[PATCH] uio-hv-generic: store physical addresses instead of virtual

From: Arnd Bergmann
Date: Fri Dec 09 2016 - 06:45:13 EST


gcc warns about the newly added driver when phys_addr_t is wider than
a pointer:

drivers/uio/uio_hv_generic.c: In function 'hv_uio_mmap':
drivers/uio/uio_hv_generic.c:71:17: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
virt_to_phys((void *)info->mem[mi].addr) >> PAGE_SHIFT,
drivers/uio/uio_hv_generic.c: In function 'hv_uio_probe':
drivers/uio/uio_hv_generic.c:140:5: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
= (phys_addr_t)dev->channel->ringbuffer_pages;
drivers/uio/uio_hv_generic.c:147:3: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
(phys_addr_t)vmbus_connection.int_page;
drivers/uio/uio_hv_generic.c:153:3: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
(phys_addr_t)vmbus_connection.monitor_pages[1];

I can't see why we store a virtual address in a phys_addr_t here,
as the only user of that variable converts it into a physical
address anyway, so this moves the conversion to where it logically
fits according to the types.

Fixes: 95096f2fbd10 ("uio-hv-generic: new userspace i/o driver for VMBus")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/uio/uio_hv_generic.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index ad3ab5805ad8..50958f167305 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -68,7 +68,7 @@ hv_uio_mmap(struct uio_info *info, struct vm_area_struct *vma)
mi = (int)vma->vm_pgoff;

return remap_pfn_range(vma, vma->vm_start,
- virt_to_phys((void *)info->mem[mi].addr) >> PAGE_SHIFT,
+ info->mem[mi].addr >> PAGE_SHIFT,
vma->vm_end - vma->vm_start, vma->vm_page_prot);
}

@@ -137,20 +137,20 @@ hv_uio_probe(struct hv_device *dev,
/* mem resources */
pdata->info.mem[TXRX_RING_MAP].name = "txrx_rings";
pdata->info.mem[TXRX_RING_MAP].addr
- = (phys_addr_t)dev->channel->ringbuffer_pages;
+ = virt_to_phys(dev->channel->ringbuffer_pages);
pdata->info.mem[TXRX_RING_MAP].size
= dev->channel->ringbuffer_pagecount * PAGE_SIZE;
pdata->info.mem[TXRX_RING_MAP].memtype = UIO_MEM_LOGICAL;

pdata->info.mem[INT_PAGE_MAP].name = "int_page";
pdata->info.mem[INT_PAGE_MAP].addr =
- (phys_addr_t)vmbus_connection.int_page;
+ virt_to_phys(vmbus_connection.int_page);
pdata->info.mem[INT_PAGE_MAP].size = PAGE_SIZE;
pdata->info.mem[INT_PAGE_MAP].memtype = UIO_MEM_LOGICAL;

pdata->info.mem[MON_PAGE_MAP].name = "monitor_pages";
pdata->info.mem[MON_PAGE_MAP].addr =
- (phys_addr_t)vmbus_connection.monitor_pages[1];
+ virt_to_phys(vmbus_connection.monitor_pages[1]);
pdata->info.mem[MON_PAGE_MAP].size = PAGE_SIZE;
pdata->info.mem[MON_PAGE_MAP].memtype = UIO_MEM_LOGICAL;

--
2.9.0