Add support for changing devices alignment. On kernels that do not support per-device align sysfs property we set it to 0. Signed-off-by: Joao Martins <joao.m.martins(a)oracle.com&gt; --- daxctl/lib/libdaxctl-private.h | 1 + daxctl/lib/libdaxctl.c | 36 ++++++++++++++++++++++++++++++++++++ daxctl/lib/libdaxctl.sym | 2 ++ daxctl/libdaxctl.h | 2 ++ 4 files changed, 41 insertions(+) diff --git a/daxctl/lib/libdaxctl-private.h b/daxctl/lib/libdaxctl-private.h index 9f9c70d6024f..b307a8bc9438 100644 --- a/daxctl/lib/libdaxctl-private.h +++ b/daxctl/lib/libdaxctl-private.h @@ -99,6 +99,7 @@ struct daxctl_dev { struct list_node list; unsigned long long resource; unsigned long long size; + unsigned long align; struct kmod_module *module; struct daxctl_region *region; struct daxctl_memory *mem; diff --git a/daxctl/lib/libdaxctl.c b/daxctl/lib/libdaxctl.c index 9b43b68facfe..39871427c799 100644 --- a/daxctl/lib/libdaxctl.c +++ b/daxctl/lib/libdaxctl.c @@ -498,6 +498,13 @@ static void *add_dax_dev(void *parent, int id, const char *daxdev_base) goto err_read; dev->size = strtoull(buf, NULL, 0); + /* Device align attribute is only available in v5.10 or up */ + sprintf(path, "%s/align", daxdev_base); + if (!sysfs_read_attr(ctx, path, buf)) + dev->align = strtoull(buf, NULL, 0); + else + dev->align = 0; + dev->dev_path = strdup(daxdev_base); if (!dev->dev_path) goto err_read; @@ -1086,6 +1093,35 @@ DAXCTL_EXPORT int daxctl_dev_set_size(struct daxctl_dev *dev, unsigned long long return 0; } +DAXCTL_EXPORT unsigned long daxctl_dev_get_align(struct daxctl_dev *dev) +{ + return dev->align; +} + +DAXCTL_EXPORT int daxctl_dev_set_align(struct daxctl_dev *dev, unsigned long align) +{ + struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev); + char buf[SYSFS_ATTR_SIZE]; + char *path = dev->dev_buf; + int len = dev->buf_len; + + if (snprintf(path, len, "%s/align", dev->dev_path) >= len) { + err(ctx, "%s: buffer too small!\n", + daxctl_dev_get_devname(dev)); + return -ENXIO; + } + + sprintf(buf, "%#lx\n", align); + if (sysfs_write_attr(ctx, path, buf) < 0) { + err(ctx, "%s: failed to set align\n", + daxctl_dev_get_devname(dev)); + return -ENXIO; + } + + dev->align = align; + return 0; +} + DAXCTL_EXPORT int daxctl_dev_get_target_node(struct daxctl_dev *dev) { return dev->target_node; diff --git a/daxctl/lib/libdaxctl.sym b/daxctl/lib/libdaxctl.sym index 33c926411037..c3d08179c9fd 100644 --- a/daxctl/lib/libdaxctl.sym +++ b/daxctl/lib/libdaxctl.sym @@ -81,4 +81,6 @@ global: daxctl_dev_set_size; daxctl_region_create_dev; daxctl_region_destroy_dev; + daxctl_dev_get_align; + daxctl_dev_set_align; } LIBDAXCTL_7; diff --git a/daxctl/libdaxctl.h b/daxctl/libdaxctl.h index 2b14faad1895..b0bb5d78d357 100644 --- a/daxctl/libdaxctl.h +++ b/daxctl/libdaxctl.h @@ -71,6 +71,8 @@ int daxctl_dev_get_minor(struct daxctl_dev *dev); unsigned long long daxctl_dev_get_resource(struct daxctl_dev *dev); unsigned long long daxctl_dev_get_size(struct daxctl_dev *dev); int daxctl_dev_set_size(struct daxctl_dev *dev, unsigned long long size); +unsigned long daxctl_dev_get_align(struct daxctl_dev *dev); +int daxctl_dev_set_align(struct daxctl_dev *dev, unsigned long align); struct daxctl_ctx *daxctl_dev_get_ctx(struct daxctl_dev *dev); int daxctl_dev_is_enabled(struct daxctl_dev *dev); int daxctl_dev_disable(struct daxctl_dev *dev); -- 1.8.3.1

Add an alignment option to reconfigure-device and use the newly added libdaxctl API to set the alignment of the device prior to setting size. Signed-off-by: Joao Martins <joao.m.martins(a)oracle.com&gt; --- Documentation/daxctl/daxctl-reconfigure-device.txt | 12 +++++++++++ daxctl/device.c | 24 +++++++++++++++++----- 2 files changed, 31 insertions(+), 5 deletions(-) diff --git a/Documentation/daxctl/daxctl-reconfigure-device.txt b/Documentation/daxctl/daxctl-reconfigure-device.txt index 8caae436faae..272d5d80222d 100644 --- a/Documentation/daxctl/daxctl-reconfigure-device.txt +++ b/Documentation/daxctl/daxctl-reconfigure-device.txt @@ -136,6 +136,18 @@ OPTIONS The size must be a multiple of the region alignment. + This option is mutually exclusive with -m or --mode. + +-a:: +--align:: + Applications that want to establish dax memory mappings with + page table entries greater than system base page size (4K on + x86) need a device that is sufficiently aligned. This defaults + to 2M. Note that "devdax" mode enforces all mappings to be + aligned to this value, i.e. it fails unaligned mapping attempts. + + This option is mutually exclusive with -m or --mode. + -m:: --mode=:: Specify the mode to which the dax device(s) should be reconfigured. diff --git a/daxctl/device.c b/daxctl/device.c index 05293d6c38ee..a5394577908d 100644 --- a/daxctl/device.c +++ b/daxctl/device.c @@ -22,6 +22,7 @@ static struct { const char *mode; const char *region; const char *size; + const char *align; bool no_online; bool no_movable; bool force; @@ -36,6 +37,7 @@ enum dev_mode { }; static enum dev_mode reconfig_mode = DAXCTL_DEV_MODE_UNKNOWN; +static long long align = -1; static long long size = -1; static unsigned long flags; @@ -68,7 +70,8 @@ OPT_BOOLEAN('f', "force", &param.force, \ "attempt to offline memory sections before reconfiguration") #define CREATE_OPTIONS() \ -OPT_STRING('s', "size", &param.size, "size", "size to switch the device to") +OPT_STRING('s', "size", &param.size, "size", "size to switch the device to"), \ +OPT_STRING('a', "align", &param.align, "align", "alignment to switch the device to") #define DESTROY_OPTIONS() \ OPT_BOOLEAN('f', "force", &param.force, \ @@ -185,13 +188,18 @@ static const char *parse_device_options(int argc, const char **argv, /* Handle action-specific options */ switch (action) { case ACTION_RECONFIG: - if (!param.size && !param.mode) { - fprintf(stderr, "error: a 'mode' or 'size' option is required\n"); + if (!param.size && + !param.align && + !param.mode) { + fprintf(stderr, "error: a 'align', 'mode' or 'size' option is required\n"); usage_with_options(u, reconfig_options); rc = -EINVAL; } - if (param.size) { - size = __parse_size64(param.size, &units); + if (param.size || param.align) { + if (param.size) + size = __parse_size64(param.size, &units); + if (param.align) + align = __parse_size64(param.align, &units); } else if (strcmp(param.mode, "system-ram") == 0) { reconfig_mode = DAXCTL_DEV_MODE_RAM; if (param.no_movable) @@ -558,6 +566,12 @@ static int do_reconfig(struct daxctl_dev *dev, enum dev_mode mode, struct json_object *jdev; int rc = 0; + if (align > 0) { + rc = daxctl_dev_set_align(dev, align); + if (rc < 0) + return rc; + } + if (size >= 0) { rc = dev_resize(dev, size); return rc; -- 1.8.3.1

Add a test which uses the newly added --align property which allows a device created with daxctl create-device to select its page size. If the available size is bigger than 1G then use 1G as page size, otherwise use 2M. Signed-off-by: Joao Martins <joao.m.martins(a)oracle.com&gt; --- test/daxctl-create.sh | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/test/daxctl-create.sh b/test/daxctl-create.sh index 0d35112b4119..5598e5a89aaf 100755 --- a/test/daxctl-create.sh +++ b/test/daxctl-create.sh @@ -281,6 +281,34 @@ daxctl_test5() test_pass } +# Test 6: align +# Successfully creates a device with a align property +daxctl_test6() +{ + local daxdev + local align + local size + + # Available size + size=$available + + # Use 2M by default or 1G if supported + align=2097152 + if [[ $((available >= 1073741824 )) ]]; then + align=1073741824 + size=$align + fi + + daxdev=$("$DAXCTL" create-device -r 0 -s $size -a $align | jq -er '.[].chardev') + + test -n "$daxdev" + + "$DAXCTL" disable-device "$daxdev" && "$DAXCTL" destroy-device "$daxdev" + + clear_dev + test_pass +} + find_testdev rc=1 setup_dev @@ -290,5 +318,6 @@ daxctl_test2 daxctl_test3 daxctl_test4 daxctl_test5 +daxctl_test6 reset_dev exit 0 -- 1.8.3.1