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SubjectRe: [PATCH] PCI: thunder-pem: Add support for cn81xx and cn83xx SoCs.
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On 01/11/2017 11:11 AM, David Daney wrote:
> From: David Daney <david.daney@cavium.com>
>
> The pci-thunder-pem driver was initially developed for cn88xx SoCs.
> The cn81xx and cn83xx members of the same family of SoCs has a
> slightly different configuration of interrupt resources in the PEM
> hardware, which prevents the INTA legacy interrupt source from
> functioning with the current driver.
>
> There are two fixes required:
>
> 1) Don't fixup the PME interrupt on the newer SoCs as it already has
> the proper value.
>
> 2) Report MSI-X Capability Table Size of 2 for the newer SoCs, so the
> core MSI-X code doesn't inadvertently clobber the INTA machinery that
> happens to reside immediately following the table.
>
> Signed-off-by: David Daney <david.daney@cavium.com>
> ---
> drivers/pci/host/pci-thunder-pem.c | 25 ++++++++++++++++++++-----
> 1 file changed, 20 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/pci/host/pci-thunder-pem.c b/drivers/pci/host/pci-thunder-pem.c
> index af722eb..eea466f 100644
> --- a/drivers/pci/host/pci-thunder-pem.c
> +++ b/drivers/pci/host/pci-thunder-pem.c
> @@ -36,7 +36,7 @@ struct thunder_pem_pci {
> static int thunder_pem_bridge_read(struct pci_bus *bus, unsigned int devfn,
> int where, int size, u32 *val)
> {
> - u64 read_val;
> + u64 read_val, tmp_val;
> struct pci_config_window *cfg = bus->sysdata;
> struct thunder_pem_pci *pem_pci = (struct thunder_pem_pci *)cfg->priv;
>
> @@ -65,13 +65,28 @@ static int thunder_pem_bridge_read(struct pci_bus *bus, unsigned int devfn,
> read_val |= 0x00007000; /* Skip MSI CAP */
> break;
> case 0x70: /* Express Cap */
> - /* PME interrupt on vector 2*/
> - read_val |= (2u << 25);
> + /*
> + * Change PME interrupt to vector 2 on T88 where it
> + * reads as 0, else leave it alone.
> + */
> + if (!(read_val & (0x1f << 25)))
> + read_val |= (2u << 25);
> break;
> case 0xb0: /* MSI-X Cap */
> - /* TableSize=4, Next Cap is EA */
> + /* TableSize=2 or 4, Next Cap is EA */
> read_val &= 0xc00000ff;
> - read_val |= 0x0003bc00;
> + /*
> + * If Express Cap(0x70) raw PME vector reads as 2 we are on

Crap! The comment is incorrect s/2/0/, I guess I will send a corrected
patch. The code is correct though.


> + * T88 and TableSize is reported as 4, else TableSize
> + * is 2.
> + */
> + writeq(0x70, pem_pci->pem_reg_base + PEM_CFG_RD);
> + tmp_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
> + tmp_val >>= 32;
> + if (!(tmp_val & (0x1f << 25)))
> + read_val |= 0x0003bc00;
> + else
> + read_val |= 0x0001bc00;
> break;
> case 0xb4:
> /* Table offset=0, BIR=0 */
>

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