From: Alex Williamson <alex.williamson@redhat.com> To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, alex.williamson@redhat.com, peterx@redhat.com, eric.auger@redhat.com, aik@ozlabs.ru Subject: [PATCH v2 2/3] vfio/pci: Use endian neutral helpers Date: Thu, 15 Mar 2018 15:31:51 -0600 [thread overview] Message-ID: <20180315213151.15150.70257.stgit@gimli.home> (raw) In-Reply-To: <20180315212634.15150.88094.stgit@gimli.home> The iowriteXX/ioreadXX functions assume little endian hardware and convert to little endian on a write and from little endian on a read. We currently do our own explicit conversion to negate this. Instead, add some endian dependent defines to avoid all byte swaps. There should be no functional change other than big endian systems aren't penalized with wasted swaps. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> --- drivers/vfio/pci/vfio_pci_rdwr.c | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c index 5f2b376dcebd..925419e0f459 100644 --- a/drivers/vfio/pci/vfio_pci_rdwr.c +++ b/drivers/vfio/pci/vfio_pci_rdwr.c @@ -21,6 +21,24 @@ #include "vfio_pci_private.h" +#ifdef __LITTLE_ENDIAN +#define vfio_ioread64 ioread64 +#define vfio_iowrite64 iowrite64 +#define vfio_ioread32 ioread32 +#define vfio_iowrite32 iowrite32 +#define vfio_ioread16 ioread16 +#define vfio_iowrite16 iowrite16 +#else +#define vfio_ioread64 ioread64be +#define vfio_iowrite64 iowrite64be +#define vfio_ioread32 ioread32be +#define vfio_iowrite32 iowrite32be +#define vfio_ioread16 ioread16be +#define vfio_iowrite16 iowrite16be +#endif +#define vfio_ioread8 ioread8 +#define vfio_iowrite8 iowrite8 + /* * 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 @@ -44,15 +62,15 @@ static ssize_t do_io_rw(void __iomem *io, char __user *buf, fillable = 0; if (fillable >= 4 && !(off % 4)) { - __le32 val; + u32 val; if (iswrite) { if (copy_from_user(&val, buf, 4)) return -EFAULT; - iowrite32(le32_to_cpu(val), io + off); + vfio_iowrite32(val, io + off); } else { - val = cpu_to_le32(ioread32(io + off)); + val = vfio_ioread32(io + off); if (copy_to_user(buf, &val, 4)) return -EFAULT; @@ -60,15 +78,15 @@ static ssize_t do_io_rw(void __iomem *io, char __user *buf, filled = 4; } else if (fillable >= 2 && !(off % 2)) { - __le16 val; + u16 val; if (iswrite) { if (copy_from_user(&val, buf, 2)) return -EFAULT; - iowrite16(le16_to_cpu(val), io + off); + vfio_iowrite16(val, io + off); } else { - val = cpu_to_le16(ioread16(io + off)); + val = vfio_ioread16(io + off); if (copy_to_user(buf, &val, 2)) return -EFAULT; @@ -82,9 +100,9 @@ static ssize_t do_io_rw(void __iomem *io, char __user *buf, if (copy_from_user(&val, buf, 1)) return -EFAULT; - iowrite8(val, io + off); + vfio_iowrite8(val, io + off); } else { - val = ioread8(io + off); + val = vfio_ioread8(io + off); if (copy_to_user(buf, &val, 1)) return -EFAULT;
WARNING: multiple messages have this Message-ID (diff)
From: Alex Williamson <alex.williamson@redhat.com> To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, alex.williamson@redhat.com, peterx@redhat.com, eric.auger@redhat.com, aik@ozlabs.ru Subject: [Qemu-devel] [PATCH v2 2/3] vfio/pci: Use endian neutral helpers Date: Thu, 15 Mar 2018 15:31:51 -0600 [thread overview] Message-ID: <20180315213151.15150.70257.stgit@gimli.home> (raw) In-Reply-To: <20180315212634.15150.88094.stgit@gimli.home> The iowriteXX/ioreadXX functions assume little endian hardware and convert to little endian on a write and from little endian on a read. We currently do our own explicit conversion to negate this. Instead, add some endian dependent defines to avoid all byte swaps. There should be no functional change other than big endian systems aren't penalized with wasted swaps. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> --- drivers/vfio/pci/vfio_pci_rdwr.c | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c index 5f2b376dcebd..925419e0f459 100644 --- a/drivers/vfio/pci/vfio_pci_rdwr.c +++ b/drivers/vfio/pci/vfio_pci_rdwr.c @@ -21,6 +21,24 @@ #include "vfio_pci_private.h" +#ifdef __LITTLE_ENDIAN +#define vfio_ioread64 ioread64 +#define vfio_iowrite64 iowrite64 +#define vfio_ioread32 ioread32 +#define vfio_iowrite32 iowrite32 +#define vfio_ioread16 ioread16 +#define vfio_iowrite16 iowrite16 +#else +#define vfio_ioread64 ioread64be +#define vfio_iowrite64 iowrite64be +#define vfio_ioread32 ioread32be +#define vfio_iowrite32 iowrite32be +#define vfio_ioread16 ioread16be +#define vfio_iowrite16 iowrite16be +#endif +#define vfio_ioread8 ioread8 +#define vfio_iowrite8 iowrite8 + /* * 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 @@ -44,15 +62,15 @@ static ssize_t do_io_rw(void __iomem *io, char __user *buf, fillable = 0; if (fillable >= 4 && !(off % 4)) { - __le32 val; + u32 val; if (iswrite) { if (copy_from_user(&val, buf, 4)) return -EFAULT; - iowrite32(le32_to_cpu(val), io + off); + vfio_iowrite32(val, io + off); } else { - val = cpu_to_le32(ioread32(io + off)); + val = vfio_ioread32(io + off); if (copy_to_user(buf, &val, 4)) return -EFAULT; @@ -60,15 +78,15 @@ static ssize_t do_io_rw(void __iomem *io, char __user *buf, filled = 4; } else if (fillable >= 2 && !(off % 2)) { - __le16 val; + u16 val; if (iswrite) { if (copy_from_user(&val, buf, 2)) return -EFAULT; - iowrite16(le16_to_cpu(val), io + off); + vfio_iowrite16(val, io + off); } else { - val = cpu_to_le16(ioread16(io + off)); + val = vfio_ioread16(io + off); if (copy_to_user(buf, &val, 2)) return -EFAULT; @@ -82,9 +100,9 @@ static ssize_t do_io_rw(void __iomem *io, char __user *buf, if (copy_from_user(&val, buf, 1)) return -EFAULT; - iowrite8(val, io + off); + vfio_iowrite8(val, io + off); } else { - val = ioread8(io + off); + val = vfio_ioread8(io + off); if (copy_to_user(buf, &val, 1)) return -EFAULT;
next prev parent reply other threads:[~2018-03-15 21:31 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-03-15 21:31 [PATCH v2 0/3] vfio/pci: ioeventfd support Alex Williamson 2018-03-15 21:31 ` [Qemu-devel] " Alex Williamson 2018-03-15 21:31 ` [PATCH v2 1/3] vfio/pci: Pull BAR mapping setup from read-write path Alex Williamson 2018-03-15 21:31 ` [Qemu-devel] " Alex Williamson 2018-03-15 21:31 ` Alex Williamson [this message] 2018-03-15 21:31 ` [Qemu-devel] [PATCH v2 2/3] vfio/pci: Use endian neutral helpers Alex Williamson 2018-03-15 21:31 ` [PATCH v2 3/3] vfio/pci: Add ioeventfd support Alex Williamson 2018-03-15 21:31 ` [Qemu-devel] " Alex Williamson 2018-03-16 4:40 ` Peter Xu 2018-03-16 4:40 ` [Qemu-devel] " Peter Xu 2018-03-19 9:09 ` [PATCH v2 0/3] vfio/pci: " Alexey Kardashevskiy 2018-03-19 9:09 ` [Qemu-devel] " Alexey Kardashevskiy
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