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authorKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>2009-05-13 03:21:48 (GMT)
committerJesse Barnes <jbarnes@virtuousgeek.org>2009-06-18 21:02:21 (GMT)
commit5e0eaa7d3679c3ef8618803bc9311270e5816641 (patch)
tree895538798c0fd42aa499ac78ed0cb40a8fec27fa /drivers/pci/pcie/aspm.c
parent7ab709910323a8af20722c066267516b3e7680a2 (diff)
downloadlinux-5e0eaa7d3679c3ef8618803bc9311270e5816641.tar.xz
PCI ASPM: cleanup calc_Lx_latency
Cleanup for calc_L0S_latency() and calc_L1_latency(). - Separate exit latency and acceptable latency calculation. - Some minor cleanups. Acked-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci/pcie/aspm.c')
-rw-r--r--drivers/pci/pcie/aspm.c73
1 files changed, 34 insertions, 39 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index d85f77f..23fabb3 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -257,38 +257,36 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
pci_write_config_word(parent, ppos + PCI_EXP_LNKCTL, parent_reg);
}
-/*
- * calc_L0S_latency: Convert L0s latency encoding to ns
- */
-static unsigned int calc_L0S_latency(unsigned int latency_encoding, int ac)
+/* Convert L0s latency encoding to ns */
+static u32 calc_l0s_latency(u32 encoding)
{
- unsigned int ns = 64;
+ if (encoding == 0x7)
+ return (5 * 1000); /* > 4us */
+ return (64 << encoding);
+}
- if (latency_encoding == 0x7) {
- if (ac)
- ns = -1U;
- else
- ns = 5*1000; /* > 4us */
- } else
- ns *= (1 << latency_encoding);
- return ns;
+/* Convert L0s acceptable latency encoding to ns */
+static u32 calc_l0s_acceptable(u32 encoding)
+{
+ if (encoding == 0x7)
+ return -1U;
+ return (64 << encoding);
}
-/*
- * calc_L1_latency: Convert L1 latency encoding to ns
- */
-static unsigned int calc_L1_latency(unsigned int latency_encoding, int ac)
+/* Convert L1 latency encoding to ns */
+static u32 calc_l1_latency(u32 encoding)
{
- unsigned int ns = 1000;
+ if (encoding == 0x7)
+ return (65 * 1000); /* > 64us */
+ return (1000 << encoding);
+}
- if (latency_encoding == 0x7) {
- if (ac)
- ns = -1U;
- else
- ns = 65*1000; /* > 64us */
- } else
- ns *= (1 << latency_encoding);
- return ns;
+/* Convert L1 acceptable latency encoding to ns */
+static u32 calc_l1_acceptable(u32 encoding)
+{
+ if (encoding == 0x7)
+ return -1U;
+ return (1000 << encoding);
}
static void pcie_aspm_get_cap_device(struct pci_dev *pdev, u32 *state,
@@ -296,7 +294,7 @@ static void pcie_aspm_get_cap_device(struct pci_dev *pdev, u32 *state,
{
int pos;
u16 reg16;
- u32 reg32, latency;
+ u32 reg32, encoding;
*l0s = *l1 = *enabled = 0;
pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
@@ -308,11 +306,11 @@ static void pcie_aspm_get_cap_device(struct pci_dev *pdev, u32 *state,
if (*state == 0)
return;
- latency = (reg32 & PCI_EXP_LNKCAP_L0SEL) >> 12;
- *l0s = calc_L0S_latency(latency, 0);
+ encoding = (reg32 & PCI_EXP_LNKCAP_L0SEL) >> 12;
+ *l0s = calc_l0s_latency(encoding);
if (*state & PCIE_LINK_STATE_L1) {
- latency = (reg32 & PCI_EXP_LNKCAP_L1EL) >> 15;
- *l1 = calc_L1_latency(latency, 0);
+ encoding = (reg32 & PCI_EXP_LNKCAP_L1EL) >> 15;
+ *l1 = calc_l1_latency(encoding);
}
pci_read_config_word(pdev, pos + PCI_EXP_LNKCTL, &reg16);
*enabled = reg16 & (PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1);
@@ -358,8 +356,7 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
/* ENDPOINT states*/
list_for_each_entry(child, &linkbus->devices, bus_list) {
int pos;
- u32 reg32;
- unsigned int latency;
+ u32 reg32, encoding;
struct aspm_latency *acceptable =
&link->acceptable[PCI_FUNC(child->devfn)];
@@ -369,13 +366,11 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
pos = pci_find_capability(child, PCI_CAP_ID_EXP);
pci_read_config_dword(child, pos + PCI_EXP_DEVCAP, &reg32);
- latency = (reg32 & PCI_EXP_DEVCAP_L0S) >> 6;
- latency = calc_L0S_latency(latency, 1);
- acceptable->l0s = latency;
+ encoding = (reg32 & PCI_EXP_DEVCAP_L0S) >> 6;
+ acceptable->l0s = calc_l0s_acceptable(encoding);
if (link->aspm_support & PCIE_LINK_STATE_L1) {
- latency = (reg32 & PCI_EXP_DEVCAP_L1) >> 9;
- latency = calc_L1_latency(latency, 1);
- acceptable->l1 = latency;
+ encoding = (reg32 & PCI_EXP_DEVCAP_L1) >> 9;
+ acceptable->l1 = calc_l1_acceptable(encoding);
}
}
}