Hi Jim,
On 7/3/24 21:02, Jim Quinlan wrote:
> Previously, our chips provided three inbound "BARS" with fixed purposes:
> the first was for mapping SOC registers, the second was for memory, and the
> third was for memory but with the endian swapped. We typically only used
> one of these BARs.
>
> Complicating that BARs usage was the fact that the PCIe HW would do a
> baroque internal mapping of system memory, and concatenate the regions of
> multiple memory controllers.
>
> Newer chips such as the 7712 and Cable Modem SOCs have taken a step forward
> and now provide multiple inbound BARs. This works in concert with the
> dma-ranges property, where each provided range becomes an inbound BAR.
>
> This commit provides support for these new chips and their multiple
> inbound BARs but also keeps the legacy support for the older system.
>
> Signed-off-by: Jim Quinlan <james.quinlan@xxxxxxxxxxxx>
> ---
> drivers/pci/controller/pcie-brcmstb.c | 199 +++++++++++++++++++-------
> 1 file changed, 150 insertions(+), 49 deletions(-)
>
> diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> index ffb3e8d8fb2a..5f632fdc0052 100644
> --- a/drivers/pci/controller/pcie-brcmstb.c
> +++ b/drivers/pci/controller/pcie-brcmstb.c
> @@ -75,15 +75,12 @@
> #define PCIE_MEM_WIN0_HI(win) \
> PCIE_MISC_CPU_2_PCIE_MEM_WIN0_HI + ((win) * 8)
>
> +#define PCIE_BRCM_MAX_RC_BARS 16
> #define PCIE_MISC_RC_BAR1_CONFIG_LO 0x402c
> #define PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK 0x1f
>
> -#define PCIE_MISC_RC_BAR2_CONFIG_LO 0x4034
> -#define PCIE_MISC_RC_BAR2_CONFIG_LO_SIZE_MASK 0x1f
> -#define PCIE_MISC_RC_BAR2_CONFIG_HI 0x4038
> +#define PCIE_MISC_RC_BAR4_CONFIG_LO 0x40d4
>
> -#define PCIE_MISC_RC_BAR3_CONFIG_LO 0x403c
> -#define PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK 0x1f
>
> #define PCIE_MISC_MSI_BAR_CONFIG_LO 0x4044
> #define PCIE_MISC_MSI_BAR_CONFIG_HI 0x4048
> @@ -130,6 +127,10 @@
> (PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK | \
> PCIE_MISC_HARD_PCIE_HARD_DEBUG_L1SS_ENABLE_MASK)
>
> +#define PCIE_MISC_UBUS_BAR1_CONFIG_REMAP 0x40ac
> +#define PCIE_MISC_UBUS_BAR1_CONFIG_REMAP_ACCESS_EN_MASK 0x1
> +#define PCIE_MISC_UBUS_BAR4_CONFIG_REMAP 0x410c
> +
> #define PCIE_MSI_INTR2_BASE 0x4500
>
> /* Offsets from INTR2_CPU and MSI_INTR2 BASE offsets */
> @@ -217,6 +218,13 @@ enum pcie_type {
> BCM4908,
> BCM7278,
> BCM2711,
> + BCM7712,
> +};
> +
> +struct rc_bar {
> + u64 size;
> + u64 pci_offset;
> + u64 cpu_addr;
> };
>
> struct pcie_cfg_data {
> @@ -274,6 +282,7 @@ struct brcm_pcie {
> struct subdev_regulators *sr;
> bool ep_wakeup_capable;
> bool has_phy;
> + int num_inbound;
> };
>
> static inline bool is_bmips(const struct brcm_pcie *pcie)
> @@ -789,23 +798,60 @@ static void brcm_pcie_perst_set_generic(struct brcm_pcie *pcie, u32 val)
> writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
> }
>
> -static int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie,
> - u64 *rc_bar2_size,
> - u64 *rc_bar2_offset)
> +static inline void set_bar(struct rc_bar *b, int *count, u64 size,
> + u64 cpu_addr, u64 pci_offset)
> +{
> + b->size = size;
> + b->cpu_addr = cpu_addr;
> + b->pci_offset = pci_offset;
> + (*count)++;
> +}
> +
> +static int brcm_pcie_get_rc_bar_sizes_and_offsets(struct brcm_pcie *pcie,
> + struct rc_bar rc_bars[])
> {
> struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
> + u64 pci_offset, cpu_addr, size = 0, tot_size = 0;
> struct resource_entry *entry;
> struct device *dev = pcie->dev;
> u64 lowest_pcie_addr = ~(u64)0;
> - int ret, i = 0;
> - u64 size = 0;
> +
Drop this ^^^ blank line.
> + int ret, i = 0, n = 0;
> +
> + /*
> + * The HW registers (and PCIe) use order-1 numbering for BARs. As
> + * such, we have rc_bars[0] unused and BAR1 starts at rc_bars[1].
> + */
> + struct rc_bar *b_begin = &rc_bars[1];
> + struct rc_bar *b = b_begin;
> +
> + /*
> + * STB chips beside 7712 disable BAR1 by default. It is mapped not
> + * to system memory but to a regiion all of the SOC registers. No
typo.
Also I really do not understand the sentence "but to a regiion all of
the SOC registers" can you improve it, please?
> + * one uses this anymore.
> + */
> + if (pcie->type != BCM7712)
> + set_bar(b++, &n, 0, 0, 0);
It'd be nice if we can avoid such type (model) checks in the common
functions, but I don't have better idea.
>
> resource_list_for_each_entry(entry, &bridge->dma_ranges) {
> u64 pcie_beg = entry->res->start - entry->offset;
> + u64 cpu_beg = entry->res->start;
>
> - size += entry->res->end - entry->res->start + 1;
> + size = entry->res->end - entry->res->start + 1;
resource_size(entry->res) ?
> + tot_size += size;
> if (pcie_beg < lowest_pcie_addr)
> lowest_pcie_addr = pcie_beg;
> + /*
> + * 7712 and newer chips may have many BARs, with each
> + * offering a non-overlapping viewport to system memory.
> + * That being said, each BARs size must still be a power of
> + * two.
> + */
> + if (pcie->type == BCM7712)
> + set_bar(b++, &n, size, cpu_beg, pcie_beg);
> +
> + if (n > pcie->num_inbound)
> + break;
> }
>
> if (lowest_pcie_addr == ~(u64)0) {
> @@ -813,13 +859,20 @@ static int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie,
> return -EINVAL;
> }
>
> + /*
> + * 7712 and newer chips do not have an internal memory mapping system
> + * that enables multiple memory controllers. As such, it can return
> + * now w/o doing special configuration.
> + */
> + if (pcie->type == BCM7712)
> + return n;
> +
> 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] = 1ULL << fls64(size - 1);
> + pcie->memc_size[0] = 1ULL << fls64(tot_size - 1);
> } else {
> pcie->num_memc = ret;
> }
> @@ -828,10 +881,15 @@ static int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie,
> 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);
> + /* Our HW mandates that the window size must be a power of 2 */
> + size = 1ULL << fls64(size - 1);
> +
> + /*
> + * For STB chips, the BAR2 cpu_addr is hardwired to the start
> + * of system memory, so we set it to 0.
> + */
> + cpu_addr = 0;
> + pci_offset = lowest_pcie_addr;
>
> /*
> * We validate the inbound memory view even though we should trust
> @@ -866,25 +924,50 @@ static int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie,
> * outbound memory @ 3GB). So instead it will start at the 1x
> * multiple of its size
> */
> - if (!*rc_bar2_size || (*rc_bar2_offset & (*rc_bar2_size - 1)) ||
> - (*rc_bar2_offset < SZ_4G && *rc_bar2_offset > SZ_2G)) {
> + if (!size || (pci_offset & (size - 1)) ||
> + (pci_offset < SZ_4G && pci_offset > SZ_2G)) {
> dev_err(dev, "Invalid rc_bar2_offset/size: size 0x%llx, off 0x%llx\n",
> - *rc_bar2_size, *rc_bar2_offset);
> + size, pci_offset);
> return -EINVAL;
> }
>
> - return 0;
> + /* Enable BAR2, the inbound window for STB chips */
> + set_bar(b++, &n, size, cpu_addr, pci_offset);
> +
> + /*
> + * Disable BAR3. On some chips presents the same window as BAR2
> + * but the data appears in a settable endianness.
> + */
> + set_bar(b++, &n, 0, 0, 0);
> +
> + return n;
> +}
> +
> +static unsigned int brcm_calc_bar_reg_offset(int bar)
IMO brcm_bar_reg_offset name is better, i.e. drop "calc"
> +{
> + 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 unsigned int brcm_calc_ubus_reg_offset(int bar)
ditto
> +{
> + if (bar <= 3)
> + return PCIE_MISC_UBUS_BAR1_CONFIG_REMAP + 8 * (bar - 1);
> + else
> + return PCIE_MISC_UBUS_BAR4_CONFIG_REMAP + 8 * (bar - 4);
> }
>
> static int brcm_pcie_setup(struct brcm_pcie *pcie)
> {
> - u64 rc_bar2_offset, rc_bar2_size;
> + struct rc_bar rc_bars[PCIE_BRCM_MAX_RC_BARS];
> void __iomem *base = pcie->base;
> struct pci_host_bridge *bridge;
> struct resource_entry *entry;
> u32 tmp, burst, aspm_support;
> - int num_out_wins = 0;
> - int ret, memc;
> + int num_out_wins = 0, num_rc_bars = 0;
> + int i, memc;
>
> /* Reset the bridge */
> pcie->bridge_sw_init_set(pcie, 1);
> @@ -933,17 +1016,47 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
> u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_PCIE_RCB_64B_MODE_MASK);
> writel(tmp, base + PCIE_MISC_MISC_CTRL);
>
> - ret = brcm_pcie_get_rc_bar2_size_and_offset(pcie, &rc_bar2_size,
> - &rc_bar2_offset);
> - if (ret)
> - return ret;
> + num_rc_bars = brcm_pcie_get_rc_bar_sizes_and_offsets(pcie, rc_bars);
Can we change the function name to brcm_pcie_get_inbound_regions? ...
> + if (num_rc_bars < 0)
> + return num_rc_bars;
> +
> + for (i = 1; i <= num_rc_bars; i++) {
> + u64 pci_offset = rc_bars[i].pci_offset;
> + u64 cpu_addr = rc_bars[i].cpu_addr;
> + u64 size = rc_bars[i].size;
> + u32 reg_offset = brcm_calc_bar_reg_offset(i);
u32 is good type for reg offset but brcm_calc_bar_reg_offset() is
returning "unsigned int", could you unify the types to u32?
> +
> + tmp = lower_32_bits(pci_offset);
> + u32p_replace_bits(&tmp, brcm_pcie_encode_ibar_size(size),
> + PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK);
> +
> + /* Write low */
> + writel(tmp, base + reg_offset);
> + /* Write high */
> + writel(upper_32_bits(pci_offset),
> + base + reg_offset + 4);
no need of a new line for the second function argument.
> +
> + /*
> + * Most STB chips:
> + * Do nothing.
> + * 7712:
> + * All of their BARs need to be set.
> + */
> + if (pcie->type == BCM7712) {
> + /* BUS remap register settings */
> + reg_offset = brcm_calc_ubus_reg_offset(i);
> + tmp = lower_32_bits(cpu_addr) & ~0xfff;
> + tmp |= PCIE_MISC_UBUS_BAR1_CONFIG_REMAP_ACCESS_EN_MASK;
> + writel(tmp, base + reg_offset);
> + tmp = upper_32_bits(cpu_addr);
> + writel(tmp, base + reg_offset + 4);
> + }
> + }
>
... and move this for loop in separate brcm_pcie_set_inbound_regions()
function?
> - tmp = lower_32_bits(rc_bar2_offset);
> - u32p_replace_bits(&tmp, brcm_pcie_encode_ibar_size(rc_bar2_size),
> - PCIE_MISC_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);
> + if (!brcm_pcie_rc_mode(pcie)) {
> + dev_err(pcie->dev, "PCIe RC controller misconfigured as Endpoint\n");
> + return -EINVAL;
> + }
>
> tmp = readl(base + PCIE_MISC_MISC_CTRL);
> for (memc = 0; memc < pcie->num_memc; memc++) {
> @@ -965,25 +1078,12 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
> * 4GB or when the inbound area is smaller than 4GB (taking into
> * account the rounding-up we're forced to perform).
> */
> - if (rc_bar2_offset >= SZ_4G || (rc_bar2_size + rc_bar2_offset) < SZ_4G)
> + if (rc_bars[2].pci_offset >= SZ_4G ||
> + (rc_bars[2].size + rc_bars[2].pci_offset) < SZ_4G)
> pcie->msi_target_addr = BRCM_MSI_TARGET_ADDR_LT_4GB;
> else
> pcie->msi_target_addr = BRCM_MSI_TARGET_ADDR_GT_4GB;
>
> - if (!brcm_pcie_rc_mode(pcie)) {
> - dev_err(pcie->dev, "PCIe RC controller misconfigured as Endpoint\n");
> - return -EINVAL;
> - }
> -
> - /* disable the PCIe->GISB memory window (RC_BAR1) */
> - tmp = readl(base + PCIE_MISC_RC_BAR1_CONFIG_LO);
> - tmp &= ~PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK;
> - writel(tmp, base + PCIE_MISC_RC_BAR1_CONFIG_LO);
> -
> - /* disable the PCIe->SCB memory window (RC_BAR3) */
> - tmp = readl(base + PCIE_MISC_RC_BAR3_CONFIG_LO);
> - tmp &= ~PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK;
> - writel(tmp, base + PCIE_MISC_RC_BAR3_CONFIG_LO);
>
> /* Don't advertise L0s capability if 'aspm-no-l0s' */
> aspm_support = PCIE_LINK_STATE_L1;
> @@ -1623,6 +1723,7 @@ static int brcm_pcie_probe(struct platform_device *pdev)
> pcie->perst_set = data->perst_set;
> pcie->bridge_sw_init_set = data->bridge_sw_init_set;
> pcie->has_phy = data->has_phy;
> + pcie->num_inbound = (pcie->type == BCM7712) ? 10 : 3;
num_inbound could be part of struct pcie_cfg_data ?
>
> pcie->base = devm_platform_ioremap_resource(pdev, 0);
> if (IS_ERR(pcie->base))
regards,
Stan
