Hi,
As a lab upgrade I have recently replaced a dated 32-bit x86 server with
a new POWER9 system. One of the purposes of the system has been providing
network based resources to clients over my FDDI network. As such the new
server has also received a new DEFPA FDDI network adapter.
As it turned out the interface did not work with the driver as shipped by
the most recent stable Debian release (Linux version 5.9.15) for ppc64el.
Symptoms were inconclusive, and the DEFPA adapter turned out to have a
manufacturing defect as well, however eventually I have figured out the
PCIe host bridge used with the system, Power Systems Host Bridge 4 (PHB4),
does not (anymore) implement PCI I/O transactions, while the binary defxx
driver as shipped by Debian comes configured for port I/O, and then a bug
in resource handling causes the driver to try and use an unassigned port
I/O range for adapter's PDQ main ASIC's CSR access.
Fortunately the PFI PCI interface ASIC used with the DEFPA adapter has
been designed such as to provide for both PCI I/O and PCI memory accesses
to be used for PDQ CSR access, via a pair of BARs to be alternatively
used.
Originally the defxx driver only supported port I/O access, but in the
course of interfacing it to the TURBOchannel bus I had to implement MMIO
access too, and while at it I have added a kernel configuration option to
globally switch between port I/O and MMIO at compilation time, however
conservatively defaulting to port I/O for EISA bus support where the use
of MMIO currently requires the adapter to have been suitably configured
via ECU (EISA Configuration Utility), supplied externally.
With the kernel configuration option set to MMIO the DEFPA interface
works correctly with my POWER9 system. Therefore I have prepared this
small patch series consisting of a pair of conservative bug fixes, to be
backported to stable branches, and then a pair of improvements for the
robustness of the driver.
So changes 1/4 and 2/4 apply both to net and net-next, and then changes
3/4 and 4/4 apply on top of them to net-next only. In particular there
are diff context dependencies going like this: 1/4 -> 3/4 -> 4/4. Let me
know if this submission needs to be sorted differently.
See individual change descriptions for further details as to the actual
changes made.
NB the ESIC interface chip used for slave address decoding with the DEFEA
EISA adapter has decoding implemented for address bits 31:10 and therefore
supports full 32-bit range for the allocation of the CSR decoding window.
For DOS compatibility reasons ECU however only allows allocations between
0x000c0000 and 0x000effff.
Given that for other compatibility reasons EISA is subtractively decoded
on mixed PCI/EISA systems we could allocate an MMIO region from arbitrary
unoccupied memory space and program the ESIC suitably without regard for
that compatibility limitation. In fact I have a proof-of-concept change
and it seems to work reliably.
However with these patches applied the driver continues supporting port
I/O as fallback and the EISA product ID register is located in the EISA
slot-specific port I/O address space, so any EISA system however modern
(sounds like a joke, eh?) also has to support port I/O access somehow.
So while I think such a dynamic MMIO allocation would be an example of
good engineering, but it would require changes to our EISA core and
therefore it may have had sense 25 years ago when EISA was still
mainstream, but not nowadays when EISA systems are I suppose more of a
curiosity rather than the usual equipment.
This patch series has been thoroughly verified with Linux 5.11.0 as
released and then a Raptor Talos II POWER9 system and a Malta 5Kc MIPS64
system for PCI DEFPA adapter support, an Advanced Integrated Research
486EI x86 system for EISA DEFEA adapter support, and a Digital Equipment
DECstation 5000 model 260 MIPS III system for TURBOchannel DEFTA adapter
support, covering both port I/O and MMIO operation where applicable.
Please apply.
Maciej
Recent versions of the PCI Express specification have deprecated support
for I/O transactions and actually some PCIe host bridges, such as Power
Systems Host Bridge 4 (PHB4), do not implement them.
The default kernel configuration choice for the defxx driver is the use
of I/O ports rather than MMIO for PCI and EISA systems. It may have
made sense as a conservative backwards compatible choice back when MMIO
operation support was added to the driver as a part of TURBOchannel bus
support. However nowadays this configuration choice makes the driver
unusable with systems that do not implement I/O transactions for PCIe.
Make DEFXX_MMIO the configuration default then, except where configured
for EISA. This exception is because an EISA adapter can have its MMIO
decoding disabled with ECU (EISA Configuration Utility) and therefore
not available with the resource allocation infrastructure we implement,
while port I/O is always readily available as it uses slot-specific
addressing, directly mapped to the slot an option card has been placed
in and handled with our EISA bus support core. Conversely a kernel that
supports modern systems which may not have I/O transactions implemented
for PCIe will usually not be expected to handle legacy EISA systems.
The change of the default will make it easier for people, including but
not limited to distribution packagers, to make a working choice for the
driver.
Update the option description accordingly and while at it replace the
potentially ambiguous PIO acronym with IOP for "port I/O" vs "I/O ports"
according to our nomenclature used elsewhere.
Signed-off-by: Maciej W. Rozycki <[email protected]>
Fixes: e89a2cfb7d7b ("[TC] defxx: TURBOchannel support")
Cc: [email protected] # v2.6.21+
---
drivers/net/fddi/Kconfig | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
Index: linux-defxx/drivers/net/fddi/Kconfig
===================================================================
--- linux-defxx.orig/drivers/net/fddi/Kconfig
+++ linux-defxx/drivers/net/fddi/Kconfig
@@ -40,17 +40,20 @@ config DEFXX
config DEFXX_MMIO
bool
- prompt "Use MMIO instead of PIO" if PCI || EISA
+ prompt "Use MMIO instead of IOP" if PCI || EISA
depends on DEFXX
- default n if PCI || EISA
+ default n if EISA
default y
help
This instructs the driver to use EISA or PCI memory-mapped I/O
- (MMIO) as appropriate instead of programmed I/O ports (PIO).
+ (MMIO) as appropriate instead of programmed I/O ports (IOP).
Enabling this gives an improvement in processing time in parts
- of the driver, but it may cause problems with EISA (DEFEA)
- adapters. TURBOchannel does not have the concept of I/O ports,
- so MMIO is always used for these (DEFTA) adapters.
+ of the driver, but it requires a memory window to be configured
+ for EISA (DEFEA) adapters that may not always be available.
+ Conversely some PCIe host bridges do not support IOP, so MMIO
+ may be required to access PCI (DEFPA) adapters on downstream PCI
+ buses with some systems. TURBOchannel does not have the concept
+ of I/O ports, so MMIO is always used for these (DEFTA) adapters.
If unsure, say N.
Replace repeated "defxx" strings with a reference to the DRV_NAME macro
and then use the driver's name rather that the bus address with resource
requests so as to have contents of /proc/iomem and /proc/ioports more
meaningful to the user, in line with what drivers usually do.
So rather than say:
5000-50ff : DEC FDDIcontroller/EISA Adapter
5000-503f : 00:05
5040-5043 : 00:05
5400-54ff : DEC FDDIcontroller/EISA Adapter
5800-58ff : DEC FDDIcontroller/EISA Adapter
5c00-5cff : DEC FDDIcontroller/EISA Adapter
5c80-5cbf : 00:05
or:
620c080020000-620c08002007f : 0031:02:04.0
620c080020000-620c08002007f : 0031:02:04.0
620c080030000-620c08003ffff : 0031:02:04.0
or:
1f100000-1f10003f : tc2
we report:
5000-50ff : DEC FDDIcontroller/EISA Adapter
5000-503f : defxx
5040-5043 : defxx
5400-54ff : DEC FDDIcontroller/EISA Adapter
5800-58ff : DEC FDDIcontroller/EISA Adapter
5c00-5cff : DEC FDDIcontroller/EISA Adapter
5c80-5cbf : defxx
and:
620c080020000-620c08002007f : 0031:02:04.0
620c080020000-620c08002007f : defxx
620c080030000-620c08003ffff : 0031:02:04.0
and:
1f100000-1f10003f : defxx
respectively for the DEFEA (EISA), DEFPA (PCI), and DEFTA (TURBOchannel)
adapters.
Signed-off-by: Maciej W. Rozycki <[email protected]>
---
drivers/net/fddi/defxx.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
Index: linux-defxx/drivers/net/fddi/defxx.c
===================================================================
--- linux-defxx.orig/drivers/net/fddi/defxx.c
+++ linux-defxx/drivers/net/fddi/defxx.c
@@ -580,14 +580,15 @@ static int dfx_register(struct device *b
if (dfx_use_mmio) {
region = request_mem_region(bar_start[0], bar_len[0],
- print_name);
+ bdev->driver->name);
if (!region && (dfx_bus_eisa || dfx_bus_pci)) {
bp->mmio = false;
dfx_get_bars(bp, bar_start, bar_len);
}
}
if (!dfx_use_mmio)
- region = request_region(bar_start[0], bar_len[0], print_name);
+ region = request_region(bar_start[0], bar_len[0],
+ bdev->driver->name);
if (!region) {
dfx_register_res_err(print_name, dfx_use_mmio,
bar_start[0], bar_len[0]);
@@ -595,7 +596,8 @@ static int dfx_register(struct device *b
goto err_out_disable;
}
if (bar_start[1] != 0) {
- region = request_region(bar_start[1], bar_len[1], print_name);
+ region = request_region(bar_start[1], bar_len[1],
+ bdev->driver->name);
if (!region) {
dfx_register_res_err(print_name, 0,
bar_start[1], bar_len[1]);
@@ -604,7 +606,8 @@ static int dfx_register(struct device *b
}
}
if (bar_start[2] != 0) {
- region = request_region(bar_start[2], bar_len[2], print_name);
+ region = request_region(bar_start[2], bar_len[2],
+ bdev->driver->name);
if (!region) {
dfx_register_res_err(print_name, 0,
bar_start[2], bar_len[2]);
@@ -3745,7 +3748,7 @@ static const struct pci_device_id dfx_pc
MODULE_DEVICE_TABLE(pci, dfx_pci_table);
static struct pci_driver dfx_pci_driver = {
- .name = "defxx",
+ .name = DRV_NAME,
.id_table = dfx_pci_table,
.probe = dfx_pci_register,
.remove = dfx_pci_unregister,
@@ -3776,7 +3779,7 @@ MODULE_DEVICE_TABLE(eisa, dfx_eisa_table
static struct eisa_driver dfx_eisa_driver = {
.id_table = dfx_eisa_table,
.driver = {
- .name = "defxx",
+ .name = DRV_NAME,
.bus = &eisa_bus_type,
.probe = dfx_dev_register,
.remove = dfx_dev_unregister,
@@ -3797,7 +3800,7 @@ MODULE_DEVICE_TABLE(tc, dfx_tc_table);
static struct tc_driver dfx_tc_driver = {
.id_table = dfx_tc_table,
.driver = {
- .name = "defxx",
+ .name = DRV_NAME,
.bus = &tc_bus_type,
.probe = dfx_dev_register,
.remove = dfx_dev_unregister,
Recent versions of the PCI Express specification have deprecated support
for I/O transactions and actually some PCIe host bridges, such as Power
Systems Host Bridge 4 (PHB4), do not implement them. Conversely a DEFEA
adapter can have its MMIO decoding disabled with ECU (EISA Configuration
Utility) and therefore not available for us with the resource allocation
infrastructure we implement.
However either I/O address space will always be available for use with
the DEFEA (EISA) and DEFPA (PCI) adapters and both have double address
decoding implemented in hardware for Control and Status Register access.
The two kinds of adapters can be present both at once in a single mixed
PCI/EISA system. For the DEFTA (TURBOchannel) variant there is no issue
as there has been no port I/O address space defined for that bus.
To make people's life easier and the driver more robust remove the
DEFXX_MMIO configuration option so as to rather than making the choice
for the I/O address space to use at build time for all the adapters
installed in the system let the driver choose the most suitable address
space dynamically on a case-by-case basis at run time. Make MMIO the
default and resort to port I/O should the default fail for some reason.
This way multiple adapters installed in one system can use different I/O
address spaces each, in particular in the presence of DEFEA adapters in
a pure-EISA or a mixed EISA/PCI system (it is expected that DEFPA boards
will use MMIO in normal circumstances).
The choice of the I/O address space to use continues being reported by
the driver on startup, e.g.:
eisa 00:05: EISA: slot 5: DEC3002 detected
defxx: v1.12 2021/03/10 Lawrence V. Stefani and others
00:05: DEFEA at I/O addr = 0x5000, IRQ = 10, Hardware addr = 00-00-f8-c8-b3-b6
00:05: registered as fddi0
and:
defxx: v1.12 2021/03/10 Lawrence V. Stefani and others
0031:02:04.0: DEFPA at MMIO addr = 0x620c080020000, IRQ = 57, Hardware addr = 00-60-6d-93-91-98
0031:02:04.0: registered as fddi0
and:
defxx: v1.12 2021/03/10 Lawrence V. Stefani and others
tc2: DEFTA at MMIO addr = 0x1f100000, IRQ = 21, Hardware addr = 08-00-2b-b0-8b-1e
tc2: registered as fddi0
so there is no need to add further information.
The change is supposed to cause a negligible performance hit as I/O
accessors will now have code executed conditionally at run time.
Signed-off-by: Maciej W. Rozycki <[email protected]>
---
drivers/net/fddi/Kconfig | 19 --------------
drivers/net/fddi/defxx.c | 60 +++++++++++++++++------------------------------
drivers/net/fddi/defxx.h | 3 ++
3 files changed, 25 insertions(+), 57 deletions(-)
Index: linux-defxx/drivers/net/fddi/Kconfig
===================================================================
--- linux-defxx.orig/drivers/net/fddi/Kconfig
+++ linux-defxx/drivers/net/fddi/Kconfig
@@ -38,25 +38,6 @@ config DEFXX
To compile this driver as a module, choose M here: the module
will be called defxx. If unsure, say N.
-config DEFXX_MMIO
- bool
- prompt "Use MMIO instead of IOP" if PCI || EISA
- depends on DEFXX
- default n if EISA
- default y
- help
- This instructs the driver to use EISA or PCI memory-mapped I/O
- (MMIO) as appropriate instead of programmed I/O ports (IOP).
- Enabling this gives an improvement in processing time in parts
- of the driver, but it requires a memory window to be configured
- for EISA (DEFEA) adapters that may not always be available.
- Conversely some PCIe host bridges do not support IOP, so MMIO
- may be required to access PCI (DEFPA) adapters on downstream PCI
- buses with some systems. TURBOchannel does not have the concept
- of I/O ports, so MMIO is always used for these (DEFTA) adapters.
-
- If unsure, say N.
-
config SKFP
tristate "SysKonnect FDDI PCI support"
depends on FDDI && PCI
Index: linux-defxx/drivers/net/fddi/defxx.c
===================================================================
--- linux-defxx.orig/drivers/net/fddi/defxx.c
+++ linux-defxx/drivers/net/fddi/defxx.c
@@ -197,6 +197,7 @@
* 23 Oct 2006 macro Big-endian host support.
* 14 Dec 2006 macro TURBOchannel support.
* 01 Jul 2014 macro Fixes for DMA on 64-bit hosts.
+ * 10 Mar 2021 macro Dynamic MMIO vs port I/O.
*/
/* Include files */
@@ -225,8 +226,8 @@
/* Version information string should be updated prior to each new release! */
#define DRV_NAME "defxx"
-#define DRV_VERSION "v1.11"
-#define DRV_RELDATE "2014/07/01"
+#define DRV_VERSION "v1.12"
+#define DRV_RELDATE "2021/03/10"
static const char version[] =
DRV_NAME ": " DRV_VERSION " " DRV_RELDATE
@@ -253,10 +254,10 @@ static const char version[] =
#define DFX_BUS_TC(dev) 0
#endif
-#ifdef CONFIG_DEFXX_MMIO
-#define DFX_MMIO 1
+#if defined(CONFIG_EISA) || defined(CONFIG_PCI)
+#define dfx_use_mmio bp->mmio
#else
-#define DFX_MMIO 0
+#define dfx_use_mmio true
#endif
/* Define module-wide (static) routines */
@@ -374,8 +375,6 @@ static inline void dfx_outl(DFX_board_t
static void dfx_port_write_long(DFX_board_t *bp, int offset, u32 data)
{
struct device __maybe_unused *bdev = bp->bus_dev;
- int dfx_bus_tc = DFX_BUS_TC(bdev);
- int dfx_use_mmio = DFX_MMIO || dfx_bus_tc;
if (dfx_use_mmio)
dfx_writel(bp, offset, data);
@@ -398,8 +397,6 @@ static inline void dfx_inl(DFX_board_t *
static void dfx_port_read_long(DFX_board_t *bp, int offset, u32 *data)
{
struct device __maybe_unused *bdev = bp->bus_dev;
- int dfx_bus_tc = DFX_BUS_TC(bdev);
- int dfx_use_mmio = DFX_MMIO || dfx_bus_tc;
if (dfx_use_mmio)
dfx_readl(bp, offset, data);
@@ -421,7 +418,7 @@ static void dfx_port_read_long(DFX_board
* None
*
* Arguments:
- * bdev - pointer to device information
+ * bp - pointer to board information
* bar_start - pointer to store the start addresses
* bar_len - pointer to store the lengths of the areas
*
@@ -431,13 +428,13 @@ static void dfx_port_read_long(DFX_board
* Side Effects:
* None
*/
-static void dfx_get_bars(struct device *bdev,
+static void dfx_get_bars(DFX_board_t *bp,
resource_size_t *bar_start, resource_size_t *bar_len)
{
+ struct device *bdev = bp->bus_dev;
int dfx_bus_pci = dev_is_pci(bdev);
int dfx_bus_eisa = DFX_BUS_EISA(bdev);
int dfx_bus_tc = DFX_BUS_TC(bdev);
- int dfx_use_mmio = DFX_MMIO || dfx_bus_tc;
if (dfx_bus_pci) {
int num = dfx_use_mmio ? 0 : 1;
@@ -495,18 +492,6 @@ static const struct net_device_ops dfx_n
.ndo_set_mac_address = dfx_ctl_set_mac_address,
};
-static void dfx_register_res_alloc_err(const char *print_name, bool mmio,
- bool eisa)
-{
- pr_err("%s: Cannot use %s, no address set, aborting\n",
- print_name, mmio ? "MMIO" : "I/O");
- pr_err("%s: Recompile driver with \"CONFIG_DEFXX_MMIO=%c\"\n",
- print_name, mmio ? 'n' : 'y');
- if (eisa && mmio)
- pr_err("%s: Or run ECU and set adapter's MMIO location\n",
- print_name);
-}
-
static void dfx_register_res_err(const char *print_name, bool mmio,
unsigned long start, unsigned long len)
{
@@ -547,8 +532,6 @@ static int dfx_register(struct device *b
static int version_disp;
int dfx_bus_pci = dev_is_pci(bdev);
int dfx_bus_eisa = DFX_BUS_EISA(bdev);
- int dfx_bus_tc = DFX_BUS_TC(bdev);
- int dfx_use_mmio = DFX_MMIO || dfx_bus_tc;
const char *print_name = dev_name(bdev);
struct net_device *dev;
DFX_board_t *bp; /* board pointer */
@@ -586,19 +569,24 @@ static int dfx_register(struct device *b
bp->bus_dev = bdev;
dev_set_drvdata(bdev, dev);
- dfx_get_bars(bdev, bar_start, bar_len);
+ bp->mmio = true;
+
+ dfx_get_bars(bp, bar_start, bar_len);
if (bar_len[0] == 0 ||
(dfx_bus_eisa && dfx_use_mmio && bar_start[0] == 0)) {
- dfx_register_res_alloc_err(print_name, dfx_use_mmio,
- dfx_bus_eisa);
- err = -ENXIO;
- goto err_out_disable;
+ bp->mmio = false;
+ dfx_get_bars(bp, bar_start, bar_len);
}
- if (dfx_use_mmio)
+ if (dfx_use_mmio) {
region = request_mem_region(bar_start[0], bar_len[0],
print_name);
- else
+ if (!region && (dfx_bus_eisa || dfx_bus_pci)) {
+ bp->mmio = false;
+ dfx_get_bars(bp, bar_start, bar_len);
+ }
+ }
+ if (!dfx_use_mmio)
region = request_region(bar_start[0], bar_len[0], print_name);
if (!region) {
dfx_register_res_err(print_name, dfx_use_mmio,
@@ -734,7 +722,6 @@ static void dfx_bus_init(struct net_devi
int dfx_bus_pci = dev_is_pci(bdev);
int dfx_bus_eisa = DFX_BUS_EISA(bdev);
int dfx_bus_tc = DFX_BUS_TC(bdev);
- int dfx_use_mmio = DFX_MMIO || dfx_bus_tc;
u8 val;
DBG_printk("In dfx_bus_init...\n");
@@ -1054,7 +1041,6 @@ static int dfx_driver_init(struct net_de
int dfx_bus_pci = dev_is_pci(bdev);
int dfx_bus_eisa = DFX_BUS_EISA(bdev);
int dfx_bus_tc = DFX_BUS_TC(bdev);
- int dfx_use_mmio = DFX_MMIO || dfx_bus_tc;
int alloc_size; /* total buffer size needed */
char *top_v, *curr_v; /* virtual addrs into memory block */
dma_addr_t top_p, curr_p; /* physical addrs into memory block */
@@ -3708,8 +3694,6 @@ static void dfx_unregister(struct device
struct net_device *dev = dev_get_drvdata(bdev);
DFX_board_t *bp = netdev_priv(dev);
int dfx_bus_pci = dev_is_pci(bdev);
- int dfx_bus_tc = DFX_BUS_TC(bdev);
- int dfx_use_mmio = DFX_MMIO || dfx_bus_tc;
resource_size_t bar_start[3] = {0}; /* pointers to ports */
resource_size_t bar_len[3] = {0}; /* resource lengths */
int alloc_size; /* total buffer size used */
@@ -3729,7 +3713,7 @@ static void dfx_unregister(struct device
dfx_bus_uninit(dev);
- dfx_get_bars(bdev, bar_start, bar_len);
+ dfx_get_bars(bp, bar_start, bar_len);
if (bar_start[2] != 0)
release_region(bar_start[2], bar_len[2]);
if (bar_start[1] != 0)
Index: linux-defxx/drivers/net/fddi/defxx.h
===================================================================
--- linux-defxx.orig/drivers/net/fddi/defxx.h
+++ linux-defxx/drivers/net/fddi/defxx.h
@@ -27,6 +27,7 @@
* 04 Aug 2003 macro Converted to the DMA API.
* 23 Oct 2006 macro Big-endian host support.
* 14 Dec 2006 macro TURBOchannel support.
+ * 10 Mar 2021 macro Dynamic MMIO vs port I/O.
*/
#ifndef _DEFXX_H_
@@ -1776,6 +1777,8 @@ typedef struct DFX_board_tag
int port;
} base; /* base address */
struct device *bus_dev;
+ /* Whether to use MMIO or port I/O. */
+ bool mmio;
u32 full_duplex_enb; /* FDDI Full Duplex enable (1 == on, 2 == off) */
u32 req_ttrt; /* requested TTRT value (in 80ns units) */
u32 burst_size; /* adapter burst size (enumerated) */
Recent versions of the PCI Express specification have deprecated support
for I/O transactions and actually some PCIe host bridges, such as Power
Systems Host Bridge 4 (PHB4), do not implement them.
For those systems the PCI BARs that request a mapping in the I/O space
have the length recorded in the corresponding PCI resource set to zero,
which makes it unassigned:
# lspci -s 0031:02:04.0 -v
0031:02:04.0 FDDI network controller: Digital Equipment Corporation PCI-to-PDQ Interface Chip [PFI] FDDI (DEFPA) (rev 02)
Subsystem: Digital Equipment Corporation FDDIcontroller/PCI (DEFPA)
Flags: bus master, medium devsel, latency 136, IRQ 57, NUMA node 8
Memory at 620c080020000 (32-bit, non-prefetchable) [size=128]
I/O ports at <unassigned> [disabled]
Memory at 620c080030000 (32-bit, non-prefetchable) [size=64K]
Capabilities: [50] Power Management version 2
Kernel driver in use: defxx
Kernel modules: defxx
#
Regardless the driver goes ahead and requests it (here observed with a
Raptor Talos II POWER9 system), resulting in an odd /proc/ioport entry:
# cat /proc/ioports
00000000-ffffffffffffffff : 0031:02:04.0
#
Furthermore, the system gets confused as the driver actually continues
and pokes at those locations, causing a flood of messages being output
to the system console by the underlying system firmware, like:
defxx: v1.11 2014/07/01 Lawrence V. Stefani and others
defxx 0031:02:04.0: enabling device (0140 -> 0142)
LPC[000]: Got SYNC no-response error. Error address reg: 0xd0010000
IPMI: dropping non severe PEL event
LPC[000]: Got SYNC no-response error. Error address reg: 0xd0010014
IPMI: dropping non severe PEL event
LPC[000]: Got SYNC no-response error. Error address reg: 0xd0010014
IPMI: dropping non severe PEL event
and so on and so on (possibly intermixed actually, as there's no locking
between the kernel and the firmware in console port access with this
particular system, but cleaned up above for clarity), and once some 10k
of such pairs of the latter two messages have been produced an interace
eventually shows up in a useless state:
0031:02:04.0: DEFPA at I/O addr = 0x0, IRQ = 57, Hardware addr = 00-00-00-00-00-00
This was not expected to happen as resource handling was added to the
driver a while ago, because it was not known at that time that a PCI
system would be possible that cannot assign port I/O resources, and
oddly enough `request_region' does not fail, which would have caught it.
Correct the problem then by checking for the length of zero for the CSR
resource and bail out gracefully refusing to register an interface if
that turns out to be the case, producing messages like:
defxx: v1.11 2014/07/01 Lawrence V. Stefani and others
0031:02:04.0: Cannot use I/O, no address set, aborting
0031:02:04.0: Recompile driver with "CONFIG_DEFXX_MMIO=y"
Keep the original check for the EISA MMIO resource as implemented,
because in that case the length is hardwired to 0x400 as a consequence
of how the compare/mask address decoding works in the ESIC chip and it
is only the base address that is set to zero if MMIO has been disabled
for the adapter in EISA configuration, which in turn could be a valid
bus address in a legacy-free system implementing PCI, especially for
port I/O.
Where the EISA MMIO resource has been disabled for the adapter in EISA
configuration this arrangement keeps producing messages like:
eisa 00:05: EISA: slot 5: DEC3002 detected
defxx: v1.11 2014/07/01 Lawrence V. Stefani and others
00:05: Cannot use MMIO, no address set, aborting
00:05: Recompile driver with "CONFIG_DEFXX_MMIO=n"
00:05: Or run ECU and set adapter's MMIO location
with the last two lines now swapped for easier handling in the driver.
There is no need to check for and catch the case of a port I/O resource
not having been assigned for EISA as the adapter uses the slot-specific
I/O space, which gets assigned by how EISA has been specified and maps
directly to the particular slot an option card has been placed in. And
the EISA variant of the adapter has additional registers that are only
accessible via the port I/O space anyway.
While at it factor out the error message calls into helpers and fix an
argument order bug with the `pr_err' call now in `dfx_register_res_err'.
Signed-off-by: Maciej W. Rozycki <[email protected]>
Fixes: 4d0438e56a8f ("defxx: Clean up DEFEA resource management")
Cc: [email protected] # v3.19+
---
drivers/net/fddi/defxx.c | 47 ++++++++++++++++++++++++++++++-----------------
1 file changed, 30 insertions(+), 17 deletions(-)
Index: linux-defxx/drivers/net/fddi/defxx.c
===================================================================
--- linux-defxx.orig/drivers/net/fddi/defxx.c
+++ linux-defxx/drivers/net/fddi/defxx.c
@@ -495,6 +495,25 @@ static const struct net_device_ops dfx_n
.ndo_set_mac_address = dfx_ctl_set_mac_address,
};
+static void dfx_register_res_alloc_err(const char *print_name, bool mmio,
+ bool eisa)
+{
+ pr_err("%s: Cannot use %s, no address set, aborting\n",
+ print_name, mmio ? "MMIO" : "I/O");
+ pr_err("%s: Recompile driver with \"CONFIG_DEFXX_MMIO=%c\"\n",
+ print_name, mmio ? 'n' : 'y');
+ if (eisa && mmio)
+ pr_err("%s: Or run ECU and set adapter's MMIO location\n",
+ print_name);
+}
+
+static void dfx_register_res_err(const char *print_name, bool mmio,
+ unsigned long start, unsigned long len)
+{
+ pr_err("%s: Cannot reserve %s resource 0x%lx @ 0x%lx, aborting\n",
+ print_name, mmio ? "MMIO" : "I/O", len, start);
+}
+
/*
* ================
* = dfx_register =
@@ -568,15 +587,12 @@ static int dfx_register(struct device *b
dev_set_drvdata(bdev, dev);
dfx_get_bars(bdev, bar_start, bar_len);
- if (dfx_bus_eisa && dfx_use_mmio && bar_start[0] == 0) {
- pr_err("%s: Cannot use MMIO, no address set, aborting\n",
- print_name);
- pr_err("%s: Run ECU and set adapter's MMIO location\n",
- print_name);
- pr_err("%s: Or recompile driver with \"CONFIG_DEFXX_MMIO=n\""
- "\n", print_name);
+ if (bar_len[0] == 0 ||
+ (dfx_bus_eisa && dfx_use_mmio && bar_start[0] == 0)) {
+ dfx_register_res_alloc_err(print_name, dfx_use_mmio,
+ dfx_bus_eisa);
err = -ENXIO;
- goto err_out;
+ goto err_out_disable;
}
if (dfx_use_mmio)
@@ -585,18 +601,16 @@ static int dfx_register(struct device *b
else
region = request_region(bar_start[0], bar_len[0], print_name);
if (!region) {
- pr_err("%s: Cannot reserve %s resource 0x%lx @ 0x%lx, "
- "aborting\n", dfx_use_mmio ? "MMIO" : "I/O", print_name,
- (long)bar_len[0], (long)bar_start[0]);
+ dfx_register_res_err(print_name, dfx_use_mmio,
+ bar_start[0], bar_len[0]);
err = -EBUSY;
goto err_out_disable;
}
if (bar_start[1] != 0) {
region = request_region(bar_start[1], bar_len[1], print_name);
if (!region) {
- pr_err("%s: Cannot reserve I/O resource "
- "0x%lx @ 0x%lx, aborting\n", print_name,
- (long)bar_len[1], (long)bar_start[1]);
+ dfx_register_res_err(print_name, 0,
+ bar_start[1], bar_len[1]);
err = -EBUSY;
goto err_out_csr_region;
}
@@ -604,9 +618,8 @@ static int dfx_register(struct device *b
if (bar_start[2] != 0) {
region = request_region(bar_start[2], bar_len[2], print_name);
if (!region) {
- pr_err("%s: Cannot reserve I/O resource "
- "0x%lx @ 0x%lx, aborting\n", print_name,
- (long)bar_len[2], (long)bar_start[2]);
+ dfx_register_res_err(print_name, 0,
+ bar_start[2], bar_len[2]);
err = -EBUSY;
goto err_out_bh_region;
}