Re: [Qemu-devel] [PATCH v2 1/6] hw/pci: Use pow2ceil() rather than hand-calculation

2015-08-12 Thread Michael S. Tsirkin 
On Fri, Jul 24, 2015 at 01:33:07PM +0100, Peter Maydell wrote:
 A couple of places in hw/pci use an inline calculation to round a
 size up to the next largest power of 2. We have a utility routine
 for this, so use it.
 
 (The behaviour of the old code is different if the size value
 is 0 -- it would leave it as 0 rather than rounding up to 1,
 but in both cases we know the size can't be 0.
 In the case where the size value had bit 31 set, the old code
 would invoke undefined behaviour; the new code will give a
 result of 0. Presumably that could never happen either.)
 
 Signed-off-by: Peter Maydell peter.mayd...@linaro.org

Reviewed-by: Michael S. Tsirkin m...@redhat.com

 ---
  hw/pci/msix.c | 4 +---
  hw/pci/pci.c  | 4 +---
  2 files changed, 2 insertions(+), 6 deletions(-)
 
 diff --git a/hw/pci/msix.c b/hw/pci/msix.c
 index 7716bf3..2fdada4 100644
 --- a/hw/pci/msix.c
 +++ b/hw/pci/msix.c
 @@ -314,9 +314,7 @@ int msix_init_exclusive_bar(PCIDevice *dev, unsigned 
 short nentries,
  bar_size = bar_pba_offset + bar_pba_size;
  }
  
 -if (bar_size  (bar_size - 1)) {
 -bar_size = 1  qemu_fls(bar_size);
 -}
 +bar_size = pow2ceil(bar_size);
  
  name = g_strdup_printf(%s-msix, dev-name);
  memory_region_init(dev-msix_exclusive_bar, OBJECT(dev), name, 
 bar_size);
 diff --git a/hw/pci/pci.c b/hw/pci/pci.c
 index a017614..502da8d 100644
 --- a/hw/pci/pci.c
 +++ b/hw/pci/pci.c
 @@ -2065,9 +2065,7 @@ static void pci_add_option_rom(PCIDevice *pdev, bool 
 is_default_rom,
  g_free(path);
  return;
  }
 -if (size  (size - 1)) {
 -size = 1  qemu_fls(size);
 -}
 +size = pow2ceil(size);
  
  vmsd = qdev_get_vmsd(DEVICE(pdev));
  
 -- 
 1.9.1

[Qemu-devel] [PATCH v2 1/6] hw/pci: Use pow2ceil() rather than hand-calculation

2015-07-24 Thread Peter Maydell 
A couple of places in hw/pci use an inline calculation to round a
size up to the next largest power of 2. We have a utility routine
for this, so use it.

(The behaviour of the old code is different if the size value
is 0 -- it would leave it as 0 rather than rounding up to 1,
but in both cases we know the size can't be 0.
In the case where the size value had bit 31 set, the old code
would invoke undefined behaviour; the new code will give a
result of 0. Presumably that could never happen either.)

Signed-off-by: Peter Maydell peter.mayd...@linaro.org
---
 hw/pci/msix.c | 4 +---
 hw/pci/pci.c  | 4 +---
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/hw/pci/msix.c b/hw/pci/msix.c
index 7716bf3..2fdada4 100644
--- a/hw/pci/msix.c
+++ b/hw/pci/msix.c
@@ -314,9 +314,7 @@ int msix_init_exclusive_bar(PCIDevice *dev, unsigned short 
nentries,
 bar_size = bar_pba_offset + bar_pba_size;
 }
 
-if (bar_size  (bar_size - 1)) {
-bar_size = 1  qemu_fls(bar_size);
-}
+bar_size = pow2ceil(bar_size);
 
 name = g_strdup_printf(%s-msix, dev-name);
 memory_region_init(dev-msix_exclusive_bar, OBJECT(dev), name, bar_size);
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index a017614..502da8d 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -2065,9 +2065,7 @@ static void pci_add_option_rom(PCIDevice *pdev, bool 
is_default_rom,
 g_free(path);
 return;
 }
-if (size  (size - 1)) {
-size = 1  qemu_fls(size);
-}
+size = pow2ceil(size);
 
 vmsd = qdev_get_vmsd(DEVICE(pdev));
 
-- 
1.9.1