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path: root/drivers/misc/mic/scif/scif_rb.c
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Diffstat (limited to 'drivers/misc/mic/scif/scif_rb.c')
-rw-r--r--drivers/misc/mic/scif/scif_rb.c240
1 files changed, 0 insertions, 240 deletions
diff --git a/drivers/misc/mic/scif/scif_rb.c b/drivers/misc/mic/scif/scif_rb.c
deleted file mode 100644
index e425882ae06d..000000000000
--- a/drivers/misc/mic/scif/scif_rb.c
+++ /dev/null
@@ -1,240 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Intel MIC Platform Software Stack (MPSS)
- *
- * Copyright(c) 2014 Intel Corporation.
- *
- * Intel SCIF driver.
- */
-#include <linux/circ_buf.h>
-#include <linux/types.h>
-#include <linux/io.h>
-#include <linux/errno.h>
-
-#include "scif_rb.h"
-
-#define scif_rb_ring_cnt(head, tail, size) CIRC_CNT(head, tail, size)
-#define scif_rb_ring_space(head, tail, size) CIRC_SPACE(head, tail, size)
-
-/**
- * scif_rb_init - Initializes the ring buffer
- * @rb: ring buffer
- * @read_ptr: A pointer to the read offset
- * @write_ptr: A pointer to the write offset
- * @rb_base: A pointer to the base of the ring buffer
- * @size: The size of the ring buffer in powers of two
- */
-void scif_rb_init(struct scif_rb *rb, u32 *read_ptr, u32 *write_ptr,
- void *rb_base, u8 size)
-{
- rb->rb_base = rb_base;
- rb->size = (1 << size);
- rb->read_ptr = read_ptr;
- rb->write_ptr = write_ptr;
- rb->current_read_offset = *read_ptr;
- rb->current_write_offset = *write_ptr;
-}
-
-/* Copies a message to the ring buffer -- handles the wrap around case */
-static void memcpy_torb(struct scif_rb *rb, void *header,
- void *msg, u32 size)
-{
- u32 size1, size2;
-
- if (header + size >= rb->rb_base + rb->size) {
- /* Need to call two copies if it wraps around */
- size1 = (u32)(rb->rb_base + rb->size - header);
- size2 = size - size1;
- memcpy_toio((void __iomem __force *)header, msg, size1);
- memcpy_toio((void __iomem __force *)rb->rb_base,
- msg + size1, size2);
- } else {
- memcpy_toio((void __iomem __force *)header, msg, size);
- }
-}
-
-/* Copies a message from the ring buffer -- handles the wrap around case */
-static void memcpy_fromrb(struct scif_rb *rb, void *header,
- void *msg, u32 size)
-{
- u32 size1, size2;
-
- if (header + size >= rb->rb_base + rb->size) {
- /* Need to call two copies if it wraps around */
- size1 = (u32)(rb->rb_base + rb->size - header);
- size2 = size - size1;
- memcpy_fromio(msg, (void __iomem __force *)header, size1);
- memcpy_fromio(msg + size1,
- (void __iomem __force *)rb->rb_base, size2);
- } else {
- memcpy_fromio(msg, (void __iomem __force *)header, size);
- }
-}
-
-/**
- * scif_rb_space - Query space available for writing to the RB
- * @rb: ring buffer
- *
- * Return: size available for writing to RB in bytes.
- */
-u32 scif_rb_space(struct scif_rb *rb)
-{
- rb->current_read_offset = *rb->read_ptr;
- /*
- * Update from the HW read pointer only once the peer has exposed the
- * new empty slot. This barrier is paired with the memory barrier
- * scif_rb_update_read_ptr()
- */
- mb();
- return scif_rb_ring_space(rb->current_write_offset,
- rb->current_read_offset, rb->size);
-}
-
-/**
- * scif_rb_write - Write a message to the RB
- * @rb: ring buffer
- * @msg: buffer to send the message. Must be at least size bytes long
- * @size: the size (in bytes) to be copied to the RB
- *
- * This API does not block if there isn't enough space in the RB.
- * Returns: 0 on success or -ENOMEM on failure
- */
-int scif_rb_write(struct scif_rb *rb, void *msg, u32 size)
-{
- void *header;
-
- if (scif_rb_space(rb) < size)
- return -ENOMEM;
- header = rb->rb_base + rb->current_write_offset;
- memcpy_torb(rb, header, msg, size);
- /*
- * Wait until scif_rb_commit(). Update the local ring
- * buffer data, not the shared data until commit.
- */
- rb->current_write_offset =
- (rb->current_write_offset + size) & (rb->size - 1);
- return 0;
-}
-
-/**
- * scif_rb_commit - To submit the message to let the peer fetch it
- * @rb: ring buffer
- */
-void scif_rb_commit(struct scif_rb *rb)
-{
- /*
- * We must ensure ordering between the all the data committed
- * previously before we expose the new message to the peer by
- * updating the write_ptr. This write barrier is paired with
- * the read barrier in scif_rb_count(..)
- */
- wmb();
- WRITE_ONCE(*rb->write_ptr, rb->current_write_offset);
-#ifdef CONFIG_INTEL_MIC_CARD
- /*
- * X100 Si bug: For the case where a Core is performing an EXT_WR
- * followed by a Doorbell Write, the Core must perform two EXT_WR to the
- * same address with the same data before it does the Doorbell Write.
- * This way, if ordering is violated for the Interrupt Message, it will
- * fall just behind the first Posted associated with the first EXT_WR.
- */
- WRITE_ONCE(*rb->write_ptr, rb->current_write_offset);
-#endif
-}
-
-/**
- * scif_rb_get - To get next message from the ring buffer
- * @rb: ring buffer
- * @size: Number of bytes to be read
- *
- * Return: NULL if no bytes to be read from the ring buffer, otherwise the
- * pointer to the next byte
- */
-static void *scif_rb_get(struct scif_rb *rb, u32 size)
-{
- void *header = NULL;
-
- if (scif_rb_count(rb, size) >= size)
- header = rb->rb_base + rb->current_read_offset;
- return header;
-}
-
-/*
- * scif_rb_get_next - Read from ring buffer.
- * @rb: ring buffer
- * @msg: buffer to hold the message. Must be at least size bytes long
- * @size: Number of bytes to be read
- *
- * Return: number of bytes read if available bytes are >= size, otherwise
- * returns zero.
- */
-u32 scif_rb_get_next(struct scif_rb *rb, void *msg, u32 size)
-{
- void *header = NULL;
- int read_size = 0;
-
- header = scif_rb_get(rb, size);
- if (header) {
- u32 next_cmd_offset =
- (rb->current_read_offset + size) & (rb->size - 1);
-
- read_size = size;
- rb->current_read_offset = next_cmd_offset;
- memcpy_fromrb(rb, header, msg, size);
- }
- return read_size;
-}
-
-/**
- * scif_rb_update_read_ptr
- * @rb: ring buffer
- */
-void scif_rb_update_read_ptr(struct scif_rb *rb)
-{
- u32 new_offset;
-
- new_offset = rb->current_read_offset;
- /*
- * We must ensure ordering between the all the data committed or read
- * previously before we expose the empty slot to the peer by updating
- * the read_ptr. This barrier is paired with the memory barrier in
- * scif_rb_space(..)
- */
- mb();
- WRITE_ONCE(*rb->read_ptr, new_offset);
-#ifdef CONFIG_INTEL_MIC_CARD
- /*
- * X100 Si Bug: For the case where a Core is performing an EXT_WR
- * followed by a Doorbell Write, the Core must perform two EXT_WR to the
- * same address with the same data before it does the Doorbell Write.
- * This way, if ordering is violated for the Interrupt Message, it will
- * fall just behind the first Posted associated with the first EXT_WR.
- */
- WRITE_ONCE(*rb->read_ptr, new_offset);
-#endif
-}
-
-/**
- * scif_rb_count
- * @rb: ring buffer
- * @size: Number of bytes expected to be read
- *
- * Return: number of bytes that can be read from the RB
- */
-u32 scif_rb_count(struct scif_rb *rb, u32 size)
-{
- if (scif_rb_ring_cnt(rb->current_write_offset,
- rb->current_read_offset,
- rb->size) < size) {
- rb->current_write_offset = *rb->write_ptr;
- /*
- * Update from the HW write pointer if empty only once the peer
- * has exposed the new message. This read barrier is paired
- * with the write barrier in scif_rb_commit(..)
- */
- smp_rmb();
- }
- return scif_rb_ring_cnt(rb->current_write_offset,
- rb->current_read_offset,
- rb->size);
-}