[PATCH 30/40] sandbox: iommu: remove lmb allocation in the driver

[Simon Glass]

Hi Sughosh,

On Wed, 24 Jul 2024 at 00:05, Sughosh Ganu <sughosh.ganu at linaro.org> wrote:
>
> The sandbox iommu driver uses the LMB module to allocate a particular
> range of memory for the device virtual address(DVA). This used to work
> earlier since the LMB memory map was caller specific and not
> global. But with the change to make the LMB allocations global and
> persistent, adding this memory range has other side effects. On the
> other hand, the sandbox iommu test expects to see this particular
> value of the DVA. Use the DVA address directly, instead of mapping it
> in the LMB memory map, and then have it allocated.
>
> Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
> ---
> Changes since rfc: None
>
>  drivers/iommu/sandbox_iommu.c | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/iommu/sandbox_iommu.c b/drivers/iommu/sandbox_iommu.c
> index 505f2c3250..15ecaacbb3 100644
> --- a/drivers/iommu/sandbox_iommu.c
> +++ b/drivers/iommu/sandbox_iommu.c
> @@ -5,10 +5,10 @@
>
>  #include <dm.h>
>  #include <iommu.h>
> -#include <lmb.h>
>  #include <asm/io.h>
>  #include <linux/sizes.h>
>
> +#define DVA_ADDR               0x89abc000

This is a very strange address. You can put this in
arch/sandbox/include/asm/test.h and check it in the test. I suggest
using something like 0x12345678 so it is obviously meaningless.

>  #define IOMMU_PAGE_SIZE                SZ_4K
>
>  static dma_addr_t sandbox_iommu_map(struct udevice *dev, void *addr,
> @@ -20,8 +20,7 @@ static dma_addr_t sandbox_iommu_map(struct udevice *dev, void *addr,
>         paddr = ALIGN_DOWN(virt_to_phys(addr), IOMMU_PAGE_SIZE);
>         off = virt_to_phys(addr) - paddr;
>         psize = ALIGN(size + off, IOMMU_PAGE_SIZE);
> -
> -       dva = lmb_alloc(psize, IOMMU_PAGE_SIZE, LMB_NONE);
> +       dva = (phys_addr_t)DVA_ADDR;
>
>         return dva + off;
>  }
> @@ -35,8 +34,6 @@ static void sandbox_iommu_unmap(struct udevice *dev, dma_addr_t addr,
>         dva = ALIGN_DOWN(addr, IOMMU_PAGE_SIZE);
>         psize = size + (addr - dva);
>         psize = ALIGN(psize, IOMMU_PAGE_SIZE);
> -
> -       lmb_free(dva, psize, LMB_NONE);
>  }
>
>  static struct iommu_ops sandbox_iommu_ops = {
> @@ -46,8 +43,6 @@ static struct iommu_ops sandbox_iommu_ops = {
>
>  static int sandbox_iommu_probe(struct udevice *dev)
>  {
> -       lmb_add(0x89abc000, SZ_16K, LMB_NONE);
> -
>         return 0;
>  }

If this function is empty, you should remove it.

>
> --
> 2.34.1
>

Regards,
Simon