Commit c6e5f02b authored by Saheed O. Bolarinwa's avatar Saheed O. Bolarinwa Committed by Bjorn Helgaas

PCI/ASPM: Remove struct aspm_register_info.support

Previously we stored the "ASPM Support" field from the Link Capabilities
register in the struct aspm_register_info.

Read the Link Capabilities directly when needed and remove it from the
struct aspm_register_info.  No functional change intended.

[bhelgaas: remove pci_dev cached copy since LNKCAP isn't truly read-only,
add PCI_EXP_LNKCAP_ASPM_L0S & PCI_EXP_LNKCAP_ASPM_L1, check them directly
instead of adding aspm_support()]
Link: https://lore.kernel.org/r/20201015193039.12585-5-helgaas@kernel.orgSigned-off-by: default avatarSaheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 190cd42c
......@@ -381,7 +381,6 @@ static void encode_l12_threshold(u32 threshold_us, u32 *scale, u32 *value)
}
struct aspm_register_info {
u32 support:2;
u32 enabled:2;
u32 latency_encoding_l0s;
u32 latency_encoding_l1;
......@@ -400,7 +399,6 @@ static void pcie_get_aspm_reg(struct pci_dev *pdev,
u32 reg32;
pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &reg32);
info->support = (reg32 & PCI_EXP_LNKCAP_ASPMS) >> 10;
info->latency_encoding_l0s = (reg32 & PCI_EXP_LNKCAP_L0SEL) >> 12;
info->latency_encoding_l1 = (reg32 & PCI_EXP_LNKCAP_L1EL) >> 15;
pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &reg16);
......@@ -550,6 +548,7 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link,
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;
struct pci_bus *linkbus = parent->subordinate;
struct aspm_register_info upreg, dwreg;
......@@ -560,24 +559,26 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
return;
}
/* Get upstream/downstream components' register state */
pcie_get_aspm_reg(parent, &upreg);
pcie_get_aspm_reg(child, &dwreg);
/*
* If ASPM not supported, don't mess with the clocks and link,
* bail out now.
*/
if (!(upreg.support & dwreg.support))
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))
return;
/* Configure common clock before checking latencies */
pcie_aspm_configure_common_clock(link);
/*
* Re-read upstream/downstream components' register state
* after clock configuration
* Re-read upstream/downstream components' register state after
* clock configuration. L0s & L1 exit latencies in the otherwise
* 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_get_aspm_reg(parent, &upreg);
pcie_get_aspm_reg(child, &dwreg);
......@@ -588,8 +589,9 @@ 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 (dwreg.support & upreg.support & PCIE_LINK_STATE_L0S)
if (parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPM_L0S)
link->aspm_support |= ASPM_STATE_L0S;
if (dwreg.enabled & PCIE_LINK_STATE_L0S)
link->aspm_enabled |= ASPM_STATE_L0S_UP;
if (upreg.enabled & PCIE_LINK_STATE_L0S)
......@@ -598,8 +600,9 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
link->latency_dw.l0s = calc_l0s_latency(dwreg.latency_encoding_l0s);
/* Setup L1 state */
if (upreg.support & dwreg.support & PCIE_LINK_STATE_L1)
if (parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPM_L1)
link->aspm_support |= ASPM_STATE_L1;
if (upreg.enabled & dwreg.enabled & PCIE_LINK_STATE_L1)
link->aspm_enabled |= ASPM_STATE_L1;
link->latency_up.l1 = calc_l1_latency(upreg.latency_encoding_l1);
......
......@@ -532,6 +532,8 @@
#define PCI_EXP_LNKCAP_SLS_32_0GB 0x00000005 /* LNKCAP2 SLS Vector bit 4 */
#define PCI_EXP_LNKCAP_MLW 0x000003f0 /* Maximum Link Width */
#define PCI_EXP_LNKCAP_ASPMS 0x00000c00 /* ASPM Support */
#define PCI_EXP_LNKCAP_ASPM_L0S 0x00000400 /* ASPM L0s Support */
#define PCI_EXP_LNKCAP_ASPM_L1 0x00000800 /* ASPM L1 Support */
#define PCI_EXP_LNKCAP_L0SEL 0x00007000 /* L0s Exit Latency */
#define PCI_EXP_LNKCAP_L1EL 0x00038000 /* L1 Exit Latency */
#define PCI_EXP_LNKCAP_CLKPM 0x00040000 /* Clock Power Management */
......
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