March 2025 - Linux-stable-mirror

[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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[PATCH] PM: EM: fix an API misuse issue in em_create_pd()

by Haoxiang Li

Replace kfree() with em_table_free() to free the memory allocated by em_table_alloc(). Fixes: 24e9fb635df2 ("PM: EM: Remove old table") Cc: stable(a)vger.kernel.org Signed-off-by: Haoxiang Li <haoxiang_li2024(a)163.com> --- kernel/power/energy_model.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 3874f0e97651..71b60aa20227 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -447,7 +447,7 @@ static int em_create_pd(struct device *dev, int nr_states, return 0; free_pd_table: - kfree(em_table); + em_table_free(em_table); free_pd: kfree(pd); return -EINVAL; -- 2.25.1

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[PATCH v2] drm/imagination: only init job done fences once

by Brendan King via B4 Relay

From: Brendan King <Brendan.King(a)imgtec.com> Ensure job done fences are only initialised once. This fixes a memory manager not clean warning from drm_mm_takedown on module unload. Cc: stable(a)vger.kernel.org Fixes: eaf01ee5ba28 ("drm/imagination: Implement job submission and scheduling") Signed-off-by: Brendan King <brendan.king(a)imgtec.com> --- Changes in v2: - Added 'Cc:' and 'Fixes:' tags - Link to v1: https://lore.kernel.org/r/20250203-init-done-fences-once-v1-1-a2d62406564b@… --- drivers/gpu/drm/imagination/pvr_queue.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/imagination/pvr_queue.c b/drivers/gpu/drm/imagination/pvr_queue.c index c4f08432882b12f5cdfeb7fc991fd941f0946676..9a67e646f1eae709859f664c796e1940f0b45300 100644 --- a/drivers/gpu/drm/imagination/pvr_queue.c +++ b/drivers/gpu/drm/imagination/pvr_queue.c @@ -304,8 +304,9 @@ pvr_queue_cccb_fence_init(struct dma_fence *fence, struct pvr_queue *queue) static void pvr_queue_job_fence_init(struct dma_fence *fence, struct pvr_queue *queue) { - pvr_queue_fence_init(fence, queue, &pvr_queue_job_fence_ops, - &queue->job_fence_ctx); + if (!fence->ops) + pvr_queue_fence_init(fence, queue, &pvr_queue_job_fence_ops, + &queue->job_fence_ctx); } /** --- base-commit: 3ab334814dc7dff39075e055e12847d51878916e change-id: 20250131-init-done-fences-once-c55c5d0f4d8c Best regards, -- Brendan King <Brendan.King(a)imgtec.com>

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[PATCH v2] drm/imagination: Hold drm_gem_gpuva lock for unmap

by Brendan King via B4 Relay

From: Brendan King <Brendan.King(a)imgtec.com> Avoid a warning from drm_gem_gpuva_assert_lock_held in drm_gpuva_unlink. The Imagination driver uses the GEM object reservation lock to protect the gpuva list, but the GEM object was not always known in the code paths that ended up calling drm_gpuva_unlink. When the GEM object isn't known, it is found by calling drm_gpuva_find to lookup the object associated with a given virtual address range, or by calling drm_gpuva_find_first when removing all mappings. Cc: stable(a)vger.kernel.org Fixes: 4bc736f890ce ("drm/imagination: vm: make use of GPUVM's drm_exec helper") Signed-off-by: Brendan King <brendan.king(a)imgtec.com> --- Changes in v2: - Added 'Cc:' and 'Fixes:' tags - Link to v1: https://lore.kernel.org/r/20250203-hold-drm_gem_gpuva-lock-for-unmap-v1-1-d… --- drivers/gpu/drm/imagination/pvr_fw_meta.c | 6 +- drivers/gpu/drm/imagination/pvr_vm.c | 134 ++++++++++++++++++++++++------ drivers/gpu/drm/imagination/pvr_vm.h | 3 + 3 files changed, 115 insertions(+), 28 deletions(-) diff --git a/drivers/gpu/drm/imagination/pvr_fw_meta.c b/drivers/gpu/drm/imagination/pvr_fw_meta.c index c39beb70c3173ebdab13b4e810ce5d9a3419f0ba..6d13864851fc2e83bdaa94f16435b97841e5de94 100644 --- a/drivers/gpu/drm/imagination/pvr_fw_meta.c +++ b/drivers/gpu/drm/imagination/pvr_fw_meta.c @@ -527,8 +527,10 @@ pvr_meta_vm_map(struct pvr_device *pvr_dev, struct pvr_fw_object *fw_obj) static void pvr_meta_vm_unmap(struct pvr_device *pvr_dev, struct pvr_fw_object *fw_obj) { - pvr_vm_unmap(pvr_dev->kernel_vm_ctx, fw_obj->fw_mm_node.start, - fw_obj->fw_mm_node.size); + struct pvr_gem_object *pvr_obj = fw_obj->gem; + + pvr_vm_unmap_obj(pvr_dev->kernel_vm_ctx, pvr_obj, + fw_obj->fw_mm_node.start, fw_obj->fw_mm_node.size); } static bool diff --git a/drivers/gpu/drm/imagination/pvr_vm.c b/drivers/gpu/drm/imagination/pvr_vm.c index 363f885a709826efa3d45a906c5f65131f7ed7b9..2896fa7501b1ccddaae48b212b6a724d152df9f2 100644 --- a/drivers/gpu/drm/imagination/pvr_vm.c +++ b/drivers/gpu/drm/imagination/pvr_vm.c @@ -293,8 +293,9 @@ pvr_vm_bind_op_map_init(struct pvr_vm_bind_op *bind_op, static int pvr_vm_bind_op_unmap_init(struct pvr_vm_bind_op *bind_op, - struct pvr_vm_context *vm_ctx, u64 device_addr, - u64 size) + struct pvr_vm_context *vm_ctx, + struct pvr_gem_object *pvr_obj, + u64 device_addr, u64 size) { int err; @@ -318,6 +319,7 @@ pvr_vm_bind_op_unmap_init(struct pvr_vm_bind_op *bind_op, goto err_bind_op_fini; } + bind_op->pvr_obj = pvr_obj; bind_op->vm_ctx = vm_ctx; bind_op->device_addr = device_addr; bind_op->size = size; @@ -597,20 +599,6 @@ pvr_vm_create_context(struct pvr_device *pvr_dev, bool is_userspace_context) return ERR_PTR(err); } -/** - * pvr_vm_unmap_all() - Unmap all mappings associated with a VM context. - * @vm_ctx: Target VM context. - * - * This function ensures that no mappings are left dangling by unmapping them - * all in order of ascending device-virtual address. - */ -void -pvr_vm_unmap_all(struct pvr_vm_context *vm_ctx) -{ - WARN_ON(pvr_vm_unmap(vm_ctx, vm_ctx->gpuvm_mgr.mm_start, - vm_ctx->gpuvm_mgr.mm_range)); -} - /** * pvr_vm_context_release() - Teardown a VM context. * @ref_count: Pointer to reference counter of the VM context. @@ -703,11 +691,7 @@ pvr_vm_lock_extra(struct drm_gpuvm_exec *vm_exec) struct pvr_vm_bind_op *bind_op = vm_exec->extra.priv; struct pvr_gem_object *pvr_obj = bind_op->pvr_obj; - /* Unmap operations don't have an object to lock. */ - if (!pvr_obj) - return 0; - - /* Acquire lock on the GEM being mapped. */ + /* Acquire lock on the GEM object being mapped/unmapped. */ return drm_exec_lock_obj(&vm_exec->exec, gem_from_pvr_gem(pvr_obj)); } @@ -772,8 +756,10 @@ pvr_vm_map(struct pvr_vm_context *vm_ctx, struct pvr_gem_object *pvr_obj, } /** - * pvr_vm_unmap() - Unmap an already mapped section of device-virtual memory. + * pvr_vm_unmap_obj_locked() - Unmap an already mapped section of device-virtual + * memory. * @vm_ctx: Target VM context. + * @pvr_obj: Target PowerVR memory object. * @device_addr: Virtual device address at the start of the target mapping. * @size: Size of the target mapping. * @@ -784,9 +770,13 @@ pvr_vm_map(struct pvr_vm_context *vm_ctx, struct pvr_gem_object *pvr_obj, * * Any error encountered while performing internal operations required to * destroy the mapping (returned from pvr_vm_gpuva_unmap or * pvr_vm_gpuva_remap). + * + * The vm_ctx->lock must be held when calling this function. */ -int -pvr_vm_unmap(struct pvr_vm_context *vm_ctx, u64 device_addr, u64 size) +static int +pvr_vm_unmap_obj_locked(struct pvr_vm_context *vm_ctx, + struct pvr_gem_object *pvr_obj, + u64 device_addr, u64 size) { struct pvr_vm_bind_op bind_op = {0}; struct drm_gpuvm_exec vm_exec = { @@ -799,11 +789,13 @@ pvr_vm_unmap(struct pvr_vm_context *vm_ctx, u64 device_addr, u64 size) }, }; - int err = pvr_vm_bind_op_unmap_init(&bind_op, vm_ctx, device_addr, - size); + int err = pvr_vm_bind_op_unmap_init(&bind_op, vm_ctx, pvr_obj, + device_addr, size); if (err) return err; + pvr_gem_object_get(pvr_obj); + err = drm_gpuvm_exec_lock(&vm_exec); if (err) goto err_cleanup; @@ -818,6 +810,96 @@ pvr_vm_unmap(struct pvr_vm_context *vm_ctx, u64 device_addr, u64 size) return err; } +/** + * pvr_vm_unmap_obj() - Unmap an already mapped section of device-virtual + * memory. + * @vm_ctx: Target VM context. + * @pvr_obj: Target PowerVR memory object. + * @device_addr: Virtual device address at the start of the target mapping. + * @size: Size of the target mapping. + * + * Return: + * * 0 on success, + * * Any error encountered by pvr_vm_unmap_obj_locked. + */ +int +pvr_vm_unmap_obj(struct pvr_vm_context *vm_ctx, struct pvr_gem_object *pvr_obj, + u64 device_addr, u64 size) +{ + int err; + + mutex_lock(&vm_ctx->lock); + err = pvr_vm_unmap_obj_locked(vm_ctx, pvr_obj, device_addr, size); + mutex_unlock(&vm_ctx->lock); + + return err; +} + +/** + * pvr_vm_unmap() - Unmap an already mapped section of device-virtual memory. + * @vm_ctx: Target VM context. + * @device_addr: Virtual device address at the start of the target mapping. + * @size: Size of the target mapping. + * + * Return: + * * 0 on success, + * * Any error encountered by drm_gpuva_find, + * * Any error encountered by pvr_vm_unmap_obj_locked. + */ +int +pvr_vm_unmap(struct pvr_vm_context *vm_ctx, u64 device_addr, u64 size) +{ + struct pvr_gem_object *pvr_obj; + struct drm_gpuva *va; + int err; + + mutex_lock(&vm_ctx->lock); + + va = drm_gpuva_find(&vm_ctx->gpuvm_mgr, device_addr, size); + if (va) { + pvr_obj = gem_to_pvr_gem(va->gem.obj); + err = pvr_vm_unmap_obj_locked(vm_ctx, pvr_obj, + va->va.addr, va->va.range); + } else { + err = -ENOENT; + } + + mutex_unlock(&vm_ctx->lock); + + return err; +} + +/** + * pvr_vm_unmap_all() - Unmap all mappings associated with a VM context. + * @vm_ctx: Target VM context. + * + * This function ensures that no mappings are left dangling by unmapping them + * all in order of ascending device-virtual address. + */ +void +pvr_vm_unmap_all(struct pvr_vm_context *vm_ctx) +{ + mutex_lock(&vm_ctx->lock); + + for (;;) { + struct pvr_gem_object *pvr_obj; + struct drm_gpuva *va; + + va = drm_gpuva_find_first(&vm_ctx->gpuvm_mgr, + vm_ctx->gpuvm_mgr.mm_start, + vm_ctx->gpuvm_mgr.mm_range); + if (!va) + break; + + pvr_obj = gem_to_pvr_gem(va->gem.obj); + + WARN_ON(pvr_vm_unmap_obj_locked(vm_ctx, pvr_obj, + va->va.addr, va->va.range)); + } + + mutex_unlock(&vm_ctx->lock); +} + /* Static data areas are determined by firmware. */ static const struct drm_pvr_static_data_area static_data_areas[] = { { diff --git a/drivers/gpu/drm/imagination/pvr_vm.h b/drivers/gpu/drm/imagination/pvr_vm.h index 79406243617c1f025c0119eb8deeaa13c0415586..b0528dffa7f1ba4342c98c2abd7fac31d254d0e7 100644 --- a/drivers/gpu/drm/imagination/pvr_vm.h +++ b/drivers/gpu/drm/imagination/pvr_vm.h @@ -38,6 +38,9 @@ struct pvr_vm_context *pvr_vm_create_context(struct pvr_device *pvr_dev, int pvr_vm_map(struct pvr_vm_context *vm_ctx, struct pvr_gem_object *pvr_obj, u64 pvr_obj_offset, u64 device_addr, u64 size); +int pvr_vm_unmap_obj(struct pvr_vm_context *vm_ctx, + struct pvr_gem_object *pvr_obj, + u64 device_addr, u64 size); int pvr_vm_unmap(struct pvr_vm_context *vm_ctx, u64 device_addr, u64 size); void pvr_vm_unmap_all(struct pvr_vm_context *vm_ctx); --- base-commit: 3ab334814dc7dff39075e055e12847d51878916e change-id: 20250203-hold-drm_gem_gpuva-lock-for-unmap-da4338395b23 Best regards, -- Brendan King <Brendan.King(a)imgtec.com>

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[PATCH v2] drm/imagination: avoid deadlock on fence release

by Brendan King via B4 Relay

From: Brendan King <Brendan.King(a)imgtec.com> Do scheduler queue fence release processing on a workqueue, rather than in the release function itself. Fixes deadlock issues such as the following: [ 607.400437] ============================================ [ 607.405755] WARNING: possible recursive locking detected [ 607.415500] -------------------------------------------- [ 607.420817] weston:zfq0/24149 is trying to acquire lock: [ 607.426131] ffff000017d041a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: pvr_gem_object_vunmap+0x40/0xc0 [powervr] [ 607.436728] but task is already holding lock: [ 607.442554] ffff000017d105a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: dma_buf_ioctl+0x250/0x554 [ 607.451727] other info that might help us debug this: [ 607.458245] Possible unsafe locking scenario: [ 607.464155] CPU0 [ 607.466601] ---- [ 607.469044] lock(reservation_ww_class_mutex); [ 607.473584] lock(reservation_ww_class_mutex); [ 607.478114] *** DEADLOCK *** Cc: stable(a)vger.kernel.org Fixes: eaf01ee5ba28 ("drm/imagination: Implement job submission and scheduling") Signed-off-by: Brendan King <brendan.king(a)imgtec.com> --- Changes in v2: - Added 'Cc:' and 'Fixes:' tags - Link to v1: https://lore.kernel.org/r/20250203-fence-release-deadlock-v1-1-6e1de1260b38… --- drivers/gpu/drm/imagination/pvr_queue.c | 13 +++++++++++-- drivers/gpu/drm/imagination/pvr_queue.h | 4 ++++ 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/imagination/pvr_queue.c b/drivers/gpu/drm/imagination/pvr_queue.c index c4f08432882b12f5cdfeb7fc991fd941f0946676..f3f1c5212df7432161919ddc510cececacbbe143 100644 --- a/drivers/gpu/drm/imagination/pvr_queue.c +++ b/drivers/gpu/drm/imagination/pvr_queue.c @@ -109,12 +109,20 @@ pvr_queue_fence_get_driver_name(struct dma_fence *f) return PVR_DRIVER_NAME; } +static void pvr_queue_fence_release_work(struct work_struct *w) +{ + struct pvr_queue_fence *fence = container_of(w, struct pvr_queue_fence, release_work); + + pvr_context_put(fence->queue->ctx); + dma_fence_free(&fence->base); +} + static void pvr_queue_fence_release(struct dma_fence *f) { struct pvr_queue_fence *fence = container_of(f, struct pvr_queue_fence, base); + struct pvr_device *pvr_dev = fence->queue->ctx->pvr_dev; - pvr_context_put(fence->queue->ctx); - dma_fence_free(f); + queue_work(pvr_dev->sched_wq, &fence->release_work); } static const char * @@ -268,6 +276,7 @@ pvr_queue_fence_init(struct dma_fence *f, pvr_context_get(queue->ctx); fence->queue = queue; + INIT_WORK(&fence->release_work, pvr_queue_fence_release_work); dma_fence_init(&fence->base, fence_ops, &fence_ctx->lock, fence_ctx->id, atomic_inc_return(&fence_ctx->seqno)); diff --git a/drivers/gpu/drm/imagination/pvr_queue.h b/drivers/gpu/drm/imagination/pvr_queue.h index e06ced69302fca47fc26451dfb09ebbb24b57f52..93fe9ac9f58ccc020615485e86be438548dcee43 100644 --- a/drivers/gpu/drm/imagination/pvr_queue.h +++ b/drivers/gpu/drm/imagination/pvr_queue.h @@ -5,6 +5,7 @@ #define PVR_QUEUE_H #include <drm/gpu_scheduler.h> +#include <linux/workqueue.h> #include "pvr_cccb.h" #include "pvr_device.h" @@ -63,6 +64,9 @@ struct pvr_queue_fence { /** @queue: Queue that created this fence. */ struct pvr_queue *queue; + + /** @release_work: Fence release work structure. */ + struct work_struct release_work; }; /** --- base-commit: 3ab334814dc7dff39075e055e12847d51878916e change-id: 20250203-fence-release-deadlock-a0753c07bfdd Best regards, -- Brendan King <Brendan.King(a)imgtec.com>

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Re: [PATCH] pps: fix poll support

by Rodolfo Giometti

On 03/03/25 09:02, Denis OSTERLAND-HEIM wrote: > [BUG] > A user space program that calls select/poll get always an immediate data > ready-to-read response. As a result the intended use to wait until next > data becomes ready does not work. > > User space snippet: > > struct pollfd pollfd = { > .fd = open("/dev/pps0", O_RDONLY), > .events = POLLIN|POLLERR, > .revents = 0 }; > while(1) { > poll(&pollfd, 1, 2000/*ms*/); // returns immediate, but should wait > if(revents & EPOLLIN) { // always true > struct pps_fdata fdata; > memset(&fdata, 0, sizeof(memdata)); > ioctl(PPS_FETCH, &fdata); // currently fetches data at max speed > } > } > > [CAUSE] > pps_cdev_poll() returns unconditionally EPOLLIN. > > [FIX] > Remember the last fetch event counter and compare this value in > pps_cdev_poll() with most recent event counter > and return 0 if they are equal. > > Signed-off-by: Denis OSTERLAND-HEIM <denis.osterland(a)diehl.com> > Co-developed-by: Rodolfo Giometti <giometti(a)enneenne.com> > Signed-off-by: Rodolfo Giometti <giometti(a)enneenne.com> Acked-by: Rodolfo Giometti <giometti(a)enneenne.com> If needed. :) > Fixes: eae9d2ba0cfc ("LinuxPPS: core support") > CC: stable(a)vger.linux.org # 5.4+ > --- > drivers/pps/pps.c | 11 +++++++++-- > include/linux/pps_kernel.h | 1 + > 2 files changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c > index 6a02245ea35f..9463232af8d2 100644 > --- a/drivers/pps/pps.c > +++ b/drivers/pps/pps.c > @@ -41,6 +41,9 @@ static __poll_t pps_cdev_poll(struct file *file, poll_table *wait) > > poll_wait(file, &pps->queue, wait); > > + if (pps->last_fetched_ev == pps->last_ev) > + return 0; > + > return EPOLLIN | EPOLLRDNORM; > } > > @@ -186,9 +189,11 @@ static long pps_cdev_ioctl(struct file *file, > if (err) > return err; > > - /* Return the fetched timestamp */ > + /* Return the fetched timestamp and save last fetched event */ > spin_lock_irq(&pps->lock); > > + pps->last_fetched_ev = pps->last_ev; > + > fdata.info.assert_sequence = pps->assert_sequence; > fdata.info.clear_sequence = pps->clear_sequence; > fdata.info.assert_tu = pps->assert_tu; > @@ -272,9 +277,11 @@ static long pps_cdev_compat_ioctl(struct file *file, > if (err) > return err; > > - /* Return the fetched timestamp */ > + /* Return the fetched timestamp and save last fetched event */ > spin_lock_irq(&pps->lock); > > + pps->last_fetched_ev = pps->last_ev; > + > compat.info.assert_sequence = pps->assert_sequence; > compat.info.clear_sequence = pps->clear_sequence; > compat.info.current_mode = pps->current_mode; > diff --git a/include/linux/pps_kernel.h b/include/linux/pps_kernel.h > index c7abce28ed29..aab0aebb529e 100644 > --- a/include/linux/pps_kernel.h > +++ b/include/linux/pps_kernel.h > @@ -52,6 +52,7 @@ struct pps_device { > int current_mode; /* PPS mode at event time */ > > unsigned int last_ev; /* last PPS event id */ > + unsigned int last_fetched_ev; /* last fetched PPS event id */ > wait_queue_head_t queue; /* PPS event queue */ > > unsigned int id; /* PPS source unique ID */ -- GNU/Linux Solutions e-mail: giometti(a)enneenne.com Linux Device Driver giometti(a)linux.it Embedded Systems phone: +39 349 2432127 UNIX programming

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[PATCH v2] mtd: rawnand: brcmnand: fix PM resume warning

by Kamal Dasu

Fixed warning on PM resume as shown below caused due to uninitialized struct nand_operation that checks chip select field : WARN_ON(op->cs >= nanddev_ntargets(&chip->base) [ 14.588522] ------------[ cut here ]------------ [ 14.588529] WARNING: CPU: 0 PID: 1392 at drivers/mtd/nand/raw/internals.h:139 nand_reset_op+0x1e0/0x1f8 [ 14.588553] Modules linked in: bdc udc_core [ 14.588579] CPU: 0 UID: 0 PID: 1392 Comm: rtcwake Tainted: G W 6.14.0-rc4-g5394eea10651 #16 [ 14.588590] Tainted: [W]=WARN [ 14.588593] Hardware name: Broadcom STB (Flattened Device Tree) [ 14.588598] Call trace: [ 14.588604] dump_backtrace from show_stack+0x18/0x1c [ 14.588622] r7:00000009 r6:0000008b r5:60000153 r4:c0fa558c [ 14.588625] show_stack from dump_stack_lvl+0x70/0x7c [ 14.588639] dump_stack_lvl from dump_stack+0x18/0x1c [ 14.588653] r5:c08d40b0 r4:c1003cb0 [ 14.588656] dump_stack from __warn+0x84/0xe4 [ 14.588668] __warn from warn_slowpath_fmt+0x18c/0x194 [ 14.588678] r7:c08d40b0 r6:c1003cb0 r5:00000000 r4:00000000 [ 14.588681] warn_slowpath_fmt from nand_reset_op+0x1e0/0x1f8 [ 14.588695] r8:70c40dff r7:89705f41 r6:36b4a597 r5:c26c9444 r4:c26b0048 [ 14.588697] nand_reset_op from brcmnand_resume+0x13c/0x150 [ 14.588714] r9:00000000 r8:00000000 r7:c24f8010 r6:c228a3f8 r5:c26c94bc r4:c26b0040 [ 14.588717] brcmnand_resume from platform_pm_resume+0x34/0x54 [ 14.588735] r5:00000010 r4:c0840a50 [ 14.588738] platform_pm_resume from dpm_run_callback+0x5c/0x14c [ 14.588757] dpm_run_callback from device_resume+0xc0/0x324 [ 14.588776] r9:c24f8054 r8:c24f80a0 r7:00000000 r6:00000000 r5:00000010 r4:c24f8010 [ 14.588779] device_resume from dpm_resume+0x130/0x160 [ 14.588799] r9:c22539e4 r8:00000010 r7:c22bebb0 r6:c24f8010 r5:c22539dc r4:c22539b0 [ 14.588802] dpm_resume from dpm_resume_end+0x14/0x20 [ 14.588822] r10:c2204e40 r9:00000000 r8:c228a3fc r7:00000000 r6:00000003 r5:c228a414 [ 14.588826] r4:00000010 [ 14.588828] dpm_resume_end from suspend_devices_and_enter+0x274/0x6f8 [ 14.588848] r5:c228a414 r4:00000000 [ 14.588851] suspend_devices_and_enter from pm_suspend+0x228/0x2bc [ 14.588868] r10:c3502910 r9:c3501f40 r8:00000004 r7:c228a438 r6:c0f95e18 r5:00000000 [ 14.588871] r4:00000003 [ 14.588874] pm_suspend from state_store+0x74/0xd0 [ 14.588889] r7:c228a438 r6:c0f934c8 r5:00000003 r4:00000003 [ 14.588892] state_store from kobj_attr_store+0x1c/0x28 [ 14.588913] r9:00000000 r8:00000000 r7:f09f9f08 r6:00000004 r5:c3502900 r4:c0283250 [ 14.588916] kobj_attr_store from sysfs_kf_write+0x40/0x4c [ 14.588936] r5:c3502900 r4:c0d92a48 [ 14.588939] sysfs_kf_write from kernfs_fop_write_iter+0x104/0x1f0 [ 14.588956] r5:c3502900 r4:c3501f40 [ 14.588960] kernfs_fop_write_iter from vfs_write+0x250/0x420 [ 14.588980] r10:c0e14b48 r9:00000000 r8:c25f5780 r7:00443398 r6:f09f9f68 r5:c34f7f00 [ 14.588983] r4:c042a88c [ 14.588987] vfs_write from ksys_write+0x74/0xe4 [ 14.589005] r10:00000004 r9:c25f5780 r8:c02002fA0 r7:00000000 r6:00000000 r5:c34f7f00 [ 14.589008] r4:c34f7f00 [ 14.589011] ksys_write from sys_write+0x10/0x14 [ 14.589029] r7:00000004 r6:004421c0 r5:00443398 r4:00000004 [ 14.589032] sys_write from ret_fast_syscall+0x0/0x5c [ 14.589044] Exception stack(0xf09f9fa8 to 0xf09f9ff0) [ 14.589050] 9fa0: 00000004 00443398 00000004 00443398 00000004 00000001 [ 14.589056] 9fc0: 00000004 00443398 004421c0 00000004 b6ecbd58 00000008 bebfbc38 0043eb78 [ 14.589062] 9fe0: 00440eb0 bebfbaf8 b6de18a0 b6e579e8 [ 14.589065] ---[ end trace 0000000000000000 ]--- The fix uses the higher level nand_reset(chip, chipnr); where chipnr = 0, when doing PM resume operation in compliance with the controller support for single die nand chip. Switching from nand_reset_op() to nand_reset() implies more than just setting the cs field op->cs, it also reconfigures the data interface (ie. the timings). Tested and confirmed the NAND chip is in sync timing wise with host after the fix. Fixes: 97d90da8a886 ("mtd: nand: provide several helpers to do common NAND operations") Cc: stable(a)vger.kernel.org Signed-off-by: Kamal Dasu <kamal.dasu(a)broadcom.com> --- drivers/mtd/nand/raw/brcmnand/brcmnand.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c index fea5b6119956..17f6d9723df9 100644 --- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c +++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c @@ -3008,7 +3008,7 @@ static int brcmnand_resume(struct device *dev) brcmnand_save_restore_cs_config(host, 1); /* Reset the chip, required by some chips after power-up */ - nand_reset_op(chip); + nand_reset(chip, 0); } return 0; -- 2.17.1

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Ref: Yes//

by alex_ Star

Hi I was doing some research on your industry and I landed on your website.We will see some bugs on your website. Would you like me to send over a screenshot & Specific report of those bugs? Best"

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[PATCH V5 1/4] x86/paravirt: Move halt paravirt calls under CONFIG_PARAVIRT

by Vishal Annapurve

From: "Kirill A. Shutemov" <kirill.shutemov(a)linux.intel.com> CONFIG_PARAVIRT_XXL is mainly defined/used by XEN PV guests. For other VM guest types, features supported under CONFIG_PARAVIRT are self sufficient. CONFIG_PARAVIRT mainly provides support for TLB flush operations and time related operations. For TDX guest as well, paravirt calls under CONFIG_PARVIRT meets most of its requirement except the need of HLT and SAFE_HLT paravirt calls, which is currently defined under CONFIG_PARAVIRT_XXL. Since enabling CONFIG_PARAVIRT_XXL is too bloated for TDX guest like platforms, move HLT and SAFE_HLT paravirt calls under CONFIG_PARAVIRT. Moving HLT and SAFE_HLT paravirt calls are not fatal and should not break any functionality for current users of CONFIG_PARAVIRT. Cc: stable(a)vger.kernel.org Fixes: bfe6ed0c6727 ("x86/tdx: Add HLT support for TDX guests") Co-developed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy(a)linux.intel.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy(a)linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com> Reviewed-by: Andi Kleen <ak(a)linux.intel.com> Reviewed-by: Tony Luck <tony.luck(a)intel.com> Signed-off-by: Vishal Annapurve <vannapurve(a)google.com> --- arch/x86/include/asm/irqflags.h | 40 +++++++++++++++------------ arch/x86/include/asm/paravirt.h | 20 +++++++------- arch/x86/include/asm/paravirt_types.h | 3 +- arch/x86/kernel/paravirt.c | 14 ++++++---- 4 files changed, 41 insertions(+), 36 deletions(-) diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h index cf7fc2b8e3ce..1c2db11a2c3c 100644 --- a/arch/x86/include/asm/irqflags.h +++ b/arch/x86/include/asm/irqflags.h @@ -76,6 +76,28 @@ static __always_inline void native_local_irq_restore(unsigned long flags) #endif +#ifndef CONFIG_PARAVIRT +#ifndef __ASSEMBLY__ +/* + * Used in the idle loop; sti takes one instruction cycle + * to complete: + */ +static __always_inline void arch_safe_halt(void) +{ + native_safe_halt(); +} + +/* + * Used when interrupts are already enabled or to + * shutdown the processor: + */ +static __always_inline void halt(void) +{ + native_halt(); +} +#endif /* __ASSEMBLY__ */ +#endif /* CONFIG_PARAVIRT */ + #ifdef CONFIG_PARAVIRT_XXL #include <asm/paravirt.h> #else @@ -97,24 +119,6 @@ static __always_inline void arch_local_irq_enable(void) native_irq_enable(); } -/* - * Used in the idle loop; sti takes one instruction cycle - * to complete: - */ -static __always_inline void arch_safe_halt(void) -{ - native_safe_halt(); -} - -/* - * Used when interrupts are already enabled or to - * shutdown the processor: - */ -static __always_inline void halt(void) -{ - native_halt(); -} - /* * For spinlocks, etc: */ diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index 041aff51eb50..29e7331a0c98 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -107,6 +107,16 @@ static inline void notify_page_enc_status_changed(unsigned long pfn, PVOP_VCALL3(mmu.notify_page_enc_status_changed, pfn, npages, enc); } +static __always_inline void arch_safe_halt(void) +{ + PVOP_VCALL0(irq.safe_halt); +} + +static inline void halt(void) +{ + PVOP_VCALL0(irq.halt); +} + #ifdef CONFIG_PARAVIRT_XXL static inline void load_sp0(unsigned long sp0) { @@ -170,16 +180,6 @@ static inline void __write_cr4(unsigned long x) PVOP_VCALL1(cpu.write_cr4, x); } -static __always_inline void arch_safe_halt(void) -{ - PVOP_VCALL0(irq.safe_halt); -} - -static inline void halt(void) -{ - PVOP_VCALL0(irq.halt); -} - static inline u64 paravirt_read_msr(unsigned msr) { return PVOP_CALL1(u64, cpu.read_msr, msr); diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index fea56b04f436..abccfccc2e3f 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -120,10 +120,9 @@ struct pv_irq_ops { struct paravirt_callee_save save_fl; struct paravirt_callee_save irq_disable; struct paravirt_callee_save irq_enable; - +#endif void (*safe_halt)(void); void (*halt)(void); -#endif } __no_randomize_layout; struct pv_mmu_ops { diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index 1ccaa3397a67..c5bb980b8a67 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -110,6 +110,11 @@ int paravirt_disable_iospace(void) return request_resource(&ioport_resource, &reserve_ioports); } +static noinstr void pv_native_safe_halt(void) +{ + native_safe_halt(); +} + #ifdef CONFIG_PARAVIRT_XXL static noinstr void pv_native_write_cr2(unsigned long val) { @@ -125,11 +130,6 @@ static noinstr void pv_native_set_debugreg(int regno, unsigned long val) { native_set_debugreg(regno, val); } - -static noinstr void pv_native_safe_halt(void) -{ - native_safe_halt(); -} #endif struct pv_info pv_info = { @@ -186,9 +186,11 @@ struct paravirt_patch_template pv_ops = { .irq.save_fl = __PV_IS_CALLEE_SAVE(pv_native_save_fl), .irq.irq_disable = __PV_IS_CALLEE_SAVE(pv_native_irq_disable), .irq.irq_enable = __PV_IS_CALLEE_SAVE(pv_native_irq_enable), +#endif /* CONFIG_PARAVIRT_XXL */ + + /* Irq HLT ops. */ .irq.safe_halt = pv_native_safe_halt, .irq.halt = native_halt, -#endif /* CONFIG_PARAVIRT_XXL */ /* Mmu ops. */ .mmu.flush_tlb_user = native_flush_tlb_local, -- 2.48.1.601.g30ceb7b040-goog

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[PATCH] pps: fix poll support

by Denis OSTERLAND-HEIM

[BUG] A user space program that calls select/poll get always an immediate data ready-to-read response. As a result the intended use to wait until next data becomes ready does not work. User space snippet: struct pollfd pollfd = { .fd = open("/dev/pps0", O_RDONLY), .events = POLLIN|POLLERR, .revents = 0 }; while(1) { poll(&pollfd, 1, 2000/*ms*/); // returns immediate, but should wait if(revents & EPOLLIN) { // always true struct pps_fdata fdata; memset(&fdata, 0, sizeof(memdata)); ioctl(PPS_FETCH, &fdata); // currently fetches data at max speed } } [CAUSE] pps_cdev_poll() returns unconditionally EPOLLIN. [FIX] Remember the last fetch event counter and compare this value in pps_cdev_poll() with most recent event counter and return 0 if they are equal. Signed-off-by: Denis OSTERLAND-HEIM <denis.osterland(a)diehl.com> Co-developed-by: Rodolfo Giometti <giometti(a)enneenne.com> Signed-off-by: Rodolfo Giometti <giometti(a)enneenne.com> Fixes: eae9d2ba0cfc ("LinuxPPS: core support") CC: stable(a)vger.kernel.org # 5.4+ --- drivers/pps/pps.c | 11 +++++++++-- include/linux/pps_kernel.h | 1 + 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c index 6a02245ea35f..9463232af8d2 100644 --- a/drivers/pps/pps.c +++ b/drivers/pps/pps.c @@ -41,6 +41,9 @@ static __poll_t pps_cdev_poll(struct file *file, poll_table *wait) poll_wait(file, &pps->queue, wait); +if (pps->last_fetched_ev == pps->last_ev) +return 0; + return EPOLLIN | EPOLLRDNORM; } @@ -186,9 +189,11 @@ static long pps_cdev_ioctl(struct file *file, if (err) return err; -/* Return the fetched timestamp */ +/* Return the fetched timestamp and save last fetched event */ spin_lock_irq(&pps->lock); +pps->last_fetched_ev = pps->last_ev; + fdata.info.assert_sequence = pps->assert_sequence; fdata.info.clear_sequence = pps->clear_sequence; fdata.info.assert_tu = pps->assert_tu; @@ -272,9 +277,11 @@ static long pps_cdev_compat_ioctl(struct file *file, if (err) return err; -/* Return the fetched timestamp */ +/* Return the fetched timestamp and save last fetched event */ spin_lock_irq(&pps->lock); +pps->last_fetched_ev = pps->last_ev; + compat.info.assert_sequence = pps->assert_sequence; compat.info.clear_sequence = pps->clear_sequence; compat.info.current_mode = pps->current_mode; diff --git a/include/linux/pps_kernel.h b/include/linux/pps_kernel.h index c7abce28ed29..aab0aebb529e 100644 --- a/include/linux/pps_kernel.h +++ b/include/linux/pps_kernel.h @@ -52,6 +52,7 @@ struct pps_device { int current_mode;/* PPS mode at event time */ unsigned int last_ev;/* last PPS event id */ +unsigned int last_fetched_ev;/* last fetched PPS event id */ wait_queue_head_t queue;/* PPS event queue */ unsigned int id;/* PPS source unique ID */ -- 2.47.2 Diehl Metering GmbH, Donaustrasse 120, 90451 Nuernberg Sitz der Gesellschaft: Ansbach, Registergericht: Ansbach HRB 69 Geschaeftsfuehrer: Dr. Christof Bosbach (Sprecher), Dipl.-Dolm. Annette Geuther, Dipl.-Kfm. Reiner Edel, Jean-Claude Luttringer Bitte denken Sie an die Umwelt, bevor Sie diese E-Mail drucken. Diese E-Mail kann vertrauliche Informationen enthalten. Sollten die in dieser E-Mail enthaltenen Informationen nicht für Sie bestimmt sein, informieren Sie bitte unverzueglich den Absender per E-Mail und loeschen Sie diese E-Mail in Ihrem System. Jede unberechtigte Form der Reproduktion, Bekanntgabe, Aenderung, Verteilung und/oder Publikation dieser E-Mail ist strengstens untersagt. Informationen zum Datenschutz finden Sie auf unserer Homepage<https://www.diehl.com/metering/de/impressum-und-rechtliche-hinweise/>. Before printing, think about environmental responsibility.This message may contain confidential information. If you are not authorized to receive this information please advise the sender immediately by reply e-mail and delete this message without making any copies. Any form of unauthorized use, publication, reproduction, copying or disclosure of the e-mail is not permitted. Information about data protection can be found on our homepage<https://www.diehl.com/metering/en/data-protection/>.

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