kernel_samsung_a34x-permissive/drivers/misc/ocxl/context.c

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// SPDX-License-Identifier: GPL-2.0+
// Copyright 2017 IBM Corp.
#include <linux/sched/mm.h>
#include "trace.h"
#include "ocxl_internal.h"
struct ocxl_context *ocxl_context_alloc(void)
{
return kzalloc(sizeof(struct ocxl_context), GFP_KERNEL);
}
int ocxl_context_init(struct ocxl_context *ctx, struct ocxl_afu *afu,
struct address_space *mapping)
{
int pasid;
ctx->afu = afu;
mutex_lock(&afu->contexts_lock);
pasid = idr_alloc(&afu->contexts_idr, ctx, afu->pasid_base,
afu->pasid_base + afu->pasid_max, GFP_KERNEL);
if (pasid < 0) {
mutex_unlock(&afu->contexts_lock);
return pasid;
}
afu->pasid_count++;
mutex_unlock(&afu->contexts_lock);
ctx->pasid = pasid;
ctx->status = OPENED;
mutex_init(&ctx->status_mutex);
ctx->mapping = mapping;
mutex_init(&ctx->mapping_lock);
init_waitqueue_head(&ctx->events_wq);
mutex_init(&ctx->xsl_error_lock);
mutex_init(&ctx->irq_lock);
idr_init(&ctx->irq_idr);
ctx->tidr = 0;
/*
* Keep a reference on the AFU to make sure it's valid for the
* duration of the life of the context
*/
ocxl_afu_get(afu);
return 0;
}
/*
* Callback for when a translation fault triggers an error
* data: a pointer to the context which triggered the fault
* addr: the address that triggered the error
* dsisr: the value of the PPC64 dsisr register
*/
static void xsl_fault_error(void *data, u64 addr, u64 dsisr)
{
struct ocxl_context *ctx = (struct ocxl_context *) data;
mutex_lock(&ctx->xsl_error_lock);
ctx->xsl_error.addr = addr;
ctx->xsl_error.dsisr = dsisr;
ctx->xsl_error.count++;
mutex_unlock(&ctx->xsl_error_lock);
wake_up_all(&ctx->events_wq);
}
int ocxl_context_attach(struct ocxl_context *ctx, u64 amr)
{
int rc;
// Locks both status & tidr
mutex_lock(&ctx->status_mutex);
if (ctx->status != OPENED) {
rc = -EIO;
goto out;
}
rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid,
current->mm->context.id, ctx->tidr, amr, current->mm,
xsl_fault_error, ctx);
if (rc)
goto out;
ctx->status = ATTACHED;
out:
mutex_unlock(&ctx->status_mutex);
return rc;
}
static vm_fault_t map_afu_irq(struct vm_area_struct *vma, unsigned long address,
u64 offset, struct ocxl_context *ctx)
{
u64 trigger_addr;
trigger_addr = ocxl_afu_irq_get_addr(ctx, offset);
if (!trigger_addr)
return VM_FAULT_SIGBUS;
return vmf_insert_pfn(vma, address, trigger_addr >> PAGE_SHIFT);
}
static vm_fault_t map_pp_mmio(struct vm_area_struct *vma, unsigned long address,
u64 offset, struct ocxl_context *ctx)
{
u64 pp_mmio_addr;
int pasid_off;
vm_fault_t ret;
if (offset >= ctx->afu->config.pp_mmio_stride)
return VM_FAULT_SIGBUS;
mutex_lock(&ctx->status_mutex);
if (ctx->status != ATTACHED) {
mutex_unlock(&ctx->status_mutex);
pr_debug("%s: Context not attached, failing mmio mmap\n",
__func__);
return VM_FAULT_SIGBUS;
}
pasid_off = ctx->pasid - ctx->afu->pasid_base;
pp_mmio_addr = ctx->afu->pp_mmio_start +
pasid_off * ctx->afu->config.pp_mmio_stride +
offset;
ret = vmf_insert_pfn(vma, address, pp_mmio_addr >> PAGE_SHIFT);
mutex_unlock(&ctx->status_mutex);
return ret;
}
static vm_fault_t ocxl_mmap_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct ocxl_context *ctx = vma->vm_file->private_data;
u64 offset;
vm_fault_t ret;
offset = vmf->pgoff << PAGE_SHIFT;
pr_debug("%s: pasid %d address 0x%lx offset 0x%llx\n", __func__,
ctx->pasid, vmf->address, offset);
if (offset < ctx->afu->irq_base_offset)
ret = map_pp_mmio(vma, vmf->address, offset, ctx);
else
ret = map_afu_irq(vma, vmf->address, offset, ctx);
return ret;
}
static const struct vm_operations_struct ocxl_vmops = {
.fault = ocxl_mmap_fault,
};
static int check_mmap_afu_irq(struct ocxl_context *ctx,
struct vm_area_struct *vma)
{
/* only one page */
if (vma_pages(vma) != 1)
return -EINVAL;
/* check offset validty */
if (!ocxl_afu_irq_get_addr(ctx, vma->vm_pgoff << PAGE_SHIFT))
return -EINVAL;
/*
* trigger page should only be accessible in write mode.
*
* It's a bit theoretical, as a page mmaped with only
* PROT_WRITE is currently readable, but it doesn't hurt.
*/
if ((vma->vm_flags & VM_READ) || (vma->vm_flags & VM_EXEC) ||
!(vma->vm_flags & VM_WRITE))
return -EINVAL;
vma->vm_flags &= ~(VM_MAYREAD | VM_MAYEXEC);
return 0;
}
static int check_mmap_mmio(struct ocxl_context *ctx,
struct vm_area_struct *vma)
{
if ((vma_pages(vma) + vma->vm_pgoff) >
(ctx->afu->config.pp_mmio_stride >> PAGE_SHIFT))
return -EINVAL;
return 0;
}
int ocxl_context_mmap(struct ocxl_context *ctx, struct vm_area_struct *vma)
{
int rc;
if ((vma->vm_pgoff << PAGE_SHIFT) < ctx->afu->irq_base_offset)
rc = check_mmap_mmio(ctx, vma);
else
rc = check_mmap_afu_irq(ctx, vma);
if (rc)
return rc;
vma->vm_flags |= VM_IO | VM_PFNMAP;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
vma->vm_ops = &ocxl_vmops;
return 0;
}
int ocxl_context_detach(struct ocxl_context *ctx)
{
struct pci_dev *dev;
int afu_control_pos;
enum ocxl_context_status status;
int rc;
mutex_lock(&ctx->status_mutex);
status = ctx->status;
ctx->status = CLOSED;
mutex_unlock(&ctx->status_mutex);
if (status != ATTACHED)
return 0;
dev = to_pci_dev(ctx->afu->fn->dev.parent);
afu_control_pos = ctx->afu->config.dvsec_afu_control_pos;
mutex_lock(&ctx->afu->afu_control_lock);
rc = ocxl_config_terminate_pasid(dev, afu_control_pos, ctx->pasid);
mutex_unlock(&ctx->afu->afu_control_lock);
trace_ocxl_terminate_pasid(ctx->pasid, rc);
if (rc) {
/*
* If we timeout waiting for the AFU to terminate the
* pasid, then it's dangerous to clean up the Process
* Element entry in the SPA, as it may be referenced
* in the future by the AFU. In which case, we would
* checkstop because of an invalid PE access (FIR
* register 2, bit 42). So leave the PE
* defined. Caller shouldn't free the context so that
* PASID remains allocated.
*
* A link reset will be required to cleanup the AFU
* and the SPA.
*/
if (rc == -EBUSY)
return rc;
}
rc = ocxl_link_remove_pe(ctx->afu->fn->link, ctx->pasid);
if (rc) {
dev_warn(&ctx->afu->dev,
"Couldn't remove PE entry cleanly: %d\n", rc);
}
return 0;
}
void ocxl_context_detach_all(struct ocxl_afu *afu)
{
struct ocxl_context *ctx;
int tmp;
mutex_lock(&afu->contexts_lock);
idr_for_each_entry(&afu->contexts_idr, ctx, tmp) {
ocxl_context_detach(ctx);
/*
* We are force detaching - remove any active mmio
* mappings so userspace cannot interfere with the
* card if it comes back. Easiest way to exercise
* this is to unbind and rebind the driver via sysfs
* while it is in use.
*/
mutex_lock(&ctx->mapping_lock);
if (ctx->mapping)
unmap_mapping_range(ctx->mapping, 0, 0, 1);
mutex_unlock(&ctx->mapping_lock);
}
mutex_unlock(&afu->contexts_lock);
}
void ocxl_context_free(struct ocxl_context *ctx)
{
mutex_lock(&ctx->afu->contexts_lock);
ctx->afu->pasid_count--;
idr_remove(&ctx->afu->contexts_idr, ctx->pasid);
mutex_unlock(&ctx->afu->contexts_lock);
ocxl_afu_irq_free_all(ctx);
idr_destroy(&ctx->irq_idr);
/* reference to the AFU taken in ocxl_context_init */
ocxl_afu_put(ctx->afu);
kfree(ctx);
}