4.17-stable review patch. If anyone has any objections, please let me know.
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From: Jan Glauber jglauber@cavium.com
commit c782a8c43e94ba6c09e9de2d69b5e3a5840ce61c upstream.
After issuing a request an endless loop was used to read the completion state from memory which is asynchronously updated by the ZIP coprocessor.
Add an upper bound to the retry attempts to prevent a CPU getting stuck forever in case of an error. Additionally, add a read memory barrier and a small delay between the reading attempts.
Signed-off-by: Jan Glauber jglauber@cavium.com Reviewed-by: Robert Richter rrichter@cavium.com Cc: stable stable@vger.kernel.org # 4.14 Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/crypto/cavium/zip/common.h | 21 +++++++++++++++++++++ drivers/crypto/cavium/zip/zip_deflate.c | 4 ++-- drivers/crypto/cavium/zip/zip_inflate.c | 4 ++-- 3 files changed, 25 insertions(+), 4 deletions(-)
--- a/drivers/crypto/cavium/zip/common.h +++ b/drivers/crypto/cavium/zip/common.h @@ -46,8 +46,10 @@ #ifndef __COMMON_H__ #define __COMMON_H__
+#include <linux/delay.h> #include <linux/init.h> #include <linux/interrupt.h> +#include <linux/io.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/pci.h> @@ -149,6 +151,25 @@ struct zip_operation { u32 sizeofzops; };
+static inline int zip_poll_result(union zip_zres_s *result) +{ + int retries = 1000; + + while (!result->s.compcode) { + if (!--retries) { + pr_err("ZIP ERR: request timed out"); + return -ETIMEDOUT; + } + udelay(10); + /* + * Force re-reading of compcode which is updated + * by the ZIP coprocessor. + */ + rmb(); + } + return 0; +} + /* error messages */ #define zip_err(fmt, args...) pr_err("ZIP ERR:%s():%d: " \ fmt "\n", __func__, __LINE__, ## args) --- a/drivers/crypto/cavium/zip/zip_deflate.c +++ b/drivers/crypto/cavium/zip/zip_deflate.c @@ -129,8 +129,8 @@ int zip_deflate(struct zip_operation *zi /* Stats update for compression requests submitted */ atomic64_inc(&zip_dev->stats.comp_req_submit);
- while (!result_ptr->s.compcode) - continue; + /* Wait for completion or error */ + zip_poll_result(result_ptr);
/* Stats update for compression requests completed */ atomic64_inc(&zip_dev->stats.comp_req_complete); --- a/drivers/crypto/cavium/zip/zip_inflate.c +++ b/drivers/crypto/cavium/zip/zip_inflate.c @@ -143,8 +143,8 @@ int zip_inflate(struct zip_operation *zi /* Decompression requests submitted stats update */ atomic64_inc(&zip_dev->stats.decomp_req_submit);
- while (!result_ptr->s.compcode) - continue; + /* Wait for completion or error */ + zip_poll_result(result_ptr);
/* Decompression requests completed stats update */ atomic64_inc(&zip_dev->stats.decomp_req_complete);