You probably want to add Jason for an audit of new notifier uses.
On Fri, Nov 20, 2020 at 06:32:40PM +0100, Christophe Lombard wrote:
> Add invalidate_range mmu notifier, when required (ATSD access of MMIO
> registers is available), to initiate TLB invalidation commands.
> For the time being, the ATSD0 set of registers is used by default.
>
> The pasid and bdf values have to be configured in the Process Element
> Entry.
> The PEE must be set up to match the BDF/PASID of the AFU.
>
> Signed-off-by: Christophe Lombard <clomb...@linux.vnet.ibm.com>
> ---
> drivers/misc/ocxl/link.c | 58 +++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 57 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c
> index 20444db8a2bb..100bdfe9ec37 100644
> --- a/drivers/misc/ocxl/link.c
> +++ b/drivers/misc/ocxl/link.c
> @@ -2,8 +2,10 @@
> // Copyright 2017 IBM Corp.
> #include <linux/sched/mm.h>
> #include <linux/mutex.h>
> +#include <linux/mm.h>
> #include <linux/mm_types.h>
> #include <linux/mmu_context.h>
> +#include <linux/mmu_notifier.h>
> #include <asm/copro.h>
> #include <asm/pnv-ocxl.h>
> #include <asm/xive.h>
> @@ -33,6 +35,7 @@
>
> #define SPA_PE_VALID 0x80000000
>
> +struct ocxl_link;
>
> struct pe_data {
> struct mm_struct *mm;
> @@ -41,6 +44,8 @@ struct pe_data {
> /* opaque pointer to be passed to the above callback */
> void *xsl_err_data;
> struct rcu_head rcu;
> + struct ocxl_link *link;
> + struct mmu_notifier mmu_notifier;
> };
>
> struct spa {
> @@ -83,6 +88,8 @@ struct ocxl_link {
> int domain;
> int bus;
> int dev;
> + void __iomem *arva; /* ATSD register virtual address */
> + spinlock_t atsd_lock; /* to serialize shootdowns */
> atomic_t irq_available;
> struct spa *spa;
> void *platform_data;
> @@ -403,6 +410,11 @@ static int alloc_link(struct pci_dev *dev, int PE_mask,
> struct ocxl_link **out_l
> if (rc)
> goto err_xsl_irq;
>
> + rc = pnv_ocxl_map_lpar(dev, mfspr(SPRN_LPID), 0,
> + &link->arva);
> + if (!rc)
> + spin_lock_init(&link->atsd_lock);
> +
> *out_link = link;
> return 0;
>
> @@ -454,6 +466,11 @@ static void release_xsl(struct kref *ref)
> {
> struct ocxl_link *link = container_of(ref, struct ocxl_link, ref);
>
> + if (link->arva) {
> + pnv_ocxl_unmap_lpar(&link->arva);
> + link->arva = NULL;
> + }
> +
> list_del(&link->list);
> /* call platform code before releasing data */
> pnv_ocxl_spa_release(link->platform_data);
> @@ -470,6 +487,26 @@ void ocxl_link_release(struct pci_dev *dev, void
> *link_handle)
> }
> EXPORT_SYMBOL_GPL(ocxl_link_release);
>
> +static void invalidate_range(struct mmu_notifier *mn,
> + struct mm_struct *mm,
> + unsigned long start, unsigned long end)
> +{
> + struct pe_data *pe_data = container_of(mn, struct pe_data,
> mmu_notifier);
> + struct ocxl_link *link = pe_data->link;
> + unsigned long addr, pid, page_size = PAGE_SIZE;
> +
> + pid = mm->context.id;
> +
> + spin_lock(&link->atsd_lock);
> + for (addr = start; addr < end; addr += page_size)
> + pnv_ocxl_tlb_invalidate(&link->arva, pid, addr);
> + spin_unlock(&link->atsd_lock);
> +}
> +
> +static const struct mmu_notifier_ops ocxl_mmu_notifier_ops = {
> + .invalidate_range = invalidate_range,
> +};
> +
> static u64 calculate_cfg_state(bool kernel)
> {
> u64 state;
> @@ -526,6 +563,8 @@ int ocxl_link_add_pe(void *link_handle, int pasid, u32
> pidr, u32 tidr,
> pe_data->mm = mm;
> pe_data->xsl_err_cb = xsl_err_cb;
> pe_data->xsl_err_data = xsl_err_data;
> + pe_data->link = link;
> + pe_data->mmu_notifier.ops = &ocxl_mmu_notifier_ops;
>
> memset(pe, 0, sizeof(struct ocxl_process_element));
> pe->config_state = cpu_to_be64(calculate_cfg_state(pidr == 0));
> @@ -542,8 +581,16 @@ int ocxl_link_add_pe(void *link_handle, int pasid, u32
> pidr, u32 tidr,
> * by the nest MMU. If we have a kernel context, TLBIs are
> * already global.
> */
> - if (mm)
> + if (mm) {
> mm_context_add_copro(mm);
> + if (link->arva) {
> + /* Use MMIO registers for the TLB Invalidate
> + * operations.
> + */
> + mmu_notifier_register(&pe_data->mmu_notifier, mm);
> + }
> + }
> +
> /*
> * Barrier is to make sure PE is visible in the SPA before it
> * is used by the device. It also helps with the global TLBI
> @@ -674,6 +721,15 @@ int ocxl_link_remove_pe(void *link_handle, int pasid)
> WARN(1, "Couldn't find pe data when removing PE\n");
> } else {
> if (pe_data->mm) {
> + if (link->arva) {
> + mmu_notifier_unregister(&pe_data->mmu_notifier,
> + pe_data->mm);
> + spin_lock(&link->atsd_lock);
> + pnv_ocxl_tlb_invalidate(&link->arva,
> + pe_data->mm->context.id,
> + 0ull);
> + spin_unlock(&link->atsd_lock);
> + }
> mm_context_remove_copro(pe_data->mm);
> mmdrop(pe_data->mm);
> }
> --
> 2.28.0
>
---end quoted text---
