From 5e0eaa7d3679c3ef8618803bc9311270e5816641 Mon Sep 17 00:00:00 2001 From: Kenji Kaneshige Date: Wed, 13 May 2009 12:21:48 +0900 Subject: [PATCH] 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 Signed-off-by: Kenji Kaneshige Signed-off-by: Jesse Barnes --- drivers/pci/pcie/aspm.c | 75 +++++++++++++++++++---------------------- 1 file changed, 35 insertions(+), 40 deletions(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index d85f77ff150c..23fabb303e82 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 (latency_encoding == 0x7) { - if (ac) - ns = -1U; - else - ns = 5*1000; /* > 4us */ - } else - ns *= (1 << latency_encoding); - return ns; + if (encoding == 0x7) + return (5 * 1000); /* > 4us */ + 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 L0s acceptable latency encoding to ns */ +static u32 calc_l0s_acceptable(u32 encoding) { - unsigned int ns = 1000; + if (encoding == 0x7) + return -1U; + return (64 << encoding); +} - if (latency_encoding == 0x7) { - if (ac) - ns = -1U; - else - ns = 65*1000; /* > 64us */ - } else - ns *= (1 << latency_encoding); - return ns; +/* Convert L1 latency encoding to ns */ +static u32 calc_l1_latency(u32 encoding) +{ + if (encoding == 0x7) + return (65 * 1000); /* > 64us */ + return (1000 << encoding); +} + +/* 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, ®16); *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, ®32); - 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); } } }