On Tue, Sep 06, 2016 at 02:59:41PM +0200, Arnd Bergmann wrote:
> casting between dma_addr_t and a pointer is generally tricky,
> as they might not be the same size and almost never point into
> the same address space. With 32-bit ARM systems and LPAE, we
> get this warning for the vme_fake driver that stores a pointer
> in a dma_addr_t variable:
>
> drivers/vme/bridges/vme_fake.c: In function 'fake_slave_set':
> drivers/vme/bridges/vme_fake.c:204:29: error: assignment makes pointer from integer without a cast [-Werror=int-conversion]
>
> To make this clearer while fixing the warning, I'm adding
> a set of helper functions for the type conversion.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Acked-by: Martyn Welch <martyn@xxxxxxxxxxxx>
> ---
> drivers/vme/bridges/vme_fake.c | 26 ++++++++++++++++++--------
> 1 file changed, 18 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/vme/bridges/vme_fake.c b/drivers/vme/bridges/vme_fake.c
> index 7ef298b289f4..ebf35d305321 100644
> --- a/drivers/vme/bridges/vme_fake.c
> +++ b/drivers/vme/bridges/vme_fake.c
> @@ -48,7 +48,7 @@ struct fake_slave_window {
> int enabled;
> unsigned long long vme_base;
> unsigned long long size;
> - dma_addr_t buf_base;
> + void *buf_base;
> u32 aspace;
> u32 cycle;
> };
> @@ -114,6 +114,16 @@ static void fake_irq_set(struct vme_bridge *fake_bridge, int level,
> /* Nothing to do */
> }
>
> +static void *fake_pci_to_ptr(dma_addr_t addr)
> +{
> + return (void *)(uintptr_t)addr;
> +}
> +
> +static dma_addr_t fake_ptr_to_pci(void *addr)
> +{
> + return (dma_addr_t)(uintptr_t)addr;
> +}
> +
> /*
> * Generate a VME bus interrupt at the requested level & vector. Wait for
> * interrupt to be acked.
> @@ -202,7 +212,7 @@ static int fake_slave_set(struct vme_slave_resource *image, int enabled,
> bridge->slaves[i].enabled = enabled;
> bridge->slaves[i].vme_base = vme_base;
> bridge->slaves[i].size = size;
> - bridge->slaves[i].buf_base = buf_base;
> + bridge->slaves[i].buf_base = fake_pci_to_ptr(buf_base);
> bridge->slaves[i].aspace = aspace;
> bridge->slaves[i].cycle = cycle;
>
> @@ -230,7 +240,7 @@ static int fake_slave_get(struct vme_slave_resource *image, int *enabled,
> *enabled = bridge->slaves[i].enabled;
> *vme_base = bridge->slaves[i].vme_base;
> *size = bridge->slaves[i].size;
> - *buf_base = bridge->slaves[i].buf_base;
> + *buf_base = fake_ptr_to_pci(bridge->slaves[i].buf_base);
> *aspace = bridge->slaves[i].aspace;
> *cycle = bridge->slaves[i].cycle;
>
> @@ -431,7 +441,7 @@ static u8 fake_vmeread8(struct fake_driver *bridge, unsigned long long addr,
>
> if ((addr >= start) && (addr < end)) {
> offset = addr - bridge->slaves[i].vme_base;
> - loc = (u8 *)((void *)bridge->slaves[i].buf_base + offset);
> + loc = (u8 *)(bridge->slaves[i].buf_base + offset);
> retval = *loc;
>
> break;
> @@ -463,7 +473,7 @@ static u16 fake_vmeread16(struct fake_driver *bridge, unsigned long long addr,
>
> if ((addr >= start) && ((addr + 1) < end)) {
> offset = addr - bridge->slaves[i].vme_base;
> - loc = (u16 *)((void *)bridge->slaves[i].buf_base + offset);
> + loc = (u16 *)(bridge->slaves[i].buf_base + offset);
> retval = *loc;
>
> break;
> @@ -495,7 +505,7 @@ static u32 fake_vmeread32(struct fake_driver *bridge, unsigned long long addr,
>
> if ((addr >= start) && ((addr + 3) < end)) {
> offset = addr - bridge->slaves[i].vme_base;
> - loc = (u32 *)((void *)bridge->slaves[i].buf_base + offset);
> + loc = (u32 *)(bridge->slaves[i].buf_base + offset);
> retval = *loc;
>
> break;
> @@ -997,7 +1007,7 @@ static void *fake_alloc_consistent(struct device *parent, size_t size,
> void *alloc = kmalloc(size, GFP_KERNEL);
>
> if (alloc != NULL)
> - *dma = (dma_addr_t)(unsigned long)alloc;
> + *dma = fake_ptr_to_pci(alloc);
>
> return alloc;
> }
> @@ -1031,7 +1041,7 @@ static int fake_crcsr_init(struct vme_bridge *fake_bridge)
>
> /* Allocate mem for CR/CSR image */
> bridge->crcsr_kernel = kzalloc(VME_CRCSR_BUF_SIZE, GFP_KERNEL);
> - bridge->crcsr_bus = (dma_addr_t)bridge->crcsr_kernel;
> + bridge->crcsr_bus = fake_ptr_to_pci(bridge->crcsr_kernel);
> if (bridge->crcsr_kernel == NULL)
> return -ENOMEM;
>
> --
> 2.9.0
>
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