| Message ID | 1456349042-16275-6-git-send-email-jakeo@microsoft.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
> -----Original Message----- > From: jakeo@microsoft.com [mailto:jakeo@microsoft.com] > Sent: Wednesday, February 24, 2016 1:24 PM > To: linux-pci@vger.kernel.org; gregkh@linuxfoundation.org; KY Srinivasan > <kys@microsoft.com>; linux-kernel@vger.kernel.org; > devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com; > vkuznets@redhat.com; Haiyang Zhang <haiyangz@microsoft.com>; Hadden > Hoppert <haddenh@microsoft.com> > Cc: Jake Oshins <jakeo@microsoft.com> > Subject: [PATCH 5/5] hv: Track allocations of children of hv_vmbus in private > resource tree > > From: Jake Oshins <jakeo@microsoft.com> > > This patch changes vmbus_allocate_mmio() and vmbus_free_mmio() so > that when child paravirtual devices allocate memory-mapped I/O > space, they allocate it privately from a resource tree pointed > at by hyperv_mmio and also by the public resource tree > iomem_resource. This allows the region to be marked as "busy" > in the private tree, but a "bridge window" in the public tree, > guaranteeing that no two bridge windows will overlap each other > but while also allowing the PCI device children of the bridge > windows to overlap that window. > > One might conclude that this belongs in the pnp layer, rather > than in this driver. Rafael Wysocki, the maintainter of the > pnp layer, has previously asked that we not modify the pnp layer > as it is considered deprecated. This patch is thus essentially > a workaround. > > Signed-off-by: Jake Oshins <jakeo@microsoft.com> > --- > drivers/hv/vmbus_drv.c | 22 +++++++++++++++++++++- > 1 file changed, 21 insertions(+), 1 deletion(-) > > diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c > index b090548..2a7eb3f 100644 > --- a/drivers/hv/vmbus_drv.c > +++ b/drivers/hv/vmbus_drv.c > @@ -1169,7 +1169,7 @@ int vmbus_allocate_mmio(struct resource **new, > struct hv_device *device_obj, > resource_size_t size, resource_size_t align, > bool fb_overlap_ok) > { > - struct resource *iter; > + struct resource *iter, *shadow; > resource_size_t range_min, range_max, start, local_min, local_max; > const char *dev_n = dev_name(&device_obj->device); > u32 fb_end = screen_info.lfb_base + (screen_info.lfb_size << 1); > @@ -1211,12 +1211,22 @@ int vmbus_allocate_mmio(struct resource > **new, struct hv_device *device_obj, > > start = (local_min + align - 1) & ~(align - 1); > for (; start + size - 1 <= local_max; start += align) { > + shadow = __request_region(iter, start, > + size, > + NULL, > + IORESOURCE_BUSY); > + if (!shadow) > + continue; > + > *new = > request_mem_region_exclusive(start, size, > dev_n); > if (*new) { > + shadow->name = (char*)*new; Why are you not correctly setting the name field in the shadow structure? Regards, K. Y -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> -----Original Message----- > From: KY Srinivasan > Sent: Friday, February 26, 2016 5:09 PM > To: Jake Oshins <jakeo@microsoft.com>; linux-pci@vger.kernel.org; > gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; > devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com; > vkuznets@redhat.com; Haiyang Zhang <haiyangz@microsoft.com>; Hadden > Hoppert <haddenh@microsoft.com> > Cc: Jake Oshins <jakeo@microsoft.com> > Subject: RE: [PATCH 5/5] hv: Track allocations of children of hv_vmbus in > private resource tree > > > -----Original Message----- > > From: jakeo@microsoft.com [mailto:jakeo@microsoft.com] > > Sent: Wednesday, February 24, 2016 1:24 PM > > To: linux-pci@vger.kernel.org; gregkh@linuxfoundation.org; KY Srinivasan > > <kys@microsoft.com>; linux-kernel@vger.kernel.org; > > devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com; > > vkuznets@redhat.com; Haiyang Zhang <haiyangz@microsoft.com>; > Hadden > > Hoppert <haddenh@microsoft.com> > > Cc: Jake Oshins <jakeo@microsoft.com> > > Subject: [PATCH 5/5] hv: Track allocations of children of hv_vmbus in > private > > resource tree > > > > From: Jake Oshins <jakeo@microsoft.com> > > > > This patch changes vmbus_allocate_mmio() and vmbus_free_mmio() so > > that when child paravirtual devices allocate memory-mapped I/O > > space, they allocate it privately from a resource tree pointed > > at by hyperv_mmio and also by the public resource tree > > iomem_resource. This allows the region to be marked as "busy" > > in the private tree, but a "bridge window" in the public tree, > > guaranteeing that no two bridge windows will overlap each other > > but while also allowing the PCI device children of the bridge > > windows to overlap that window. > > > > One might conclude that this belongs in the pnp layer, rather > > than in this driver. Rafael Wysocki, the maintainter of the > > pnp layer, has previously asked that we not modify the pnp layer > > as it is considered deprecated. This patch is thus essentially > > a workaround. > > > > Signed-off-by: Jake Oshins <jakeo@microsoft.com> > > --- > > drivers/hv/vmbus_drv.c | 22 +++++++++++++++++++++- > > 1 file changed, 21 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c > > index b090548..2a7eb3f 100644 > > --- a/drivers/hv/vmbus_drv.c > > +++ b/drivers/hv/vmbus_drv.c > > @@ -1169,7 +1169,7 @@ int vmbus_allocate_mmio(struct resource > **new, > > struct hv_device *device_obj, > > resource_size_t size, resource_size_t align, > > bool fb_overlap_ok) > > { > > - struct resource *iter; > > + struct resource *iter, *shadow; > > resource_size_t range_min, range_max, start, local_min, local_max; > > const char *dev_n = dev_name(&device_obj->device); > > u32 fb_end = screen_info.lfb_base + (screen_info.lfb_size << 1); > > @@ -1211,12 +1211,22 @@ int vmbus_allocate_mmio(struct resource > > **new, struct hv_device *device_obj, > > > > start = (local_min + align - 1) & ~(align - 1); > > for (; start + size - 1 <= local_max; start += align) { > > + shadow = __request_region(iter, start, > > + size, > > + NULL, > > + IORESOURCE_BUSY); > > + if (!shadow) > > + continue; > > + > > *new = > > request_mem_region_exclusive(start, size, > > dev_n); > > if (*new) { > > + shadow->name = (char*)*new; > > Why are you not correctly setting the name field in the shadow structure? > > Regards, > > K. Y Nothing looks at the name fields in the shadow resource tree. So it seemed like that pointer could point to anything. I figured by making it point to the resource claim from the iomem_resource that might be useful in debugging someday. If you'd rather see something different here, it doesn't make much difference to me. Thanks for the review, Jake Oshins -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index b090548..2a7eb3f 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1169,7 +1169,7 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj, resource_size_t size, resource_size_t align, bool fb_overlap_ok) { - struct resource *iter; + struct resource *iter, *shadow; resource_size_t range_min, range_max, start, local_min, local_max; const char *dev_n = dev_name(&device_obj->device); u32 fb_end = screen_info.lfb_base + (screen_info.lfb_size << 1); @@ -1211,12 +1211,22 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj, start = (local_min + align - 1) & ~(align - 1); for (; start + size - 1 <= local_max; start += align) { + shadow = __request_region(iter, start, + size, + NULL, + IORESOURCE_BUSY); + if (!shadow) + continue; + *new = request_mem_region_exclusive(start, size, dev_n); if (*new) { + shadow->name = (char*)*new; retval = 0; goto exit; } + + __release_region(iter, start, size); } } } @@ -1237,7 +1247,17 @@ EXPORT_SYMBOL_GPL(vmbus_allocate_mmio); */ void vmbus_free_mmio(resource_size_t start, resource_size_t size) { + struct resource *iter; + + down(&hyperv_mmio_lock); + for (iter = hyperv_mmio; iter; iter = iter->sibling) { + if ((iter->start >= start + size) || (iter->end <= start)) + continue; + + __release_region(iter, start, size); + } release_mem_region(start, size); + up(&hyperv_mmio_lock); } EXPORT_SYMBOL_GPL(vmbus_free_mmio);