Files
opensbi/lib/sbi/sbi_tlb.c
Anup Patel 5f762d14f0 lib: Introduce sbi_ipi_event_create/destroy() APIs
This patch introduces sbi_ipi_event_create/destroy() APIs and
struct sbi_ipi_event_ops for creating/destroying IPI events
at runtime based of event operations.

This new APIs will help platform code and utils code to create
custom IPI events which are not part of generic OpenSBI library.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-01-22 12:10:44 +05:30

441 lines
11 KiB
C

/*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2019 Western Digital Corporation or its affiliates.
*
* Authors:
* Atish Patra <atish.patra@wdc.com>
* Anup Patel <anup.patel@wdc.com>
*/
#include <sbi/riscv_asm.h>
#include <sbi/riscv_atomic.h>
#include <sbi/riscv_barrier.h>
#include <sbi/sbi_error.h>
#include <sbi/sbi_fifo.h>
#include <sbi/sbi_hart.h>
#include <sbi/sbi_ipi.h>
#include <sbi/sbi_scratch.h>
#include <sbi/sbi_tlb.h>
#include <sbi/sbi_hfence.h>
#include <sbi/sbi_string.h>
#include <sbi/sbi_console.h>
#include <sbi/sbi_platform.h>
static unsigned long tlb_sync_off;
static unsigned long tlb_fifo_off;
static unsigned long tlb_fifo_mem_off;
static unsigned long tlb_range_flush_limit;
static void sbi_tlb_flush_all(void)
{
__asm__ __volatile("sfence.vma");
}
static void sbi_tlb_fifo_hfence_vvma(struct sbi_tlb_info *tinfo)
{
unsigned long start = tinfo->start;
unsigned long size = tinfo->size;
unsigned long i;
if ((start == 0 && size == 0) || (size == SBI_TLB_FLUSH_ALL)) {
__sbi_hfence_vvma_all();
return;
}
for (i = 0; i < size; i += PAGE_SIZE) {
__sbi_hfence_vvma_va(start+i);
}
}
static void sbi_tlb_fifo_hfence_gvma(struct sbi_tlb_info *tinfo)
{
unsigned long start = tinfo->start;
unsigned long size = tinfo->size;
unsigned long i;
if ((start == 0 && size == 0) || (size == SBI_TLB_FLUSH_ALL)) {
__sbi_hfence_gvma_all();
return;
}
for (i = 0; i < size; i += PAGE_SIZE) {
__sbi_hfence_gvma_gpa(start+i);
}
}
static void sbi_tlb_fifo_sfence_vma(struct sbi_tlb_info *tinfo)
{
unsigned long start = tinfo->start;
unsigned long size = tinfo->size;
unsigned long i;
if ((start == 0 && size == 0) || (size == SBI_TLB_FLUSH_ALL)) {
sbi_tlb_flush_all();
return;
}
for (i = 0; i < size; i += PAGE_SIZE) {
__asm__ __volatile__("sfence.vma %0"
:
: "r"(start + i)
: "memory");
}
}
static void sbi_tlb_fifo_hfence_vvma_asid(struct sbi_tlb_info *tinfo)
{
unsigned long start = tinfo->start;
unsigned long size = tinfo->size;
unsigned long asid = tinfo->asid;
unsigned long i;
if (start == 0 && size == 0) {
__sbi_hfence_vvma_all();
return;
}
if (size == SBI_TLB_FLUSH_ALL) {
__sbi_hfence_vvma_asid(asid);
return;
}
for (i = 0; i < size; i += PAGE_SIZE) {
__sbi_hfence_vvma_asid_va(asid, start + i);
}
}
static void sbi_tlb_fifo_hfence_gvma_vmid(struct sbi_tlb_info *tinfo)
{
unsigned long start = tinfo->start;
unsigned long size = tinfo->size;
unsigned long vmid = tinfo->asid;
unsigned long i;
if (start == 0 && size == 0) {
__sbi_hfence_gvma_all();
return;
}
if (size == SBI_TLB_FLUSH_ALL) {
__sbi_hfence_gvma_vmid(vmid);
return;
}
for (i = 0; i < size; i += PAGE_SIZE) {
__sbi_hfence_gvma_vmid_gpa(vmid, start+i);
}
}
static void sbi_tlb_fifo_sfence_vma_asid(struct sbi_tlb_info *tinfo)
{
unsigned long start = tinfo->start;
unsigned long size = tinfo->size;
unsigned long asid = tinfo->asid;
unsigned long i;
if (start == 0 && size == 0) {
sbi_tlb_flush_all();
return;
}
/* Flush entire MM context for a given ASID */
if (size == SBI_TLB_FLUSH_ALL) {
__asm__ __volatile__("sfence.vma x0, %0"
:
: "r"(asid)
: "memory");
return;
}
for (i = 0; i < size; i += PAGE_SIZE) {
__asm__ __volatile__("sfence.vma %0, %1"
:
: "r"(start + i), "r"(asid)
: "memory");
}
}
static void sbi_tlb_local_flush(struct sbi_tlb_info *tinfo)
{
switch (tinfo->type) {
case SBI_TLB_FLUSH_VMA:
sbi_tlb_fifo_sfence_vma(tinfo);
break;
case SBI_TLB_FLUSH_VMA_ASID:
sbi_tlb_fifo_sfence_vma_asid(tinfo);
break;
case SBI_TLB_FLUSH_GVMA:
sbi_tlb_fifo_hfence_gvma(tinfo);
break;
case SBI_TLB_FLUSH_GVMA_VMID:
sbi_tlb_fifo_hfence_gvma_vmid(tinfo);
break;
case SBI_TLB_FLUSH_VVMA:
sbi_tlb_fifo_hfence_vvma(tinfo);
break;
case SBI_TLB_FLUSH_VVMA_ASID:
sbi_tlb_fifo_hfence_vvma_asid(tinfo);
break;
case SBI_ITLB_FLUSH:
__asm__ __volatile("fence.i");
break;
default:
sbi_printf("Invalid tlb flush request type [%lu]\n",
tinfo->type);
}
return;
}
static void sbi_tlb_entry_process(struct sbi_scratch *scratch,
struct sbi_tlb_info *tinfo)
{
u32 i;
u64 m;
struct sbi_scratch *rscratch = NULL;
unsigned long *rtlb_sync = NULL;
sbi_tlb_local_flush(tinfo);
for (i = 0, m = tinfo->shart_mask; m; i++, m >>= 1) {
if (!(m & 1UL))
continue;
rscratch = sbi_hart_id_to_scratch(scratch, i);
rtlb_sync = sbi_scratch_offset_ptr(rscratch, tlb_sync_off);
while (atomic_raw_xchg_ulong(rtlb_sync, 1)) ;
}
}
static void sbi_tlb_fifo_process_count(struct sbi_scratch *scratch, int count)
{
struct sbi_tlb_info tinfo;
u32 deq_count = 0;
struct sbi_fifo *tlb_fifo =
sbi_scratch_offset_ptr(scratch, tlb_fifo_off);
while (!sbi_fifo_dequeue(tlb_fifo, &tinfo)) {
sbi_tlb_entry_process(scratch, &tinfo);
deq_count++;
if (deq_count > count)
break;
}
}
static void sbi_tlb_fifo_process(struct sbi_scratch *scratch)
{
struct sbi_tlb_info tinfo;
struct sbi_fifo *tlb_fifo =
sbi_scratch_offset_ptr(scratch, tlb_fifo_off);
while (!sbi_fifo_dequeue(tlb_fifo, &tinfo))
sbi_tlb_entry_process(scratch, &tinfo);
}
static void sbi_tlb_fifo_sync(struct sbi_scratch *scratch)
{
unsigned long *tlb_sync =
sbi_scratch_offset_ptr(scratch, tlb_sync_off);
while (!atomic_raw_xchg_ulong(tlb_sync, 0)) {
/*
* While we are waiting for remote hart to set the sync,
* consume fifo requests to avoid deadlock.
*/
sbi_tlb_fifo_process_count(scratch, 1);
}
return;
}
static inline int __sbi_tlb_fifo_range_check(struct sbi_tlb_info *curr,
struct sbi_tlb_info *next)
{
unsigned long curr_end;
unsigned long next_end;
int ret = SBI_FIFO_UNCHANGED;
if (!curr || !next)
return ret;
next_end = next->start + next->size;
curr_end = curr->start + curr->size;
if (next->start <= curr->start && next_end > curr_end) {
curr->start = next->start;
curr->size = next->size;
curr->shart_mask = curr->shart_mask | next->shart_mask;
ret = SBI_FIFO_UPDATED;
} else if (next->start >= curr->start && next_end <= curr_end) {
curr->shart_mask = curr->shart_mask | next->shart_mask;
ret = SBI_FIFO_SKIP;
}
return ret;
}
/**
* Call back to decide if an inplace fifo update is required or next entry can
* can be skipped. Here are the different cases that are being handled.
*
* Case1:
* if next flush request range lies within one of the existing entry, skip
* the next entry.
* Case2:
* if flush request range in current fifo entry lies within next flush
* request, update the current entry.
*
* Note:
* We can not issue a fifo reset anymore if a complete vma flush is requested.
* This is because we are queueing FENCE.I requests as well now.
* To ease up the pressure in enqueue/fifo sync path, try to dequeue 1 element
* before continuing the while loop. This method is preferred over wfi/ipi because
* of MMIO cost involved in later method.
*/
static int sbi_tlb_fifo_update_cb(void *in, void *data)
{
struct sbi_tlb_info *curr;
struct sbi_tlb_info *next;
int ret = SBI_FIFO_UNCHANGED;
if (!in || !data)
return ret;
curr = (struct sbi_tlb_info *)data;
next = (struct sbi_tlb_info *)in;
if (next->type == SBI_TLB_FLUSH_VMA_ASID &&
curr->type == SBI_TLB_FLUSH_VMA_ASID) {
if (next->asid == curr->asid)
ret = __sbi_tlb_fifo_range_check(curr, next);
} else if (next->type == SBI_TLB_FLUSH_VMA &&
curr->type == SBI_TLB_FLUSH_VMA) {
ret = __sbi_tlb_fifo_range_check(curr, next);
}
return ret;
}
static int sbi_tlb_fifo_update(struct sbi_scratch *scratch,
struct sbi_scratch *remote_scratch,
u32 remote_hartid, void *data)
{
int ret;
struct sbi_fifo *tlb_fifo_r;
struct sbi_tlb_info *tinfo = data;
u32 curr_hartid = sbi_current_hartid();
/*
* If address range to flush is too big then simply
* upgrade it to flush all because we can only flush
* 4KB at a time.
*/
if (tinfo->size > tlb_range_flush_limit) {
tinfo->start = 0;
tinfo->size = SBI_TLB_FLUSH_ALL;
}
/*
* If the request is to queue a tlb flush entry for itself
* then just do a local flush and return;
*/
if (remote_hartid == curr_hartid) {
sbi_tlb_local_flush(tinfo);
return -1;
}
tlb_fifo_r = sbi_scratch_offset_ptr(remote_scratch, tlb_fifo_off);
ret = sbi_fifo_inplace_update(tlb_fifo_r, data, sbi_tlb_fifo_update_cb);
if (ret != SBI_FIFO_UNCHANGED) {
return 1;
}
while (sbi_fifo_enqueue(tlb_fifo_r, data) < 0) {
/**
* For now, Busy loop until there is space in the fifo.
* There may be case where target hart is also
* enqueue in source hart's fifo. Both hart may busy
* loop leading to a deadlock.
* TODO: Introduce a wait/wakeup event mechanism to handle
* this properly.
*/
sbi_tlb_fifo_process_count(scratch, 1);
sbi_dprintf(remote_scratch, "hart%d: hart%d tlb fifo full\n",
curr_hartid, remote_hartid);
}
return 0;
}
static struct sbi_ipi_event_ops tlb_ops = {
.name = "IPI_TLB",
.update = sbi_tlb_fifo_update,
.sync = sbi_tlb_fifo_sync,
.process = sbi_tlb_fifo_process,
};
static u32 tlb_event = SBI_IPI_EVENT_MAX;
int sbi_tlb_fifo_request(struct sbi_scratch *scratch, ulong hmask,
ulong hbase, struct sbi_tlb_info *tinfo)
{
return sbi_ipi_send_many(scratch, hmask, hbase, tlb_event, tinfo);
}
int sbi_tlb_fifo_init(struct sbi_scratch *scratch, bool cold_boot)
{
int ret;
void *tlb_mem;
unsigned long *tlb_sync;
struct sbi_fifo *tlb_q;
const struct sbi_platform *plat = sbi_platform_ptr(scratch);
if (cold_boot) {
tlb_sync_off = sbi_scratch_alloc_offset(sizeof(*tlb_sync),
"IPI_TLB_SYNC");
if (!tlb_sync_off)
return SBI_ENOMEM;
tlb_fifo_off = sbi_scratch_alloc_offset(sizeof(*tlb_q),
"IPI_TLB_FIFO");
if (!tlb_fifo_off) {
sbi_scratch_free_offset(tlb_sync_off);
return SBI_ENOMEM;
}
tlb_fifo_mem_off = sbi_scratch_alloc_offset(
SBI_TLB_FIFO_NUM_ENTRIES * SBI_TLB_INFO_SIZE,
"IPI_TLB_FIFO_MEM");
if (!tlb_fifo_mem_off) {
sbi_scratch_free_offset(tlb_fifo_off);
sbi_scratch_free_offset(tlb_sync_off);
return SBI_ENOMEM;
}
ret = sbi_ipi_event_create(&tlb_ops);
if (ret < 0) {
sbi_scratch_free_offset(tlb_fifo_mem_off);
sbi_scratch_free_offset(tlb_fifo_off);
sbi_scratch_free_offset(tlb_sync_off);
return ret;
}
tlb_event = ret;
tlb_range_flush_limit = sbi_platform_tlbr_flush_limit(plat);
} else {
if (!tlb_sync_off ||
!tlb_fifo_off ||
!tlb_fifo_mem_off)
return SBI_ENOMEM;
if (SBI_IPI_EVENT_MAX <= tlb_event)
return SBI_ENOSPC;
}
tlb_sync = sbi_scratch_offset_ptr(scratch, tlb_sync_off);
tlb_q = sbi_scratch_offset_ptr(scratch, tlb_fifo_off);
tlb_mem = sbi_scratch_offset_ptr(scratch, tlb_fifo_mem_off);
*tlb_sync = 0;
sbi_fifo_init(tlb_q, tlb_mem,
SBI_TLB_FIFO_NUM_ENTRIES, SBI_TLB_INFO_SIZE);
return 0;
}