diff options
| -rw-r--r-- | arch/powerpc/platforms/pseries/vas.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c index f5a44f2f0e99..3385b5400cc6 100644 --- a/arch/powerpc/platforms/pseries/vas.c +++ b/arch/powerpc/platforms/pseries/vas.c @@ -11,6 +11,7 @@ #include <linux/types.h> #include <linux/delay.h> #include <linux/slab.h> +#include <linux/interrupt.h> #include <asm/machdep.h> #include <asm/hvcall.h> #include <asm/plpar_wrappers.h> @@ -156,6 +157,50 @@ int h_query_vas_capabilities(const u64 hcall, u8 query_type, u64 result) EXPORT_SYMBOL_GPL(h_query_vas_capabilities); /* + * hcall to get fault CRB from the hypervisor. + */ +static int h_get_nx_fault(u32 winid, u64 buffer) +{ + long rc; + + rc = plpar_hcall_norets(H_GET_NX_FAULT, winid, buffer); + + if (rc == H_SUCCESS) + return 0; + + pr_err("H_GET_NX_FAULT error: %ld, winid %u, buffer 0x%llx\n", + rc, winid, buffer); + return -EIO; + +} + +/* + * Handle the fault interrupt. + * When the fault interrupt is received for each window, query the + * hypervisor to get the fault CRB on the specific fault. Then + * process the CRB by updating CSB or send signal if the user space + * CSB is invalid. + * Note: The hypervisor forwards an interrupt for each fault request. + * So one fault CRB to process for each H_GET_NX_FAULT hcall. + */ +irqreturn_t pseries_vas_fault_thread_fn(int irq, void *data) +{ + struct pseries_vas_window *txwin = data; + struct coprocessor_request_block crb; + struct vas_user_win_ref *tsk_ref; + int rc; + + rc = h_get_nx_fault(txwin->vas_win.winid, (u64)virt_to_phys(&crb)); + if (!rc) { + tsk_ref = &txwin->vas_win.task_ref; + vas_dump_crb(&crb); + vas_update_csb(&crb, tsk_ref); + } + + return IRQ_HANDLED; +} + +/* * Allocate window and setup IRQ mapping. */ static int allocate_setup_window(struct pseries_vas_window *txwin, @@ -166,10 +211,51 @@ static int allocate_setup_window(struct pseries_vas_window *txwin, rc = h_allocate_vas_window(txwin, domain, wintype, DEF_WIN_CREDS); if (rc) return rc; + /* + * On PowerVM, the hypervisor setup and forwards the fault + * interrupt per window. So the IRQ setup and fault handling + * will be done for each open window separately. + */ + txwin->fault_virq = irq_create_mapping(NULL, txwin->fault_irq); + if (!txwin->fault_virq) { + pr_err("Failed irq mapping %d\n", txwin->fault_irq); + rc = -EINVAL; + goto out_win; + } + + txwin->name = kasprintf(GFP_KERNEL, "vas-win-%d", + txwin->vas_win.winid); + if (!txwin->name) { + rc = -ENOMEM; + goto out_irq; + } + + rc = request_threaded_irq(txwin->fault_virq, NULL, + pseries_vas_fault_thread_fn, IRQF_ONESHOT, + txwin->name, txwin); + if (rc) { + pr_err("VAS-Window[%d]: Request IRQ(%u) failed with %d\n", + txwin->vas_win.winid, txwin->fault_virq, rc); + goto out_free; + } txwin->vas_win.wcreds_max = DEF_WIN_CREDS; return 0; +out_free: + kfree(txwin->name); +out_irq: + irq_dispose_mapping(txwin->fault_virq); +out_win: + h_deallocate_vas_window(txwin->vas_win.winid); + return rc; +} + +static inline void free_irq_setup(struct pseries_vas_window *txwin) +{ + free_irq(txwin->fault_virq, txwin); + kfree(txwin->name); + irq_dispose_mapping(txwin->fault_virq); } static struct vas_window *vas_allocate_window(int vas_id, u64 flags, @@ -284,6 +370,11 @@ static struct vas_window *vas_allocate_window(int vas_id, u64 flags, return &txwin->vas_win; out_free: + /* + * Window is not operational. Free IRQ before closing + * window so that do not have to hold mutex. + */ + free_irq_setup(txwin); h_deallocate_vas_window(txwin->vas_win.winid); out: atomic_dec(&cop_feat_caps->used_lpar_creds); @@ -303,7 +394,18 @@ static int deallocate_free_window(struct pseries_vas_window *win) { int rc = 0; + /* + * The hypervisor waits for all requests including faults + * are processed before closing the window - Means all + * credits have to be returned. In the case of fault + * request, a credit is returned after OS issues + * H_GET_NX_FAULT hcall. + * So free IRQ after executing H_DEALLOCATE_VAS_WINDOW + * hcall. + */ rc = h_deallocate_vas_window(win->vas_win.winid); + if (!rc) + free_irq_setup(win); return rc; } |