ #endif /* _ASM_GENERIC__TLB_H */ diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 03c8725efa289..63b248c6bfd47 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -240,8 +240,9 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr, unsigned long sz); unsigned long hugetlb_mask_last_page(struct hstate *h); -int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep); +int huge_pmd_unshare(struct mmu_gather *tlb, struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep); +void huge_pmd_unshare_flush(struct mmu_gather *tlb, struct vm_area_struct *vma); void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, unsigned long *start, unsigned long *end); @@ -271,7 +272,7 @@ void hugetlb_vma_unlock_write(struct vm_area_struct *vma); int hugetlb_vma_trylock_write(struct vm_area_struct *vma); void hugetlb_vma_assert_locked(struct vm_area_struct *vma); void hugetlb_vma_lock_release(struct kref *kref); -long hugetlb_change_protection(struct vm_area_struct *vma, +long hugetlb_change_protection(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot, unsigned long cp_flags); void hugetlb_unshare_all_pmds(struct vm_area_struct *vma); @@ -300,13 +301,17 @@ static inline struct address_space *hugetlb_folio_mapping_lock_write( return NULL; } -static inline int huge_pmd_unshare(struct mm_struct *mm, - struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) +static inline int huge_pmd_unshare(struct mmu_gather *tlb, + struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { return 0; } +static inline void huge_pmd_unshare_flush(struct mmu_gather *tlb, + struct vm_area_struct *vma) +{ +} + static inline void adjust_range_if_pmd_sharing_possible( struct vm_area_struct *vma, unsigned long *start, unsigned long *end) @@ -432,7 +437,7 @@ static inline void move_hugetlb_state(struct folio *old_folio, { } -static inline long hugetlb_change_protection( +static inline long hugetlb_change_protection(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot, unsigned long cp_flags) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 3c77cdef12a32..7fef0b94b5d1e 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5096,8 +5096,9 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma, unsigned long last_addr_mask; pte_t *src_pte, *dst_pte; struct mmu_notifier_range range; - bool shared_pmd = false; + struct mmu_gather tlb; + tlb_gather_mmu(&tlb, vma->vm_mm); mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, mm, old_addr, old_end); adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); @@ -5122,12 +5123,12 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma, if (huge_pte_none(huge_ptep_get(mm, old_addr, src_pte))) continue; - if (huge_pmd_unshare(mm, vma, old_addr, src_pte)) { - shared_pmd = true; + if (huge_pmd_unshare(&tlb, vma, old_addr, src_pte)) { old_addr |= last_addr_mask; new_addr |= last_addr_mask; continue; } + tlb_remove_huge_tlb_entry(h, &tlb, src_pte, old_addr); dst_pte = huge_pte_alloc(mm, new_vma, new_addr, sz); if (!dst_pte) @@ -5136,13 +5137,13 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma, move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte, sz); } - if (shared_pmd) - flush_hugetlb_tlb_range(vma, range.start, range.end); - else - flush_hugetlb_tlb_range(vma, old_end - len, old_end); + tlb_flush_mmu_tlbonly(&tlb); + huge_pmd_unshare_flush(&tlb, vma); + mmu_notifier_invalidate_range_end(&range); i_mmap_unlock_write(mapping); hugetlb_vma_unlock_write(vma); + tlb_finish_mmu(&tlb); return len + old_addr - old_end; } @@ -5161,7 +5162,6 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long sz = huge_page_size(h); bool adjust_reservation; unsigned long last_addr_mask; - bool force_flush = false; WARN_ON(!is_vm_hugetlb_page(vma)); BUG_ON(start & ~huge_page_mask(h)); @@ -5184,10 +5184,8 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, } ptl = huge_pte_lock(h, mm, ptep); - if (huge_pmd_unshare(mm, vma, address, ptep)) { + if (huge_pmd_unshare(tlb, vma, address, ptep)) { spin_unlock(ptl); - tlb_flush_pmd_range(tlb, address & PUD_MASK, PUD_SIZE); - force_flush = true; address |= last_addr_mask; continue; } @@ -5303,14 +5301,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, } tlb_end_vma(tlb, vma); - /* - * There is nothing protecting a previously-shared page table that we - * unshared through huge_pmd_unshare() from getting freed after we - * release i_mmap_rwsem, so flush the TLB now. If huge_pmd_unshare() - * succeeded, flush the range corresponding to the pud. - */ - if (force_flush) - tlb_flush_mmu_tlbonly(tlb); + huge_pmd_unshare_flush(tlb, vma); } void __hugetlb_zap_begin(struct vm_area_struct *vma, @@ -6399,7 +6390,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte, } #endif /* CONFIG_USERFAULTFD */ -long hugetlb_change_protection(struct vm_area_struct *vma, +long hugetlb_change_protection(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot, unsigned long cp_flags) { @@ -6409,7 +6400,6 @@ long hugetlb_change_protection(struct vm_area_struct *vma, pte_t pte; struct hstate *h = hstate_vma(vma); long pages = 0, psize = huge_page_size(h); - bool shared_pmd = false; struct mmu_notifier_range range; unsigned long last_addr_mask; bool uffd_wp = cp_flags & MM_CP_UFFD_WP; @@ -6452,7 +6442,7 @@ long hugetlb_change_protection(struct vm_area_struct *vma, } } ptl = huge_pte_lock(h, mm, ptep); - if (huge_pmd_unshare(mm, vma, address, ptep)) { + if (huge_pmd_unshare(tlb, vma, address, ptep)) { /* * When uffd-wp is enabled on the vma, unshare * shouldn't happen at all. Warn about it if it @@ -6461,7 +6451,6 @@ long hugetlb_change_protection(struct vm_area_struct *vma, WARN_ON_ONCE(uffd_wp || uffd_wp_resolve); pages++; spin_unlock(ptl); - shared_pmd = true; address |= last_addr_mask; continue; } @@ -6522,22 +6511,16 @@ long hugetlb_change_protection(struct vm_area_struct *vma, pte = huge_pte_clear_uffd_wp(pte); huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); pages++; + tlb_remove_huge_tlb_entry(h, tlb, ptep, address); } next: spin_unlock(ptl); cond_resched(); } - /* - * There is nothing protecting a previously-shared page table that we - * unshared through huge_pmd_unshare() from getting freed after we - * release i_mmap_rwsem, so flush the TLB now. If huge_pmd_unshare() - * succeeded, flush the range corresponding to the pud. - */ - if (shared_pmd) - flush_hugetlb_tlb_range(vma, range.start, range.end); - else - flush_hugetlb_tlb_range(vma, start, end); + + tlb_flush_mmu_tlbonly(tlb); + huge_pmd_unshare_flush(tlb, vma); /* * No need to call mmu_notifier_arch_invalidate_secondary_tlbs() we are * downgrading page table protection not changing it to point to a new @@ -6904,18 +6887,27 @@ pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, return pte; } -/* - * unmap huge page backed by shared pte. +/** + * huge_pmd_unshare - Unmap a pmd table if it is shared by multiple users + * @tlb: the current mmu_gather. + * @vma: the vma covering the pmd table. + * @addr: the address we are trying to unshare. + * @ptep: pointer into the (pmd) page table. + * + * Called with the page table lock held, the i_mmap_rwsem held in write mode + * and the hugetlb vma lock held in write mode. * - * Called with page table lock held. + * Note: The caller must call huge_pmd_unshare_flush() before dropping the + * i_mmap_rwsem. * - * returns: 1 successfully unmapped a shared pte page - * 0 the underlying pte page is not shared, or it is the last user + * Returns: 1 if it was a shared PMD table and it got unmapped, or 0 if it + * was not a shared PMD table. */ -int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) +int huge_pmd_unshare(struct mmu_gather *tlb, struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) { unsigned long sz = huge_page_size(hstate_vma(vma)); + struct mm_struct *mm = vma->vm_mm; pgd_t *pgd = pgd_offset(mm, addr); p4d_t *p4d = p4d_offset(pgd, addr); pud_t *pud = pud_offset(p4d, addr); @@ -6927,18 +6919,36 @@ int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, i_mmap_assert_write_locked(vma->vm_file->f_mapping); hugetlb_vma_assert_locked(vma); pud_clear(pud); - /* - * Once our caller drops the rmap lock, some other process might be - * using this page table as a normal, non-hugetlb page table. - * Wait for pending gup_fast() in other threads to finish before letting - * that happen. - */ - tlb_remove_table_sync_one(); - ptdesc_pmd_pts_dec(virt_to_ptdesc(ptep)); + + tlb_unshare_pmd_ptdesc(tlb, virt_to_ptdesc(ptep), addr); + mm_dec_nr_pmds(mm); return 1; } +/* + * huge_pmd_unshare_flush - Complete a sequence of huge_pmd_unshare() calls + * @tlb: the current mmu_gather. + * @vma: the vma covering the pmd table. + * + * Perform necessary TLB flushes or IPI broadcasts to synchronize PMD table + * unsharing with concurrent page table walkers. + * + * This function must be called after a sequence of huge_pmd_unshare() + * calls while still holding the i_mmap_rwsem. + */ +void huge_pmd_unshare_flush(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ + /* + * We must synchronize page table unsharing such that nobody will + * try reusing a previously-shared page table while it might still + * be in use by previous sharers (TLB, GUP_fast). + */ + i_mmap_assert_write_locked(vma->vm_file->f_mapping); + + tlb_flush_unshared_tables(tlb); +} + #else /* !CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING */ pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, @@ -6947,12 +6957,16 @@ pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, return NULL; } -int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) +int huge_pmd_unshare(struct mmu_gather *tlb, struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) { return 0; } +void huge_pmd_unshare_flush(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ +} + void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, unsigned long *start, unsigned long *end) { @@ -7219,6 +7233,7 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, unsigned long sz = huge_page_size(h); struct mm_struct *mm = vma->vm_mm; struct mmu_notifier_range range; + struct mmu_gather tlb; unsigned long address; spinlock_t *ptl; pte_t *ptep; @@ -7229,6 +7244,7 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, if (start >= end) return; + tlb_gather_mmu(&tlb, mm); flush_cache_range(vma, start, end); /* * No need to call adjust_range_if_pmd_sharing_possible(), because @@ -7248,10 +7264,10 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, if (!ptep) continue; ptl = huge_pte_lock(h, mm, ptep); - huge_pmd_unshare(mm, vma, address, ptep); + huge_pmd_unshare(&tlb, vma, address, ptep); spin_unlock(ptl); } - flush_hugetlb_tlb_range(vma, start, end); + huge_pmd_unshare_flush(&tlb, vma); if (take_locks) { i_mmap_unlock_write(vma->vm_file->f_mapping); hugetlb_vma_unlock_write(vma); @@ -7261,6 +7277,7 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, * Documentation/mm/mmu_notifier.rst. */ mmu_notifier_invalidate_range_end(&range); + tlb_finish_mmu(&tlb); } /* diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c index 247e3f9db6c7a..030a162a263ba 100644 --- a/mm/mmu_gather.c +++ b/mm/mmu_gather.c @@ -426,6 +426,7 @@ static void __tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, #endif tlb->vma_pfn = 0; + tlb->fully_unshared_tables = 0; __tlb_reset_range(tlb); inc_tlb_flush_pending(tlb->mm); } @@ -468,6 +469,12 @@ void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm) */ void tlb_finish_mmu(struct mmu_gather *tlb) { + /* + * We expect an earlier huge_pmd_unshare_flush() call to sort this out, + * due to complicated locking requirements with page table unsharing. + */ + VM_WARN_ON_ONCE(tlb->fully_unshared_tables); + /* * If there are parallel threads are doing PTE changes on same range * under non-exclusive lock (e.g., mmap_lock read-side) but defer TLB diff --git a/mm/mprotect.c b/mm/mprotect.c index 283889e4f1cec..5c330e817129e 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -652,7 +652,7 @@ long change_protection(struct mmu_gather *tlb, #endif if (is_vm_hugetlb_page(vma)) - pages = hugetlb_change_protection(vma, start, end, newprot, + pages = hugetlb_change_protection(tlb, vma, start, end, newprot, cp_flags); else pages = change_protection_range(tlb, vma, start, end, newprot, diff --git a/mm/rmap.c b/mm/rmap.c index 748f48727a162..d6799afe11147 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -76,7 +76,7 @@ #include <linux/mm_inline.h> #include <linux/oom.h> -#include <asm/tlbflush.h> +#include <asm/tlb.h> #define CREATE_TRACE_POINTS #include <trace/events/migrate.h> @@ -2008,13 +2008,17 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, * if unsuccessful. */ if (!anon) { + struct mmu_gather tlb; + VM_BUG_ON(!(flags & TTU_RMAP_LOCKED)); if (!hugetlb_vma_trylock_write(vma)) goto walk_abort; - if (huge_pmd_unshare(mm, vma, address, pvmw.pte)) { + + tlb_gather_mmu(&tlb, mm); + if (huge_pmd_unshare(&tlb, vma, address, pvmw.pte)) { hugetlb_vma_unlock_write(vma); - flush_tlb_range(vma, - range.start, range.end); + huge_pmd_unshare_flush(&tlb, vma); + tlb_finish_mmu(&tlb); /* * The PMD table was unmapped, * consequently unmapping the folio. @@ -2022,6 +2026,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, goto walk_done; } hugetlb_vma_unlock_write(vma); + tlb_finish_mmu(&tlb); } pteval = huge_ptep_clear_flush(vma, address, pvmw.pte); if (pte_dirty(pteval)) @@ -2398,17 +2403,20 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, * fail if unsuccessful. */ if (!anon) { + struct mmu_gather tlb; + VM_BUG_ON(!(flags & TTU_RMAP_LOCKED)); if (!hugetlb_vma_trylock_write(vma)) { page_vma_mapped_walk_done(&pvmw); ret = false; break; } - if (huge_pmd_unshare(mm, vma, address, pvmw.pte)) { - hugetlb_vma_unlock_write(vma); - flush_tlb_range(vma, - range.start, range.end); + tlb_gather_mmu(&tlb, mm); + if (huge_pmd_unshare(&tlb, vma, address, pvmw.pte)) { + hugetlb_vma_unlock_write(vma); + huge_pmd_unshare_flush(&tlb, vma); + tlb_finish_mmu(&tlb); /* * The PMD table was unmapped, * consequently unmapping the folio. @@ -2417,6 +2425,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, break; } hugetlb_vma_unlock_write(vma); + tlb_finish_mmu(&tlb); } /* Nuke the hugetlb page table entry */ pteval = huge_ptep_clear_flush(vma, address, pvmw.pte); -- 2.52.0

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Re: [PATCH v2] net: usb: sr9700: fix incorrect command used to write single register

by Andrew Lunn

On Sun, Dec 21, 2025 at 03:42:58PM -0800, Ethan Nelson-Moore wrote: > Hi, Andrew, > > The other two are correct because they intend to write multiple registers - > they are used with a length parameter. Please don't top post. How finished do you think this driver is? Are there likely to be more instances of SR_WR_REG/SR_WR_REGS added in the future? If so, it might make sense to change the code to make this sort of error less likely. SR_WR_MULTIPLE_REG and SR_WR_ONE_REG? Andrew

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[PATCH v2 6/6] Revert "PCI: dwc: Don't wait for link up if driver can detect Link Up event"

by Niklas Cassel

This reverts commit 8d3bf19f1b585a3cc0027f508b64c33484db8d0d. While this fake hotplugging was a nice idea, it has shown that this feature does not handle PCIe switches correctly: pci_bus 0004:43: busn_res: can not insert [bus 43-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:43: busn_res: [bus 43-41] end is updated to 43 pci_bus 0004:43: busn_res: can not insert [bus 43] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:00.0: devices behind bridge are unusable because [bus 43] cannot be assigned for them pci_bus 0004:44: busn_res: can not insert [bus 44-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:44: busn_res: [bus 44-41] end is updated to 44 pci_bus 0004:44: busn_res: can not insert [bus 44] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:02.0: devices behind bridge are unusable because [bus 44] cannot be assigned for them pci_bus 0004:45: busn_res: can not insert [bus 45-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:45: busn_res: [bus 45-41] end is updated to 45 pci_bus 0004:45: busn_res: can not insert [bus 45] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:06.0: devices behind bridge are unusable because [bus 45] cannot be assigned for them pci_bus 0004:46: busn_res: can not insert [bus 46-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:46: busn_res: [bus 46-41] end is updated to 46 pci_bus 0004:46: busn_res: can not insert [bus 46] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:0e.0: devices behind bridge are unusable because [bus 46] cannot be assigned for them pci_bus 0004:42: busn_res: [bus 42-41] end is updated to 46 pci_bus 0004:42: busn_res: can not insert [bus 42-46] under [bus 41] (conflicts with (null) [bus 41]) pci 0004:41:00.0: devices behind bridge are unusable because [bus 42-46] cannot be assigned for them pcieport 0004:40:00.0: bridge has subordinate 41 but max busn 46 During the initial scan, PCI core doesn't see the switch and since the Root Port is not hot plug capable, the secondary bus number gets assigned as the subordinate bus number. This means, the PCI core assumes that only one bus will appear behind the Root Port since the Root Port is not hot plug capable. This works perfectly fine for PCIe endpoints connected to the Root Port, since they don't extend the bus. However, if a PCIe switch is connected, then there is a problem when the downstream busses starts showing up and the PCI core doesn't extend the subordinate bus number after initial scan during boot. The long term plan is to migrate this driver to the pwrctrl framework, once it adds proper support for powering up and enumerating PCIe switches. Cc: stable(a)vger.kernel.org Suggested-by: Manivannan Sadhasivam <mani(a)kernel.org> Acked-by: Shawn Lin <shawn.lin(a)rock-chips.com> Tested-by: Shawn Lin <shawn.lin(a)rock-chips.com> Signed-off-by: Niklas Cassel <cassel(a)kernel.org> --- drivers/pci/controller/dwc/pcie-designware-host.c | 10 ++-------- drivers/pci/controller/dwc/pcie-designware.h | 1 - 2 files changed, 2 insertions(+), 9 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index 8c41b90a1db1..06c02fcc76c8 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -665,14 +665,8 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp) goto err_remove_edma; } - /* - * Note: Skip the link up delay only when a Link Up IRQ is present. - * If there is no Link Up IRQ, we should not bypass the delay - * because that would require users to manually rescan for devices. - */ - if (!pp->use_linkup_irq) - /* Ignore errors, the link may come up later */ - dw_pcie_wait_for_link(pci); + /* Ignore errors, the link may come up later */ + dw_pcie_wait_for_link(pci); ret = pci_host_probe(bridge); if (ret) diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index fc9cf8ce8629..a3a3f6e89a81 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -438,7 +438,6 @@ struct dw_pcie_rp { bool use_atu_msg; int msg_atu_index; struct resource *msg_res; - bool use_linkup_irq; struct pci_eq_presets presets; struct pci_config_window *cfg; bool ecam_enabled; -- 2.52.0

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[PATCH v2 3/6] Revert "PCI: qcom: Don't wait for link if we can detect Link Up"

by Niklas Cassel

This reverts commit 36971d6c5a9a134c15760ae9fd13c6d5f9a36abb. While this fake hotplugging was a nice idea, it has shown that this feature does not handle PCIe switches correctly: pci_bus 0004:43: busn_res: can not insert [bus 43-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:43: busn_res: [bus 43-41] end is updated to 43 pci_bus 0004:43: busn_res: can not insert [bus 43] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:00.0: devices behind bridge are unusable because [bus 43] cannot be assigned for them pci_bus 0004:44: busn_res: can not insert [bus 44-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:44: busn_res: [bus 44-41] end is updated to 44 pci_bus 0004:44: busn_res: can not insert [bus 44] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:02.0: devices behind bridge are unusable because [bus 44] cannot be assigned for them pci_bus 0004:45: busn_res: can not insert [bus 45-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:45: busn_res: [bus 45-41] end is updated to 45 pci_bus 0004:45: busn_res: can not insert [bus 45] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:06.0: devices behind bridge are unusable because [bus 45] cannot be assigned for them pci_bus 0004:46: busn_res: can not insert [bus 46-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:46: busn_res: [bus 46-41] end is updated to 46 pci_bus 0004:46: busn_res: can not insert [bus 46] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:0e.0: devices behind bridge are unusable because [bus 46] cannot be assigned for them pci_bus 0004:42: busn_res: [bus 42-41] end is updated to 46 pci_bus 0004:42: busn_res: can not insert [bus 42-46] under [bus 41] (conflicts with (null) [bus 41]) pci 0004:41:00.0: devices behind bridge are unusable because [bus 42-46] cannot be assigned for them pcieport 0004:40:00.0: bridge has subordinate 41 but max busn 46 During the initial scan, PCI core doesn't see the switch and since the Root Port is not hot plug capable, the secondary bus number gets assigned as the subordinate bus number. This means, the PCI core assumes that only one bus will appear behind the Root Port since the Root Port is not hot plug capable. This works perfectly fine for PCIe endpoints connected to the Root Port, since they don't extend the bus. However, if a PCIe switch is connected, then there is a problem when the downstream busses starts showing up and the PCI core doesn't extend the subordinate bus number after initial scan during boot. The long term plan is to migrate this driver to the pwrctrl framework, once it adds proper support for powering up and enumerating PCIe switches. Cc: stable(a)vger.kernel.org Suggested-by: Manivannan Sadhasivam <mani(a)kernel.org> Acked-by: Shawn Lin <shawn.lin(a)rock-chips.com> Tested-by: Shawn Lin <shawn.lin(a)rock-chips.com> Signed-off-by: Niklas Cassel <cassel(a)kernel.org> --- drivers/pci/controller/dwc/pcie-qcom.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index 60373fe1362f..e87ec6779d44 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -1958,10 +1958,6 @@ static int qcom_pcie_probe(struct platform_device *pdev) platform_set_drvdata(pdev, pcie); - irq = platform_get_irq_byname_optional(pdev, "global"); - if (irq > 0) - pp->use_linkup_irq = true; - ret = dw_pcie_host_init(pp); if (ret) { dev_err(dev, "cannot initialize host\n"); @@ -1975,6 +1971,7 @@ static int qcom_pcie_probe(struct platform_device *pdev) goto err_host_deinit; } + irq = platform_get_irq_byname_optional(pdev, "global"); if (irq > 0) { ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, qcom_pcie_global_irq_thread, -- 2.52.0

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[PATCH v2 2/6] Revert "PCI: dw-rockchip: Enumerate endpoints based on dll_link_up IRQ"

by Niklas Cassel

This reverts commit 0e0b45ab5d770a748487ba0ae8f77d1fb0f0de3e. While this fake hotplugging was a nice idea, it has shown that this feature does not handle PCIe switches correctly: pci_bus 0004:43: busn_res: can not insert [bus 43-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:43: busn_res: [bus 43-41] end is updated to 43 pci_bus 0004:43: busn_res: can not insert [bus 43] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:00.0: devices behind bridge are unusable because [bus 43] cannot be assigned for them pci_bus 0004:44: busn_res: can not insert [bus 44-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:44: busn_res: [bus 44-41] end is updated to 44 pci_bus 0004:44: busn_res: can not insert [bus 44] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:02.0: devices behind bridge are unusable because [bus 44] cannot be assigned for them pci_bus 0004:45: busn_res: can not insert [bus 45-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:45: busn_res: [bus 45-41] end is updated to 45 pci_bus 0004:45: busn_res: can not insert [bus 45] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:06.0: devices behind bridge are unusable because [bus 45] cannot be assigned for them pci_bus 0004:46: busn_res: can not insert [bus 46-41] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci_bus 0004:46: busn_res: [bus 46-41] end is updated to 46 pci_bus 0004:46: busn_res: can not insert [bus 46] under [bus 42-41] (conflicts with (null) [bus 42-41]) pci 0004:42:0e.0: devices behind bridge are unusable because [bus 46] cannot be assigned for them pci_bus 0004:42: busn_res: [bus 42-41] end is updated to 46 pci_bus 0004:42: busn_res: can not insert [bus 42-46] under [bus 41] (conflicts with (null) [bus 41]) pci 0004:41:00.0: devices behind bridge are unusable because [bus 42-46] cannot be assigned for them pcieport 0004:40:00.0: bridge has subordinate 41 but max busn 46 During the initial scan, PCI core doesn't see the switch and since the Root Port is not hot plug capable, the secondary bus number gets assigned as the subordinate bus number. This means, the PCI core assumes that only one bus will appear behind the Root Port since the Root Port is not hot plug capable. This works perfectly fine for PCIe endpoints connected to the Root Port, since they don't extend the bus. However, if a PCIe switch is connected, then there is a problem when the downstream busses starts showing up and the PCI core doesn't extend the subordinate bus number after initial scan during boot. The long term plan is to migrate this driver to the pwrctrl framework, once it adds proper support for powering up and enumerating PCIe switches. Cc: stable(a)vger.kernel.org Suggested-by: Manivannan Sadhasivam <mani(a)kernel.org> Acked-by: Shawn Lin <shawn.lin(a)rock-chips.com> Tested-by: Shawn Lin <shawn.lin(a)rock-chips.com> Signed-off-by: Niklas Cassel <cassel(a)kernel.org> --- drivers/pci/controller/dwc/pcie-dw-rockchip.c | 59 +------------------ 1 file changed, 3 insertions(+), 56 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c index ca808d8f7975..352f513ebf03 100644 --- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c +++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c @@ -508,34 +508,6 @@ static const struct dw_pcie_ops dw_pcie_ops = { .get_ltssm = rockchip_pcie_get_ltssm, }; -static irqreturn_t rockchip_pcie_rc_sys_irq_thread(int irq, void *arg) -{ - struct rockchip_pcie *rockchip = arg; - struct dw_pcie *pci = &rockchip->pci; - struct dw_pcie_rp *pp = &pci->pp; - struct device *dev = pci->dev; - u32 reg; - - reg = rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_INTR_STATUS_MISC); - rockchip_pcie_writel_apb(rockchip, reg, PCIE_CLIENT_INTR_STATUS_MISC); - - dev_dbg(dev, "PCIE_CLIENT_INTR_STATUS_MISC: %#x\n", reg); - dev_dbg(dev, "LTSSM_STATUS: %#x\n", rockchip_pcie_get_ltssm_reg(rockchip)); - - if (reg & PCIE_RDLH_LINK_UP_CHGED) { - if (rockchip_pcie_link_up(pci)) { - msleep(PCIE_RESET_CONFIG_WAIT_MS); - dev_dbg(dev, "Received Link up event. Starting enumeration!\n"); - /* Rescan the bus to enumerate endpoint devices */ - pci_lock_rescan_remove(); - pci_rescan_bus(pp->bridge->bus); - pci_unlock_rescan_remove(); - } - } - - return IRQ_HANDLED; -} - static irqreturn_t rockchip_pcie_ep_sys_irq_thread(int irq, void *arg) { struct rockchip_pcie *rockchip = arg; @@ -568,29 +540,14 @@ static irqreturn_t rockchip_pcie_ep_sys_irq_thread(int irq, void *arg) return IRQ_HANDLED; } -static int rockchip_pcie_configure_rc(struct platform_device *pdev, - struct rockchip_pcie *rockchip) +static int rockchip_pcie_configure_rc(struct rockchip_pcie *rockchip) { - struct device *dev = &pdev->dev; struct dw_pcie_rp *pp; - int irq, ret; u32 val; if (!IS_ENABLED(CONFIG_PCIE_ROCKCHIP_DW_HOST)) return -ENODEV; - irq = platform_get_irq_byname(pdev, "sys"); - if (irq < 0) - return irq; - - ret = devm_request_threaded_irq(dev, irq, NULL, - rockchip_pcie_rc_sys_irq_thread, - IRQF_ONESHOT, "pcie-sys-rc", rockchip); - if (ret) { - dev_err(dev, "failed to request PCIe sys IRQ\n"); - return ret; - } - /* LTSSM enable control mode */ val = FIELD_PREP_WM16(PCIE_LTSSM_ENABLE_ENHANCE, 1); rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_HOT_RESET_CTRL); @@ -602,17 +559,7 @@ static int rockchip_pcie_configure_rc(struct platform_device *pdev, pp = &rockchip->pci.pp; pp->ops = &rockchip_pcie_host_ops; - ret = dw_pcie_host_init(pp); - if (ret) { - dev_err(dev, "failed to initialize host\n"); - return ret; - } - - /* unmask DLL up/down indicator */ - val = FIELD_PREP_WM16(PCIE_RDLH_LINK_UP_CHGED, 0); - rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_INTR_MASK_MISC); - - return ret; + return dw_pcie_host_init(pp); } static int rockchip_pcie_configure_ep(struct platform_device *pdev, @@ -731,7 +678,7 @@ static int rockchip_pcie_probe(struct platform_device *pdev) switch (data->mode) { case DW_PCIE_RC_TYPE: - ret = rockchip_pcie_configure_rc(pdev, rockchip); + ret = rockchip_pcie_configure_rc(rockchip); if (ret) goto deinit_clk; break; -- 2.52.0

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[PATCH] clockevents: add a error handling in tick_broadcast_init_sysfs()

by Haoxiang Li

If device_register() fails, call put_device() to drop the device reference. Fixes: 501f867064e9 ("clockevents: Provide sysfs interface") Cc: stable(a)vger.kernel.org Signed-off-by: Haoxiang Li <lihaoxiang(a)isrc.iscas.ac.cn> --- kernel/time/clockevents.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index a59bc75ab7c5..94e223cf9c74 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -733,8 +733,12 @@ static __init int tick_broadcast_init_sysfs(void) { int err = device_register(&tick_bc_dev); - if (!err) - err = device_create_file(&tick_bc_dev, &dev_attr_current_device); + if (err) { + put_deivce(&tick_bc_dev); + return err; + } + + err = device_create_file(&tick_bc_dev, &dev_attr_current_device); return err; } #else -- 2.25.1

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[PATCH] powerpc/pseries/cmm: fix the error handling in cmm_sysfs_register()

by Haoxiang Li

If device_register() fails, put_device() should be called to drop the device reference. Thus add put_device() after subsys_unregister label and change device_unregister() to device_del() in fail label. Found by code review. Fixes: 6c9d29095264 ("power: cmm - convert sysdev_class to a regular subsystem") Cc: stable(a)vger.kernel.org Signed-off-by: Haoxiang Li <lihaoxiang(a)isrc.iscas.ac.cn> --- arch/powerpc/platforms/pseries/cmm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c index 4cbbe2ee58ab..0666d3300bdb 100644 --- a/arch/powerpc/platforms/pseries/cmm.c +++ b/arch/powerpc/platforms/pseries/cmm.c @@ -419,8 +419,9 @@ static int cmm_sysfs_register(struct device *dev) fail: while (--i >= 0) device_remove_file(dev, cmm_attrs[i]); - device_unregister(dev); + device_del(dev); subsys_unregister: + put_device(dev); bus_unregister(&cmm_subsys); return rc; } -- 2.25.1

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