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path: root/drivers/pci/pcie/aspm.c
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Diffstat (limited to 'drivers/pci/pcie/aspm.c')
-rw-r--r--drivers/pci/pcie/aspm.c882
1 files changed, 633 insertions, 249 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 3dafba0b5f41..cedea47a3547 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -7,40 +7,223 @@
* Copyright (C) Shaohua Li (shaohua.li@intel.com)
*/
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/build_bug.h>
#include <linux/kernel.h>
+#include <linux/limits.h>
#include <linux/math.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/of.h>
#include <linux/pci.h>
#include <linux/pci_regs.h>
#include <linux/errno.h>
#include <linux/pm.h>
#include <linux/init.h>
+#include <linux/printk.h>
#include <linux/slab.h>
-#include <linux/jiffies.h>
-#include <linux/delay.h>
+#include <linux/time.h>
+
#include "../pci.h"
+void pci_save_ltr_state(struct pci_dev *dev)
+{
+ int ltr;
+ struct pci_cap_saved_state *save_state;
+ u32 *cap;
+
+ if (!pci_is_pcie(dev))
+ return;
+
+ ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
+ if (!ltr)
+ return;
+
+ save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR);
+ if (!save_state) {
+ pci_err(dev, "no suspend buffer for LTR; ASPM issues possible after resume\n");
+ return;
+ }
+
+ /* Some broken devices only support dword access to LTR */
+ cap = &save_state->cap.data[0];
+ pci_read_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, cap);
+}
+
+void pci_restore_ltr_state(struct pci_dev *dev)
+{
+ struct pci_cap_saved_state *save_state;
+ int ltr;
+ u32 *cap;
+
+ save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR);
+ ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
+ if (!save_state || !ltr)
+ return;
+
+ /* Some broken devices only support dword access to LTR */
+ cap = &save_state->cap.data[0];
+ pci_write_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap);
+}
+
+void pci_configure_aspm_l1ss(struct pci_dev *pdev)
+{
+ int rc;
+
+ pdev->l1ss = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_L1SS);
+
+ rc = pci_add_ext_cap_save_buffer(pdev, PCI_EXT_CAP_ID_L1SS,
+ 2 * sizeof(u32));
+ if (rc)
+ pci_err(pdev, "unable to allocate ASPM L1SS save buffer (%pe)\n",
+ ERR_PTR(rc));
+}
+
+void pci_save_aspm_l1ss_state(struct pci_dev *pdev)
+{
+ struct pci_dev *parent = pdev->bus->self;
+ struct pci_cap_saved_state *save_state;
+ u32 *cap;
+
+ /*
+ * If this is a Downstream Port, we never restore the L1SS state
+ * directly; we only restore it when we restore the state of the
+ * Upstream Port below it.
+ */
+ if (pcie_downstream_port(pdev) || !parent)
+ return;
+
+ if (!pdev->l1ss || !parent->l1ss)
+ return;
+
+ /*
+ * Save L1 substate configuration. The ASPM L0s/L1 configuration
+ * in PCI_EXP_LNKCTL_ASPMC is saved by pci_save_pcie_state().
+ */
+ save_state = pci_find_saved_ext_cap(pdev, PCI_EXT_CAP_ID_L1SS);
+ if (!save_state)
+ return;
+
+ cap = &save_state->cap.data[0];
+ pci_read_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL2, cap++);
+ pci_read_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1, cap++);
+
+ /*
+ * Save parent's L1 substate configuration so we have it for
+ * pci_restore_aspm_l1ss_state(pdev) to restore.
+ */
+ save_state = pci_find_saved_ext_cap(parent, PCI_EXT_CAP_ID_L1SS);
+ if (!save_state)
+ return;
+
+ cap = &save_state->cap.data[0];
+ pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL2, cap++);
+ pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, cap++);
+}
+
+void pci_restore_aspm_l1ss_state(struct pci_dev *pdev)
+{
+ struct pci_cap_saved_state *pl_save_state, *cl_save_state;
+ struct pci_dev *parent = pdev->bus->self;
+ u32 *cap, pl_ctl1, pl_ctl2, pl_l1_2_enable;
+ u32 cl_ctl1, cl_ctl2, cl_l1_2_enable;
+ u16 clnkctl, plnkctl;
+
+ /*
+ * In case BIOS enabled L1.2 when resuming, we need to disable it first
+ * on the downstream component before the upstream. So, don't attempt to
+ * restore either until we are at the downstream component.
+ */
+ if (pcie_downstream_port(pdev) || !parent)
+ return;
+
+ if (!pdev->l1ss || !parent->l1ss)
+ return;
+
+ cl_save_state = pci_find_saved_ext_cap(pdev, PCI_EXT_CAP_ID_L1SS);
+ pl_save_state = pci_find_saved_ext_cap(parent, PCI_EXT_CAP_ID_L1SS);
+ if (!cl_save_state || !pl_save_state)
+ return;
+
+ cap = &cl_save_state->cap.data[0];
+ cl_ctl2 = *cap++;
+ cl_ctl1 = *cap;
+ cap = &pl_save_state->cap.data[0];
+ pl_ctl2 = *cap++;
+ pl_ctl1 = *cap;
+
+ /* Make sure L0s/L1 are disabled before updating L1SS config */
+ pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &clnkctl);
+ pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &plnkctl);
+ if (FIELD_GET(PCI_EXP_LNKCTL_ASPMC, clnkctl) ||
+ FIELD_GET(PCI_EXP_LNKCTL_ASPMC, plnkctl)) {
+ pcie_capability_write_word(pdev, PCI_EXP_LNKCTL,
+ clnkctl & ~PCI_EXP_LNKCTL_ASPMC);
+ pcie_capability_write_word(parent, PCI_EXP_LNKCTL,
+ plnkctl & ~PCI_EXP_LNKCTL_ASPMC);
+ }
+
+ /*
+ * Disable L1.2 on this downstream endpoint device first, followed
+ * by the upstream
+ */
+ pci_clear_and_set_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_L1_2_MASK, 0);
+ pci_clear_and_set_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_L1_2_MASK, 0);
+
+ /*
+ * In addition, Common_Mode_Restore_Time and LTR_L1.2_THRESHOLD
+ * in PCI_L1SS_CTL1 must be programmed *before* setting the L1.2
+ * enable bits, even though they're all in PCI_L1SS_CTL1.
+ */
+ pl_l1_2_enable = pl_ctl1 & PCI_L1SS_CTL1_L1_2_MASK;
+ pl_ctl1 &= ~PCI_L1SS_CTL1_L1_2_MASK;
+ cl_l1_2_enable = cl_ctl1 & PCI_L1SS_CTL1_L1_2_MASK;
+ cl_ctl1 &= ~PCI_L1SS_CTL1_L1_2_MASK;
+
+ /* Write back without enables first (above we cleared them in ctl1) */
+ pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL2, pl_ctl2);
+ pci_write_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL2, cl_ctl2);
+ pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, pl_ctl1);
+ pci_write_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1, cl_ctl1);
+
+ /* Then write back the enables */
+ if (pl_l1_2_enable || cl_l1_2_enable) {
+ pci_write_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
+ pl_ctl1 | pl_l1_2_enable);
+ pci_write_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1,
+ cl_ctl1 | cl_l1_2_enable);
+ }
+
+ /* Restore L0s/L1 if they were enabled */
+ if (FIELD_GET(PCI_EXP_LNKCTL_ASPMC, clnkctl) ||
+ FIELD_GET(PCI_EXP_LNKCTL_ASPMC, plnkctl)) {
+ pcie_capability_write_word(parent, PCI_EXP_LNKCTL, plnkctl);
+ pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, clnkctl);
+ }
+}
+
+#ifdef CONFIG_PCIEASPM
+
#ifdef MODULE_PARAM_PREFIX
#undef MODULE_PARAM_PREFIX
#endif
#define MODULE_PARAM_PREFIX "pcie_aspm."
-/* Note: those are not register definitions */
-#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 | \
- ASPM_STATE_L1SS)
+/* Note: these are not register definitions */
+#define PCIE_LINK_STATE_L0S_UP BIT(0) /* Upstream direction L0s state */
+#define PCIE_LINK_STATE_L0S_DW BIT(1) /* Downstream direction L0s state */
+static_assert(PCIE_LINK_STATE_L0S == (PCIE_LINK_STATE_L0S_UP | PCIE_LINK_STATE_L0S_DW));
+
+#define PCIE_LINK_STATE_L1_SS_PCIPM (PCIE_LINK_STATE_L1_1_PCIPM |\
+ PCIE_LINK_STATE_L1_2_PCIPM)
+#define PCIE_LINK_STATE_L1_2_MASK (PCIE_LINK_STATE_L1_2 |\
+ PCIE_LINK_STATE_L1_2_PCIPM)
+#define PCIE_LINK_STATE_L1SS (PCIE_LINK_STATE_L1_1 |\
+ PCIE_LINK_STATE_L1_1_PCIPM |\
+ PCIE_LINK_STATE_L1_2_MASK)
struct pcie_link_state {
struct pci_dev *pdev; /* Upstream component of the Link */
@@ -53,7 +236,8 @@ struct pcie_link_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_default:7; /* Default ASPM state by BIOS or
+ override */
u32 aspm_disable:7; /* Disabled ASPM state */
/* Clock PM state */
@@ -63,7 +247,7 @@ struct pcie_link_state {
u32 clkpm_disable:1; /* Clock PM disabled */
};
-static int aspm_disabled, aspm_force;
+static bool aspm_disabled, aspm_force;
static bool aspm_support_enabled = true;
static DEFINE_MUTEX(aspm_lock);
static LIST_HEAD(link_list);
@@ -112,10 +296,10 @@ 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);
+ return PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1;
case POLICY_POWER_SUPERSAVE:
/* Enable Everything */
- return ASPM_STATE_ALL;
+ return PCIE_LINK_STATE_ASPM_ALL;
case POLICY_DEFAULT:
return link->aspm_default;
}
@@ -138,16 +322,42 @@ static int policy_to_clkpm_state(struct pcie_link_state *link)
return 0;
}
+static void pci_update_aspm_saved_state(struct pci_dev *dev)
+{
+ struct pci_cap_saved_state *save_state;
+ u16 *cap, lnkctl, aspm_ctl;
+
+ save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
+ if (!save_state)
+ return;
+
+ pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &lnkctl);
+
+ /*
+ * Update ASPM and CLKREQ bits of LNKCTL in save_state. We only
+ * write PCI_EXP_LNKCTL_CCC during enumeration, so it shouldn't
+ * change after being captured in save_state.
+ */
+ aspm_ctl = lnkctl & (PCI_EXP_LNKCTL_ASPMC | PCI_EXP_LNKCTL_CLKREQ_EN);
+ lnkctl &= ~(PCI_EXP_LNKCTL_ASPMC | PCI_EXP_LNKCTL_CLKREQ_EN);
+
+ /* Depends on pci_save_pcie_state(): cap[1] is LNKCTL */
+ cap = (u16 *)&save_state->cap.data[0];
+ cap[1] = lnkctl | aspm_ctl;
+}
+
static void pcie_set_clkpm_nocheck(struct pcie_link_state *link, int enable)
{
struct pci_dev *child;
struct pci_bus *linkbus = link->pdev->subordinate;
u32 val = enable ? PCI_EXP_LNKCTL_CLKREQ_EN : 0;
- list_for_each_entry(child, &linkbus->devices, bus_list)
+ list_for_each_entry(child, &linkbus->devices, bus_list) {
pcie_capability_clear_and_set_word(child, PCI_EXP_LNKCTL,
PCI_EXP_LNKCTL_CLKREQ_EN,
val);
+ pci_update_aspm_saved_state(child);
+ }
link->clkpm_enabled = !!enable;
}
@@ -199,7 +409,7 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist)
static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
{
int same_clock = 1;
- u16 reg16, parent_reg, child_reg[8];
+ u16 reg16, ccc, parent_old_ccc, child_old_ccc[8];
struct pci_dev *child, *parent = link->pdev;
struct pci_bus *linkbus = parent->subordinate;
/*
@@ -221,6 +431,7 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
/* Port might be already in common clock mode */
pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &reg16);
+ parent_old_ccc = reg16 & PCI_EXP_LNKCTL_CCC;
if (same_clock && (reg16 & PCI_EXP_LNKCTL_CCC)) {
bool consistent = true;
@@ -237,44 +448,39 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
pci_info(parent, "ASPM: current common clock configuration is inconsistent, reconfiguring\n");
}
+ ccc = same_clock ? PCI_EXP_LNKCTL_CCC : 0;
/* Configure downstream component, all functions */
list_for_each_entry(child, &linkbus->devices, bus_list) {
pcie_capability_read_word(child, PCI_EXP_LNKCTL, &reg16);
- child_reg[PCI_FUNC(child->devfn)] = reg16;
- if (same_clock)
- reg16 |= PCI_EXP_LNKCTL_CCC;
- else
- reg16 &= ~PCI_EXP_LNKCTL_CCC;
- pcie_capability_write_word(child, PCI_EXP_LNKCTL, reg16);
+ child_old_ccc[PCI_FUNC(child->devfn)] = reg16 & PCI_EXP_LNKCTL_CCC;
+ pcie_capability_clear_and_set_word(child, PCI_EXP_LNKCTL,
+ PCI_EXP_LNKCTL_CCC, ccc);
}
/* Configure upstream component */
- pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &reg16);
- parent_reg = reg16;
- if (same_clock)
- reg16 |= PCI_EXP_LNKCTL_CCC;
- else
- reg16 &= ~PCI_EXP_LNKCTL_CCC;
- pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
+ pcie_capability_clear_and_set_word(parent, PCI_EXP_LNKCTL,
+ PCI_EXP_LNKCTL_CCC, ccc);
if (pcie_retrain_link(link->pdev, true)) {
/* Training failed. Restore common clock configurations */
pci_err(parent, "ASPM: Could not configure common clock\n");
list_for_each_entry(child, &linkbus->devices, bus_list)
- pcie_capability_write_word(child, PCI_EXP_LNKCTL,
- child_reg[PCI_FUNC(child->devfn)]);
- pcie_capability_write_word(parent, PCI_EXP_LNKCTL, parent_reg);
+ pcie_capability_clear_and_set_word(child, PCI_EXP_LNKCTL,
+ PCI_EXP_LNKCTL_CCC,
+ child_old_ccc[PCI_FUNC(child->devfn)]);
+ pcie_capability_clear_and_set_word(parent, PCI_EXP_LNKCTL,
+ PCI_EXP_LNKCTL_CCC, parent_old_ccc);
}
}
/* Convert L0s latency encoding to ns */
static u32 calc_l0s_latency(u32 lnkcap)
{
- u32 encoding = (lnkcap & PCI_EXP_LNKCAP_L0SEL) >> 12;
+ u32 encoding = FIELD_GET(PCI_EXP_LNKCAP_L0SEL, lnkcap);
if (encoding == 0x7)
- return (5 * 1000); /* > 4us */
+ return 5 * NSEC_PER_USEC; /* > 4us */
return (64 << encoding);
}
@@ -282,26 +488,26 @@ static u32 calc_l0s_latency(u32 lnkcap)
static u32 calc_l0s_acceptable(u32 encoding)
{
if (encoding == 0x7)
- return -1U;
+ return U32_MAX;
return (64 << encoding);
}
/* Convert L1 latency encoding to ns */
static u32 calc_l1_latency(u32 lnkcap)
{
- u32 encoding = (lnkcap & PCI_EXP_LNKCAP_L1EL) >> 15;
+ u32 encoding = FIELD_GET(PCI_EXP_LNKCAP_L1EL, lnkcap);
if (encoding == 0x7)
- return (65 * 1000); /* > 64us */
- return (1000 << encoding);
+ return 65 * NSEC_PER_USEC; /* > 64us */
+ return NSEC_PER_USEC << encoding;
}
/* Convert L1 acceptable latency encoding to ns */
static u32 calc_l1_acceptable(u32 encoding)
{
if (encoding == 0x7)
- return -1U;
- return (1000 << encoding);
+ return U32_MAX;
+ return NSEC_PER_USEC << encoding;
}
/* Convert L1SS T_pwr encoding to usec */
@@ -329,33 +535,33 @@ static u32 calc_l12_pwron(struct pci_dev *pdev, u32 scale, u32 val)
*/
static void encode_l12_threshold(u32 threshold_us, u32 *scale, u32 *value)
{
- u64 threshold_ns = (u64) threshold_us * 1000;
+ u64 threshold_ns = (u64)threshold_us * NSEC_PER_USEC;
/*
* LTR_L1.2_THRESHOLD_Value ("value") is a 10-bit field with max
* value of 0x3ff.
*/
- if (threshold_ns <= 0x3ff * 1) {
+ if (threshold_ns <= 1 * FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE)) {
*scale = 0; /* Value times 1ns */
*value = threshold_ns;
- } else if (threshold_ns <= 0x3ff * 32) {
+ } else if (threshold_ns <= 32 * FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE)) {
*scale = 1; /* Value times 32ns */
*value = roundup(threshold_ns, 32) / 32;
- } else if (threshold_ns <= 0x3ff * 1024) {
+ } else if (threshold_ns <= 1024 * FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE)) {
*scale = 2; /* Value times 1024ns */
*value = roundup(threshold_ns, 1024) / 1024;
- } else if (threshold_ns <= 0x3ff * 32768) {
+ } else if (threshold_ns <= 32768 * FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE)) {
*scale = 3; /* Value times 32768ns */
*value = roundup(threshold_ns, 32768) / 32768;
- } else if (threshold_ns <= 0x3ff * 1048576) {
+ } else if (threshold_ns <= 1048576 * FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE)) {
*scale = 4; /* Value times 1048576ns */
*value = roundup(threshold_ns, 1048576) / 1048576;
- } else if (threshold_ns <= 0x3ff * (u64) 33554432) {
+ } else if (threshold_ns <= (u64)33554432 * FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE)) {
*scale = 5; /* Value times 33554432ns */
*value = roundup(threshold_ns, 33554432) / 33554432;
} else {
*scale = 5;
- *value = 0x3ff; /* Max representable value */
+ *value = FIELD_MAX(PCI_L1SS_CTL1_LTR_L12_TH_VALUE);
}
}
@@ -375,11 +581,11 @@ static void pcie_aspm_check_latency(struct pci_dev *endpoint)
link = endpoint->bus->self->link_state;
/* Calculate endpoint L0s acceptable latency */
- encoding = (endpoint->devcap & PCI_EXP_DEVCAP_L0S) >> 6;
+ encoding = FIELD_GET(PCI_EXP_DEVCAP_L0S, endpoint->devcap);
acceptable_l0s = calc_l0s_acceptable(encoding);
/* Calculate endpoint L1 acceptable latency */
- encoding = (endpoint->devcap & PCI_EXP_DEVCAP_L1) >> 9;
+ encoding = FIELD_GET(PCI_EXP_DEVCAP_L1, endpoint->devcap);
acceptable_l1 = calc_l1_acceptable(encoding);
while (link) {
@@ -396,14 +602,14 @@ static void pcie_aspm_check_latency(struct pci_dev *endpoint)
latency_dw_l1 = calc_l1_latency(lnkcap_dw);
/* Check upstream direction L0s latency */
- if ((link->aspm_capable & ASPM_STATE_L0S_UP) &&
+ if ((link->aspm_capable & PCIE_LINK_STATE_L0S_UP) &&
(latency_up_l0s > acceptable_l0s))
- link->aspm_capable &= ~ASPM_STATE_L0S_UP;
+ link->aspm_capable &= ~PCIE_LINK_STATE_L0S_UP;
/* Check downstream direction L0s latency */
- if ((link->aspm_capable & ASPM_STATE_L0S_DW) &&
+ if ((link->aspm_capable & PCIE_LINK_STATE_L0S_DW) &&
(latency_dw_l0s > acceptable_l0s))
- link->aspm_capable &= ~ASPM_STATE_L0S_DW;
+ link->aspm_capable &= ~PCIE_LINK_STATE_L0S_DW;
/*
* Check L1 latency.
* Every switch on the path to root complex need 1
@@ -418,26 +624,15 @@ static void pcie_aspm_check_latency(struct pci_dev *endpoint)
* substate latencies (and hence do not do any check).
*/
latency = max_t(u32, latency_up_l1, latency_dw_l1);
- if ((link->aspm_capable & ASPM_STATE_L1) &&
+ if ((link->aspm_capable & PCIE_LINK_STATE_L1) &&
(latency + l1_switch_latency > acceptable_l1))
- link->aspm_capable &= ~ASPM_STATE_L1;
- l1_switch_latency += 1000;
+ link->aspm_capable &= ~PCIE_LINK_STATE_L1;
+ l1_switch_latency += NSEC_PER_USEC;
link = link->parent;
}
}
-static void pci_clear_and_set_dword(struct pci_dev *pdev, int pos,
- u32 clear, u32 set)
-{
- u32 val;
-
- pci_read_config_dword(pdev, pos, &val);
- val &= ~clear;
- val |= set;
- pci_write_config_dword(pdev, pos, val);
-}
-
/* Calculate L1.2 PM substate timing parameters */
static void aspm_calc_l12_info(struct pcie_link_state *link,
u32 parent_l1ss_cap, u32 child_l1ss_cap)
@@ -450,22 +645,24 @@ static void aspm_calc_l12_info(struct pcie_link_state *link,
u32 pl1_2_enables, cl1_2_enables;
/* Choose the greater of the two Port Common_Mode_Restore_Times */
- val1 = (parent_l1ss_cap & PCI_L1SS_CAP_CM_RESTORE_TIME) >> 8;
- val2 = (child_l1ss_cap & PCI_L1SS_CAP_CM_RESTORE_TIME) >> 8;
+ val1 = FIELD_GET(PCI_L1SS_CAP_CM_RESTORE_TIME, parent_l1ss_cap);
+ val2 = FIELD_GET(PCI_L1SS_CAP_CM_RESTORE_TIME, child_l1ss_cap);
t_common_mode = max(val1, val2);
/* Choose the greater of the two Port T_POWER_ON times */
- val1 = (parent_l1ss_cap & PCI_L1SS_CAP_P_PWR_ON_VALUE) >> 19;
- scale1 = (parent_l1ss_cap & PCI_L1SS_CAP_P_PWR_ON_SCALE) >> 16;
- val2 = (child_l1ss_cap & PCI_L1SS_CAP_P_PWR_ON_VALUE) >> 19;
- scale2 = (child_l1ss_cap & PCI_L1SS_CAP_P_PWR_ON_SCALE) >> 16;
+ val1 = FIELD_GET(PCI_L1SS_CAP_P_PWR_ON_VALUE, parent_l1ss_cap);
+ scale1 = FIELD_GET(PCI_L1SS_CAP_P_PWR_ON_SCALE, parent_l1ss_cap);
+ val2 = FIELD_GET(PCI_L1SS_CAP_P_PWR_ON_VALUE, child_l1ss_cap);
+ scale2 = FIELD_GET(PCI_L1SS_CAP_P_PWR_ON_SCALE, child_l1ss_cap);
if (calc_l12_pwron(parent, scale1, val1) >
calc_l12_pwron(child, scale2, val2)) {
- ctl2 |= scale1 | (val1 << 3);
+ ctl2 |= FIELD_PREP(PCI_L1SS_CTL2_T_PWR_ON_SCALE, scale1) |
+ FIELD_PREP(PCI_L1SS_CTL2_T_PWR_ON_VALUE, val1);
t_power_on = calc_l12_pwron(parent, scale1, val1);
} else {
- ctl2 |= scale2 | (val2 << 3);
+ ctl2 |= FIELD_PREP(PCI_L1SS_CTL2_T_PWR_ON_SCALE, scale2) |
+ FIELD_PREP(PCI_L1SS_CTL2_T_PWR_ON_VALUE, val2);
t_power_on = calc_l12_pwron(child, scale2, val2);
}
@@ -481,7 +678,9 @@ static void aspm_calc_l12_info(struct pcie_link_state *link,
*/
l1_2_threshold = 2 + 4 + t_common_mode + t_power_on;
encode_l12_threshold(l1_2_threshold, &scale, &value);
- ctl1 |= t_common_mode << 8 | scale << 29 | value << 16;
+ ctl1 |= FIELD_PREP(PCI_L1SS_CTL1_CM_RESTORE_TIME, t_common_mode) |
+ FIELD_PREP(PCI_L1SS_CTL1_LTR_L12_TH_VALUE, value) |
+ FIELD_PREP(PCI_L1SS_CTL1_LTR_L12_TH_SCALE, scale);
/* Some broken devices only support dword access to L1 SS */
pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, &pctl1);
@@ -498,10 +697,12 @@ static void aspm_calc_l12_info(struct pcie_link_state *link,
cl1_2_enables = cctl1 & PCI_L1SS_CTL1_L1_2_MASK;
if (pl1_2_enables || cl1_2_enables) {
- pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1,
- PCI_L1SS_CTL1_L1_2_MASK, 0);
- pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
- PCI_L1SS_CTL1_L1_2_MASK, 0);
+ pci_clear_and_set_config_dword(child,
+ child->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_L1_2_MASK, 0);
+ pci_clear_and_set_config_dword(parent,
+ parent->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_L1_2_MASK, 0);
}
/* Program T_POWER_ON times in both ports */
@@ -509,22 +710,26 @@ static void aspm_calc_l12_info(struct pcie_link_state *link,
pci_write_config_dword(child, child->l1ss + PCI_L1SS_CTL2, ctl2);
/* Program Common_Mode_Restore_Time in upstream device */
- pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
- PCI_L1SS_CTL1_CM_RESTORE_TIME, ctl1);
+ pci_clear_and_set_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_CM_RESTORE_TIME, ctl1);
/* Program LTR_L1.2_THRESHOLD time in both ports */
- pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
- PCI_L1SS_CTL1_LTR_L12_TH_VALUE |
- PCI_L1SS_CTL1_LTR_L12_TH_SCALE, ctl1);
- pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1,
- PCI_L1SS_CTL1_LTR_L12_TH_VALUE |
- PCI_L1SS_CTL1_LTR_L12_TH_SCALE, ctl1);
+ pci_clear_and_set_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_LTR_L12_TH_VALUE |
+ PCI_L1SS_CTL1_LTR_L12_TH_SCALE,
+ ctl1);
+ pci_clear_and_set_config_dword(child, child->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_LTR_L12_TH_VALUE |
+ PCI_L1SS_CTL1_LTR_L12_TH_SCALE,
+ ctl1);
if (pl1_2_enables || cl1_2_enables) {
- pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1, 0,
- pl1_2_enables);
- pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1, 0,
- cl1_2_enables);
+ pci_clear_and_set_config_dword(parent,
+ parent->l1ss + PCI_L1SS_CTL1, 0,
+ pl1_2_enables);
+ pci_clear_and_set_config_dword(child,
+ child->l1ss + PCI_L1SS_CTL1, 0,
+ cl1_2_enables);
}
}
@@ -557,13 +762,13 @@ static void aspm_l1ss_init(struct pcie_link_state *link)
child_l1ss_cap &= ~PCI_L1SS_CAP_ASPM_L1_2;
if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_ASPM_L1_1)
- link->aspm_support |= ASPM_STATE_L1_1;
+ link->aspm_support |= PCIE_LINK_STATE_L1_1;
if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_ASPM_L1_2)
- link->aspm_support |= ASPM_STATE_L1_2;
+ link->aspm_support |= PCIE_LINK_STATE_L1_2;
if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_PCIPM_L1_1)
- link->aspm_support |= ASPM_STATE_L1_1_PCIPM;
+ link->aspm_support |= PCIE_LINK_STATE_L1_1_PCIPM;
if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_PCIPM_L1_2)
- link->aspm_support |= ASPM_STATE_L1_2_PCIPM;
+ link->aspm_support |= PCIE_LINK_STATE_L1_2_PCIPM;
if (parent_l1ss_cap)
pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
@@ -573,29 +778,49 @@ static void aspm_l1ss_init(struct pcie_link_state *link)
&child_l1ss_ctl1);
if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_ASPM_L1_1)
- link->aspm_enabled |= ASPM_STATE_L1_1;
+ link->aspm_enabled |= PCIE_LINK_STATE_L1_1;
if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_ASPM_L1_2)
- link->aspm_enabled |= ASPM_STATE_L1_2;
+ link->aspm_enabled |= PCIE_LINK_STATE_L1_2;
if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_PCIPM_L1_1)
- link->aspm_enabled |= ASPM_STATE_L1_1_PCIPM;
+ link->aspm_enabled |= PCIE_LINK_STATE_L1_1_PCIPM;
if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_PCIPM_L1_2)
- link->aspm_enabled |= ASPM_STATE_L1_2_PCIPM;
+ link->aspm_enabled |= PCIE_LINK_STATE_L1_2_PCIPM;
- if (link->aspm_support & ASPM_STATE_L1_2_MASK)
+ if (link->aspm_support & PCIE_LINK_STATE_L1_2_MASK)
aspm_calc_l12_info(link, parent_l1ss_cap, child_l1ss_cap);
}
+#define FLAG(x, y, d) (((x) & (PCIE_LINK_STATE_##y)) ? d : "")
+
+static void pcie_aspm_override_default_link_state(struct pcie_link_state *link)
+{
+ struct pci_dev *pdev = link->downstream;
+ u32 override;
+
+ /* For devicetree platforms, enable L0s and L1 by default */
+ if (of_have_populated_dt()) {
+ if (link->aspm_support & PCIE_LINK_STATE_L0S)
+ link->aspm_default |= PCIE_LINK_STATE_L0S;
+ if (link->aspm_support & PCIE_LINK_STATE_L1)
+ link->aspm_default |= PCIE_LINK_STATE_L1;
+ override = link->aspm_default & ~link->aspm_enabled;
+ if (override)
+ pci_info(pdev, "ASPM: default states%s%s\n",
+ FLAG(override, L0S, " L0s"),
+ FLAG(override, L1, " L1"));
+ }
+}
+
static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
{
struct pci_dev *child = link->downstream, *parent = link->pdev;
- u32 parent_lnkcap, child_lnkcap;
u16 parent_lnkctl, child_lnkctl;
struct pci_bus *linkbus = parent->subordinate;
if (blacklist) {
/* Set enabled/disable so that we will disable ASPM later */
- link->aspm_enabled = ASPM_STATE_ALL;
- link->aspm_disable = ASPM_STATE_ALL;
+ link->aspm_enabled = PCIE_LINK_STATE_ASPM_ALL;
+ link->aspm_disable = PCIE_LINK_STATE_ASPM_ALL;
return;
}
@@ -603,9 +828,8 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
* If ASPM not supported, don't mess with the clocks and link,
* bail out now.
*/
- pcie_capability_read_dword(parent, PCI_EXP_LNKCAP, &parent_lnkcap);
- pcie_capability_read_dword(child, PCI_EXP_LNKCAP, &child_lnkcap);
- if (!(parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPMS))
+ if (!(parent->aspm_l0s_support && child->aspm_l0s_support) &&
+ !(parent->aspm_l1_support && child->aspm_l1_support))
return;
/* Configure common clock before checking latencies */
@@ -617,11 +841,18 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
* read-only Link Capabilities may change depending on common clock
* configuration (PCIe r5.0, sec 7.5.3.6).
*/
- pcie_capability_read_dword(parent, PCI_EXP_LNKCAP, &parent_lnkcap);
- pcie_capability_read_dword(child, PCI_EXP_LNKCAP, &child_lnkcap);
pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &parent_lnkctl);
pcie_capability_read_word(child, PCI_EXP_LNKCTL, &child_lnkctl);
+ /* Disable L0s/L1 before updating L1SS config */
+ if (FIELD_GET(PCI_EXP_LNKCTL_ASPMC, child_lnkctl) ||
+ FIELD_GET(PCI_EXP_LNKCTL_ASPMC, parent_lnkctl)) {
+ pcie_capability_write_word(child, PCI_EXP_LNKCTL,
+ child_lnkctl & ~PCI_EXP_LNKCTL_ASPMC);
+ pcie_capability_write_word(parent, PCI_EXP_LNKCTL,
+ parent_lnkctl & ~PCI_EXP_LNKCTL_ASPMC);
+ }
+
/*
* Setup L0s state
*
@@ -629,26 +860,35 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
* given link unless components on both sides of the link each
* support L0s.
*/
- if (parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPM_L0S)
- link->aspm_support |= ASPM_STATE_L0S;
+ if (parent->aspm_l0s_support && child->aspm_l0s_support)
+ link->aspm_support |= PCIE_LINK_STATE_L0S;
if (child_lnkctl & PCI_EXP_LNKCTL_ASPM_L0S)
- link->aspm_enabled |= ASPM_STATE_L0S_UP;
+ link->aspm_enabled |= PCIE_LINK_STATE_L0S_UP;
if (parent_lnkctl & PCI_EXP_LNKCTL_ASPM_L0S)
- link->aspm_enabled |= ASPM_STATE_L0S_DW;
+ link->aspm_enabled |= PCIE_LINK_STATE_L0S_DW;
/* Setup L1 state */
- if (parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPM_L1)
- link->aspm_support |= ASPM_STATE_L1;
+ if (parent->aspm_l1_support && child->aspm_l1_support)
+ link->aspm_support |= PCIE_LINK_STATE_L1;
if (parent_lnkctl & child_lnkctl & PCI_EXP_LNKCTL_ASPM_L1)
- link->aspm_enabled |= ASPM_STATE_L1;
+ link->aspm_enabled |= PCIE_LINK_STATE_L1;
aspm_l1ss_init(link);
+ /* Restore L0s/L1 if they were enabled */
+ if (FIELD_GET(PCI_EXP_LNKCTL_ASPMC, child_lnkctl) ||
+ FIELD_GET(PCI_EXP_LNKCTL_ASPMC, parent_lnkctl)) {
+ pcie_capability_write_word(parent, PCI_EXP_LNKCTL, parent_lnkctl);
+ pcie_capability_write_word(child, PCI_EXP_LNKCTL, child_lnkctl);
+ }
+
/* Save default state */
link->aspm_default = link->aspm_enabled;
+ pcie_aspm_override_default_link_state(link);
+
/* Setup initial capable state. Will be updated later */
link->aspm_capable = link->aspm_support;
@@ -662,58 +902,40 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
}
}
-/* Configure the ASPM L1 substates */
+/* Configure the ASPM L1 substates. Caller must disable L1 first. */
static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state)
{
- u32 val, enable_req;
+ u32 val = 0;
struct pci_dev *child = link->downstream, *parent = link->pdev;
- enable_req = (link->aspm_enabled ^ state) & state;
+ if (state & PCIE_LINK_STATE_L1_1)
+ val |= PCI_L1SS_CTL1_ASPM_L1_1;
+ if (state & PCIE_LINK_STATE_L1_2)
+ val |= PCI_L1SS_CTL1_ASPM_L1_2;
+ if (state & PCIE_LINK_STATE_L1_1_PCIPM)
+ val |= PCI_L1SS_CTL1_PCIPM_L1_1;
+ if (state & PCIE_LINK_STATE_L1_2_PCIPM)
+ val |= PCI_L1SS_CTL1_PCIPM_L1_2;
/*
- * Here are the rules specified in the PCIe spec for enabling L1SS:
- * - When enabling L1.x, enable bit at parent first, then at child
- * - When disabling L1.x, disable bit at child first, then at parent
- * - When enabling ASPM L1.x, need to disable L1
- * (at child followed by parent).
- * - The ASPM/PCIPM L1.2 must be disabled while programming timing
+ * PCIe r6.2, sec 5.5.4, rules for enabling L1 PM Substates:
+ * - Clear L1.x enable bits at child first, then at parent
+ * - Set L1.x enable bits at parent first, then at child
+ * - ASPM/PCIPM L1.2 must be disabled while programming timing
* parameters
- *
- * To keep it simple, disable all L1SS bits first, and later enable
- * what is needed.
*/
/* Disable all L1 substates */
- pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1,
- PCI_L1SS_CTL1_L1SS_MASK, 0);
- pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
- PCI_L1SS_CTL1_L1SS_MASK, 0);
- /*
- * If needed, disable L1, and it gets enabled later
- * in pcie_config_aspm_link().
- */
- if (enable_req & (ASPM_STATE_L1_1 | ASPM_STATE_L1_2)) {
- pcie_capability_clear_and_set_word(child, PCI_EXP_LNKCTL,
- PCI_EXP_LNKCTL_ASPM_L1, 0);
- pcie_capability_clear_and_set_word(parent, PCI_EXP_LNKCTL,
- PCI_EXP_LNKCTL_ASPM_L1, 0);
- }
-
- val = 0;
- if (state & ASPM_STATE_L1_1)
- val |= PCI_L1SS_CTL1_ASPM_L1_1;
- if (state & ASPM_STATE_L1_2)
- val |= PCI_L1SS_CTL1_ASPM_L1_2;
- if (state & ASPM_STATE_L1_1_PCIPM)
- val |= PCI_L1SS_CTL1_PCIPM_L1_1;
- if (state & ASPM_STATE_L1_2_PCIPM)
- val |= PCI_L1SS_CTL1_PCIPM_L1_2;
+ pci_clear_and_set_config_dword(child, child->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_L1SS_MASK, 0);
+ pci_clear_and_set_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_L1SS_MASK, 0);
/* Enable what we need to enable */
- pci_clear_and_set_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
- PCI_L1SS_CTL1_L1SS_MASK, val);
- pci_clear_and_set_dword(child, child->l1ss + PCI_L1SS_CTL1,
- PCI_L1SS_CTL1_L1SS_MASK, val);
+ pci_clear_and_set_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_L1SS_MASK, val);
+ pci_clear_and_set_config_dword(child, child->l1ss + PCI_L1SS_CTL1,
+ PCI_L1SS_CTL1_L1SS_MASK, val);
}
static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 val)
@@ -732,45 +954,60 @@ static void pcie_config_aspm_link(struct pcie_link_state *link, u32 state)
state &= (link->aspm_capable & ~link->aspm_disable);
/* Can't enable any substates if L1 is not enabled */
- if (!(state & ASPM_STATE_L1))
- state &= ~ASPM_STATE_L1SS;
+ if (!(state & PCIE_LINK_STATE_L1))
+ state &= ~PCIE_LINK_STATE_L1SS;
/* Spec says both ports must be in D0 before enabling PCI PM substates*/
if (parent->current_state != PCI_D0 || child->current_state != PCI_D0) {
- state &= ~ASPM_STATE_L1_SS_PCIPM;
- state |= (link->aspm_enabled & ASPM_STATE_L1_SS_PCIPM);
+ state &= ~PCIE_LINK_STATE_L1_SS_PCIPM;
+ state |= (link->aspm_enabled & PCIE_LINK_STATE_L1_SS_PCIPM);
}
/* Nothing to do if the link is already in the requested state */
if (link->aspm_enabled == state)
return;
/* Convert ASPM state to upstream/downstream ASPM register state */
- if (state & ASPM_STATE_L0S_UP)
+ if (state & PCIE_LINK_STATE_L0S_UP)
dwstream |= PCI_EXP_LNKCTL_ASPM_L0S;
- if (state & ASPM_STATE_L0S_DW)
+ if (state & PCIE_LINK_STATE_L0S_DW)
upstream |= PCI_EXP_LNKCTL_ASPM_L0S;
- if (state & ASPM_STATE_L1) {
+ if (state & PCIE_LINK_STATE_L1) {
upstream |= PCI_EXP_LNKCTL_ASPM_L1;
dwstream |= PCI_EXP_LNKCTL_ASPM_L1;
}
- if (link->aspm_capable & ASPM_STATE_L1SS)
- pcie_config_aspm_l1ss(link, state);
-
/*
- * Spec 2.0 suggests all functions should be configured the
- * same setting for ASPM. Enabling ASPM L1 should be done in
- * upstream component first and then downstream, and vice
- * versa for disabling ASPM L1. Spec doesn't mention L0S.
+ * Per PCIe r6.2, sec 5.5.4, setting either or both of the enable
+ * bits for ASPM L1 PM Substates must be done while ASPM L1 is
+ * disabled. Disable L1 here and apply new configuration after L1SS
+ * configuration has been completed.
+ *
+ * Per sec 7.5.3.7, when disabling ASPM L1, software must disable
+ * it in the Downstream component prior to disabling it in the
+ * Upstream component, and ASPM L1 must be enabled in the Upstream
+ * component prior to enabling it in the Downstream component.
+ *
+ * Sec 7.5.3.7 also recommends programming the same ASPM Control
+ * value for all functions of a multi-function device.
*/
- if (state & ASPM_STATE_L1)
- pcie_config_aspm_dev(parent, upstream);
+ list_for_each_entry(child, &linkbus->devices, bus_list)
+ pcie_config_aspm_dev(child, 0);
+ pcie_config_aspm_dev(parent, 0);
+
+ if (link->aspm_capable & PCIE_LINK_STATE_L1SS)
+ pcie_config_aspm_l1ss(link, state);
+
+ pcie_config_aspm_dev(parent, upstream);
list_for_each_entry(child, &linkbus->devices, bus_list)
pcie_config_aspm_dev(child, dwstream);
- if (!(state & ASPM_STATE_L1))
- pcie_config_aspm_dev(parent, upstream);
link->aspm_enabled = state;
+
+ /* Update latest ASPM configuration in saved context */
+ pci_save_aspm_l1ss_state(link->downstream);
+ pci_update_aspm_saved_state(link->downstream);
+ pci_save_aspm_l1ss_state(parent);
+ pci_update_aspm_saved_state(parent);
}
static void pcie_config_aspm_path(struct pcie_link_state *link)
@@ -940,6 +1177,78 @@ out:
up_read(&pci_bus_sem);
}
+void pci_bridge_reconfigure_ltr(struct pci_dev *pdev)
+{
+ struct pci_dev *bridge;
+ u32 ctl;
+
+ bridge = pci_upstream_bridge(pdev);
+ if (bridge && bridge->ltr_path) {
+ pcie_capability_read_dword(bridge, PCI_EXP_DEVCTL2, &ctl);
+ if (!(ctl & PCI_EXP_DEVCTL2_LTR_EN)) {
+ pci_dbg(bridge, "re-enabling LTR\n");
+ pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2,
+ PCI_EXP_DEVCTL2_LTR_EN);
+ }
+ }
+}
+
+void pci_configure_ltr(struct pci_dev *pdev)
+{
+ struct pci_host_bridge *host = pci_find_host_bridge(pdev->bus);
+ struct pci_dev *bridge;
+ u32 cap, ctl;
+
+ if (!pci_is_pcie(pdev))
+ return;
+
+ pcie_capability_read_dword(pdev, PCI_EXP_DEVCAP2, &cap);
+ if (!(cap & PCI_EXP_DEVCAP2_LTR))
+ return;
+
+ pcie_capability_read_dword(pdev, PCI_EXP_DEVCTL2, &ctl);
+ if (ctl & PCI_EXP_DEVCTL2_LTR_EN) {
+ if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT) {
+ pdev->ltr_path = 1;
+ return;
+ }
+
+ bridge = pci_upstream_bridge(pdev);
+ if (bridge && bridge->ltr_path)
+ pdev->ltr_path = 1;
+
+ return;
+ }
+
+ if (!host->native_ltr)
+ return;
+
+ /*
+ * Software must not enable LTR in an Endpoint unless the Root
+ * Complex and all intermediate Switches indicate support for LTR.
+ * PCIe r4.0, sec 6.18.
+ */
+ if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT) {
+ pcie_capability_set_word(pdev, PCI_EXP_DEVCTL2,
+ PCI_EXP_DEVCTL2_LTR_EN);
+ pdev->ltr_path = 1;
+ return;
+ }
+
+ /*
+ * If we're configuring a hot-added device, LTR was likely
+ * disabled in the upstream bridge, so re-enable it before enabling
+ * it in the new device.
+ */
+ bridge = pci_upstream_bridge(pdev);
+ if (bridge && bridge->ltr_path) {
+ pci_bridge_reconfigure_ltr(pdev);
+ pcie_capability_set_word(pdev, PCI_EXP_DEVCTL2,
+ PCI_EXP_DEVCTL2_LTR_EN);
+ pdev->ltr_path = 1;
+ }
+}
+
/* Recheck latencies and update aspm_capable for links under the root */
static void pcie_update_aspm_capable(struct pcie_link_state *root)
{
@@ -981,16 +1290,16 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev)
parent_link = link->parent;
/*
- * link->downstream is a pointer to the pci_dev of function 0. If
- * we remove that function, the pci_dev is about to be deallocated,
- * so we can't use link->downstream again. Free the link state to
- * avoid this.
+ * Free the parent link state, no later than function 0 (i.e.
+ * link->downstream) being removed.
*
- * If we're removing a non-0 function, it's possible we could
- * retain the link state, but PCIe r6.0, sec 7.5.3.7, recommends
- * programming the same ASPM Control value for all functions of
- * multi-function devices, so disable ASPM for all of them.
+ * Do not free the link state any earlier. If function 0 is a
+ * switch upstream port, this link state is parent_link to all
+ * subordinate ones.
*/
+ if (pdev != link->downstream)
+ goto out;
+
pcie_config_aspm_link(link, 0);
list_del(&link->sibling);
free_link_state(link);
@@ -1001,10 +1310,35 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev)
pcie_config_aspm_path(parent_link);
}
+ out:
mutex_unlock(&aspm_lock);
up_read(&pci_bus_sem);
}
+/*
+ * @pdev: the root port or switch downstream port
+ * @locked: whether pci_bus_sem is held
+ */
+void pcie_aspm_pm_state_change(struct pci_dev *pdev, bool locked)
+{
+ struct pcie_link_state *link = pdev->link_state;
+
+ if (aspm_disabled || !link)
+ return;
+ /*
+ * Devices changed PM state, we should recheck if latency
+ * meets all functions' requirement
+ */
+ if (!locked)
+ down_read(&pci_bus_sem);
+ mutex_lock(&aspm_lock);
+ pcie_update_aspm_capable(link->root);
+ pcie_config_aspm_path(link);
+ mutex_unlock(&aspm_lock);
+ if (!locked)
+ up_read(&pci_bus_sem);
+}
+
void pcie_aspm_powersave_config_link(struct pci_dev *pdev)
{
struct pcie_link_state *link = pdev->link_state;
@@ -1038,7 +1372,29 @@ static struct pcie_link_state *pcie_aspm_get_link(struct pci_dev *pdev)
return bridge->link_state;
}
-static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem)
+static u8 pci_calc_aspm_disable_mask(int state)
+{
+ state &= ~PCIE_LINK_STATE_CLKPM;
+
+ /* L1 PM substates require L1 */
+ if (state & PCIE_LINK_STATE_L1)
+ state |= PCIE_LINK_STATE_L1SS;
+
+ return state;
+}
+
+static u8 pci_calc_aspm_enable_mask(int state)
+{
+ state &= ~PCIE_LINK_STATE_CLKPM;
+
+ /* L1 PM substates require L1 */
+ if (state & PCIE_LINK_STATE_L1SS)
+ state |= PCIE_LINK_STATE_L1;
+
+ return state;
+}
+
+static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool locked)
{
struct pcie_link_state *link = pcie_aspm_get_link(pdev);
@@ -1057,28 +1413,17 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem)
return -EPERM;
}
- if (sem)
+ if (!locked)
down_read(&pci_bus_sem);
mutex_lock(&aspm_lock);
- if (state & PCIE_LINK_STATE_L0S)
- link->aspm_disable |= ASPM_STATE_L0S;
- if (state & PCIE_LINK_STATE_L1)
- link->aspm_disable |= ASPM_STATE_L1;
- if (state & PCIE_LINK_STATE_L1_1)
- link->aspm_disable |= ASPM_STATE_L1_1;
- if (state & PCIE_LINK_STATE_L1_2)
- link->aspm_disable |= ASPM_STATE_L1_2;
- if (state & PCIE_LINK_STATE_L1_1_PCIPM)
- link->aspm_disable |= ASPM_STATE_L1_1_PCIPM;
- if (state & PCIE_LINK_STATE_L1_2_PCIPM)
- link->aspm_disable |= ASPM_STATE_L1_2_PCIPM;
+ link->aspm_disable |= pci_calc_aspm_disable_mask(state);
pcie_config_aspm_link(link, policy_to_aspm_state(link));
if (state & PCIE_LINK_STATE_CLKPM)
link->clkpm_disable = 1;
pcie_set_clkpm(link, policy_to_clkpm_state(link));
mutex_unlock(&aspm_lock);
- if (sem)
+ if (!locked)
up_read(&pci_bus_sem);
return 0;
@@ -1086,7 +1431,9 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem)
int pci_disable_link_state_locked(struct pci_dev *pdev, int state)
{
- return __pci_disable_link_state(pdev, state, false);
+ lockdep_assert_held_read(&pci_bus_sem);
+
+ return __pci_disable_link_state(pdev, state, true);
}
EXPORT_SYMBOL(pci_disable_link_state_locked);
@@ -1101,21 +1448,11 @@ EXPORT_SYMBOL(pci_disable_link_state_locked);
*/
int pci_disable_link_state(struct pci_dev *pdev, int state)
{
- return __pci_disable_link_state(pdev, state, true);
+ return __pci_disable_link_state(pdev, state, false);
}
EXPORT_SYMBOL(pci_disable_link_state);
-/**
- * pci_enable_link_state - Clear and set the default device link state so that
- * the link may be allowed to enter the specified states. Note that if the
- * BIOS didn't grant ASPM control to the OS, this does nothing because we can't
- * touch the LNKCTL register. Also note that this does not enable states
- * disabled by pci_disable_link_state(). Return 0 or a negative errno.
- *
- * @pdev: PCI device
- * @state: Mask of ASPM link states to enable
- */
-int pci_enable_link_state(struct pci_dev *pdev, int state)
+static int __pci_enable_link_state(struct pci_dev *pdev, int state, bool locked)
{
struct pcie_link_state *link = pcie_aspm_get_link(pdev);
@@ -1132,33 +1469,76 @@ int pci_enable_link_state(struct pci_dev *pdev, int state)
return -EPERM;
}
- down_read(&pci_bus_sem);
+ if (!locked)
+ down_read(&pci_bus_sem);
mutex_lock(&aspm_lock);
- link->aspm_default = 0;
- if (state & PCIE_LINK_STATE_L0S)
- link->aspm_default |= ASPM_STATE_L0S;
- if (state & PCIE_LINK_STATE_L1)
- link->aspm_default |= ASPM_STATE_L1;
- /* L1 PM substates require L1 */
- if (state & PCIE_LINK_STATE_L1_1)
- link->aspm_default |= ASPM_STATE_L1_1 | ASPM_STATE_L1;
- if (state & PCIE_LINK_STATE_L1_2)
- link->aspm_default |= ASPM_STATE_L1_2 | ASPM_STATE_L1;
- if (state & PCIE_LINK_STATE_L1_1_PCIPM)
- link->aspm_default |= ASPM_STATE_L1_1_PCIPM | ASPM_STATE_L1;
- if (state & PCIE_LINK_STATE_L1_2_PCIPM)
- link->aspm_default |= ASPM_STATE_L1_2_PCIPM | ASPM_STATE_L1;
+ link->aspm_default = pci_calc_aspm_enable_mask(state);
pcie_config_aspm_link(link, policy_to_aspm_state(link));
link->clkpm_default = (state & PCIE_LINK_STATE_CLKPM) ? 1 : 0;
pcie_set_clkpm(link, policy_to_clkpm_state(link));
mutex_unlock(&aspm_lock);
- up_read(&pci_bus_sem);
+ if (!locked)
+ up_read(&pci_bus_sem);
return 0;
}
+
+/**
+ * pci_enable_link_state - Clear and set the default device link state so that
+ * the link may be allowed to enter the specified states. Note that if the
+ * BIOS didn't grant ASPM control to the OS, this does nothing because we can't
+ * touch the LNKCTL register. Also note that this does not enable states
+ * disabled by pci_disable_link_state(). Return 0 or a negative errno.
+ *
+ * Note: Ensure devices are in D0 before enabling PCI-PM L1 PM Substates, per
+ * PCIe r6.0, sec 5.5.4.
+ *
+ * @pdev: PCI device
+ * @state: Mask of ASPM link states to enable
+ */
+int pci_enable_link_state(struct pci_dev *pdev, int state)
+{
+ return __pci_enable_link_state(pdev, state, false);
+}
EXPORT_SYMBOL(pci_enable_link_state);
+/**
+ * pci_enable_link_state_locked - Clear and set the default device link state
+ * so that the link may be allowed to enter the specified states. Note that if
+ * the BIOS didn't grant ASPM control to the OS, this does nothing because we
+ * can't touch the LNKCTL register. Also note that this does not enable states
+ * disabled by pci_disable_link_state(). Return 0 or a negative errno.
+ *
+ * Note: Ensure devices are in D0 before enabling PCI-PM L1 PM Substates, per
+ * PCIe r6.0, sec 5.5.4.
+ *
+ * @pdev: PCI device
+ * @state: Mask of ASPM link states to enable
+ *
+ * Context: Caller holds pci_bus_sem read lock.
+ */
+int pci_enable_link_state_locked(struct pci_dev *pdev, int state)
+{
+ lockdep_assert_held_read(&pci_bus_sem);
+
+ return __pci_enable_link_state(pdev, state, true);
+}
+EXPORT_SYMBOL(pci_enable_link_state_locked);
+
+void pcie_aspm_remove_cap(struct pci_dev *pdev, u32 lnkcap)
+{
+ if (lnkcap & PCI_EXP_LNKCAP_ASPM_L0S)
+ pdev->aspm_l0s_support = 0;
+ if (lnkcap & PCI_EXP_LNKCAP_ASPM_L1)
+ pdev->aspm_l1_support = 0;
+
+ pci_info(pdev, "ASPM: Link Capabilities%s%s treated as unsupported to avoid device defect\n",
+ lnkcap & PCI_EXP_LNKCAP_ASPM_L0S ? " L0s" : "",
+ lnkcap & PCI_EXP_LNKCAP_ASPM_L1 ? " L1" : "");
+
+}
+
static int pcie_aspm_set_policy(const char *val,
const struct kernel_param *kp)
{
@@ -1247,10 +1627,12 @@ static ssize_t aspm_attr_store_common(struct device *dev,
if (state_enable) {
link->aspm_disable &= ~state;
/* need to enable L1 for substates */
- if (state & ASPM_STATE_L1SS)
- link->aspm_disable &= ~ASPM_STATE_L1;
+ if (state & PCIE_LINK_STATE_L1SS)
+ link->aspm_disable &= ~PCIE_LINK_STATE_L1;
} else {
link->aspm_disable |= state;
+ if (state & PCIE_LINK_STATE_L1)
+ link->aspm_disable |= PCIE_LINK_STATE_L1SS;
}
pcie_config_aspm_link(link, policy_to_aspm_state(link));
@@ -1264,12 +1646,12 @@ static ssize_t aspm_attr_store_common(struct device *dev,
#define ASPM_ATTR(_f, _s) \
static ssize_t _f##_show(struct device *dev, \
struct device_attribute *attr, char *buf) \
-{ return aspm_attr_show_common(dev, attr, buf, ASPM_STATE_##_s); } \
+{ return aspm_attr_show_common(dev, attr, buf, PCIE_LINK_STATE_##_s); } \
\
static ssize_t _f##_store(struct device *dev, \
struct device_attribute *attr, \
const char *buf, size_t len) \
-{ return aspm_attr_store_common(dev, attr, buf, len, ASPM_STATE_##_s); }
+{ return aspm_attr_store_common(dev, attr, buf, len, PCIE_LINK_STATE_##_s); }
ASPM_ATTR(l0s_aspm, L0S)
ASPM_ATTR(l1_aspm, L1)
@@ -1336,12 +1718,12 @@ static umode_t aspm_ctrl_attrs_are_visible(struct kobject *kobj,
struct pci_dev *pdev = to_pci_dev(dev);
struct pcie_link_state *link = pcie_aspm_get_link(pdev);
static const u8 aspm_state_map[] = {
- ASPM_STATE_L0S,
- ASPM_STATE_L1,
- ASPM_STATE_L1_1,
- ASPM_STATE_L1_2,
- ASPM_STATE_L1_1_PCIPM,
- ASPM_STATE_L1_2_PCIPM,
+ PCIE_LINK_STATE_L0S,
+ PCIE_LINK_STATE_L1,
+ PCIE_LINK_STATE_L1_1,
+ PCIE_LINK_STATE_L1_2,
+ PCIE_LINK_STATE_L1_1_PCIPM,
+ PCIE_LINK_STATE_L1_2_PCIPM,
};
if (aspm_disabled || !link)
@@ -1363,12 +1745,12 @@ static int __init pcie_aspm_disable(char *str)
{
if (!strcmp(str, "off")) {
aspm_policy = POLICY_DEFAULT;
- aspm_disabled = 1;
+ aspm_disabled = true;
aspm_support_enabled = false;
- printk(KERN_INFO "PCIe ASPM is disabled\n");
+ pr_info("PCIe ASPM is disabled\n");
} else if (!strcmp(str, "force")) {
- aspm_force = 1;
- printk(KERN_INFO "PCIe ASPM is forcibly enabled\n");
+ aspm_force = true;
+ pr_info("PCIe ASPM is forcibly enabled\n");
}
return 1;
}
@@ -1385,7 +1767,7 @@ void pcie_no_aspm(void)
*/
if (!aspm_force) {
aspm_policy = POLICY_DEFAULT;
- aspm_disabled = 1;
+ aspm_disabled = true;
}
}
@@ -1393,3 +1775,5 @@ bool pcie_aspm_support_enabled(void)
{
return aspm_support_enabled;
}
+
+#endif /* CONFIG_PCIEASPM */
generated by cgit (git 2.34.1) at 2025-12-24 22:46:07 +0000