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Message-Id: <1483425255-101923-3-git-send-email-rajatja@google.com>
Date: Mon, 2 Jan 2017 22:34:11 -0800
From: Rajat Jain <rajatja@...gle.com>
To: Bjorn Helgaas <bhelgaas@...gle.com>,
Keith Busch <keith.busch@...el.com>,
Andreas Ziegler <andreas.ziegler@....de>,
Jonathan Yong <jonathan.yong@...el.com>,
Shawn Lin <shawn.lin@...k-chips.com>,
David Daney <david.daney@...ium.com>,
Julia Lawall <Julia.Lawall@...6.fr>,
Ram Amrani <Ram.Amrani@...ium.com>,
Doug Ledford <dledford@...hat.com>,
Wang Sheng-Hui <shhuiw@...mail.com>, linux-pci@...r.kernel.org,
linux-kernel@...r.kernel.org
Cc: Rajat Jain <rajatja@...gle.com>, Rajat Jain <rajatxjain@...il.com>,
Brian Norris <briannorris@...gle.com>
Subject: [PATCH 2/6] PCI/ASPM: Introduce L1 substates and a Kconfig for it
Introduce the L1 sub states. (For details about L1 substates,
please refer to:
https://pcisig.com/sites/default/files/specification_documents/ECN_L1_PM_Substates_with_CLKREQ_31_May_2013_Rev10a.pdf)
This patch adds macros for the 4 new L1 substates, and adds
a new ASPM "POWER_SUPERSAVE" policy that can be used to enable
L1 substates on a system if desired. The new policy is in a sense,
a super set of the existing POWERSAVE policy. The 4 policies are now:
DEFAULT: Reads and uses whatever ASPM states BIOS enabled
PERFORMANCE: Everything except L0 disabled.
POWERSAVE: L0s and L1 enabled (but not L1 substates)
POWER_SUPERSAVE: L0s + L1 + L1 substates also enabled.
Signed-off-by: Rajat Jain <rajatja@...gle.com>
---
drivers/pci/pcie/Kconfig | 8 ++++++++
drivers/pci/pcie/aspm.c | 39 +++++++++++++++++++++++++++++----------
2 files changed, 37 insertions(+), 10 deletions(-)
diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig
index 7ce7763..ac53edb 100644
--- a/drivers/pci/pcie/Kconfig
+++ b/drivers/pci/pcie/Kconfig
@@ -71,6 +71,14 @@ config PCIEASPM_POWERSAVE
Enable PCI Express ASPM L0s and L1 where possible, even if the
BIOS did not.
+config PCIEASPM_POWER_SUPERSAVE
+ bool "Power Supersave"
+ depends on PCIEASPM
+ help
+ Same as PCIEASPM_POWERSAVE, except it also enables L1 substates where
+ possible. This would result in higher power savings while staying in L1
+ where the components support it.
+
config PCIEASPM_PERFORMANCE
bool "Performance"
depends on PCIEASPM
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 17ac1dc..402c229 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -30,8 +30,17 @@
#define ASPM_STATE_L0S_UP (1) /* Upstream direction L0s state */
#define ASPM_STATE_L0S_DW (2) /* Downstream direction L0s state */
#define ASPM_STATE_L1 (4) /* L1 state */
+#define ASPM_STATE_L1_1 (8) /* ASPM L1.1 state */
+#define ASPM_STATE_L1_2 (0x10) /* ASPM L1.2 state */
+#define ASPM_STATE_L1_1_PCIPM (0x20) /* PCI PM L1.1 state */
+#define ASPM_STATE_L1_2_PCIPM (0x40) /* PCI PM L1.2 state */
+#define ASPM_STATE_L1_SS_PCIPM (ASPM_STATE_L1_1_PCIPM | ASPM_STATE_L1_2_PCIPM)
+#define ASPM_STATE_L1_2_MASK (ASPM_STATE_L1_2 | ASPM_STATE_L1_2_PCIPM)
+#define ASPM_STATE_L1SS (ASPM_STATE_L1_1 | ASPM_STATE_L1_1_PCIPM |\
+ ASPM_STATE_L1_2_MASK)
#define ASPM_STATE_L0S (ASPM_STATE_L0S_UP | ASPM_STATE_L0S_DW)
-#define ASPM_STATE_ALL (ASPM_STATE_L0S | ASPM_STATE_L1)
+#define ASPM_STATE_ALL (ASPM_STATE_L0S | ASPM_STATE_L1 | \
+ ASPM_STATE_L1SS)
struct aspm_latency {
u32 l0s; /* L0s latency (nsec) */
@@ -47,11 +56,11 @@ struct pcie_link_state {
struct list_head link; /* node in parent's children list */
/* ASPM state */
- u32 aspm_support:3; /* Supported ASPM state */
- u32 aspm_enabled:3; /* Enabled ASPM state */
- u32 aspm_capable:3; /* Capable ASPM state with latency */
- u32 aspm_default:3; /* Default ASPM state by BIOS */
- u32 aspm_disable:3; /* Disabled ASPM state */
+ u32 aspm_support:7; /* Supported ASPM state */
+ u32 aspm_enabled:7; /* Enabled ASPM state */
+ u32 aspm_capable:7; /* Capable ASPM state with latency */
+ u32 aspm_default:7; /* Default ASPM state by BIOS */
+ u32 aspm_disable:7; /* Disabled ASPM state */
/* Clock PM state */
u32 clkpm_capable:1; /* Clock PM capable? */
@@ -76,11 +85,14 @@ static LIST_HEAD(link_list);
#define POLICY_DEFAULT 0 /* BIOS default setting */
#define POLICY_PERFORMANCE 1 /* high performance */
#define POLICY_POWERSAVE 2 /* high power saving */
+#define POLICY_POWER_SUPERSAVE 3 /* Possibly Even higher power saving */
#ifdef CONFIG_PCIEASPM_PERFORMANCE
static int aspm_policy = POLICY_PERFORMANCE;
#elif defined CONFIG_PCIEASPM_POWERSAVE
static int aspm_policy = POLICY_POWERSAVE;
+#elif defined CONFIG_PCIEASPM_POWER_SUPERSAVE
+static int aspm_policy = POLICY_POWER_SUPERSAVE;
#else
static int aspm_policy;
#endif
@@ -88,7 +100,8 @@ static int aspm_policy;
static const char *policy_str[] = {
[POLICY_DEFAULT] = "default",
[POLICY_PERFORMANCE] = "performance",
- [POLICY_POWERSAVE] = "powersave"
+ [POLICY_POWERSAVE] = "powersave",
+ [POLICY_POWER_SUPERSAVE] = "powersupersave"
};
#define LINK_RETRAIN_TIMEOUT HZ
@@ -101,6 +114,9 @@ static int policy_to_aspm_state(struct pcie_link_state *link)
return 0;
case POLICY_POWERSAVE:
/* Enable ASPM L0s/L1 */
+ return (ASPM_STATE_L0S | ASPM_STATE_L1);
+ case POLICY_POWER_SUPERSAVE:
+ /* Enable Everything */
return ASPM_STATE_ALL;
case POLICY_DEFAULT:
return link->aspm_default;
@@ -115,7 +131,8 @@ static int policy_to_clkpm_state(struct pcie_link_state *link)
/* Disable ASPM and Clock PM */
return 0;
case POLICY_POWERSAVE:
- /* Disable Clock PM */
+ case POLICY_POWER_SUPERSAVE:
+ /* Enable Clock PM */
return 1;
case POLICY_DEFAULT:
return link->clkpm_default;
@@ -612,7 +629,8 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev)
* the BIOS's expectation, we'll do so once pci_enable_device() is
* called.
*/
- if (aspm_policy != POLICY_POWERSAVE) {
+ if (aspm_policy != POLICY_POWERSAVE &&
+ aspm_policy != POLICY_POWER_SUPERSAVE) {
pcie_config_aspm_path(link);
pcie_set_clkpm(link, policy_to_clkpm_state(link));
}
@@ -712,7 +730,8 @@ void pcie_aspm_powersave_config_link(struct pci_dev *pdev)
if (aspm_disabled || !link)
return;
- if (aspm_policy != POLICY_POWERSAVE)
+ if (aspm_policy != POLICY_POWERSAVE &&
+ aspm_policy != POLICY_POWER_SUPERSAVE)
return;
down_read(&pci_bus_sem);
--
2.8.0.rc3.226.g39d4020
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