[PATCH u-boot-marvell] pci: mvebu: Ensure that root port is always on root zero bus

Pali Rohár
2022-02-15T10:34:22Z

Writing to the PCI_PRIMARY_BUS register of the root port should not change
bus number on which is root port present.

Same change and exactly same fix as was done in commit for pci-aardvark.c.

Fixes: a7b61ab58d5d ("pci: pci_mvebu: Properly configure and use PCI Bridge (PCIe Root Port)")
Signed-off-by: Pali Rohár <pali@kernel.org>
---
drivers/pci/pci_mvebu.c | 52 +++++++++++++++++------------------------
1 file changed, 22 insertions(+), 30 deletions(-)

diff --git a/drivers/pci/pci_mvebu.c b/drivers/pci/pci_mvebu.c
index d99a99bae940..5a0a59a8b9ec 100644
--- a/drivers/pci/pci_mvebu.c
+++ b/drivers/pci/pci_mvebu.c
@@ -78,7 +78,6 @@ struct mvebu_pcie {
bool is_x4;
int devfn;
u32 lane_mask;
- int first_busno;
int sec_busno;
char name[16];
unsigned int mem_target;
@@ -140,12 +139,12 @@ static inline struct mvebu_pcie *hose_to_pcie(struct pci_controller *hose)
static bool mvebu_pcie_valid_addr(struct mvebu_pcie *pcie,
int busno, int dev, int func)
{
- /* On primary bus is only one PCI Bridge */
- if (busno == pcie->first_busno && (dev != 0 || func != 0))
+ /* On the root bus is only one PCI Bridge */
+ if (busno == 0 && (dev != 0 || func != 0))
return false;

/* Access to other buses is possible when link is up */
- if (busno != pcie->first_busno && !mvebu_pcie_link_up(pcie))
+ if (busno != 0 && !mvebu_pcie_link_up(pcie))
return false;

/* On secondary bus can be only one PCIe device */
@@ -173,15 +172,15 @@ static int mvebu_pcie_read_config(const struct udevice *bus, pci_dev_t bdf,
}

/*
- * The configuration space of the PCI Bridge on primary (first) bus is
+ * The configuration space of the PCI Bridge on the root bus (zero) is
* of Type 0 but the BAR registers (including ROM BAR) don't have the
* same meaning as in the PCIe specification. Therefore do not access
* BAR registers and non-common registers (those which have different
* meaning for Type 0 and Type 1 config space) of the PCI Bridge and
* instead read their content from driver virtual cfgcache[].
*/
- if (busno == pcie->first_busno && ((offset >= 0x10 && offset < 0x34) ||
- (offset >= 0x38 && offset < 0x3c))) {
+ if (busno == 0 && ((offset >= 0x10 && offset < 0x34) ||
+ (offset >= 0x38 && offset < 0x3c))) {
data = pcie->cfgcache[(offset - 0x10) / 4];
debug("(addr,size,val)=(0x%04x, %d, 0x%08x) from cfgcache\n",
offset, size, data);
@@ -190,10 +189,10 @@ static int mvebu_pcie_read_config(const struct udevice *bus, pci_dev_t bdf,
}

/*
- * PCI bridge is device 0 at primary bus but mvebu has it mapped on
- * secondary bus with device number 1.
+ * PCI bridge is device 0 at the root bus (zero) but mvebu has it
+ * mapped on secondary bus with device number 1.
*/
- if (busno == pcie->first_busno)
+ if (busno == 0)
addr = PCI_CONF1_EXT_ADDRESS(pcie->sec_busno, 1, 0, offset);
else
addr = PCI_CONF1_EXT_ADDRESS(busno, PCI_DEV(bdf), PCI_FUNC(bdf), offset);
@@ -216,8 +215,7 @@ static int mvebu_pcie_read_config(const struct udevice *bus, pci_dev_t bdf,
return -EINVAL;
}

- if (busno == pcie->first_busno &&
- (offset & ~3) == (PCI_HEADER_TYPE & ~3)) {
+ if (busno == 0 && (offset & ~3) == (PCI_HEADER_TYPE & ~3)) {
/*
* Change Header Type of PCI Bridge device to Type 1
* (0x01, used by PCI Bridges) because mvebu reports
@@ -257,10 +255,10 @@ static int mvebu_pcie_write_config(struct udevice *bus, pci_dev_t bdf,
* config registers are not available, so we write their content only
* into driver virtual cfgcache[].
* And as explained in mvebu_pcie_probe(), mvebu has its own specific
- * way for configuring primary and secondary bus numbers.
+ * way for configuring secondary bus number.
*/
- if (busno == pcie->first_busno && ((offset >= 0x10 && offset < 0x34) ||
- (offset >= 0x38 && offset < 0x3c))) {
+ if (busno == 0 && ((offset >= 0x10 && offset < 0x34) ||
+ (offset >= 0x38 && offset < 0x3c))) {
debug("Writing to cfgcache only\n");
data = pcie->cfgcache[(offset - 0x10) / 4];
data = pci_conv_size_to_32(data, value, offset, size);
@@ -270,12 +268,6 @@ static int mvebu_pcie_write_config(struct udevice *bus, pci_dev_t bdf,
(offset & ~3) == PCI_ROM_ADDRESS1)
data = 0x0;
pcie->cfgcache[(offset - 0x10) / 4] = data;
- /* mvebu has its own way how to set PCI primary bus number */
- if (offset == PCI_PRIMARY_BUS) {
- pcie->first_busno = data & 0xff;
- debug("Primary bus number was changed to %d\n",
- pcie->first_busno);
- }
/* mvebu has its own way how to set PCI secondary bus number */
if (offset == PCI_SECONDARY_BUS ||
(offset == PCI_PRIMARY_BUS && size != PCI_SIZE_8)) {
@@ -288,10 +280,10 @@ static int mvebu_pcie_write_config(struct udevice *bus, pci_dev_t bdf,
}

/*
- * PCI bridge is device 0 at primary bus but mvebu has it mapped on
- * secondary bus with device number 1.
+ * PCI bridge is device 0 at the root bus (zero) but mvebu has it
+ * mapped on secondary bus with device number 1.
*/
- if (busno == pcie->first_busno)
+ if (busno == 0)
addr = PCI_CONF1_EXT_ADDRESS(pcie->sec_busno, 1, 0, offset);
else
addr = PCI_CONF1_EXT_ADDRESS(busno, PCI_DEV(bdf), PCI_FUNC(bdf), offset);
@@ -473,9 +465,9 @@ static int mvebu_pcie_probe(struct udevice *dev)
* target device equals local device number then request is routed to
* PCI Bridge which represent local PCIe Root Port.
*
- * It means that PCI primary and secondary buses shares one bus number
+ * It means that PCI root and secondary buses shares one bus number
* which is configured via local bus number. Determination if config
- * request should go to primary or secondary bus is done based on local
+ * request should go to root or secondary bus is done based on local
* device number.
*
* PCIe is point-to-point bus, so at secondary bus is always exactly one
@@ -487,13 +479,13 @@ static int mvebu_pcie_probe(struct udevice *dev)
* secondary bus number. Set it to 0 as U-Boot CONFIG_PCI_PNP code will
* later configure it via config write requests to the correct value.
* mvebu_pcie_write_config() catches config write requests which tries
- * to change primary/secondary bus number and correctly updates local
- * bus number based on new secondary bus number.
+ * to change secondary bus number and correctly updates local bus number
+ * based on new secondary bus number.
*
* With this configuration is PCI Bridge available at secondary bus as
- * device number 1. But it must be available at primary bus as device
+ * device number 1. But it must be available at root bus (zero) as device
* number 0. So in mvebu_pcie_read_config() and mvebu_pcie_write_config()
- * functions rewrite address to the real one when accessing primary bus.
+ * functions rewrite address to the real one when accessing the root bus.
*/
mvebu_pcie_set_local_bus_nr(pcie, 0);
mvebu_pcie_set_local_dev_nr(pcie, 1);
--
2.20.1