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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 2014 IBM Corp.
*/
#include <linux/spinlock.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/pci.h>
#include <linux/sched/task.h>
#include <asm/cputable.h>
#include <asm/mmu.h>
#include <misc/cxl-base.h>
#include "cxl.h"
#include "trace.h"
static DEFINE_SPINLOCK(adapter_idr_lock);
static DEFINE_IDR(cxl_adapter_idr);
uint cxl_verbose;
module_param_named(verbose, cxl_verbose, uint, 0600);
MODULE_PARM_DESC(verbose, "Enable verbose dmesg output");
const struct cxl_backend_ops *cxl_ops;
int cxl_afu_slbia(struct cxl_afu *afu)
{
unsigned long timeout = jiffies + (HZ * CXL_TIMEOUT);
pr_devel("cxl_afu_slbia issuing SLBIA command\n");
cxl_p2n_write(afu, CXL_SLBIA_An, CXL_TLB_SLB_IQ_ALL);
while (cxl_p2n_read(afu, CXL_SLBIA_An) & CXL_TLB_SLB_P) {
if (time_after_eq(jiffies, timeout)) {
dev_warn(&afu->dev, "WARNING: CXL AFU SLBIA timed out!\n");
return -EBUSY;
}
/* If the adapter has gone down, we can assume that we
* will PERST it and that will invalidate everything.
*/
if (!cxl_ops->link_ok(afu->adapter, afu))
return -EIO;
cpu_relax();
}
return 0;
}
static inline void _cxl_slbia(struct cxl_context *ctx, struct mm_struct *mm)
{
unsigned long flags;
if (ctx->mm != mm)
return;
pr_devel("%s matched mm - card: %i afu: %i pe: %i\n", __func__,
ctx->afu->adapter->adapter_num, ctx->afu->slice, ctx->pe);
spin_lock_irqsave(&ctx->sste_lock, flags);
trace_cxl_slbia(ctx);
memset(ctx->sstp, 0, ctx->sst_size);
spin_unlock_irqrestore(&ctx->sste_lock, flags);
mb();
cxl_afu_slbia(ctx->afu);
}
static inline void cxl_slbia_core(struct mm_struct *mm)
{
struct cxl *adapter;
struct cxl_afu *afu;
struct cxl_context *ctx;
int card, slice, id;
pr_devel("%s called\n", __func__);
spin_lock(&adapter_idr_lock);
idr_for_each_entry(&cxl_adapter_idr, adapter, card) {
/* XXX: Make this lookup faster with link from mm to ctx */
spin_lock(&adapter->afu_list_lock);
for (slice = 0; slice < adapter->slices; slice++) {
afu = adapter->afu[slice];
if (!afu || !afu->enabled)
continue;
rcu_read_lock();
idr_for_each_entry(&afu->contexts_idr, ctx, id)
_cxl_slbia(ctx, mm);
rcu_read_unlock();
}
spin_unlock(&adapter->afu_list_lock);
}
spin_unlock(&adapter_idr_lock);
}
static struct cxl_calls cxl_calls = {
.cxl_slbia = cxl_slbia_core,
.owner = THIS_MODULE,
};
int cxl_alloc_sst(struct cxl_context *ctx)
{
unsigned long vsid;
u64 ea_mask, size, sstp0, sstp1;
sstp0 = 0;
sstp1 = 0;
ctx->sst_size = PAGE_SIZE;
ctx->sst_lru = 0;
ctx->sstp = (struct cxl_sste *)get_zeroed_page(GFP_KERNEL);
if (!ctx->sstp) {
pr_err("cxl_alloc_sst: Unable to allocate segment table\n");
return -ENOMEM;
}
pr_devel("SSTP allocated at 0x%p\n", ctx->sstp);
vsid = get_kernel_vsid((u64)ctx->sstp, mmu_kernel_ssize) << 12;
sstp0 |= (u64)mmu_kernel_ssize << CXL_SSTP0_An_B_SHIFT;
sstp0 |= (SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp) << 50;
size = (((u64)ctx->sst_size >> 8) - 1) << CXL_SSTP0_An_SegTableSize_SHIFT;
if (unlikely(size & ~CXL_SSTP0_An_SegTableSize_MASK)) {
WARN(1, "Impossible segment table size\n");
return -EINVAL;
}
sstp0 |= size;
if (mmu_kernel_ssize == MMU_SEGSIZE_256M)
ea_mask = 0xfffff00ULL;
else
ea_mask = 0xffffffff00ULL;
sstp0 |= vsid >> (50-14); /* Top 14 bits of VSID */
sstp1 |= (vsid << (64-(50-14))) & ~ea_mask;
sstp1 |= (u64)ctx->sstp & ea_mask;
sstp1 |= CXL_SSTP1_An_V;
pr_devel("Looked up %#llx: slbfee. %#llx (ssize: %x, vsid: %#lx), copied to SSTP0: %#llx, SSTP1: %#llx\n",
(u64)ctx->sstp, (u64)ctx->sstp & ESID_MASK, mmu_kernel_ssize, vsid, sstp0, sstp1);
/* Store calculated sstp hardware points for use later */
ctx->sstp0 = sstp0;
ctx->sstp1 = sstp1;
return 0;
}
/* print buffer content as integers when debugging */
void cxl_dump_debug_buffer(void *buf, size_t buf_len)
{
#ifdef DEBUG
int i, *ptr;
/*
* We want to regroup up to 4 integers per line, which means they
* need to be in the same pr_devel() statement
*/
ptr = (int *) buf;
for (i = 0; i * 4 < buf_len; i += 4) {
if ((i + 3) * 4 < buf_len)
pr_devel("%.8x %.8x %.8x %.8x\n", ptr[i], ptr[i + 1],
ptr[i + 2], ptr[i + 3]);
else if ((i + 2) * 4 < buf_len)
pr_devel("%.8x %.8x %.8x\n", ptr[i], ptr[i + 1],
ptr[i + 2]);
else if ((i + 1) * 4 < buf_len)
pr_devel("%.8x %.8x\n", ptr[i], ptr[i + 1]);
else
pr_devel("%.8x\n", ptr[i]);
}
#endif /* DEBUG */
}
/* Find a CXL adapter by it's number and increase it's refcount */
struct cxl *get_cxl_adapter(int num)
{
struct cxl *adapter;
spin_lock(&adapter_idr_lock);
if ((adapter = idr_find(&cxl_adapter_idr, num)))
get_device(&adapter->dev);
spin_unlock(&adapter_idr_lock);
return adapter;
}
static int cxl_alloc_adapter_nr(struct cxl *adapter)
{
int i;
idr_preload(GFP_KERNEL);
spin_lock(&adapter_idr_lock);
i = idr_alloc(&cxl_adapter_idr, adapter, 0, 0, GFP_NOWAIT);
spin_unlock(&adapter_idr_lock);
idr_preload_end();
if (i < 0)
return i;
adapter->adapter_num = i;
return 0;
}
void cxl_remove_adapter_nr(struct cxl *adapter)
{
idr_remove(&cxl_adapter_idr, adapter->adapter_num);
}
struct cxl *cxl_alloc_adapter(void)
{
struct cxl *adapter;
if (!(adapter = kzalloc(sizeof(struct cxl), GFP_KERNEL)))
return NULL;
spin_lock_init(&adapter->afu_list_lock);
if (cxl_alloc_adapter_nr(adapter))
goto err1;
if (dev_set_name(&adapter->dev, "card%i", adapter->adapter_num))
goto err2;
/* start with context lock taken */
atomic_set(&adapter->contexts_num, -1);
return adapter;
err2:
cxl_remove_adapter_nr(adapter);
err1:
kfree(adapter);
return NULL;
}
struct cxl_afu *cxl_alloc_afu(struct cxl *adapter, int slice)
{
struct cxl_afu *afu;
if (!(afu = kzalloc(sizeof(struct cxl_afu), GFP_KERNEL)))
return NULL;
afu->adapter = adapter;
afu->dev.parent = &adapter->dev;
afu->dev.release = cxl_ops->release_afu;
afu->slice = slice;
idr_init(&afu->contexts_idr);
mutex_init(&afu->contexts_lock);
spin_lock_init(&afu->afu_cntl_lock);
atomic_set(&afu->configured_state, -1);
afu->prefault_mode = CXL_PREFAULT_NONE;
afu->irqs_max = afu->adapter->user_irqs;
return afu;
}
int cxl_afu_select_best_mode(struct cxl_afu *afu)
{
if (afu->modes_supported & CXL_MODE_DIRECTED)
return cxl_ops->afu_activate_mode(afu, CXL_MODE_DIRECTED);
if (afu->modes_supported & CXL_MODE_DEDICATED)
return cxl_ops->afu_activate_mode(afu, CXL_MODE_DEDICATED);
dev_warn(&afu->dev, "No supported programming modes available\n");
/* We don't fail this so the user can inspect sysfs */
return 0;
}
int cxl_adapter_context_get(struct cxl *adapter)
{
int rc;
rc = atomic_inc_unless_negative(&adapter->contexts_num);
return rc ? 0 : -EBUSY;
}
void cxl_adapter_context_put(struct cxl *adapter)
{
atomic_dec_if_positive(&adapter->contexts_num);
}
int cxl_adapter_context_lock(struct cxl *adapter)
{
int rc;
/* no active contexts -> contexts_num == 0 */
rc = atomic_cmpxchg(&adapter->contexts_num, 0, -1);
return rc ? -EBUSY : 0;
}
void cxl_adapter_context_unlock(struct cxl *adapter)
{
int val = atomic_cmpxchg(&adapter->contexts_num, -1, 0);
/*
* contexts lock taken -> contexts_num == -1
* If not true then show a warning and force reset the lock.
* This will happen when context_unlock was requested without
* doing a context_lock.
*/
if (val != -1) {
atomic_set(&adapter->contexts_num, 0);
WARN(1, "Adapter context unlocked with %d active contexts",
val);
}
}
static int __init init_cxl(void)
{
int rc = 0;
if (!tlbie_capable)
return -EINVAL;
if ((rc = cxl_file_init()))
return rc;
cxl_debugfs_init();
/*
* we don't register the callback on P9. slb callack is only
* used for the PSL8 MMU and CX4.
*/
if (cxl_is_power8()) {
rc = register_cxl_calls(&cxl_calls);
if (rc)
goto err;
}
if (cpu_has_feature(CPU_FTR_HVMODE)) {
cxl_ops = &cxl_native_ops;
rc = pci_register_driver(&cxl_pci_driver);
}
#ifdef CONFIG_PPC_PSERIES
else {
cxl_ops = &cxl_guest_ops;
rc = platform_driver_register(&cxl_of_driver);
}
#endif
if (rc)
goto err1;
return 0;
err1:
if (cxl_is_power8())
unregister_cxl_calls(&cxl_calls);
err:
cxl_debugfs_exit();
cxl_file_exit();
return rc;
}
static void exit_cxl(void)
{
if (cpu_has_feature(CPU_FTR_HVMODE))
pci_unregister_driver(&cxl_pci_driver);
#ifdef CONFIG_PPC_PSERIES
else
platform_driver_unregister(&cxl_of_driver);
#endif
cxl_debugfs_exit();
cxl_file_exit();
if (cxl_is_power8())
unregister_cxl_calls(&cxl_calls);
idr_destroy(&cxl_adapter_idr);
}
module_init(init_cxl);
module_exit(exit_cxl);
MODULE_DESCRIPTION("IBM Coherent Accelerator");
MODULE_AUTHOR("Ian Munsie <imunsie@au1.ibm.com>");
MODULE_LICENSE("GPL");