[RFC PATCH v4 4/5] PCI/ASPM: Remove struct pcie_link_state.downstream

Saheed O. Bolarinwa
2021-11-07T16:30:02Z

Information on the downstream component is cached in
struct pcie_link_state.downstream it obtained within
alloc_pcie_link_state() by calling pci_function_0()

- remove *downstream* from the struct pcie_link_state.
- replaces references to pcie_link_state.downstream with
a call to pci_function_0(pdev->subordinate).

Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
---
drivers/pci/pcie/aspm.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 90c7a0b379f4..12623556f750 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -48,7 +48,6 @@ struct aspm_latency {

struct pcie_link_state {
struct pci_dev *pdev; /* Upstream component of the Link */
- struct pci_dev *downstream; /* Downstream component, function 0 */
struct list_head sibling; /* node in link_list */

/* ASPM state */
@@ -462,7 +461,8 @@ static void pci_clear_and_set_dword(struct pci_dev *pdev, int pos,
static void aspm_calc_l1ss_info(struct pcie_link_state *link,
u32 parent_l1ss_cap, u32 child_l1ss_cap)
{
- struct pci_dev *child = link->downstream, *parent = link->pdev;
+ struct pci_dev *parent = link->pdev;
+ struct pci_dev *child = pci_function_0(link->pdev->subordinate);
u32 val1, val2, scale1, scale2;
u32 t_common_mode, t_power_on, l1_2_threshold, scale, value;
u32 ctl1 = 0, ctl2 = 0;
@@ -552,7 +552,8 @@ 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;
+ struct pci_dev *parent = link->pdev;
+ struct pci_dev *child = pci_function_0(link->pdev->subordinate);
u32 parent_lnkcap, child_lnkcap;
u16 parent_lnkctl, child_lnkctl;
u32 parent_l1ss_cap, child_l1ss_cap;
@@ -694,7 +695,8 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state)
{
u32 val, enable_req;
- struct pci_dev *child = link->downstream, *parent = link->pdev;
+ struct pci_dev *parent = link->pdev;
+ struct pci_dev *child = pci_function_0(link->pdev->subordinate);

enable_req = (link->aspm_enabled ^ state) & state;

@@ -753,7 +755,8 @@ static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 val)
static void pcie_config_aspm_link(struct pcie_link_state *link, u32 state)
{
u32 upstream = 0, dwstream = 0;
- struct pci_dev *child = link->downstream, *parent = link->pdev;
+ struct pci_dev *parent = link->pdev;
+ struct pci_dev *child = pci_function_0(link->pdev->subordinate);
struct pci_bus *linkbus = parent->subordinate;

/* Enable only the states that were not explicitly disabled */
@@ -879,7 +882,6 @@ static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev)

INIT_LIST_HEAD(&link->sibling);
link->pdev = pdev;
- link->downstream = pci_function_0(pdev->subordinate);