[PATCH 3/4] intel_th: msu: Make contiguous buffers uncached

From: Alexander Shishkin
Date: Mon Jun 21 2021 - 11:13:24 EST


We already keep the multiblock mode buffers uncached, but forget the
single mode. Address this.

Signed-off-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/hwtracing/intel_th/msu.c | 48 +++++++++++++++++++++-----------
1 file changed, 32 insertions(+), 16 deletions(-)

diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c
index 2edc4666633d..432ade0842f6 100644
--- a/drivers/hwtracing/intel_th/msu.c
+++ b/drivers/hwtracing/intel_th/msu.c
@@ -1024,33 +1024,49 @@ static int __msc_buffer_win_alloc(struct msc_window *win,
}

#ifdef CONFIG_X86
-static void msc_buffer_set_uc(struct msc_window *win, unsigned int nr_segs)
+static void msc_buffer_set_uc(struct msc *msc)
{
struct scatterlist *sg_ptr;
+ struct msc_window *win;
int i;

- for_each_sg(win->sgt->sgl, sg_ptr, nr_segs, i) {
- /* Set the page as uncached */
- set_memory_uc((unsigned long)sg_virt(sg_ptr),
- PFN_DOWN(sg_ptr->length));
+ if (msc->mode == MSC_MODE_SINGLE) {
+ set_memory_uc((unsigned long)msc->base, msc->nr_pages);
+ return;
+ }
+
+ list_for_each_entry(win, &msc->win_list, entry) {
+ for_each_sg(win->sgt->sgl, sg_ptr, win->nr_segs, i) {
+ /* Set the page as uncached */
+ set_memory_uc((unsigned long)sg_virt(sg_ptr),
+ PFN_DOWN(sg_ptr->length));
+ }
}
}

-static void msc_buffer_set_wb(struct msc_window *win)
+static void msc_buffer_set_wb(struct msc *msc)
{
struct scatterlist *sg_ptr;
+ struct msc_window *win;
int i;

- for_each_sg(win->sgt->sgl, sg_ptr, win->nr_segs, i) {
- /* Reset the page to write-back */
- set_memory_wb((unsigned long)sg_virt(sg_ptr),
- PFN_DOWN(sg_ptr->length));
+ if (msc->mode == MSC_MODE_SINGLE) {
+ set_memory_wb((unsigned long)msc->base, msc->nr_pages);
+ return;
+ }
+
+ list_for_each_entry(win, &msc->win_list, entry) {
+ for_each_sg(win->sgt->sgl, sg_ptr, win->nr_segs, i) {
+ /* Reset the page to write-back */
+ set_memory_wb((unsigned long)sg_virt(sg_ptr),
+ PFN_DOWN(sg_ptr->length));
+ }
}
}
#else /* !X86 */
static inline void
-msc_buffer_set_uc(struct msc_window *win, unsigned int nr_segs) {}
-static inline void msc_buffer_set_wb(struct msc_window *win) {}
+msc_buffer_set_uc(struct msc *msc) {}
+static inline void msc_buffer_set_wb(struct msc *msc) {}
#endif /* CONFIG_X86 */

/**
@@ -1097,8 +1113,6 @@ static int msc_buffer_win_alloc(struct msc *msc, unsigned int nr_blocks)
if (ret <= 0)
goto err_nomem;

- msc_buffer_set_uc(win, ret);
-
win->nr_segs = ret;
win->nr_blocks = nr_blocks;

@@ -1152,8 +1166,6 @@ static void msc_buffer_win_free(struct msc *msc, struct msc_window *win)
msc->base_addr = 0;
}

- msc_buffer_set_wb(win);
-
if (msc->mbuf && msc->mbuf->free_window)
msc->mbuf->free_window(msc->mbuf_priv, win->sgt);
else
@@ -1260,6 +1272,8 @@ static int msc_buffer_multi_alloc(struct msc *msc, unsigned long *nr_pages,
*/
static void msc_buffer_free(struct msc *msc)
{
+ msc_buffer_set_wb(msc);
+
if (msc->mode == MSC_MODE_SINGLE)
msc_buffer_contig_free(msc);
else if (msc->mode == MSC_MODE_MULTI)
@@ -1303,6 +1317,8 @@ static int msc_buffer_alloc(struct msc *msc, unsigned long *nr_pages,
}

if (!ret) {
+ msc_buffer_set_uc(msc);
+
/* allocation should be visible before the counter goes to 0 */
smp_mb__before_atomic();

--
2.30.2