On 21/06/20 19:11 +0000, Parav Pandit wrote:
> Create a mlx5 bus driver framework for invoking drivers of
> multiple classes who have registered with the mlx5_pci bus
> driver.
>
> Validate user class arguments for supported class combinations.
>
> Signed-off-by: Parav Pandit <pa...@mellanox.com>
> ---
> Changelog:
> v1->v2:
> - Address comments from Thomas and Gaetan
> - Enhanced driver to honor RTE_PCI_DRV_PROBE_AGAIN drv_flag
> - Use anonymous structure for class search and code changes around it
> - Define static for class comination array
> - Use RTE_DIM to find array size
> - Added OOM check for strdup()
> - Renamed copy variable to nstr_orig
> - Returning negagive error code
> - Returning directly if match entry found
> - Use compat condition check
> - Avoided cutting error message string
> - USe uint32_t datatype instead of enum mlx5_class
> - Changed logic to parse device arguments only once during probe()
> - Added check to fail driver probe if multiple classes register with
> DMA ops
> - Renamed function to parse_class_options
> ---
> drivers/bus/mlx5_pci/Makefile | 2 +
> drivers/bus/mlx5_pci/meson.build | 2 +-
> drivers/bus/mlx5_pci/mlx5_pci_bus.c | 290 ++++++++++++++++++++++++
> drivers/bus/mlx5_pci/rte_bus_mlx5_pci.h | 1 +
> 4 files changed, 294 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bus/mlx5_pci/Makefile b/drivers/bus/mlx5_pci/Makefile
> index 7db977ba8..e53ed8856 100644
> --- a/drivers/bus/mlx5_pci/Makefile
> +++ b/drivers/bus/mlx5_pci/Makefile
> @@ -13,7 +13,9 @@ CFLAGS += $(WERROR_FLAGS)
> CFLAGS += -I$(RTE_SDK)/drivers/common/mlx5
> CFLAGS += -I$(BUILDDIR)/drivers/common/mlx5
> CFLAGS += -I$(RTE_SDK)/drivers/bus/pci
> +CFLAGS += -D_DEFAULT_SOURCE
> LDLIBS += -lrte_eal
> +LDLIBS += -lrte_kvargs
> LDLIBS += -lrte_common_mlx5
> LDLIBS += -lrte_pci -lrte_bus_pci
>
> diff --git a/drivers/bus/mlx5_pci/meson.build
> b/drivers/bus/mlx5_pci/meson.build
> index cc4a84e23..5111baa4e 100644
> --- a/drivers/bus/mlx5_pci/meson.build
> +++ b/drivers/bus/mlx5_pci/meson.build
> @@ -1,6 +1,6 @@
> # SPDX-License-Identifier: BSD-3-Clause
> # Copyright(c) 2020 Mellanox Technologies Ltd
>
> -deps += ['pci', 'bus_pci', 'common_mlx5']
> +deps += ['pci', 'bus_pci', 'common_mlx5', 'kvargs']
> install_headers('rte_bus_mlx5_pci.h')
> sources = files('mlx5_pci_bus.c')
> diff --git a/drivers/bus/mlx5_pci/mlx5_pci_bus.c
> b/drivers/bus/mlx5_pci/mlx5_pci_bus.c
> index 66db3c7b0..e8f1649a3 100644
> --- a/drivers/bus/mlx5_pci/mlx5_pci_bus.c
> +++ b/drivers/bus/mlx5_pci/mlx5_pci_bus.c
> @@ -3,12 +3,302 @@
> */
>
> #include "rte_bus_mlx5_pci.h"
> +#include <mlx5_common_utils.h>
>
> static TAILQ_HEAD(mlx5_pci_bus_drv_head, rte_mlx5_pci_driver) drv_list =
> TAILQ_HEAD_INITIALIZER(drv_list);
>
> +static const struct {
> + const char *name;
> + unsigned int dev_class;
Let me quote you when you refused to follow my comment:
>> Yes, I acked to changed to define, but I forgot that I use the enum here.
>> So I am going to keep the enum as code reads more clear with enum.
You refused to use a fixed-width integer type as per my past comments,
for readability reasons, but changed the type to "unsigned int" instead.
I insisted in the previous commit on uint32_t for exposed ABI (even if
between internal libs). Here I accept some leeway given the
compilation-unit scope of the definition. But at this point, your choice
is certainly *NOT* to use a vague type instead.
> +} mlx5_classes[] = {
mlx5_class_names.
> + { .name = "vdpa", .dev_class = MLX5_CLASS_VDPA },
> + { .name = "net", .dev_class = MLX5_CLASS_NET },
> +};
> +
> +static const unsigned int mlx5_valid_class_combo[] = {
> + MLX5_CLASS_NET,
> + MLX5_CLASS_VDPA,
> + /* New class combination should be added here */
This comment seems redundant, new class combo will be added wherever
appropriate, leave it to future dev.
> +};
> +
> +static int class_name_to_val(const char *class_name)
I think mlx5_class_from_name() is better.
(with mlx5_ namespace.)
> +{
> + unsigned int i;
In general, size_t is the type of array iterators in C.
> +
> + for (i = 0; i < RTE_DIM(mlx5_classes); i++) {
> + if (strcmp(class_name, mlx5_classes[i].name) == 0)
> + return mlx5_classes[i].dev_class;
> +
> + }
> + return -EINVAL;
You're mixing signed int and enum mlx5_class as return type.
Please find another way of signaling error that will make you keep the enum.
You have a sentinel value describing explicitly an invalid class, it seems
perfectly
suited instead of -EINVAL. Use it instead.
> +}
> +
> +static int
> +mlx5_bus_opt_handler(__rte_unused const char *key, const char *class_names,
> + void *opaque)
> +{
> + int *ret = opaque;
> + char *nstr_org;
> + int class_val;
> + char *found;
> + char *nstr;
> +
> + *ret = 0;
> + nstr = strdup(class_names);
> + if (!nstr) {
Please be explicit and use (nstr == NULL).
> + *ret = -ENOMEM;
> + return *ret;
> + }
> +
> + nstr_org = nstr;
nstr_orig is more readable.
> + while (nstr) {
while (nstr != NULL) {
> + /* Extract each individual class name */
> + found = strsep(&nstr, ":");
> + if (!found)
ditto
> + continue;
> +
> + /* Check if its a valid class */
> + class_val = class_name_to_val(found);
> + if (class_val < 0) {
if (class_val == MLX5_CLASS_INVALID),
with the proper API change.
> + *ret = -EINVAL;
> + goto err;
> + }
> +
> + *ret |= class_val;
Once again, mixing ints and enum mlx5_class.
You don't *have* to set *ret on error.
* Change your opaque out_arg to uint32_t, stop using variable width types for
bitmaps.
* Do not set it on error, use a tmp u32 for parsing and only set it once
everything is ok.
* rte_kvargs_process() will mask your error values anyway, so instead set
rte_errno and return -1.
On negative return, it will itself return -1. Check for < 0 in
bus_options_valid()
> + }
> +err:
> + free(nstr_org);
> + if (*ret < 0)
> + DRV_LOG(ERR, "Invalid mlx5 class options %s. Maybe typo in
> device class argument setting?",
Find a way to give the exact source of error. If it is an invalid name, show
which token failed to be parsed
(meaning move your error code before nstr_orig is freed). Remove the "Maybe"
formulation.
By the way, Thomas' comment was correct instead of mine, you should just cut
your format string after
the "%s.".
> + class_names);
> + return *ret;
> +}
> +
> +static int
> +parse_class_options(const struct rte_devargs *devargs)
> +{
> + const char *key = MLX5_CLASS_ARG_NAME;
> + struct rte_kvargs *kvlist;
> + int ret = 0;
> +
> + if (devargs == NULL)
> + return 0;
> + kvlist = rte_kvargs_parse(devargs->args, NULL);
> + if (kvlist == NULL)
> + return 0;
> + if (rte_kvargs_count(kvlist, key))
> + rte_kvargs_process(kvlist, key, mlx5_bus_opt_handler, &ret);
Set ret to rte_kvargs_process() return value instead, define a specific u32 for
bitmap.
Find a way to output the bitmap *separately* from the error code, or
set MLX5_CLASS_INVALID in the bitmap before returning it as sole return value
for this function.
(meaning having a proper bit value for MLX5_CLASS_INVALID, if you go this way.)
I already said it in previous review, I will reformulate: stop overloading your
types,
relying on implicit casts between correct and incorrect values, and merging
your returned values
and the error channel.
Please be proactive into cleaning up your APIs.
> + rte_kvargs_free(kvlist);
> + return ret;
> +}
> +
> void
> rte_mlx5_pci_driver_register(struct rte_mlx5_pci_driver *driver)
> {
> TAILQ_INSERT_TAIL(&drv_list, driver, next);
> }
> +
> +static bool
> +mlx5_bus_match(const struct rte_mlx5_pci_driver *drv,
> + const struct rte_pci_device *pci_dev)
> +{
> + const struct rte_pci_id *id_table;
> +
> + for (id_table = drv->pci_driver.id_table; id_table->vendor_id != 0;
> + id_table++) {
> + /* check if device's ids match the class driver's ones */
> + if (id_table->vendor_id != pci_dev->id.vendor_id &&
> + id_table->vendor_id != PCI_ANY_ID)
> + continue;
> + if (id_table->device_id != pci_dev->id.device_id &&
> + id_table->device_id != PCI_ANY_ID)
> + continue;
> + if (id_table->subsystem_vendor_id !=
> + pci_dev->id.subsystem_vendor_id &&
> + id_table->subsystem_vendor_id != PCI_ANY_ID)
> + continue;
> + if (id_table->subsystem_device_id !=
> + pci_dev->id.subsystem_device_id &&
> + id_table->subsystem_device_id != PCI_ANY_ID)
> + continue;
> + if (id_table->class_id != pci_dev->id.class_id &&
> + id_table->class_id != RTE_CLASS_ANY_ID)
> + continue;
> +
> + return true;
> + }
> + return false;
> +}
> +
> +static int is_valid_class_combo(uint32_t user_classes)
> +{
> + unsigned int i;
size_t
> +
> + /* Verify if user specified valid supported combination */
a valid combination.
> + for (i = 0; i < RTE_DIM(mlx5_valid_class_combo); i++) {
> + if (mlx5_valid_class_combo[i] == user_classes)
You simplified the scope of this function, which is good.
However, given the more limited scope, now it becomes a boolean
yes/no.
You are returning (0 | false) for yes, which is not ok.
reading if (is_valid_class_combo(combo)) { handle_error(combo); } is pretty
awkward.
While you're at it, you might want to use a proper bool instead.
> + return 0;
> + }
> + /* Not found any valid class combination */
> + return -EINVAL;
> +}
> +
> +static int validate_single_class_dma_ops(void)
> +{
> + struct rte_mlx5_pci_driver *class;
> + int dma_map_classes = 0;
> +
> + TAILQ_FOREACH(class, &drv_list, next) {
> + if (class->pci_driver.dma_map)
> + dma_map_classes++;
> + }
> + if (dma_map_classes > 1) {
> + DRV_LOG(ERR, "Multiple classes with DMA ops is unsupported");
> + return -EINVAL;
> + }
> + return 0;
> +}
> +
> +/**
> + * DPDK callback to register to probe multiple PCI class devices.
> + *
> + * @param[in] pci_drv
> + * PCI driver structure.
> + * @param[in] dev
> + * PCI device information.
> + *
> + * @return
> + * 0 on success, 1 to skip this driver, a negative errno value otherwise
> + * and rte_errno is set.
> + */
> +static int
> +mlx5_bus_pci_probe(struct rte_pci_driver *drv __rte_unused,
drv is not unused, you are passing it to sub-drivers below.
> + struct rte_pci_device *dev)
> +{
> + struct rte_mlx5_pci_driver *class;
This compilation unit targets a C compiler. I think only
headers should ensure compat with C++, but this name is not great still.
driver seems more appropriate anyway to designate a driver.
> + uint32_t user_classes = 0;
> + int ret;
> +
Mixing ret and user_classes as you do afterward is the result of the above API
issues
already outlined. I won't go over them again, please fix everything to have
proper
type discipline.
> + ret = validate_single_class_dma_ops();
> + if (ret)
> + return ret;
> +
> + ret = parse_class_options(dev->device.devargs);
> + if (ret < 0)
> + return ret;
> +
> + user_classes = ret;
> + if (user_classes) {
> + /* Validate combination here */
> + ret = is_valid_class_combo(user_classes);
> + if (ret) {
> + DRV_LOG(ERR, "Unsupported mlx5 classes supplied");
> + return ret;
> + }
> + }
> +
> + /* Default to net class */
> + if (user_classes == 0)
> + user_classes = MLX5_CLASS_NET;
> +
> + TAILQ_FOREACH(class, &drv_list, next) {
> + if (!mlx5_bus_match(class, dev))
> + continue;
> +
> + if ((class->dev_class & user_classes) == 0)
> + continue;
> +
> + ret = -EINVAL;
> + if (class->loaded) {
> + /* If already loaded and class driver can handle
> + * reprobe, probe such class driver again.
> + */
> + if (class->pci_driver.drv_flags &
> RTE_PCI_DRV_PROBE_AGAIN)
> + ret = class->pci_driver.probe(drv, dev);
Using "drv" here instead of "class" means you are overriding the DRV_FLAG set
by the
sub-driver.
Why not use "class" instead? dev->driver is setup by the upper layer, so will
be correctly set
to drv instead of class.
> + } else {
> + ret = class->pci_driver.probe(drv, dev);
> + }
You are ignoring probe() < 0 here, seems wrong.
> + if (!ret)
> + class->loaded = true;
loaded flag is not properly set.
You will set it on first successful probe, even on further errors.
Instead, use a u32 to mark each properly probed classes, then set loaded
outside of this loop,
only if this "probed" bitmap matches exactly the "user_classes" bitmap.
This means also not silently ignoring dev and class mismatch. If this is the
behavior you
explicitly want, then you will need to unset the mismatched class in the
user_classes, so that the
exact match on probed is correct. Otherwise, logging an error is more
appropriate.
> + }
> + return 0;
> +}
> +
> +/**
> + * DPDK callback to remove one or more class devices for a PCI device.
> + *
> + * This function removes all class devices belong to a given PCI device.
> + *
> + * @param[in] pci_dev
> + * Pointer to the PCI device.
> + *
> + * @return
> + * 0 on success, the function cannot fail.
> + */
> +static int
> +mlx5_bus_pci_remove(struct rte_pci_device *dev)
> +{
> + struct rte_mlx5_pci_driver *class;
> +
> + /* Remove each class driver in reverse order */
> + TAILQ_FOREACH_REVERSE(class, &drv_list, mlx5_pci_bus_drv_head, next) {
> + if (class->loaded)
> + class->pci_driver.remove(dev);
> + }
> + return 0;
> +}
> +
> +static int
> +mlx5_bus_pci_dma_map(struct rte_pci_device *dev, void *addr,
> + uint64_t iova, size_t len)
> +{
> + struct rte_mlx5_pci_driver *class;
> + int ret = -EINVAL;
> +
> + TAILQ_FOREACH(class, &drv_list, next) {
> + if (!class->pci_driver.dma_map)
> + continue;
> +
> + return class->pci_driver.dma_map(dev, addr, iova, len);
> + }
> + return ret;
> +}
> +
> +static int
> +mlx5_bus_pci_dma_unmap(struct rte_pci_device *dev, void *addr,
> + uint64_t iova, size_t len)
> +{
> + struct rte_mlx5_pci_driver *class;
> + int ret = -EINVAL;
> +
> + TAILQ_FOREACH_REVERSE(class, &drv_list, mlx5_pci_bus_drv_head, next) {
> + if (!class->pci_driver.dma_unmap)
> + continue;
> +
I see no additional logging about edge-cases that were discussed previously.
You can add them to the register function.
> + return class->pci_driver.dma_unmap(dev, addr, iova, len);
> + }
> + return ret;
> +}
> +
> +static const struct rte_pci_id mlx5_bus_pci_id_map[] = {
> + {
> + .vendor_id = 0
> + }
> +};
> +
> +static struct rte_pci_driver mlx5_bus_driver = {
> + .driver = {
> + .name = "mlx5_bus_pci",
> + },
> + .id_table = mlx5_bus_pci_id_map,
> + .probe = mlx5_bus_pci_probe,
> + .remove = mlx5_bus_pci_remove,
> + .dma_map = mlx5_bus_pci_dma_map,
> + .dma_unmap = mlx5_bus_pci_dma_unmap,
> + .drv_flags = RTE_PCI_DRV_INTR_LSC | RTE_PCI_DRV_INTR_RMV |
> + RTE_PCI_DRV_PROBE_AGAIN,
> +};
> +
> +RTE_PMD_REGISTER_PCI(mlx5_bus, mlx5_bus_driver);
> +RTE_PMD_REGISTER_PCI_TABLE(mlx5_bus, mlx5_bus_pci_id_map);
> diff --git a/drivers/bus/mlx5_pci/rte_bus_mlx5_pci.h
> b/drivers/bus/mlx5_pci/rte_bus_mlx5_pci.h
> index 571f7dfd6..c8cd7187b 100644
> --- a/drivers/bus/mlx5_pci/rte_bus_mlx5_pci.h
> +++ b/drivers/bus/mlx5_pci/rte_bus_mlx5_pci.h
> @@ -55,6 +55,7 @@ struct rte_mlx5_pci_driver {
> enum mlx5_class dev_class; /**< Class of this driver */
> struct rte_pci_driver pci_driver; /**< Inherit core pci driver. */
> TAILQ_ENTRY(rte_mlx5_pci_driver) next;
> + bool loaded;
> };
>
> /**
> --
> 2.25.4
>
--
Gaëtan
