[PATCH v6 10/12] PCI: brcmstb: Accommodate MSI for older chips

From: Jim Quinlan
Date: Wed Jul 01 2020 - 17:22:50 EST

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From: Jim Quinlan <jquinlan@xxxxxxxxxxxx>

Older BrcmSTB chips do not have a separate register for MSI interrupts; the
MSIs are in a register that also contains unrelated interrupts. In
addition, the interrupts lie in bits [31..24] for these legacy chips. This
commit provides common code for both legacy and non-legacy MSI interrupt
registers.

Signed-off-by: Jim Quinlan <jquinlan@xxxxxxxxxxxx>
Acked-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
drivers/pci/controller/pcie-brcmstb.c | 71 +++++++++++++++++++--------
1 file changed, 50 insertions(+), 21 deletions(-)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index a65ce8d3580f..3fb468de4f6f 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -82,7 +82,8 @@
#define PCIE_MISC_MSI_BAR_CONFIG_HI 0x4048

#define PCIE_MISC_MSI_DATA_CONFIG 0x404c
-#define PCIE_MISC_MSI_DATA_CONFIG_VAL 0xffe06540
+#define PCIE_MISC_MSI_DATA_CONFIG_VAL_32 0xffe06540
+#define PCIE_MISC_MSI_DATA_CONFIG_VAL_8 0xfff86540

#define PCIE_MISC_PCIE_CTRL 0x4064
#define PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK 0x1
@@ -94,6 +95,9 @@
#define PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_MASK 0x10
#define PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK 0x40

+#define PCIE_MISC_REVISION 0x406c
+#define BRCM_PCIE_HW_REV_33 0x0303
+
#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT 0x4070
#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_LIMIT_MASK 0xfff00000
#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK 0xfff0
@@ -114,10 +118,14 @@
#define PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK 0x2
#define PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK 0x08000000

-#define PCIE_MSI_INTR2_STATUS 0x4500
-#define PCIE_MSI_INTR2_CLR 0x4508
-#define PCIE_MSI_INTR2_MASK_SET 0x4510
-#define PCIE_MSI_INTR2_MASK_CLR 0x4514
+
+#define PCIE_INTR2_CPU_BASE 0x4300
+#define PCIE_MSI_INTR2_BASE 0x4500
+/* Offsets from PCIE_INTR2_CPU_BASE and PCIE_MSI_INTR2_BASE */
+#define MSI_INT_STATUS 0x0
+#define MSI_INT_CLR 0x8
+#define MSI_INT_MASK_SET 0x10
+#define MSI_INT_MASK_CLR 0x14

#define PCIE_EXT_CFG_DATA 0x8000

@@ -132,6 +140,8 @@
/* PCIe parameters */
#define BRCM_NUM_PCIE_OUT_WINS 0x4
#define BRCM_INT_PCI_MSI_NR 32
+#define BRCM_INT_PCI_MSI_LEGACY_NR 8
+#define BRCM_INT_PCI_MSI_SHIFT 0

/* MSI target adresses */
#define BRCM_MSI_TARGET_ADDR_LT_4GB 0x0fffffffcULL
@@ -246,6 +256,12 @@ struct brcm_msi {
int irq;
/* used indicates which MSI interrupts have been alloc'd */
unsigned long used;
+ bool legacy;
+ /* Some chips have MSIs in bits [31..24] of a shared register. */
+ int legacy_shift;
+ int nr; /* No. of MSI available, depends on chip */
+ /* This is the base pointer for interrupt status/set/clr regs */
+ void __iomem *intr_base;
};

/* Internal PCIe Host Controller Information.*/
@@ -265,6 +281,7 @@ struct brcm_pcie {
struct reset_control *rescal;
int num_memc;
u64 memc_size[PCIE_BRCM_MAX_MEMC];
+ u32 hw_rev;
};

/*
@@ -455,8 +472,10 @@ static void brcm_pcie_msi_isr(struct irq_desc *desc)
msi = irq_desc_get_handler_data(desc);
dev = msi->dev;

- status = readl(msi->base + PCIE_MSI_INTR2_STATUS);
- for_each_set_bit(bit, &status, BRCM_INT_PCI_MSI_NR) {
+ status = readl(msi->intr_base + MSI_INT_STATUS);
+ status >>= msi->legacy_shift;
+
+ for_each_set_bit(bit, &status, msi->nr) {
virq = irq_find_mapping(msi->inner_domain, bit);
if (virq)
generic_handle_irq(virq);
@@ -473,7 +492,7 @@ static void brcm_msi_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)

msg->address_lo = lower_32_bits(msi->target_addr);
msg->address_hi = upper_32_bits(msi->target_addr);
- msg->data = (0xffff & PCIE_MISC_MSI_DATA_CONFIG_VAL) | data->hwirq;
+ msg->data = (0xffff & PCIE_MISC_MSI_DATA_CONFIG_VAL_32) | data->hwirq;
}

static int brcm_msi_set_affinity(struct irq_data *irq_data,
@@ -485,8 +504,9 @@ static int brcm_msi_set_affinity(struct irq_data *irq_data,
static void brcm_msi_ack_irq(struct irq_data *data)
{
struct brcm_msi *msi = irq_data_get_irq_chip_data(data);
+ const int shift_amt = data->hwirq + msi->legacy_shift;

- writel(1 << data->hwirq, msi->base + PCIE_MSI_INTR2_CLR);
+ writel(1 << shift_amt, msi->intr_base + MSI_INT_CLR);
}

@@ -502,7 +522,7 @@ static int brcm_msi_alloc(struct brcm_msi *msi)
int hwirq;

mutex_lock(&msi->lock);
- hwirq = bitmap_find_free_region(&msi->used, BRCM_INT_PCI_MSI_NR, 0);
+ hwirq = bitmap_find_free_region(&msi->used, msi->nr, 0);
mutex_unlock(&msi->lock);

return hwirq;
@@ -551,8 +571,7 @@ static int brcm_allocate_domains(struct brcm_msi *msi)
struct fwnode_handle *fwnode = of_node_to_fwnode(msi->np);
struct device *dev = msi->dev;

- msi->inner_domain = irq_domain_add_linear(NULL, BRCM_INT_PCI_MSI_NR,
- &msi_domain_ops, msi);
+ msi->inner_domain = irq_domain_add_linear(NULL, msi->nr, &msi_domain_ops, msi);
if (!msi->inner_domain) {
dev_err(dev, "failed to create IRQ domain\n");
return -ENOMEM;
@@ -589,7 +608,10 @@ static void brcm_msi_remove(struct brcm_pcie *pcie)

static void brcm_msi_set_regs(struct brcm_msi *msi)
{
- writel(0xffffffff, msi->base + PCIE_MSI_INTR2_MASK_CLR);
+ u32 val = __GENMASK(31, msi->legacy_shift);
+
+ writel(val, msi->intr_base + MSI_INT_MASK_CLR);
+ writel(val, msi->intr_base + MSI_INT_CLR);

/*
* The 0 bit of PCIE_MISC_MSI_BAR_CONFIG_LO is repurposed to MSI
@@ -600,8 +622,8 @@ static void brcm_msi_set_regs(struct brcm_msi *msi)
writel(upper_32_bits(msi->target_addr),
msi->base + PCIE_MISC_MSI_BAR_CONFIG_HI);

- writel(PCIE_MISC_MSI_DATA_CONFIG_VAL,
- msi->base + PCIE_MISC_MSI_DATA_CONFIG);
+ val = msi->legacy ? PCIE_MISC_MSI_DATA_CONFIG_VAL_8 : PCIE_MISC_MSI_DATA_CONFIG_VAL_32;
+ writel(val, msi->base + PCIE_MISC_MSI_DATA_CONFIG);
}

static int brcm_pcie_enable_msi(struct brcm_pcie *pcie)
@@ -626,6 +648,17 @@ static int brcm_pcie_enable_msi(struct brcm_pcie *pcie)
msi->np = pcie->np;
msi->target_addr = pcie->msi_target_addr;
msi->irq = irq;
+ msi->legacy = pcie->hw_rev < BRCM_PCIE_HW_REV_33;
+
+ if (msi->legacy) {
+ msi->intr_base = msi->base + PCIE_INTR2_CPU_BASE;
+ msi->nr = BRCM_INT_PCI_MSI_LEGACY_NR;
+ msi->legacy_shift = 24;
+ } else {
+ msi->intr_base = msi->base + PCIE_MSI_INTR2_BASE;
+ msi->nr = BRCM_INT_PCI_MSI_NR;
+ msi->legacy_shift = 0;
+ }

ret = brcm_allocate_domains(msi);
if (ret)
@@ -888,12 +921,6 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
tmp &= ~PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK;
writel(tmp, base + PCIE_MISC_RC_BAR3_CONFIG_LO);

- /* Mask all interrupts since we are not handling any yet */
- writel(0xffffffff, pcie->base + PCIE_MSI_INTR2_MASK_SET);
-
- /* clear any interrupts we find on boot */
- writel(0xffffffff, pcie->base + PCIE_MSI_INTR2_CLR);
-
if (pcie->gen)
brcm_pcie_set_gen(pcie, pcie->gen);

@@ -1236,6 +1263,8 @@ static int brcm_pcie_probe(struct platform_device *pdev)
if (ret)
goto fail;

+ pcie->hw_rev = readl(pcie->base + PCIE_MISC_REVISION);
+
msi_np = of_parse_phandle(pcie->np, "msi-parent", 0);
if (pci_msi_enabled() && msi_np == pcie->np) {
ret = brcm_pcie_enable_msi(pcie);
--
2.17.1

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