From: Gerd Bayer <gbayer@linux.ibm.com>
To: Alex Williamson <alex.williamson@redhat.com>,
Jason Gunthorpe <jgg@ziepe.ca>,
Niklas Schnelle <schnelle@linux.ibm.com>
Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org,
Ankit Agrawal <ankita@nvidia.com>,
Yishai Hadas <yishaih@nvidia.com>,
Halil Pasic <pasic@linux.ibm.com>,
Julian Ruess <julianr@linux.ibm.com>,
Gerd Bayer <gbayer@linux.ibm.com>
Subject: [PATCH v3 3/3] vfio/pci: Continue to refactor vfio_pci_core_do_io_rw
Date: Thu, 25 Apr 2024 18:56:04 +0200 [thread overview]
Message-ID: <20240425165604.899447-4-gbayer@linux.ibm.com> (raw)
In-Reply-To: <20240425165604.899447-1-gbayer@linux.ibm.com>
Convert if-elseif-chain into switch-case.
Separate out and generalize the code from the if-clauses so the result
can be used in the switch statement.
Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
---
drivers/vfio/pci/vfio_pci_rdwr.c | 30 ++++++++++++++++++++++++------
1 file changed, 24 insertions(+), 6 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c
index 8ed06edaee23..634c00b03c71 100644
--- a/drivers/vfio/pci/vfio_pci_rdwr.c
+++ b/drivers/vfio/pci/vfio_pci_rdwr.c
@@ -131,6 +131,20 @@ VFIO_IORDWR(32)
VFIO_IORDWR(64)
#endif
+static int fill_size(size_t fillable, loff_t off)
+{
+ unsigned int fill_size;
+#if defined(ioread64) && defined(iowrite64)
+ for (fill_size = 8; fill_size >= 0; fill_size /= 2) {
+#else
+ for (fill_size = 4; fill_size >= 0; fill_size /= 2) {
+#endif /* defined(ioread64) && defined(iowrite64) */
+ if (fillable >= fill_size && !(off % fill_size))
+ return fill_size;
+ }
+ return -1;
+}
+
/*
* Read or write from an __iomem region (MMIO or I/O port) with an excluded
* range which is inaccessible. The excluded range drops writes and fills
@@ -155,34 +169,38 @@ ssize_t vfio_pci_core_do_io_rw(struct vfio_pci_core_device *vdev, bool test_mem,
else
fillable = 0;
+ switch (fill_size(fillable, off)) {
#if defined(ioread64) && defined(iowrite64)
- if (fillable >= 8 && !(off % 8)) {
+ case 8:
ret = vfio_pci_core_iordwr64(vdev, iswrite, test_mem,
io, buf, off, &filled);
if (ret)
return ret;
+ break;
- } else
#endif /* defined(ioread64) && defined(iowrite64) */
- if (fillable >= 4 && !(off % 4)) {
+ case 4:
ret = vfio_pci_core_iordwr32(vdev, iswrite, test_mem,
io, buf, off, &filled);
if (ret)
return ret;
+ break;
- } else if (fillable >= 2 && !(off % 2)) {
+ case 2:
ret = vfio_pci_core_iordwr16(vdev, iswrite, test_mem,
io, buf, off, &filled);
if (ret)
return ret;
+ break;
- } else if (fillable) {
+ case 1:
ret = vfio_pci_core_iordwr8(vdev, iswrite, test_mem,
io, buf, off, &filled);
if (ret)
return ret;
+ break;
- } else {
+ default:
/* Fill reads with -1, drop writes */
filled = min(count, (size_t)(x_end - off));
if (!iswrite) {
--
2.44.0
next prev parent reply other threads:[~2024-04-25 16:56 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-25 16:56 [PATCH v3 0/3] vfio/pci: Support 8-byte PCI loads and stores Gerd Bayer
2024-04-25 16:56 ` [PATCH v3 1/3] vfio/pci: Extract duplicated code into macro Gerd Bayer
2024-04-29 16:31 ` Alex Williamson
2024-05-17 14:22 ` Gerd Bayer
2024-04-29 20:09 ` Jason Gunthorpe
2024-04-29 22:11 ` Alex Williamson
2024-04-29 22:33 ` Jason Gunthorpe
2024-05-21 15:47 ` Gerd Bayer
2024-04-30 8:16 ` liulongfang
2024-05-17 10:47 ` Ramesh Thomas
2024-04-25 16:56 ` [PATCH v3 2/3] vfio/pci: Support 8-byte PCI loads and stores Gerd Bayer
2024-04-29 16:31 ` Alex Williamson
2024-05-21 15:50 ` Gerd Bayer
2024-05-17 10:29 ` Ramesh Thomas
2024-05-20 9:02 ` Tian, Kevin
2024-05-23 0:11 ` Ramesh Thomas
2024-05-23 21:52 ` Ramesh Thomas
2024-05-21 16:40 ` Gerd Bayer
2024-05-22 13:48 ` Jason Gunthorpe
2024-05-22 23:57 ` Ramesh Thomas
2024-04-25 16:56 ` Gerd Bayer [this message]
2024-04-28 6:59 ` [PATCH v3 3/3] vfio/pci: Continue to refactor vfio_pci_core_do_io_rw Tian, Kevin
2024-04-29 16:32 ` Alex Williamson
2024-05-21 16:43 ` Gerd Bayer
2024-05-17 11:41 ` Ramesh Thomas
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