From be000f93e5d71f5d43dd722f8eb110b069f9d8a2 Mon Sep 17 00:00:00 2001 From: Jake Oshins Date: Tue, 5 Apr 2016 10:22:54 -0700 Subject: [PATCH] drivers:hv: Track allocations of children of hv_vmbus in private resource tree 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 Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- 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 1ce47d03e800..dfc6149ccc93 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1128,7 +1128,7 @@ 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); @@ -1170,12 +1170,22 @@ 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); } } } @@ -1196,7 +1206,17 @@ 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); -- 2.20.1