On Fri, Jul 08, 2022 at 10:07:33AM -0400, Paul Luse wrote:
> +void pci_save_tph_state(struct pci_dev *dev)
> +{
> + struct pci_cap_saved_state *save_state;
> + int num_entries, i, offset;
> + u16 *st_entry, tph;
> + u32 *cap;
> +
> + tph = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_TPH);
> + if (!tph)
> + return;
> +
> + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_TPH);
> + if (!save_state)
> + return;
> +
> + /* Save control register as well as all ST entries */
> + cap = &save_state->cap.data[0];
> + pci_read_config_dword(dev, tph + PCI_TPH_CTL, cap++);
> + st_entry = (u16 *)cap;
> + offset = PCI_TPH_ST_TBL;
> + num_entries = pci_get_tph_st_num_entries(dev, tph);
> + for (i = 0; i < num_entries; i++) {
> + pci_read_config_word(dev, tph + offset, st_entry++);
> + offset += sizeof(u16);
> + }
> +}
It has just occurred to me that a small optimization would be possible here:
num_entries = save_state->cap.size - sizeof(u32);
Though your approach is probably more readable.
> +void pci_tph_init(struct pci_dev *dev)
> +{
> + int num_entries;
> + u32 save_size;
> + u16 tph;
> +
> + if (!pci_is_pcie(dev))
> + return;
> +
> + tph = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_TPH);
> + if (!tph)
> + return;
> +
> + num_entries = pci_get_tph_st_num_entries(dev, tph);
> + save_size = sizeof(int) + num_entries * sizeof(u16);
> + pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_TPH, save_size);
> +}
sizeof(u32) instead of sizeof(int) is probably more appropriate to account
for the Control register. I can never remember if sizeof(int) is 4 or 8
on a 64-bit architecture, but I guess it's 4.
Either way, this is
Reviewed-by: Lukas Wunner <lukas@xxxxxxxxx>
Thanks,
Lukas
