The "clk_pm_capable", "clk_pm_enable" and "bios_clk_state" fields in
the struct pcie_link_state only take 1-bit value. So those fields
don't need to be defined as unsigned int. This patch makes those
fields 1-bit, and cleans up some related code.
Acked-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Clean up latency related data structures for ASPM.

- Introduce struct acpi_latency for exit latency and acceptable
  latency management. With this change, struct endpoint_state is no
  longer needed.

- We don't need to hold both upstream latency and downstream latency
  in the current implementation.
Acked-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The "support_state", "enabled_state" and "bios_aspm_state" fields in
the struct pcie_link_state take 2-bit value. So those fields don't
need to be defined as unsigned int. This patch makes those fields
2-bit, and cleans up some related code.
Acked-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Fix a typo in struct pcie_link_state.

The "sibiling" field in the struct pcie_link_state should be
"sibling".
Acked-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

VIA has a strange chipset, it has root port under a bridge. Disable ASPM
for such strange chipset.

Cc: stable@kernel.org
Tested-by: NWolfgang Denk <wd@denx.de>
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

We only want to disable ASPM when the last function is removed from
the parent's device list. We determine this by checking to see if
the parent's device list is completely empty.

Unfortunately, we never hit that code because the parent is considered
an upstream port, and never had an ASPM link_state associated with it.

The early check for !link_state causes us to return early, we never
discover that our device list is empty, and thus we never remove the
downstream ports' link_state nodes.

Instead of checking to see if the parent's device list is empty, we can
check to see if we are the last device on the list, and if so, then we
know that we can clean up properly.

Cc: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The cpu_relax() function can be a noop on certain architectures like
IA-64 when CPU threads are disabled, so use msleep instead during link
retraining busy/wait loop.

Introduce define LINK_RETRAIN_TIMEOUT instead of hard-coding timeout in
pcie_aspm_configure_common_clock.

Use time_after() to avoid jiffy wraparound when checking for expired
timeout.

After timeout expires, recheck link status register link training bit
instead of checking for expired timeout to avoid possible false
positive.

Note that Matthew Wilcox came up with the first rough version of this
patch.
Reviewed-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NAndrew Patterson <andrew.patterson@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

In a PCIe hierarchy with a switch present, if the link state of an
endpoint device is changed, we must check the whole hierarchy from the
endpoint device to root port, and for each link in the hierarchy, the new
link state should be configured. Previously, the implementation checked
the state but forgot to configure the links between root port to switch.
Fixes Novell bz #448987.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Tested-by: NAndrew Patterson <andrew.patterson@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The _OSC capabilities OSC_ACTIVE_STATE_PWR_SUPPORT and
OSC_CLOCK_PWR_CAPABILITY_SUPPORT are set when the root bridge is added
with pci_acpi_osc_support(), so we no longer need to do it in the ASPM
driver.  Also add the function pcie_aspm_enabled, which returns true if
pcie_aspm=off is not on the kernel command-line.
Signed-off-by: NAndrew Patterson <andrew.patterson@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Makes a Compaq 6735s boot reliably again.  It used to hang in the loop
on some boots.  Give the link one second to train, otherwise break out
of the loop and reset the previously set clock bits.

Cc: stable@vger.kernel.org
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NMatthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This patch uniformizes PCI probing debug boot messages with dev_printk()
intead of manual printk()

It changes adress range output from [%llx, %llx] to [%#llx-%#llx], like
in pci_request_region().

For example, it goes from the mixed-style:

PCI: 0000:00:1b.0 reg 10 64bit mmio: [f4280000, f4283fff]
pci 0000:00:1b.0: PME# supported from D0 D3hot D3cold

to uniform:

pci 0000:00:1b.0: reg 10 64bit mmio: [0xf4280000-0xf4283fff]
pci 0000:00:1b.0: PME# supported from D0 D3hot D3cold

This patch has been runtime tested, boot log messages diffed, everything
looks OK.
Acked-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NVincent Legoll <vincent.legoll@gmail.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

pcie_aspm=force did not work because aspm_force was being double negated
leading to the sanity check failing. Moving a bracket should fix this.
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NSitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

A new option, pcie_aspm=force, will force ASPM to be enabled, even on system
with PCIe 1.0 devices.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Disable ASPM on pre-1.1 PCIe devices, as many of them don't implement it
correctly.
Tested-by: NJack Howarth <howarth@bromo.msbb.uc.edu>
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The ACPI FADT table includes an ASPM control bit. If the bit is set, do
not enable ASPM since it may indicate that the platform doesn't actually
support the feature.
Tested-by: NJack Howarth <howarth@bromo.msbb.uc.edu>
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The Slot 03:00.* of JMicron controller has two functions, but one is
PCIE endpoint the other isn't PCIE device, very strange. PCIE spec
defines all functions should have the same config for ASPM, so disable
ASPM for the whole slot in this case.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.

This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
        -default, BIOS default setting
        -powersave, highest power saving mode, enable all available ASPM
state and clock power management
        -performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.

In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.

Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This reverts commit 6c723d5b.

It caused build errors on non-x86 platforms, config file confusion, and
even some boot errors on some x86-64 boxes.  All around, not quite ready
for prime-time :(

Cc: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.

This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
        -default, BIOS default setting
        -powersave, highest power saving mode, enable all available ASPM
state
and clock power management
        -performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.

In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>