[PATCH v2 8/9] pci: brcmstb: rework iBAR handling
Torsten Duwe
duwe at lst.de
Tue Apr 28 18:39:46 CEST 2026
From: Torsten Duwe <duwe at suse.de>
Rework the setup of inbound PCIe windows: use the convenience functions
from Linux kernel commit ae6476c6de187 to calculate the BAR offsets and
factor out the setup code into a separate function.
The Linux kernel first allocates and populates an array of inbound_win[]
and sets the BARs from it later, while U-Boot does it all on the fly,
in one go, so the code is not 1:1 comparable.
Signed-off-by: Torsten Duwe <duwe at suse.de>
Tested-by: Pedro Falcato <pfalcato at suse.de>
---
drivers/pci/pcie_brcmstb.c | 150 ++++++++++++++++++++++++++++++++-----
1 file changed, 131 insertions(+), 19 deletions(-)
diff --git a/drivers/pci/pcie_brcmstb.c b/drivers/pci/pcie_brcmstb.c
index 8a25fb04563..05b80a45b50 100644
--- a/drivers/pci/pcie_brcmstb.c
+++ b/drivers/pci/pcie_brcmstb.c
@@ -50,6 +50,29 @@
#define SSC_STATUS_PLL_LOCK_MASK 0x800
#define SSC_STATUS_PLL_LOCK_SHIFT 11
+#define PCIE_RC_PL_PHY_CTL_15 0x184c
+#define PCIE_RC_PL_PHY_CTL_15_DIS_PLL_PD_MASK 0x400000
+#define PCIE_RC_PL_PHY_CTL_15_PM_CLK_PERIOD_MASK 0xff
+
+#define PCIE_MISC_UBUS_CTRL 0x40a4
+#define PCIE_MISC_UBUS_CTRL_UBUS_PCIE_REPLY_ERR_DIS_MASK BIT(13)
+#define PCIE_MISC_UBUS_CTRL_UBUS_PCIE_REPLY_DECERR_DIS_MASK BIT(19)
+#define PCIE_MISC_AXI_READ_ERROR_DATA 0x4170
+#define PCIE_MISC_UBUS_TIMEOUT 0x40A8
+#define PCIE_MISC_RC_CONFIG_RETRY_TIMEOUT 0x405c
+#define PCIE_MISC_RC_BAR4_CONFIG_LO 0x40d4
+#define PCIE_MISC_RC_BAR4_CONFIG_HI 0x40d8
+#define PCIE_MISC_UBUS_BAR_CONFIG_REMAP_HI_MASK 0xff
+#define PCIE_MISC_UBUS_BAR4_CONFIG_REMAP_HI 0x4110
+#define PCIE_MISC_UBUS_BAR_CONFIG_REMAP_ENABLE 0x1
+#define PCIE_MISC_UBUS_BAR_CONFIG_REMAP_LO_MASK 0xfffff000
+#define PCIE_MISC_UBUS_BAR4_CONFIG_REMAP_LO 0x410c
+
+#define PCIE_MISC_UBUS_BAR1_CONFIG_REMAP 0x40ac
+#define PCIE_MISC_UBUS_BAR2_CONFIG_REMAP 0x40b4
+#define PCIE_MISC_UBUS_BAR2_CONFIG_REMAP_ACCESS_ENABLE_MASK BIT(0)
+#define MISC_CTRL_PCIE_RCB_MPS_MODE_MASK 0x400
+
enum {
RGR1_SW_INIT_1,
EXT_CFG_INDEX,
@@ -437,17 +460,105 @@ static void brcm_pcie_set_outbound_win(struct brcm_pcie *pcie,
writel(tmp, base + PCIE_MEM_WIN0_LIMIT_HI(win));
}
+static u32 brcm_bar_reg_offset(int bar)
+{
+ if (bar <= 3)
+ return PCIE_MISC_RC_BAR1_CONFIG_LO + 8 * (bar - 1);
+ else
+ return PCIE_MISC_RC_BAR4_CONFIG_LO + 8 * (bar - 4);
+}
+
+static u32 brcm_ubus_reg_offset(int bar)
+{
+ if (bar <= 3)
+ return PCIE_MISC_UBUS_BAR1_CONFIG_REMAP + 8 * (bar - 1);
+ else
+ return PCIE_MISC_UBUS_BAR4_CONFIG_REMAP_LO + 8 * (bar - 4);
+}
+
+/*
+ * Round size up to the next power of two, as required by
+ * brcm_pcie_encode_ibar_size(). If size is already a power of two
+ * fls64(size - 1) still gives the correct result because the hardware
+ * encodes the exponent, not the raw value.
+ */
+static u64 brcm_ibar_round_size(u64 size)
+{
+ return 1ULL << fls64(size - 1);
+}
+
+static void brcm_pcie_set_inbound_windows(struct udevice *dev)
+{
+ struct brcm_pcie *pcie = dev_get_priv(dev);
+ void __iomem *base = pcie->base;
+ bool is_2712 = (pcie->pcie_cfg->type == BCM2712);
+ int i, ibar_no, ret;
+ u32 tmp;
+
+ ibar_no = 0;
+ /* pre-2712 chips leave the first entry empty */
+ if (pcie->pcie_cfg->type != BCM2712)
+ ibar_no++;
+
+ /* program inbound windows from OF property "dma-regions" */
+ for (i = 0; i < 7; i++, ibar_no++) {
+ u64 bar_cpu, bar_size, bar_pci;
+ struct pci_region region;
+ int ubus_bar_offset, rc_bar_offset;
+
+ ret = pci_get_dma_regions(dev, ®ion, i);
+ if (ret) /* no region #i? Then we're done. */
+ break;
+ ubus_bar_offset = brcm_ubus_reg_offset(ibar_no + 1);
+ rc_bar_offset = brcm_bar_reg_offset(ibar_no + 1);
+
+ bar_pci = region.bus_start;
+ bar_cpu = region.phys_start;
+ bar_size = region.size;
+
+ if (is_2712) {
+ /* BCM2712: BAR holds raw PCI address; UBUS remap
+ * registers supply the CPU-side translation. */
+ tmp = lower_32_bits(bar_pci);
+ u32p_replace_bits(&tmp, brcm_pcie_encode_ibar_size(bar_size),
+ RC_BAR2_CONFIG_LO_SIZE_MASK);
+ writel(tmp, base + rc_bar_offset);
+ writel(upper_32_bits(bar_pci), base + rc_bar_offset + 4);
+
+ tmp = lower_32_bits(bar_cpu) &
+ PCIE_MISC_UBUS_BAR_CONFIG_REMAP_LO_MASK;
+ tmp |= PCIE_MISC_UBUS_BAR_CONFIG_REMAP_ENABLE;
+ writel(tmp, base + ubus_bar_offset);
+
+ tmp = upper_32_bits(bar_cpu) &
+ PCIE_MISC_UBUS_BAR_CONFIG_REMAP_HI_MASK;
+ writel(tmp, base + ubus_bar_offset + 4);
+ } else {
+ /* Pre-BCM2712 (e.g. BCM2711 / RPi4): the BAR config
+ * register holds the offset (bus_start - phys_start),
+ * not the raw PCI address. The size must be rounded
+ * up to the next power of two before encoding. */
+ u64 bar_offset = bar_pci - bar_cpu;
+ u64 bar_size_po2 = brcm_ibar_round_size(bar_size);
+
+ tmp = lower_32_bits(bar_offset);
+ u32p_replace_bits(&tmp, brcm_pcie_encode_ibar_size(bar_size_po2),
+ RC_BAR2_CONFIG_LO_SIZE_MASK);
+ writel(tmp, base + rc_bar_offset);
+ writel(upper_32_bits(bar_offset), base + rc_bar_offset + 4);
+ /* UBUS remap registers are not used on pre-2712 hardware. */
+ }
+ }
+}
+
static int brcm_pcie_probe(struct udevice *dev)
{
struct udevice *ctlr = pci_get_controller(dev);
struct pci_controller *hose = dev_get_uclass_priv(ctlr);
struct brcm_pcie *pcie = dev_get_priv(dev);
void __iomem *base = pcie->base;
- struct pci_region region;
bool ssc_good = false;
int num_out_wins = 0;
- u64 rc_bar2_offset, rc_bar2_size;
- unsigned int scb_size_val;
int i, ret;
u16 nlw, cls, lnksta;
u32 tmp;
@@ -488,23 +599,22 @@ static int brcm_pcie_probe(struct udevice *dev)
MISC_CTRL_CFG_READ_UR_MODE_MASK |
MISC_CTRL_MAX_BURST_SIZE_128);
- pci_get_dma_regions(dev, ®ion, 0);
- rc_bar2_offset = region.bus_start - region.phys_start;
- rc_bar2_size = 1ULL << fls64(region.size - 1);
-
- tmp = lower_32_bits(rc_bar2_offset);
- u32p_replace_bits(&tmp, brcm_pcie_encode_ibar_size(rc_bar2_size),
- RC_BAR2_CONFIG_LO_SIZE_MASK);
- writel(tmp, base + PCIE_MISC_RC_BAR2_CONFIG_LO);
- 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,
- MISC_CTRL_SCB0_SIZE_MASK);
+ if (pcie->pcie_cfg->type == BCM2712) {
+ /* BCM2712: fixed 32GB SCB0 window */
+ u32p_replace_bits(&tmp, 20, MISC_CTRL_SCB0_SIZE_MASK);
+ } else {
+ /* Pre-BCM2712: size SCB0 to match the actual DMA region.
+ * rc_bar2_size must be a power of two; ilog2(size) - 15
+ * gives the hardware encoding (e.g. 1GB -> 15). */
+ struct pci_region region;
+ u64 rc_bar2_size;
+
+ pci_get_dma_regions(dev, ®ion, 0);
+ rc_bar2_size = brcm_ibar_round_size(region.size);
+ u32p_replace_bits(&tmp, rc_bar2_size ? ilog2(rc_bar2_size) - 15 : 0xf,
+ MISC_CTRL_SCB0_SIZE_MASK);
+ }
writel(tmp, base + PCIE_MISC_MISC_CTRL);
/* Disable the PCIe->GISB memory window (RC_BAR1) */
@@ -521,6 +631,8 @@ static int brcm_pcie_probe(struct udevice *dev)
/* Clear any interrupts we find on boot */
writel(0xffffffff, base + PCIE_MSI_INTR2_CLR);
+ brcm_pcie_set_inbound_windows(dev);
+
if (pcie->gen)
brcm_pcie_set_gen(pcie, pcie->gen);
--
2.54.0
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