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powerpc/powernv: remove unused NPU DMA code

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None of these routines were ever used anywhere in the kernel tree
since they were added to the kernel.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Christoph Hellwig 2019-06-25 16:52:38 +02:00 committed by Michael Ellerman
parent c498a4f9a7
commit 7eb3cf7619
4 changed files with 0 additions and 581 deletions
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2
arch/powerpc/include/asm/book3s/64/mmu.h
View File

@ -116,8 +116,6 @@ typedef struct {
/* Number of users of the external (Nest) MMU */
atomic_t copros;
/* NPU NMMU context */
struct npu_context *npu_context;
struct hash_mm_context *hash_context;
unsigned long vdso_base;

22
arch/powerpc/include/asm/powernv.h
View File

@ -11,35 +11,13 @@
#define _ASM_POWERNV_H
#ifdef CONFIG_PPC_POWERNV
#define NPU2_WRITE 1
extern void powernv_set_nmmu_ptcr(unsigned long ptcr);
extern struct npu_context *pnv_npu2_init_context(struct pci_dev *gpdev,
unsigned long flags,
void (*cb)(struct npu_context *, void *),
void *priv);
extern void pnv_npu2_destroy_context(struct npu_context *context,
struct pci_dev *gpdev);
extern int pnv_npu2_handle_fault(struct npu_context *context, uintptr_t *ea,
unsigned long *flags, unsigned long *status,
int count);
void pnv_program_cpu_hotplug_lpcr(unsigned int cpu, u64 lpcr_val);
void pnv_tm_init(void);
#else
static inline void powernv_set_nmmu_ptcr(unsigned long ptcr) { }
static inline struct npu_context *pnv_npu2_init_context(struct pci_dev *gpdev,
unsigned long flags,
struct npu_context *(*cb)(struct npu_context *, void *),
void *priv) { return ERR_PTR(-ENODEV); }
static inline void pnv_npu2_destroy_context(struct npu_context *context,
struct pci_dev *gpdev) { }
static inline int pnv_npu2_handle_fault(struct npu_context *context,
uintptr_t *ea, unsigned long *flags,
unsigned long *status, int count) {
return -ENODEV;
}
static inline void pnv_tm_init(void) { }
#endif

1
arch/powerpc/mm/book3s64/mmu_context.c
View File

@ -179,7 +179,6 @@ static int radix__init_new_context(struct mm_struct *mm)
*/
asm volatile("ptesync;isync" : : : "memory");
mm->context.npu_context = NULL;
mm->context.hash_context = NULL;
return index;

556
arch/powerpc/platforms/powernv/npu-dma.c
View File

@ -22,12 +22,6 @@
#include "pci.h"
/*
* spinlock to protect initialisation of an npu_context for a particular
* mm_struct.
*/
static DEFINE_SPINLOCK(npu_context_lock);
static struct pci_dev *get_pci_dev(struct device_node *dn)
{
struct pci_dn *pdn = PCI_DN(dn);
@ -375,15 +369,6 @@ struct npu_comp {
/* An NPU descriptor, valid for POWER9 only */
struct npu {
int index;
__be64 *mmio_atsd_regs[NV_NMMU_ATSD_REGS];
unsigned int mmio_atsd_count;
/* Bitmask for MMIO register usage */
unsigned long mmio_atsd_usage;
/* Do we need to explicitly flush the nest mmu? */
bool nmmu_flush;
struct npu_comp npucomp;
};
@ -640,534 +625,8 @@ struct iommu_table_group *pnv_npu_compound_attach(struct pnv_ioda_pe *pe)
}
#endif /* CONFIG_IOMMU_API */
/* Maximum number of nvlinks per npu */
#define NV_MAX_LINKS 6
/* Maximum index of npu2 hosts in the system. Always < NV_MAX_NPUS */
static int max_npu2_index;
struct npu_context {
struct mm_struct *mm;
struct pci_dev *npdev[NV_MAX_NPUS][NV_MAX_LINKS];
struct mmu_notifier mn;
struct kref kref;
bool nmmu_flush;
/* Callback to stop translation requests on a given GPU */
void (*release_cb)(struct npu_context *context, void *priv);
/*
* Private pointer passed to the above callback for usage by
* device drivers.
*/
void *priv;
};
struct mmio_atsd_reg {
struct npu *npu;
int reg;
};
/*
* Find a free MMIO ATSD register and mark it in use. Return -ENOSPC
* if none are available.
*/
static int get_mmio_atsd_reg(struct npu *npu)
{
int i;
for (i = 0; i < npu->mmio_atsd_count; i++) {
if (!test_bit(i, &npu->mmio_atsd_usage))
if (!test_and_set_bit_lock(i, &npu->mmio_atsd_usage))
return i;
}
return -ENOSPC;
}
static void put_mmio_atsd_reg(struct npu *npu, int reg)
{
clear_bit_unlock(reg, &npu->mmio_atsd_usage);
}
/* MMIO ATSD register offsets */
#define XTS_ATSD_LAUNCH 0
#define XTS_ATSD_AVA 1
#define XTS_ATSD_STAT 2
static unsigned long get_atsd_launch_val(unsigned long pid, unsigned long psize)
{
unsigned long launch = 0;
if (psize == MMU_PAGE_COUNT) {
/* IS set to invalidate entire matching PID */
launch |= PPC_BIT(12);
} else {
/* AP set to invalidate region of psize */
launch |= (u64)mmu_get_ap(psize) << PPC_BITLSHIFT(17);
}
/* PRS set to process-scoped */
launch |= PPC_BIT(13);
/* PID */
launch |= pid << PPC_BITLSHIFT(38);
/* Leave "No flush" (bit 39) 0 so every ATSD performs a flush */
return launch;
}
static void mmio_atsd_regs_write(struct mmio_atsd_reg
mmio_atsd_reg[NV_MAX_NPUS], unsigned long offset,
unsigned long val)
{
struct npu *npu;
int i, reg;
for (i = 0; i <= max_npu2_index; i++) {
reg = mmio_atsd_reg[i].reg;
if (reg < 0)
continue;
npu = mmio_atsd_reg[i].npu;
__raw_writeq_be(val, npu->mmio_atsd_regs[reg] + offset);
}
}
static void mmio_invalidate_pid(struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS],
unsigned long pid)
{
unsigned long launch = get_atsd_launch_val(pid, MMU_PAGE_COUNT);
/* Invalidating the entire process doesn't use a va */
mmio_atsd_regs_write(mmio_atsd_reg, XTS_ATSD_LAUNCH, launch);
}
static void mmio_invalidate_range(struct mmio_atsd_reg
mmio_atsd_reg[NV_MAX_NPUS], unsigned long pid,
unsigned long start, unsigned long psize)
{
unsigned long launch = get_atsd_launch_val(pid, psize);
/* Write all VAs first */
mmio_atsd_regs_write(mmio_atsd_reg, XTS_ATSD_AVA, start);
/* Issue one barrier for all address writes */
eieio();
/* Launch */
mmio_atsd_regs_write(mmio_atsd_reg, XTS_ATSD_LAUNCH, launch);
}
#define mn_to_npu_context(x) container_of(x, struct npu_context, mn)
static void mmio_invalidate_wait(
struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS])
{
struct npu *npu;
int i, reg;
/* Wait for all invalidations to complete */
for (i = 0; i <= max_npu2_index; i++) {
if (mmio_atsd_reg[i].reg < 0)
continue;
/* Wait for completion */
npu = mmio_atsd_reg[i].npu;
reg = mmio_atsd_reg[i].reg;
while (__raw_readq(npu->mmio_atsd_regs[reg] + XTS_ATSD_STAT))
cpu_relax();
}
}
/*
* Acquires all the address translation shootdown (ATSD) registers required to
* launch an ATSD on all links this npu_context is active on.
*/
static void acquire_atsd_reg(struct npu_context *npu_context,
struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS])
{
int i, j;
struct npu *npu;
struct pci_dev *npdev;
for (i = 0; i <= max_npu2_index; i++) {
mmio_atsd_reg[i].reg = -1;
for (j = 0; j < NV_MAX_LINKS; j++) {
/*
* There are no ordering requirements with respect to
* the setup of struct npu_context, but to ensure
* consistent behaviour we need to ensure npdev[][] is
* only read once.
*/
npdev = READ_ONCE(npu_context->npdev[i][j]);
if (!npdev)
continue;
npu = pci_bus_to_host(npdev->bus)->npu;
if (!npu)
continue;
mmio_atsd_reg[i].npu = npu;
mmio_atsd_reg[i].reg = get_mmio_atsd_reg(npu);
while (mmio_atsd_reg[i].reg < 0) {
mmio_atsd_reg[i].reg = get_mmio_atsd_reg(npu);
cpu_relax();
}
break;
}
}
}
/*
* Release previously acquired ATSD registers. To avoid deadlocks the registers
* must be released in the same order they were acquired above in
* acquire_atsd_reg.
*/
static void release_atsd_reg(struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS])
{
int i;
for (i = 0; i <= max_npu2_index; i++) {
/*
* We can't rely on npu_context->npdev[][] being the same here
* as when acquire_atsd_reg() was called, hence we use the
* values stored in mmio_atsd_reg during the acquire phase
* rather than re-reading npdev[][].
*/
if (mmio_atsd_reg[i].reg < 0)
continue;
put_mmio_atsd_reg(mmio_atsd_reg[i].npu, mmio_atsd_reg[i].reg);
}
}
/*
* Invalidate a virtual address range
*/
static void mmio_invalidate(struct npu_context *npu_context,
unsigned long start, unsigned long size)
{
struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS];
unsigned long pid = npu_context->mm->context.id;
unsigned long atsd_start = 0;
unsigned long end = start + size - 1;
int atsd_psize = MMU_PAGE_COUNT;
/*
* Convert the input range into one of the supported sizes. If the range
* doesn't fit, use the next larger supported size. Invalidation latency
* is high, so over-invalidation is preferred to issuing multiple
* invalidates.
*
* A 4K page size isn't supported by NPU/GPU ATS, so that case is
* ignored.
*/
if (size == SZ_64K) {
atsd_start = start;
atsd_psize = MMU_PAGE_64K;
} else if (ALIGN_DOWN(start, SZ_2M) == ALIGN_DOWN(end, SZ_2M)) {
atsd_start = ALIGN_DOWN(start, SZ_2M);
atsd_psize = MMU_PAGE_2M;
} else if (ALIGN_DOWN(start, SZ_1G) == ALIGN_DOWN(end, SZ_1G)) {
atsd_start = ALIGN_DOWN(start, SZ_1G);
atsd_psize = MMU_PAGE_1G;
}
if (npu_context->nmmu_flush)
/*
* Unfortunately the nest mmu does not support flushing specific
* addresses so we have to flush the whole mm once before
* shooting down the GPU translation.
*/
flush_all_mm(npu_context->mm);
/*
* Loop over all the NPUs this process is active on and launch
* an invalidate.
*/
acquire_atsd_reg(npu_context, mmio_atsd_reg);
if (atsd_psize == MMU_PAGE_COUNT)
mmio_invalidate_pid(mmio_atsd_reg, pid);
else
mmio_invalidate_range(mmio_atsd_reg, pid, atsd_start,
atsd_psize);
mmio_invalidate_wait(mmio_atsd_reg);
/*
* The GPU requires two flush ATSDs to ensure all entries have been
* flushed. We use PID 0 as it will never be used for a process on the
* GPU.
*/
mmio_invalidate_pid(mmio_atsd_reg, 0);
mmio_invalidate_wait(mmio_atsd_reg);
mmio_invalidate_pid(mmio_atsd_reg, 0);
mmio_invalidate_wait(mmio_atsd_reg);
release_atsd_reg(mmio_atsd_reg);
}
static void pnv_npu2_mn_release(struct mmu_notifier *mn,
struct mm_struct *mm)
{
struct npu_context *npu_context = mn_to_npu_context(mn);
/* Call into device driver to stop requests to the NMMU */
if (npu_context->release_cb)
npu_context->release_cb(npu_context, npu_context->priv);
/*
* There should be no more translation requests for this PID, but we
* need to ensure any entries for it are removed from the TLB.
*/
mmio_invalidate(npu_context, 0, ~0UL);
}
static void pnv_npu2_mn_invalidate_range(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long start, unsigned long end)
{
struct npu_context *npu_context = mn_to_npu_context(mn);
mmio_invalidate(npu_context, start, end - start);
}
static const struct mmu_notifier_ops nv_nmmu_notifier_ops = {
.release = pnv_npu2_mn_release,
.invalidate_range = pnv_npu2_mn_invalidate_range,
};
/*
* Call into OPAL to setup the nmmu context for the current task in
* the NPU. This must be called to setup the context tables before the
* GPU issues ATRs. pdev should be a pointed to PCIe GPU device.
*
* A release callback should be registered to allow a device driver to
* be notified that it should not launch any new translation requests
* as the final TLB invalidate is about to occur.
*
* Returns an error if there no contexts are currently available or a
* npu_context which should be passed to pnv_npu2_handle_fault().
*
* mmap_sem must be held in write mode and must not be called from interrupt
* context.
*/
struct npu_context *pnv_npu2_init_context(struct pci_dev *gpdev,
unsigned long flags,
void (*cb)(struct npu_context *, void *),
void *priv)
{
int rc;
u32 nvlink_index;
struct device_node *nvlink_dn;
struct mm_struct *mm = current->mm;
struct npu *npu;
struct npu_context *npu_context;
struct pci_controller *hose;
/*
* At present we don't support GPUs connected to multiple NPUs and I'm
* not sure the hardware does either.
*/
struct pci_dev *npdev = pnv_pci_get_npu_dev(gpdev, 0);
if (!npdev)
/* No nvlink associated with this GPU device */
return ERR_PTR(-ENODEV);
/* We only support DR/PR/HV in pnv_npu2_map_lpar_dev() */
if (flags & ~(MSR_DR | MSR_PR | MSR_HV))
return ERR_PTR(-EINVAL);
nvlink_dn = of_parse_phandle(npdev->dev.of_node, "ibm,nvlink", 0);
if (WARN_ON(of_property_read_u32(nvlink_dn, "ibm,npu-link-index",
&nvlink_index)))
return ERR_PTR(-ENODEV);
if (!mm || mm->context.id == 0) {
/*
* Kernel thread contexts are not supported and context id 0 is
* reserved on the GPU.
*/
return ERR_PTR(-EINVAL);
}
hose = pci_bus_to_host(npdev->bus);
npu = hose->npu;
if (!npu)
return ERR_PTR(-ENODEV);
/*
* We store the npu pci device so we can more easily get at the
* associated npus.
*/
spin_lock(&npu_context_lock);
npu_context = mm->context.npu_context;
if (npu_context) {
if (npu_context->release_cb != cb ||
npu_context->priv != priv) {
spin_unlock(&npu_context_lock);
return ERR_PTR(-EINVAL);
}
WARN_ON(!kref_get_unless_zero(&npu_context->kref));
}
spin_unlock(&npu_context_lock);
if (!npu_context) {
/*
* We can set up these fields without holding the
* npu_context_lock as the npu_context hasn't been returned to
* the caller meaning it can't be destroyed. Parallel allocation
* is protected against by mmap_sem.
*/
rc = -ENOMEM;
npu_context = kzalloc(sizeof(struct npu_context), GFP_KERNEL);
if (npu_context) {
kref_init(&npu_context->kref);
npu_context->mm = mm;
npu_context->mn.ops = &nv_nmmu_notifier_ops;
rc = __mmu_notifier_register(&npu_context->mn, mm);
}
if (rc) {
kfree(npu_context);
return ERR_PTR(rc);
}
mm->context.npu_context = npu_context;
}
npu_context->release_cb = cb;
npu_context->priv = priv;
/*
* npdev is a pci_dev pointer setup by the PCI code. We assign it to
* npdev[][] to indicate to the mmu notifiers that an invalidation
* should also be sent over this nvlink. The notifiers don't use any
* other fields in npu_context, so we just need to ensure that when they
* deference npu_context->npdev[][] it is either a valid pointer or
* NULL.
*/
WRITE_ONCE(npu_context->npdev[npu->index][nvlink_index], npdev);
if (!npu->nmmu_flush) {
/*
* If we're not explicitly flushing ourselves we need to mark
* the thread for global flushes
*/
npu_context->nmmu_flush = false;
mm_context_add_copro(mm);
} else
npu_context->nmmu_flush = true;
return npu_context;
}
EXPORT_SYMBOL(pnv_npu2_init_context);
static void pnv_npu2_release_context(struct kref *kref)
{
struct npu_context *npu_context =
container_of(kref, struct npu_context, kref);
if (!npu_context->nmmu_flush)
mm_context_remove_copro(npu_context->mm);
npu_context->mm->context.npu_context = NULL;
}
/*
* Destroy a context on the given GPU. May free the npu_context if it is no
* longer active on any GPUs. Must not be called from interrupt context.
*/
void pnv_npu2_destroy_context(struct npu_context *npu_context,
struct pci_dev *gpdev)
{
int removed;
struct npu *npu;
struct pci_dev *npdev = pnv_pci_get_npu_dev(gpdev, 0);
struct device_node *nvlink_dn;
u32 nvlink_index;
struct pci_controller *hose;
if (WARN_ON(!npdev))
return;
hose = pci_bus_to_host(npdev->bus);
npu = hose->npu;
if (!npu)
return;
nvlink_dn = of_parse_phandle(npdev->dev.of_node, "ibm,nvlink", 0);
if (WARN_ON(of_property_read_u32(nvlink_dn, "ibm,npu-link-index",
&nvlink_index)))
return;
WRITE_ONCE(npu_context->npdev[npu->index][nvlink_index], NULL);
spin_lock(&npu_context_lock);
removed = kref_put(&npu_context->kref, pnv_npu2_release_context);
spin_unlock(&npu_context_lock);
/*
* We need to do this outside of pnv_npu2_release_context so that it is
* outside the spinlock as mmu_notifier_destroy uses SRCU.
*/
if (removed) {
mmu_notifier_unregister(&npu_context->mn,
npu_context->mm);
kfree(npu_context);
}
}
EXPORT_SYMBOL(pnv_npu2_destroy_context);
/*
* Assumes mmap_sem is held for the contexts associated mm.
*/
int pnv_npu2_handle_fault(struct npu_context *context, uintptr_t *ea,
unsigned long *flags, unsigned long *status, int count)
{
u64 rc = 0, result = 0;
int i, is_write;
struct page *page[1];
const char __user *u;
char c;
/* mmap_sem should be held so the struct_mm must be present */
struct mm_struct *mm = context->mm;
WARN_ON(!rwsem_is_locked(&mm->mmap_sem));
for (i = 0; i < count; i++) {
is_write = flags[i] & NPU2_WRITE;
rc = get_user_pages_remote(NULL, mm, ea[i], 1,
is_write ? FOLL_WRITE : 0,
page, NULL, NULL);
if (rc != 1) {
status[i] = rc;
result = -EFAULT;
continue;
}
/* Make sure partition scoped tree gets a pte */
u = page_address(page[0]);
if (__get_user(c, u))
result = -EFAULT;
status[i] = 0;
put_page(page[0]);
}
return result;
}
EXPORT_SYMBOL(pnv_npu2_handle_fault);
int pnv_npu2_init(struct pci_controller *hose)
{
unsigned int i;
u64 mmio_atsd;
static int npu_index;
struct npu *npu;
int ret;
@ -1176,33 +635,18 @@ int pnv_npu2_init(struct pci_controller *hose)
if (!npu)
return -ENOMEM;
npu->nmmu_flush = of_property_read_bool(hose->dn, "ibm,nmmu-flush");
for (i = 0; i < ARRAY_SIZE(npu->mmio_atsd_regs) &&
!of_property_read_u64_index(hose->dn, "ibm,mmio-atsd",
i, &mmio_atsd); i++)
npu->mmio_atsd_regs[i] = ioremap(mmio_atsd, 32);
pr_info("NPU%d: Found %d MMIO ATSD registers", hose->global_number, i);
npu->mmio_atsd_count = i;
npu->mmio_atsd_usage = 0;
npu_index++;
if (WARN_ON(npu_index >= NV_MAX_NPUS)) {
ret = -ENOSPC;
goto fail_exit;
}
max_npu2_index = npu_index;
npu->index = npu_index;
hose->npu = npu;
return 0;
fail_exit:
for (i = 0; i < npu->mmio_atsd_count; ++i)
iounmap(npu->mmio_atsd_regs[i]);
kfree(npu);
return ret;
}