projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| 722b7c48 GKH |
1 | From foo@baz Sat Jul 28 10:14:31 CEST 2018 |
| 2 | From: "Matthew R. Ochs" <mrochs@linux.vnet.ibm.com> | |
| 3 | Date: Mon, 26 Mar 2018 11:30:22 -0500 | |
| 4 | Subject: scsi: cxlflash: Avoid clobbering context control register value | |
| 5 | ||
| 6 | From: "Matthew R. Ochs" <mrochs@linux.vnet.ibm.com> | |
| 7 | ||
| 8 | [ Upstream commit 465891fe9237b02f8d0fd26448f733fae7236f4a ] | |
| 9 | ||
| 10 | The SISLite specification originally defined the context control register with | |
| 11 | a single field of bits to represent the LISN and also stipulated that the | |
| 12 | register reset value be 0. The cxlflash driver took advantage of this when | |
| 13 | programming the LISN for the master contexts via an unconditional write - no | |
| 14 | other bits were preserved. | |
| 15 | ||
| 16 | When unmap support was added, SISLite was updated to define bit 0 of the | |
| 17 | context control register as a way for the AFU to notify the context owner that | |
| 18 | unmap operations were supported. Thus the assumptions under which the register | |
| 19 | is setup changed and the existing unconditional write is clobbering the unmap | |
| 20 | state for master contexts. This is presently not an issue due to the order in | |
| 21 | which the context control register is programmed in relation to the unmap bit | |
| 22 | being queried but should be addressed to avoid a future regression in the | |
| 23 | event this code is moved elsewhere. | |
| 24 | ||
| 25 | To remedy this issue, preserve the bits when programming the LISN field in the | |
| 26 | context control register. Since the LISN will now be programmed using a read | |
| 27 | value, assert that the initial state of the LISN field is as described in | |
| 28 | SISLite (0). | |
| 29 | ||
| 30 | Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> | |
| 31 | Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> | |
| 32 | Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> | |
| 33 | Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> | |
| 34 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
| 35 | --- | |
| 36 | drivers/scsi/cxlflash/main.c | 5 ++++- | |
| 37 | drivers/scsi/cxlflash/sislite.h | 1 + | |
| 38 | 2 files changed, 5 insertions(+), 1 deletion(-) | |
| 39 | ||
| 40 | --- a/drivers/scsi/cxlflash/main.c | |
| 41 | +++ b/drivers/scsi/cxlflash/main.c | |
| 42 | @@ -1303,7 +1303,10 @@ static void afu_err_intr_init(struct afu | |
| 43 | for (i = 0; i < afu->num_hwqs; i++) { | |
| 44 | hwq = get_hwq(afu, i); | |
| 45 | ||
| 46 | - writeq_be(SISL_MSI_SYNC_ERROR, &hwq->host_map->ctx_ctrl); | |
| 47 | + reg = readq_be(&hwq->host_map->ctx_ctrl); | |
| 48 | + WARN_ON((reg & SISL_CTX_CTRL_LISN_MASK) != 0); | |
| 49 | + reg |= SISL_MSI_SYNC_ERROR; | |
| 50 | + writeq_be(reg, &hwq->host_map->ctx_ctrl); | |
| 51 | writeq_be(SISL_ISTATUS_MASK, &hwq->host_map->intr_mask); | |
| 52 | } | |
| 53 | } | |
| 54 | --- a/drivers/scsi/cxlflash/sislite.h | |
| 55 | +++ b/drivers/scsi/cxlflash/sislite.h | |
| 56 | @@ -284,6 +284,7 @@ struct sisl_host_map { | |
| 57 | __be64 cmd_room; | |
| 58 | __be64 ctx_ctrl; /* least significant byte or b56:63 is LISN# */ | |
| 59 | #define SISL_CTX_CTRL_UNMAP_SECTOR 0x8000000000000000ULL /* b0 */ | |
| 60 | +#define SISL_CTX_CTRL_LISN_MASK (0xFFULL) | |
| 61 | __be64 mbox_w; /* restricted use */ | |
| 62 | __be64 sq_start; /* Submission Queue (R/W): write sequence and */ | |
| 63 | __be64 sq_end; /* inclusion semantics are the same as RRQ */ |