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authorArnaldo Carvalho de Melo <acme@redhat.com>2020-08-06 14:15:47 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2020-08-06 14:15:47 +0300
commit94fb1afb14c4f0ceb8c5508ddddac6819f662e95 (patch)
tree4988e5769dc7482caa7f441475ae31f50bbd37ef /arch/s390/pci/pci_mmio.c
parentc4735d990268399da9133b0ad445e488ece009ad (diff)
parent47ec5303d73ea344e84f46660fff693c57641386 (diff)
downloadlinux-94fb1afb14c4f0ceb8c5508ddddac6819f662e95.tar.xz
Mgerge remote-tracking branch 'torvalds/master' into perf/core
To sync headers, for instance, in this case tools/perf was ahead of upstream till Linus merged tip/perf/core to get the PERF_RECORD_TEXT_POKE changes: Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs from latest version at 'include/uapi/linux/perf_event.h' diff -u tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'arch/s390/pci/pci_mmio.c')
-rw-r--r--arch/s390/pci/pci_mmio.c20
1 files changed, 12 insertions, 8 deletions
diff --git a/arch/s390/pci/pci_mmio.c b/arch/s390/pci/pci_mmio.c
index 38efa3e852c4..401cf670a243 100644
--- a/arch/s390/pci/pci_mmio.c
+++ b/arch/s390/pci/pci_mmio.c
@@ -155,10 +155,12 @@ SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,
return -EINVAL;
/*
- * Only support read access to MIO capable devices on a MIO enabled
- * system. Otherwise we would have to check for every address if it is
- * a special ZPCI_ADDR and we would have to do a get_pfn() which we
- * don't need for MIO capable devices.
+ * We only support write access to MIO capable devices if we are on
+ * a MIO enabled system. Otherwise we would have to check for every
+ * address if it is a special ZPCI_ADDR and would have to do
+ * a get_pfn() which we don't need for MIO capable devices. Currently
+ * ISM devices are the only devices without MIO support and there is no
+ * known need for accessing these from userspace.
*/
if (static_branch_likely(&have_mio)) {
ret = __memcpy_toio_inuser((void __iomem *) mmio_addr,
@@ -282,10 +284,12 @@ SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr,
return -EINVAL;
/*
- * Only support write access to MIO capable devices on a MIO enabled
- * system. Otherwise we would have to check for every address if it is
- * a special ZPCI_ADDR and we would have to do a get_pfn() which we
- * don't need for MIO capable devices.
+ * We only support read access to MIO capable devices if we are on
+ * a MIO enabled system. Otherwise we would have to check for every
+ * address if it is a special ZPCI_ADDR and would have to do
+ * a get_pfn() which we don't need for MIO capable devices. Currently
+ * ISM devices are the only devices without MIO support and there is no
+ * known need for accessing these from userspace.
*/
if (static_branch_likely(&have_mio)) {
ret = __memcpy_fromio_inuser(