[net-next,v6,1/3] net: phy: extend PHY package API to support multiple global address
Commit Message
Current API for PHY package are limited to single address to configure
global settings for the PHY package.
It was found that some PHY package (for example the qca807x, a PHY
package that is shipped with a bundle of 5 PHY) requires multiple PHY
address to configure global settings. An example scenario is a PHY that
have a dedicated PHY for PSGMII/serdes calibrarion and have a specific
PHY in the package where the global PHY mode is set and affects every
other PHY in the package.
Change the API in the following way:
- Change phy_package_join() to take the base addr of the PHY package
instead of the global PHY addr.
- Make __/phy_package_write/read() require an additional arg that
select what global PHY address to use by passing the offset from the
base addr passed on phy_package_join().
Each user of this API is updated to follow this new implementation
following a pattern where an enum is defined to declare the offset of the
addr.
We also drop the check if shared is defined as any user of the
phy_package_read/write is expected to use phy_package_join first. Misuse
of this will correctly trigger a kernel panic for NULL pointer
exception.
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
Changes v2:
- Make kernel panic if shared is not init (bugged scenario)
- Fix some confusing comments
drivers/net/phy/bcm54140.c | 16 +++++++++----
drivers/net/phy/mscc/mscc.h | 5 ++++
drivers/net/phy/mscc/mscc_main.c | 4 ++--
drivers/net/phy/phy_device.c | 35 ++++++++++++++-------------
include/linux/phy.h | 41 +++++++++++++++++++-------------
5 files changed, 63 insertions(+), 38 deletions(-)
Comments
On Wed, Dec 13, 2023 at 11:57:28AM +0100, Christian Marangi wrote:
> -static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
> +static inline int phy_package_read(struct phy_device *phydev,
> + unsigned int addr_offset, u32 regnum)
> {
> struct phy_package_shared *shared = phydev->shared;
> + int addr = shared->base_addr + addr_offset;
>
> - if (!shared)
> + if (addr >= PHY_MAX_ADDR)
> return -EIO;
If we're going to check the address, I think we should check it
properly, which means also checking whether it's become negative.
Alternatively, we could consider making "addr" and "base_addr"
unsigned types, since they should never be negative. However,
that probably should be done as a separate patch before this one.
Thanks.
On Wed, Dec 13, 2023 at 03:45:24PM +0000, Russell King (Oracle) wrote:
> On Wed, Dec 13, 2023 at 11:57:28AM +0100, Christian Marangi wrote:
> > -static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
> > +static inline int phy_package_read(struct phy_device *phydev,
> > + unsigned int addr_offset, u32 regnum)
> > {
> > struct phy_package_shared *shared = phydev->shared;
> > + int addr = shared->base_addr + addr_offset;
> >
> > - if (!shared)
> > + if (addr >= PHY_MAX_ADDR)
> > return -EIO;
>
> If we're going to check the address, I think we should check it
> properly, which means also checking whether it's become negative.
>
> Alternatively, we could consider making "addr" and "base_addr"
> unsigned types, since they should never be negative. However,
> that probably should be done as a separate patch before this one.
>
Maybe I'm confused but isn't already like that?
On phy_package_join base_addr is already checked if it's negative (and
rejected)
addr_offset is unsigned so it can't be negative.
We can switch addr to unsigned just for the sake of it but if I'm not
wrong all the sanity check are already done.
On Wed, Dec 13, 2023 at 04:50:33PM +0100, Christian Marangi wrote:
> On Wed, Dec 13, 2023 at 03:45:24PM +0000, Russell King (Oracle) wrote:
> > On Wed, Dec 13, 2023 at 11:57:28AM +0100, Christian Marangi wrote:
> > > -static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
> > > +static inline int phy_package_read(struct phy_device *phydev,
> > > + unsigned int addr_offset, u32 regnum)
> > > {
> > > struct phy_package_shared *shared = phydev->shared;
> > > + int addr = shared->base_addr + addr_offset;
> > >
> > > - if (!shared)
> > > + if (addr >= PHY_MAX_ADDR)
> > > return -EIO;
> >
> > If we're going to check the address, I think we should check it
> > properly, which means also checking whether it's become negative.
> >
> > Alternatively, we could consider making "addr" and "base_addr"
> > unsigned types, since they should never be negative. However,
> > that probably should be done as a separate patch before this one.
> >
>
> Maybe I'm confused but isn't already like that?
> On phy_package_join base_addr is already checked if it's negative (and
> rejected)
>
> addr_offset is unsigned so it can't be negative.
True, but with base_addr being an int, addr_offset being unsigned int,
and addr being an int, if addr_offset is a very large number,
2-complement arithmetic will have the effect of treating it as a
negative number.
So, base_addr=0, addr_offset=~0 results in addr being -1.
If "addr" were unsigned int, and as we've already established,
"base_addr" can't be less than zero because of the checks already done
(thus it can also be unsigned int) then we'll end up with the checks
you're adding automatically doing the right thing, because...
base_addr=0, addr_offset=~0 results in addr being ~0 (a large
positive unsigned number).
On Wed, Dec 13, 2023 at 04:12:24PM +0000, Russell King (Oracle) wrote:
> On Wed, Dec 13, 2023 at 04:50:33PM +0100, Christian Marangi wrote:
> > On Wed, Dec 13, 2023 at 03:45:24PM +0000, Russell King (Oracle) wrote:
> > > On Wed, Dec 13, 2023 at 11:57:28AM +0100, Christian Marangi wrote:
> > > > -static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
> > > > +static inline int phy_package_read(struct phy_device *phydev,
> > > > + unsigned int addr_offset, u32 regnum)
> > > > {
> > > > struct phy_package_shared *shared = phydev->shared;
> > > > + int addr = shared->base_addr + addr_offset;
> > > >
> > > > - if (!shared)
> > > > + if (addr >= PHY_MAX_ADDR)
> > > > return -EIO;
> > >
> > > If we're going to check the address, I think we should check it
> > > properly, which means also checking whether it's become negative.
> > >
> > > Alternatively, we could consider making "addr" and "base_addr"
> > > unsigned types, since they should never be negative. However,
> > > that probably should be done as a separate patch before this one.
> > >
> >
> > Maybe I'm confused but isn't already like that?
> > On phy_package_join base_addr is already checked if it's negative (and
> > rejected)
> >
> > addr_offset is unsigned so it can't be negative.
>
> True, but with base_addr being an int, addr_offset being unsigned int,
> and addr being an int, if addr_offset is a very large number,
> 2-complement arithmetic will have the effect of treating it as a
> negative number.
>
> So, base_addr=0, addr_offset=~0 results in addr being -1.
>
> If "addr" were unsigned int, and as we've already established,
> "base_addr" can't be less than zero because of the checks already done
> (thus it can also be unsigned int) then we'll end up with the checks
> you're adding automatically doing the right thing, because...
>
> base_addr=0, addr_offset=~0 results in addr being ~0 (a large
> positive unsigned number).
>
Oh ok... now it makes sense. So I guess I should change "addr" to
unsigned.
Considering I'm changing addr in phy_package_shared to base_addr would
it be ok to change that also to unsigned (doesn't make sense to have
that int) in this patch? Or should I create first a small patch before
this to change addr type?
On Wed, Dec 13, 2023 at 05:24:18PM +0100, Christian Marangi wrote:
> On Wed, Dec 13, 2023 at 04:12:24PM +0000, Russell King (Oracle) wrote:
> > On Wed, Dec 13, 2023 at 04:50:33PM +0100, Christian Marangi wrote:
> > > On Wed, Dec 13, 2023 at 03:45:24PM +0000, Russell King (Oracle) wrote:
> > > > On Wed, Dec 13, 2023 at 11:57:28AM +0100, Christian Marangi wrote:
> > > > > -static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
> > > > > +static inline int phy_package_read(struct phy_device *phydev,
> > > > > + unsigned int addr_offset, u32 regnum)
> > > > > {
> > > > > struct phy_package_shared *shared = phydev->shared;
> > > > > + int addr = shared->base_addr + addr_offset;
> > > > >
> > > > > - if (!shared)
> > > > > + if (addr >= PHY_MAX_ADDR)
> > > > > return -EIO;
> > > >
> > > > If we're going to check the address, I think we should check it
> > > > properly, which means also checking whether it's become negative.
> > > >
> > > > Alternatively, we could consider making "addr" and "base_addr"
> > > > unsigned types, since they should never be negative. However,
> > > > that probably should be done as a separate patch before this one.
> > > >
> > >
> > > Maybe I'm confused but isn't already like that?
> > > On phy_package_join base_addr is already checked if it's negative (and
> > > rejected)
> > >
> > > addr_offset is unsigned so it can't be negative.
> >
> > True, but with base_addr being an int, addr_offset being unsigned int,
> > and addr being an int, if addr_offset is a very large number,
> > 2-complement arithmetic will have the effect of treating it as a
> > negative number.
> >
> > So, base_addr=0, addr_offset=~0 results in addr being -1.
> >
> > If "addr" were unsigned int, and as we've already established,
> > "base_addr" can't be less than zero because of the checks already done
> > (thus it can also be unsigned int) then we'll end up with the checks
> > you're adding automatically doing the right thing, because...
> >
> > base_addr=0, addr_offset=~0 results in addr being ~0 (a large
> > positive unsigned number).
> >
>
> Oh ok... now it makes sense. So I guess I should change "addr" to
> unsigned.
>
> Considering I'm changing addr in phy_package_shared to base_addr would
> it be ok to change that also to unsigned (doesn't make sense to have
> that int) in this patch? Or should I create first a small patch before
> this to change addr type?
What I said when I mooted the use of unsigned was:
"Alternatively, we could consider making "addr" and "base_addr"
unsigned types, since they should never be negative. However,
that probably should be done as a separate patch before this
one."
so my thoughts are that it should be a separate small patch - it's a
single logical change.
Thanks.
@@ -128,6 +128,10 @@
#define BCM54140_DEFAULT_DOWNSHIFT 5
#define BCM54140_MAX_DOWNSHIFT 9
+enum bcm54140_global_phy {
+ BCM54140_BASE_ADDR = 0,
+};
+
struct bcm54140_priv {
int port;
int base_addr;
@@ -429,11 +433,13 @@ static int bcm54140_base_read_rdb(struct phy_device *phydev, u16 rdb)
int ret;
phy_lock_mdio_bus(phydev);
- ret = __phy_package_write(phydev, MII_BCM54XX_RDB_ADDR, rdb);
+ ret = __phy_package_write(phydev, BCM54140_BASE_ADDR,
+ MII_BCM54XX_RDB_ADDR, rdb);
if (ret < 0)
goto out;
- ret = __phy_package_read(phydev, MII_BCM54XX_RDB_DATA);
+ ret = __phy_package_read(phydev, BCM54140_BASE_ADDR,
+ MII_BCM54XX_RDB_DATA);
out:
phy_unlock_mdio_bus(phydev);
@@ -446,11 +452,13 @@ static int bcm54140_base_write_rdb(struct phy_device *phydev,
int ret;
phy_lock_mdio_bus(phydev);
- ret = __phy_package_write(phydev, MII_BCM54XX_RDB_ADDR, rdb);
+ ret = __phy_package_write(phydev, BCM54140_BASE_ADDR,
+ MII_BCM54XX_RDB_ADDR, rdb);
if (ret < 0)
goto out;
- ret = __phy_package_write(phydev, MII_BCM54XX_RDB_DATA, val);
+ ret = __phy_package_write(phydev, BCM54140_BASE_ADDR,
+ MII_BCM54XX_RDB_DATA, val);
out:
phy_unlock_mdio_bus(phydev);
@@ -416,6 +416,11 @@ struct vsc8531_private {
* gpio_lock: used for PHC operations. Common for all PHYs as the load/save GPIO
* is shared.
*/
+
+enum vsc85xx_global_phy {
+ VSC88XX_BASE_ADDR = 0,
+};
+
struct vsc85xx_shared_private {
struct mutex gpio_lock;
};
@@ -711,7 +711,7 @@ int phy_base_write(struct phy_device *phydev, u32 regnum, u16 val)
dump_stack();
}
- return __phy_package_write(phydev, regnum, val);
+ return __phy_package_write(phydev, VSC88XX_BASE_ADDR, regnum, val);
}
/* phydev->bus->mdio_lock should be locked when using this function */
@@ -722,7 +722,7 @@ int phy_base_read(struct phy_device *phydev, u32 regnum)
dump_stack();
}
- return __phy_package_read(phydev, regnum);
+ return __phy_package_read(phydev, VSC88XX_BASE_ADDR, regnum);
}
u32 vsc85xx_csr_read(struct phy_device *phydev,
@@ -1648,20 +1648,22 @@ EXPORT_SYMBOL_GPL(phy_driver_is_genphy_10g);
/**
* phy_package_join - join a common PHY group
* @phydev: target phy_device struct
- * @addr: cookie and PHY address for global register access
+ * @base_addr: cookie and base PHY address of PHY package for offset
+ * calculation of global register access
* @priv_size: if non-zero allocate this amount of bytes for private data
*
* This joins a PHY group and provides a shared storage for all phydevs in
* this group. This is intended to be used for packages which contain
* more than one PHY, for example a quad PHY transceiver.
*
- * The addr parameter serves as a cookie which has to have the same value
- * for all members of one group and as a PHY address to access generic
- * registers of a PHY package. Usually, one of the PHY addresses of the
- * different PHYs in the package provides access to these global registers.
+ * The base_addr parameter serves as cookie which has to have the same values
+ * for all members of one group and as the base PHY address of the PHY package
+ * for offset calculation to access generic registers of a PHY package.
+ * Usually, one of the PHY addresses of the different PHYs in the package
+ * provides access to these global registers.
* The address which is given here, will be used in the phy_package_read()
- * and phy_package_write() convenience functions. If your PHY doesn't have
- * global registers you can just pick any of the PHY addresses.
+ * and phy_package_write() convenience functions as base and added to the
+ * passed offset in those functions.
*
* This will set the shared pointer of the phydev to the shared storage.
* If this is the first call for a this cookie the shared storage will be
@@ -1671,17 +1673,17 @@ EXPORT_SYMBOL_GPL(phy_driver_is_genphy_10g);
* Returns < 1 on error, 0 on success. Esp. calling phy_package_join()
* with the same cookie but a different priv_size is an error.
*/
-int phy_package_join(struct phy_device *phydev, int addr, size_t priv_size)
+int phy_package_join(struct phy_device *phydev, int base_addr, size_t priv_size)
{
struct mii_bus *bus = phydev->mdio.bus;
struct phy_package_shared *shared;
int ret;
- if (addr < 0 || addr >= PHY_MAX_ADDR)
+ if (base_addr < 0 || base_addr >= PHY_MAX_ADDR)
return -EINVAL;
mutex_lock(&bus->shared_lock);
- shared = bus->shared[addr];
+ shared = bus->shared[base_addr];
if (!shared) {
ret = -ENOMEM;
shared = kzalloc(sizeof(*shared), GFP_KERNEL);
@@ -1693,9 +1695,9 @@ int phy_package_join(struct phy_device *phydev, int addr, size_t priv_size)
goto err_free;
shared->priv_size = priv_size;
}
- shared->addr = addr;
+ shared->base_addr = base_addr;
refcount_set(&shared->refcnt, 1);
- bus->shared[addr] = shared;
+ bus->shared[base_addr] = shared;
} else {
ret = -EINVAL;
if (priv_size && priv_size != shared->priv_size)
@@ -1733,7 +1735,7 @@ void phy_package_leave(struct phy_device *phydev)
return;
if (refcount_dec_and_mutex_lock(&shared->refcnt, &bus->shared_lock)) {
- bus->shared[shared->addr] = NULL;
+ bus->shared[shared->base_addr] = NULL;
mutex_unlock(&bus->shared_lock);
kfree(shared->priv);
kfree(shared);
@@ -1752,7 +1754,8 @@ static void devm_phy_package_leave(struct device *dev, void *res)
* devm_phy_package_join - resource managed phy_package_join()
* @dev: device that is registering this PHY package
* @phydev: target phy_device struct
- * @addr: cookie and PHY address for global register access
+ * @base_addr: cookie and base PHY address of PHY package for offset
+ * calculation of global register access
* @priv_size: if non-zero allocate this amount of bytes for private data
*
* Managed phy_package_join(). Shared storage fetched by this function,
@@ -1760,7 +1763,7 @@ static void devm_phy_package_leave(struct device *dev, void *res)
* phy_package_join() for more information.
*/
int devm_phy_package_join(struct device *dev, struct phy_device *phydev,
- int addr, size_t priv_size)
+ int base_addr, size_t priv_size)
{
struct phy_device **ptr;
int ret;
@@ -1770,7 +1773,7 @@ int devm_phy_package_join(struct device *dev, struct phy_device *phydev,
if (!ptr)
return -ENOMEM;
- ret = phy_package_join(phydev, addr, priv_size);
+ ret = phy_package_join(phydev, base_addr, priv_size);
if (!ret) {
*ptr = phydev;
@@ -327,7 +327,8 @@ struct mdio_bus_stats {
/**
* struct phy_package_shared - Shared information in PHY packages
- * @addr: Common PHY address used to combine PHYs in one package
+ * @base_addr: Base PHY address of PHY package used to combine PHYs
+ * in one package and for offset calculation of phy_package_read/write
* @refcnt: Number of PHYs connected to this shared data
* @flags: Initialization of PHY package
* @priv_size: Size of the shared private data @priv
@@ -338,7 +339,7 @@ struct mdio_bus_stats {
* phy_package_leave().
*/
struct phy_package_shared {
- int addr;
+ int base_addr;
refcount_t refcnt;
unsigned long flags;
size_t priv_size;
@@ -1972,10 +1973,10 @@ int phy_ethtool_get_link_ksettings(struct net_device *ndev,
int phy_ethtool_set_link_ksettings(struct net_device *ndev,
const struct ethtool_link_ksettings *cmd);
int phy_ethtool_nway_reset(struct net_device *ndev);
-int phy_package_join(struct phy_device *phydev, int addr, size_t priv_size);
+int phy_package_join(struct phy_device *phydev, int base_addr, size_t priv_size);
void phy_package_leave(struct phy_device *phydev);
int devm_phy_package_join(struct device *dev, struct phy_device *phydev,
- int addr, size_t priv_size);
+ int base_addr, size_t priv_size);
int __init mdio_bus_init(void);
void mdio_bus_exit(void);
@@ -1998,46 +1999,54 @@ int __phy_hwtstamp_set(struct phy_device *phydev,
struct kernel_hwtstamp_config *config,
struct netlink_ext_ack *extack);
-static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
+static inline int phy_package_read(struct phy_device *phydev,
+ unsigned int addr_offset, u32 regnum)
{
struct phy_package_shared *shared = phydev->shared;
+ int addr = shared->base_addr + addr_offset;
- if (!shared)
+ if (addr >= PHY_MAX_ADDR)
return -EIO;
- return mdiobus_read(phydev->mdio.bus, shared->addr, regnum);
+ return mdiobus_read(phydev->mdio.bus, addr, regnum);
}
-static inline int __phy_package_read(struct phy_device *phydev, u32 regnum)
+static inline int __phy_package_read(struct phy_device *phydev,
+ unsigned int addr_offset, u32 regnum)
{
struct phy_package_shared *shared = phydev->shared;
+ int addr = shared->base_addr + addr_offset;
- if (!shared)
+ if (addr >= PHY_MAX_ADDR)
return -EIO;
- return __mdiobus_read(phydev->mdio.bus, shared->addr, regnum);
+ return __mdiobus_read(phydev->mdio.bus, addr, regnum);
}
static inline int phy_package_write(struct phy_device *phydev,
- u32 regnum, u16 val)
+ unsigned int addr_offset, u32 regnum,
+ u16 val)
{
struct phy_package_shared *shared = phydev->shared;
+ int addr = shared->base_addr + addr_offset;
- if (!shared)
+ if (addr >= PHY_MAX_ADDR)
return -EIO;
- return mdiobus_write(phydev->mdio.bus, shared->addr, regnum, val);
+ return mdiobus_write(phydev->mdio.bus, addr, regnum, val);
}
static inline int __phy_package_write(struct phy_device *phydev,
- u32 regnum, u16 val)
+ unsigned int addr_offset, u32 regnum,
+ u16 val)
{
struct phy_package_shared *shared = phydev->shared;
+ int addr = shared->base_addr + addr_offset;
- if (!shared)
+ if (addr >= PHY_MAX_ADDR)
return -EIO;
- return __mdiobus_write(phydev->mdio.bus, shared->addr, regnum, val);
+ return __mdiobus_write(phydev->mdio.bus, addr, regnum, val);
}
static inline bool __phy_package_set_once(struct phy_device *phydev,