| Message ID | 8a9fe47a17d1f89cc43885d2ef8c2f09e4e90d7a.camel@linux.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v5,01/17] powerpc/powernv/vas: Release reference to tgid during window close | expand |
Excerpts from Haren Myneni's message of June 13, 2021 9:02 pm: > > NX generates an interrupt when sees a fault on the user space > buffer and the hypervisor forwards that interrupt to OS. Then > the kernel handles the interrupt by issuing H_GET_NX_FAULT hcall > to retrieve the fault CRB information. > > This patch also adds changes to setup and free IRQ per each > window and also handles the fault by updating the CSB. > > Signed-off-by: Haren Myneni <haren@linux.ibm.com> > --- > arch/powerpc/platforms/pseries/vas.c | 108 +++++++++++++++++++++++++++ > 1 file changed, 108 insertions(+) > > diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c > index fe375f7a7029..55185bdd3776 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> > @@ -190,6 +191,58 @@ 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 pHyp. > + */ > +static int h_get_nx_fault(u32 winid, u64 buffer) > +{ > + long rc; > + > + rc = plpar_hcall_norets(H_GET_NX_FAULT, winid, buffer); > + > + switch (rc) { > + case H_SUCCESS: > + return 0; > + case H_PARAMETER: > + pr_err("HCALL(%x): Invalid window ID %u\n", H_GET_NX_FAULT, > + winid); > + return -EINVAL; > + case H_PRIVILEGE: > + pr_err("HCALL(%x): Window(%u): Invalid fault buffer 0x%llx\n", > + H_GET_NX_FAULT, winid, buffer); > + return -EACCES; > + default: > + pr_err("HCALL(%x): Failed with error %ld for window(%u)\n", > + H_GET_NX_FAULT, rc, winid); > + return -EIO; 3 error messages have 3 different formats for window ID. I agree with Michael you could just have one error message that reports the return value. Also "H_GET_NX_FAULT: " would be nicer than "HCALL(380): " Check how some other hcall failures are reported, "hcall failed: H_CALL_NAME" seems to have a few takers. > + } > +} > + > +/* > + * Handle the fault interrupt. > + * When the fault interrupt is received for each window, query pHyp 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: pHyp 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. > */ > @@ -201,10 +254,51 @@ 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, pHyp setup and forwards the fault interrupt per The hypervisor forwards the fault interrupt per-window... > + * 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); > + irq_dispose_mapping(txwin->fault_virq); > + kfree(txwin->name); Nit, but this freeing is in a different order than the error handling in the function does. I'd just keep it the same unless there is a reason to be different, in which case it could use a comment. So long as the irq can't somehow fire and try to use txwin->name, you might be okay. Otherwise I _think_ it's okay, but I don't know the irq APIs well. Thanks, Nick > } > > static struct vas_window *vas_allocate_window(struct vas_tx_win_open_attr *uattr, > @@ -320,6 +414,11 @@ static struct vas_window *vas_allocate_window(struct vas_tx_win_open_attr *uattr > return &txwin->vas_win; > > out_free: > + /* > + * Window is not operational. Free IRQ before closing > + * window so that do not have to hold mutex. > + */ Why don't you have to hold the mutex in that case? > + free_irq_setup(txwin); > h_deallocate_vas_window(txwin->vas_win.winid); > out: > atomic_dec(&ct_caps->used_lpar_creds); > @@ -339,7 +438,16 @@ static int deallocate_free_window(struct pseries_vas_window *win) > { > int rc = 0; > > + /* > + * Free IRQ after executing H_DEALLOCATE_VAS_WINDOW HCALL > + * to close the window. pHyp waits for all requests including > + * faults are processed before closing the window - Means all > + * credits are returned. In the case of fault request, credit > + * is returned after OS issues H_GET_NX_FAULT HCALL. > + */ > rc = h_deallocate_vas_window(win->vas_win.winid); > + if (!rc) > + free_irq_setup(win); > > return rc; > } > -- > 2.18.2 > > >
On Mon, 2021-06-14 at 13:07 +1000, Nicholas Piggin wrote: > Excerpts from Haren Myneni's message of June 13, 2021 9:02 pm: > > NX generates an interrupt when sees a fault on the user space > > buffer and the hypervisor forwards that interrupt to OS. Then > > the kernel handles the interrupt by issuing H_GET_NX_FAULT hcall > > to retrieve the fault CRB information. > > > > This patch also adds changes to setup and free IRQ per each > > window and also handles the fault by updating the CSB. > > > > Signed-off-by: Haren Myneni <haren@linux.ibm.com> > > --- > > arch/powerpc/platforms/pseries/vas.c | 108 > > +++++++++++++++++++++++++++ > > 1 file changed, 108 insertions(+) > > > > diff --git a/arch/powerpc/platforms/pseries/vas.c > > b/arch/powerpc/platforms/pseries/vas.c > > index fe375f7a7029..55185bdd3776 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> > > @@ -190,6 +191,58 @@ 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 pHyp. > > + */ > > +static int h_get_nx_fault(u32 winid, u64 buffer) > > +{ > > + long rc; > > + > > + rc = plpar_hcall_norets(H_GET_NX_FAULT, winid, buffer); > > + > > + switch (rc) { > > + case H_SUCCESS: > > + return 0; > > + case H_PARAMETER: > > + pr_err("HCALL(%x): Invalid window ID %u\n", > > H_GET_NX_FAULT, > > + winid); > > + return -EINVAL; > > + case H_PRIVILEGE: > > + pr_err("HCALL(%x): Window(%u): Invalid fault buffer > > 0x%llx\n", > > + H_GET_NX_FAULT, winid, buffer); > > + return -EACCES; > > + default: > > + pr_err("HCALL(%x): Failed with error %ld for > > window(%u)\n", > > + H_GET_NX_FAULT, rc, winid); > > + return -EIO; > > 3 error messages have 3 different formats for window ID. > > I agree with Michael you could just have one error message that > reports > the return value. Also "H_GET_NX_FAULT: " would be nicer than > "HCALL(380): " yes, Added just one printk for all error codes except for errors which depend on arguments to HCALL (Ex: WinID). Sure, I will add just one error message and print all arguments passed to HCALL. pr_err("H_GET_NX_FAULT: window(%u), fault buffer(0x%llx) Failed with error %ld\n", rc, winid, buffer); > > Check how some other hcall failures are reported, "hcall failed: > H_CALL_NAME" seems to have a few takers. > > > + } > > +} > > + > > +/* > > + * Handle the fault interrupt. > > + * When the fault interrupt is received for each window, query > > pHyp 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: pHyp 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. > > */ > > @@ -201,10 +254,51 @@ 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, pHyp setup and forwards the fault interrupt per > > The hypervisor forwards the fault interrupt per-window... > > > + * 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); > > + irq_dispose_mapping(txwin->fault_virq); > > + kfree(txwin->name); > > Nit, but this freeing is in a different order than the error handling > in > the function does. I'd just keep it the same unless there is a reason > to > be different, in which case it could use a comment. shouldn't matter, I can change it to: 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); } Thanks Haren > > So long as the irq can't somehow fire and try to use txwin->name, > you > might be okay. > > Otherwise I _think_ it's okay, but I don't know the irq APIs well. > > Thanks, > Nick > > > } > > > > static struct vas_window *vas_allocate_window(struct > > vas_tx_win_open_attr *uattr, > > @@ -320,6 +414,11 @@ static struct vas_window > > *vas_allocate_window(struct vas_tx_win_open_attr *uattr > > return &txwin->vas_win; > > > > out_free: > > + /* > > + * Window is not operational. Free IRQ before closing > > + * window so that do not have to hold mutex. > > + */ > > Why don't you have to hold the mutex in that case? > > > + free_irq_setup(txwin); > > h_deallocate_vas_window(txwin->vas_win.winid); > > out: > > atomic_dec(&ct_caps->used_lpar_creds); > > @@ -339,7 +438,16 @@ static int deallocate_free_window(struct > > pseries_vas_window *win) > > { > > int rc = 0; > > > > + /* > > + * Free IRQ after executing H_DEALLOCATE_VAS_WINDOW HCALL > > + * to close the window. pHyp waits for all requests including > > + * faults are processed before closing the window - Means all > > + * credits are returned. In the case of fault request, credit > > + * is returned after OS issues H_GET_NX_FAULT HCALL. > > + */ > > rc = h_deallocate_vas_window(win->vas_win.winid); > > + if (!rc) > > + free_irq_setup(win); > > > > return rc; > > } > > -- > > 2.18.2 > > > > > >
Excerpts from Haren Myneni's message of June 15, 2021 7:01 pm: > On Mon, 2021-06-14 at 13:07 +1000, Nicholas Piggin wrote: >> Excerpts from Haren Myneni's message of June 13, 2021 9:02 pm: >> > NX generates an interrupt when sees a fault on the user space >> > buffer and the hypervisor forwards that interrupt to OS. Then >> > the kernel handles the interrupt by issuing H_GET_NX_FAULT hcall >> > to retrieve the fault CRB information. >> > >> > This patch also adds changes to setup and free IRQ per each >> > window and also handles the fault by updating the CSB. >> > >> > Signed-off-by: Haren Myneni <haren@linux.ibm.com> >> > --- >> > arch/powerpc/platforms/pseries/vas.c | 108 >> > +++++++++++++++++++++++++++ >> > 1 file changed, 108 insertions(+) >> > >> > diff --git a/arch/powerpc/platforms/pseries/vas.c >> > b/arch/powerpc/platforms/pseries/vas.c >> > index fe375f7a7029..55185bdd3776 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> >> > @@ -190,6 +191,58 @@ 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 pHyp. >> > + */ >> > +static int h_get_nx_fault(u32 winid, u64 buffer) >> > +{ >> > + long rc; >> > + >> > + rc = plpar_hcall_norets(H_GET_NX_FAULT, winid, buffer); >> > + >> > + switch (rc) { >> > + case H_SUCCESS: >> > + return 0; >> > + case H_PARAMETER: >> > + pr_err("HCALL(%x): Invalid window ID %u\n", >> > H_GET_NX_FAULT, >> > + winid); >> > + return -EINVAL; >> > + case H_PRIVILEGE: >> > + pr_err("HCALL(%x): Window(%u): Invalid fault buffer >> > 0x%llx\n", >> > + H_GET_NX_FAULT, winid, buffer); >> > + return -EACCES; >> > + default: >> > + pr_err("HCALL(%x): Failed with error %ld for >> > window(%u)\n", >> > + H_GET_NX_FAULT, rc, winid); >> > + return -EIO; >> >> 3 error messages have 3 different formats for window ID. >> >> I agree with Michael you could just have one error message that >> reports >> the return value. Also "H_GET_NX_FAULT: " would be nicer than >> "HCALL(380): " > > yes, Added just one printk for all error codes except for errors which > depend on arguments to HCALL (Ex: WinID). > > Sure, I will add just one error message and print all arguments passed > to HCALL. > > pr_err("H_GET_NX_FAULT: window(%u), fault buffer(0x%llx) Failed with > error %ld\n", rc, winid, buffer); Thanks. >> >> Check how some other hcall failures are reported, "hcall failed: >> H_CALL_NAME" seems to have a few takers. >> >> > + } >> > +} >> > + >> > +/* >> > + * Handle the fault interrupt. >> > + * When the fault interrupt is received for each window, query >> > pHyp 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: pHyp 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. >> > */ >> > @@ -201,10 +254,51 @@ 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, pHyp setup and forwards the fault interrupt per >> >> The hypervisor forwards the fault interrupt per-window... >> >> > + * 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); >> > + irq_dispose_mapping(txwin->fault_virq); >> > + kfree(txwin->name); >> >> Nit, but this freeing is in a different order than the error handling >> in >> the function does. I'd just keep it the same unless there is a reason >> to >> be different, in which case it could use a comment. > > shouldn't matter, I can change it to: > 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); > } Okay, it wasn't a big deal I was just wondering. Given the changes, Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Thanks, Nick
diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c index fe375f7a7029..55185bdd3776 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> @@ -190,6 +191,58 @@ 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 pHyp. + */ +static int h_get_nx_fault(u32 winid, u64 buffer) +{ + long rc; + + rc = plpar_hcall_norets(H_GET_NX_FAULT, winid, buffer); + + switch (rc) { + case H_SUCCESS: + return 0; + case H_PARAMETER: + pr_err("HCALL(%x): Invalid window ID %u\n", H_GET_NX_FAULT, + winid); + return -EINVAL; + case H_PRIVILEGE: + pr_err("HCALL(%x): Window(%u): Invalid fault buffer 0x%llx\n", + H_GET_NX_FAULT, winid, buffer); + return -EACCES; + default: + pr_err("HCALL(%x): Failed with error %ld for window(%u)\n", + H_GET_NX_FAULT, rc, winid); + return -EIO; + } +} + +/* + * Handle the fault interrupt. + * When the fault interrupt is received for each window, query pHyp 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: pHyp 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. */ @@ -201,10 +254,51 @@ 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, pHyp 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); + irq_dispose_mapping(txwin->fault_virq); + kfree(txwin->name); } static struct vas_window *vas_allocate_window(struct vas_tx_win_open_attr *uattr, @@ -320,6 +414,11 @@ static struct vas_window *vas_allocate_window(struct vas_tx_win_open_attr *uattr 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(&ct_caps->used_lpar_creds); @@ -339,7 +438,16 @@ static int deallocate_free_window(struct pseries_vas_window *win) { int rc = 0; + /* + * Free IRQ after executing H_DEALLOCATE_VAS_WINDOW HCALL + * to close the window. pHyp waits for all requests including + * faults are processed before closing the window - Means all + * credits are returned. In the case of fault request, credit + * is returned after OS issues H_GET_NX_FAULT HCALL. + */ rc = h_deallocate_vas_window(win->vas_win.winid); + if (!rc) + free_irq_setup(win); return rc; }
NX generates an interrupt when sees a fault on the user space buffer and the hypervisor forwards that interrupt to OS. Then the kernel handles the interrupt by issuing H_GET_NX_FAULT hcall to retrieve the fault CRB information. This patch also adds changes to setup and free IRQ per each window and also handles the fault by updating the CSB. Signed-off-by: Haren Myneni <haren@linux.ibm.com> --- arch/powerpc/platforms/pseries/vas.c | 108 +++++++++++++++++++++++++++ 1 file changed, 108 insertions(+)