On Wed, Jul 31, 2024 at 06:28:23PM -0400, Jim Quinlan wrote:
> Provide support for new chips with multiple inbound windows while
> keeping the legacy support for the older chips.
>
> In existing chips there are three inbound windows with fixed purposes: the
> first was for mapping SoC internal registers, the second was for memory,
> and the third was for memory but with the endian swapped. Typically, only
> one window was used.
>
> Complicating the inbound window 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 take a step forward and
> drop the internal mapping while providing for multiple inbound windows.
> This works in concert with the dma-ranges property, where each provided
> range becomes an inbound window.
>
> Signed-off-by: Jim Quinlan <james.quinlan@xxxxxxxxxxxx>
> ---
> drivers/pci/controller/pcie-brcmstb.c | 228 ++++++++++++++++++++------
> 1 file changed, 177 insertions(+), 51 deletions(-)
>
> diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> index 4659208ae8da..0ecca3d9576f 100644
> --- a/drivers/pci/controller/pcie-brcmstb.c
> +++ b/drivers/pci/controller/pcie-brcmstb.c
> @@ -75,15 +75,19 @@
> #define PCIE_MEM_WIN0_HI(win) \
> PCIE_MISC_CPU_2_PCIE_MEM_WIN0_HI + ((win) * 8)
>
> +/*
> + * NOTE: You may see the term "BAR" in a number of register names used by
> + * this driver. The term is an artifact of when the HW core was an
> + * endpoint device (EP). Now it is a root complex (RC) and anywhere a
> + * register has the term "BAR" it is related to an inbound window.
> + */
> +
> +#define PCIE_BRCM_MAX_INBOUND_WINS 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 +134,10 @@
> (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 BIT(0)
> +#define PCIE_MISC_UBUS_BAR4_CONFIG_REMAP 0x410c
> +
> #define PCIE_MSI_INTR2_BASE 0x4500
>
> /* Offsets from INTR2_CPU and MSI_INTR2 BASE offsets */
> @@ -217,12 +225,20 @@ enum pcie_type {
> BCM4908,
> BCM7278,
> BCM2711,
> + BCM7712,
> +};
> +
> +struct inbound_win {
> + u64 size;
> + u64 pci_offset;
> + u64 cpu_addr;
> };
>
> struct pcie_cfg_data {
> const int *offsets;
> const enum pcie_type type;
> const bool has_phy;
> + unsigned int num_inbound_wins;
> void (*perst_set)(struct brcm_pcie *pcie, u32 val);
> void (*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val);
> };
> @@ -274,6 +290,7 @@ struct brcm_pcie {
> struct subdev_regulators *sr;
> bool ep_wakeup_capable;
> bool has_phy;
> + int num_inbound_wins;
> };
>
> static inline bool is_bmips(const struct brcm_pcie *pcie)
> @@ -789,23 +806,61 @@ 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 inbound_win *b, int *count, u64 size,
> + u64 cpu_addr, u64 pci_offset)
There is no need to pass 'inline' keyword in a .c file. Making a function inline
is upto the discretion of the compiler.
Also, set_bar() is quite misleading as you are not setting any BAR but just
populating the inbound_win struct. So how about, "add_inbound_window()"?
> +{
> + b->size = size;
> + b->cpu_addr = cpu_addr;
> + b->pci_offset = pci_offset;
> + (*count)++;
> +}
> +
> +static int brcm_pcie_get_inbound_wins(struct brcm_pcie *pcie,
> + struct inbound_win inbound_wins[])
> {
> 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;
> + int ret, i = 0, n = 0;
> +
> + /*
> + * The HW registers (and PCIe) use order-1 numbering for BARs. As
> + * such, we have inbound_wins[0] unused and BAR1 starts at inbound_wins[1].
> + */
Instead of wasting one array entry, you can start the array from 0 and just
decrement the index where needed? Like,
reg_offset = brcm_bar_reg_offset(i - 1);
> + struct inbound_win *b_begin = &inbound_wins[1];
> + struct inbound_win *b = b_begin;
> +
> + /*
> + * STB chips beside 7712 disable the first inbound window default.
> + * Rather being mapped to system memory it is mapped to the
> + * internal registers of the SoC. This feature is deprecated, has
> + * security considerations, and is not implemented in our modern
> + * SoCs.
> + */
> + if (pcie->type != BCM7712)
> + set_bar(b++, &n, 0, 0, 0);
>
> resource_list_for_each_entry(entry, &bridge->dma_ranges) {
> u64 pcie_beg = entry->res->start - entry->offset;
> + u64 cpu_beg = entry->res->start;
What does 'beg' mean?
>
> - size += entry->res->end - entry->res->start + 1;
> + size = 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_wins)
> + break;
> }
>
> if (lowest_pcie_addr == ~(u64)0) {
> @@ -813,13 +868,20 @@ 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 +890,15 @@ 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 +933,90 @@ 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)) {
> - dev_err(dev, "Invalid rc_bar2_offset/size: size 0x%llx, off 0x%llx\n",
> - *rc_bar2_size, *rc_bar2_offset);
> + if (!size || (pci_offset & (size - 1)) ||
> + (pci_offset < SZ_4G && pci_offset > SZ_2G)) {
> + dev_err(dev, "Invalid inbound_win2_offset/size: size 0x%llx, off 0x%llx\n",
> + size, pci_offset);
> return -EINVAL;
> }
>
> - return 0;
> + /* Enable inbound window 2, the main inbound window for STB chips */
> + set_bar(b++, &n, size, cpu_addr, pci_offset);
> +
> + /*
> + * Disable inbound window 3. On some chips presents the same
> + * window as #2 but the data appears in a settable endianness.
> + */
> + set_bar(b++, &n, 0, 0, 0);
> +
> + return n;
> +}
> +
> +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 + 8 * (bar - 4);
> +}
> +
> +static void set_inbound_win_registers(struct brcm_pcie *pcie,
> + const struct inbound_win *inbound_wins,
> + int num_inbound_wins)
> +{
> + void __iomem *base = pcie->base;
> + int i;
> +
> + for (i = 1; i <= num_inbound_wins; i++) {
> + u64 pci_offset = inbound_wins[i].pci_offset;
> + u64 cpu_addr = inbound_wins[i].cpu_addr;
> + u64 size = inbound_wins[i].size;
> + u32 reg_offset = brcm_bar_reg_offset(i);
> + 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);
Can you use writel_relaxed() instead? Here and below. I don't see a necessity to
use the barrier that comes with non-relaxed version of writel.
- Mani
--
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