[PATCH v4 09/12] PCI: brcmstb: Set internal memory viewport sizes

Jim Quinlan
2020-06-05T21:27:48Z

BrcmSTB PCIe controllers are intimately connected to the memory
controller(s) on the SOC. There is a "viewport" for each memory controller
that allows inbound accesses to CPU memory. Each viewport's size must be
set to a power of two, and that size must be equal to or larger than the
amount of memory each controller supports.

Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
---
drivers/pci/controller/pcie-brcmstb.c | 67 ++++++++++++++++++++-------
1 file changed, 49 insertions(+), 18 deletions(-)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index ca825d7ca4fc..71e5d4326a79 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -55,6 +55,8 @@
#define PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK 0x300000
#define PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_128 0x0
#define PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK 0xf8000000
+#define PCIE_MISC_MISC_CTRL_SCB1_SIZE_MASK 0x07c00000
+#define PCIE_MISC_MISC_CTRL_SCB2_SIZE_MASK 0x0000001f

#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LO 0x400c
#define PCIE_MEM_WIN0_LO(win) \
@@ -152,6 +154,7 @@
#define SSC_STATUS_OFFSET 0x1
#define SSC_STATUS_SSC_MASK 0x400
#define SSC_STATUS_PLL_LOCK_MASK 0x800
+#define PCIE_BRCM_MAX_MEMC 3

/* Rescal registers */
#define PCIE_DVT_PMU_PCIE_PHY_CTRL 0xc700
@@ -261,6 +264,8 @@ struct brcm_pcie {
const int *reg_field_info;
enum pcie_type type;
struct reset_control *rescal;
+ int num_memc;
+ u64 memc_size[PCIE_BRCM_MAX_MEMC];
};

/*
@@ -717,22 +722,40 @@ static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie,
u64 *rc_bar2_offset)
{
struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
- struct device *dev = pcie->dev;
struct resource_entry *entry;
+ struct device *dev = pcie->dev;
+ u64 lowest_pcie_addr = ~(u64)0;
+ int ret, i = 0;
+ u64 size = 0;

- entry = resource_list_first_type(&bridge->dma_ranges, IORESOURCE_MEM);
- if (!entry)
- return -ENODEV;
+ resource_list_for_each_entry(entry, &bridge->dma_ranges) {
+ u64 pcie_beg = entry->res->start - entry->offset;

+ size += entry->res->end - entry->res->start + 1;
+ if (pcie_beg < lowest_pcie_addr)
+ lowest_pcie_addr = pcie_beg;
+ }

- /*
- * The controller expects the inbound window offset to be calculated as
- * the difference between PCIe's address space and CPU's. The offset
- * provided by the firmware is calculated the opposite way, so we
- * negate it.
- */
- *rc_bar2_offset = -entry->offset;
- *rc_bar2_size = 1ULL << fls64(entry->res->end - entry->res->start);
+ ret = of_property_read_variable_u64_array(
+ pcie->np, "brcm,scb-sizes", pcie->memc_size, 1,
+ PCIE_BRCM_MAX_MEMC);
+
+ if (ret <= 0) {
+ /* Make an educated guess */
+ pcie->num_memc = 1;
+ pcie->memc_size[0] = 1 << fls64(size - 1);
+ } else {
+ pcie->num_memc = ret;
+ }
+
+ /* Each memc is viewed through a "port" that is a power of 2 */
+ for (i = 0, size = 0; i < pcie->num_memc; i++)
+ size += pcie->memc_size[i];
+
+ /* System memory starts at this address in PCIe-space */
+ *rc_bar2_offset = lowest_pcie_addr;
+ /* The sum of all memc views must also be a power of 2 */
+ *rc_bar2_size = 1ULL << fls64(size - 1);

/*
* We validate the inbound memory view even though we should trust
@@ -784,12 +807,11 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
void __iomem *base = pcie->base;
struct device *dev = pcie->dev;
struct resource_entry *entry;
- unsigned int scb_size_val;
bool ssc_good = false;
struct resource *res;
int num_out_wins = 0;
u16 nlw, cls, lnksta;
- int i, ret;
+ int i, ret, memc;
u32 tmp, aspm_support;

/* Reset the bridge */
@@ -825,11 +847,20 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
writel(upper_32_bits(rc_bar2_offset),
base + PCIE_MISC_RC_BAR2_CONFIG_HI);

- scb_size_val = rc_bar2_size ?
- ilog2(rc_bar2_size) - 15 : 0xf; /* 0xf is 1GB */
tmp = readl(base + PCIE_MISC_MISC_CTRL);
- u32p_replace_bits(&tmp, scb_size_val,
- PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK);
+ for (memc = 0; memc < pcie->num_memc; memc++) {
+ u32 scb_size_val = ilog2(pcie->memc_size[memc]) - 15;
+
+ if (memc == 0)
+ u32p_replace_bits(&tmp, scb_size_val,
+ PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK);
+ else if (memc == 1)
+ u32p_replace_bits(&tmp, scb_size_val,
+ PCIE_MISC_MISC_CTRL_SCB1_SIZE_MASK);
+ else if (memc == 2)
+ u32p_replace_bits(&tmp, scb_size_val,
+ PCIE_MISC_MISC_CTRL_SCB2_SIZE_MASK);
+ }
writel(tmp, base + PCIE_MISC_MISC_CTRL);

/*
--
2.17.1