RE: [PATCH 5/5] hv: Track allocations of children of hv_vmbus in private resource tree

[KY Srinivasan]

> -----Original Message-----
> From: jakeo@xxxxxxxxxxxxx [mailto:jakeo@xxxxxxxxxxxxx]
> Sent: Wednesday, February 24, 2016 1:24 PM
> To: linux-pci@xxxxxxxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; KY Srinivasan
> <kys@xxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx;
> devel@xxxxxxxxxxxxxxxxxxxxxx; olaf@xxxxxxxxx; apw@xxxxxxxxxxxxx;
> vkuznets@xxxxxxxxxx; Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>; Hadden
> Hoppert <haddenh@xxxxxxxxxxxxx>
> Cc: Jake Oshins <jakeo@xxxxxxxxxxxxx>
> Subject: [PATCH 5/5] hv: Track allocations of children of hv_vmbus in private
> resource tree
> 
> From: Jake Oshins <jakeo@xxxxxxxxxxxxx>
> 
> 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@xxxxxxxxxxxxx>
> ---
>  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