aboutsummaryrefslogtreecommitdiff
path: root/lib/sbi/sbi_tlb.c
diff options
context:
space:
mode:
authorAtish Patra <atish.patra@wdc.com>2019-06-18 14:54:01 -0700
committerAnup Patel <anup.patel@wdc.com>2019-06-19 09:48:51 +0530
commit749b0b093242a4c27f7c4f66121afd7852b2de48 (patch)
tree90c46fe6e750ddf08dd57347ddd498571792353a /lib/sbi/sbi_tlb.c
parenta5b37bd7d275fc65d8fd0b19bd3a08edfe4e6096 (diff)
lib: Move sbi core library to lib/sbi
Signed-off-by: Atish Patra <atish.patra@wdc.com> Acked-by: Anup Patel <anup.patel@wdc.com>
Diffstat (limited to 'lib/sbi/sbi_tlb.c')
-rw-r--r--lib/sbi/sbi_tlb.c227
1 files changed, 227 insertions, 0 deletions
diff --git a/lib/sbi/sbi_tlb.c b/lib/sbi/sbi_tlb.c
new file mode 100644
index 0000000..814d402
--- /dev/null
+++ b/lib/sbi/sbi_tlb.c
@@ -0,0 +1,227 @@
+/*
+ * 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_barrier.h>
+#include <sbi/sbi_error.h>
+#include <sbi/sbi_fifo.h>
+#include <sbi/sbi_hart.h>
+#include <sbi/sbi_bitops.h>
+#include <sbi/sbi_scratch.h>
+#include <sbi/sbi_tlb.h>
+#include <plat/string.h>
+
+static unsigned long ipi_tlb_fifo_off;
+static unsigned long ipi_tlb_fifo_mem_off;
+
+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;
+ ret = SBI_FIFO_UPDATED;
+ } else if (next->start >= curr->start && next_end <= curr_end) {
+ 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.
+ * Case3:
+ if a complete vma flush is requested, then all entries can be deleted
+ and new request can be enqueued. This will not be done for ASID case
+ as that means we have to iterate again in the fifo to figure out which
+ entries belong to that ASID.
+ */
+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) {
+ if (next->size == SBI_TLB_FLUSH_ALL)
+ ret = SBI_FIFO_RESET;
+ else
+ ret = __sbi_tlb_fifo_range_check(curr, next);
+ }
+
+ return ret;
+}
+
+int sbi_tlb_fifo_update(struct sbi_scratch *scratch, u32 event, void *data)
+{
+ int ret;
+ struct sbi_fifo *ipi_tlb_fifo;
+ struct sbi_tlb_info *tinfo = data;
+
+ ipi_tlb_fifo = sbi_scratch_offset_ptr(scratch,
+ ipi_tlb_fifo_off);
+ /*
+ * 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 >= SBI_TLB_FLUSH_MAX_SIZE) {
+ tinfo->start = 0;
+ tinfo->size = SBI_TLB_FLUSH_ALL;
+ }
+
+ ret = sbi_fifo_inplace_update(ipi_tlb_fifo, data,
+ sbi_tlb_fifo_update_cb);
+ if (ret == SBI_FIFO_SKIP || ret == SBI_FIFO_UPDATED) {
+ return 1;
+ }
+
+ while (sbi_fifo_enqueue(ipi_tlb_fifo, 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 mechansim to handle
+ * this properly.
+ */
+ __asm__ __volatile("nop");
+ __asm__ __volatile("nop");
+ }
+
+ return 0;
+}
+
+static void sbi_tlb_flush_all(void)
+{
+ __asm__ __volatile("sfence.vma");
+}
+
+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_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");
+ }
+}
+
+void sbi_tlb_fifo_process(struct sbi_scratch *scratch, u32 event)
+{
+ struct sbi_tlb_info tinfo;
+ struct sbi_fifo *ipi_tlb_fifo =
+ sbi_scratch_offset_ptr(scratch, ipi_tlb_fifo_off);
+
+ while (!sbi_fifo_dequeue(ipi_tlb_fifo, &tinfo)) {
+ if (tinfo.type == SBI_TLB_FLUSH_VMA)
+ sbi_tlb_fifo_sfence_vma(&tinfo);
+ else if (tinfo.type == SBI_TLB_FLUSH_VMA_ASID)
+ sbi_tlb_fifo_sfence_vma_asid(&tinfo);
+ memset(&tinfo, 0, SBI_TLB_INFO_SIZE);
+ }
+}
+
+int sbi_tlb_fifo_init(struct sbi_scratch *scratch, bool cold_boot)
+{
+ void *ipi_tlb_mem;
+ struct sbi_fifo *ipi_tlb_q;
+
+ if (cold_boot) {
+ ipi_tlb_fifo_off = sbi_scratch_alloc_offset(sizeof(*ipi_tlb_q),
+ "IPI_TLB_FIFO");
+ if (!ipi_tlb_fifo_off)
+ return SBI_ENOMEM;
+ ipi_tlb_fifo_mem_off = sbi_scratch_alloc_offset(
+ SBI_TLB_FIFO_NUM_ENTRIES * SBI_TLB_INFO_SIZE,
+ "IPI_TLB_FIFO_MEM");
+ if (!ipi_tlb_fifo_mem_off) {
+ sbi_scratch_free_offset(ipi_tlb_fifo_off);
+ return SBI_ENOMEM;
+ }
+ } else {
+ if (!ipi_tlb_fifo_off ||
+ !ipi_tlb_fifo_mem_off)
+ return SBI_ENOMEM;
+ }
+
+ ipi_tlb_q = sbi_scratch_offset_ptr(scratch, ipi_tlb_fifo_off);
+ ipi_tlb_mem = sbi_scratch_offset_ptr(scratch, ipi_tlb_fifo_mem_off);
+
+ sbi_fifo_init(ipi_tlb_q, ipi_tlb_mem,
+ SBI_TLB_FIFO_NUM_ENTRIES, SBI_TLB_INFO_SIZE);
+
+ return 0;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-10 20:12:39 +0000