On Thu, Jan 11, 2024 at 02:59:05PM +0000, Jonathan Cameron wrote:
> From: Hyeonggon Yoo <42.hye...@gmail.com>
>
> In the current mdev_reg_read() implementation, it consistently returns
> that the Media Status is Ready (01b). This was fine until commit
> 25a52959f99d ("hw/cxl: Add support for device sanitation") because the
> media was presumed to be ready.
>
> However, as per the CXL 3.0 spec "8.2.9.8.5.1 Sanitize (Opcode 4400h)",
> during sanitation, the Media State should be set to Disabled (11b). The
> mentioned commit correctly sets it to Disabled, but mdev_reg_read()
> still returns Media Status as Ready.
>
> To address this, update mdev_reg_read() to read register values instead
> of returning dummy values.
>
> Note __toggle_media() was overwriting the mailbox capability
> register, but nothing was reading that after this so that bug had no
> obvious effect unless the driver was reloaded.
>
> Fixes: commit 25a52959f99d ("hw/cxl: Add support for device sanitation")
> Signed-off-by: Hyeonggon Yoo <42.hye...@gmail.com>
> Link: https://lore.kernel.org/r/20231222090051.3265307-3-42.hye...@gmail.com
> Signed-off-by: Jonathan Cameron <jonathan.came...@huawei.com>
>
Reviewed-by: Fan Ni <fan...@samsung.com>
> --
>
> Hyeonggon - I've kept your sign-off. Let me know if this is ok.
> Dropped RBs etc as this has changed quite a bit.
>
> I plan to send out a group of fixes including this soon, but given
> I've been pointing out the original fix didn't work thought I'd send
> this one out for early review!
>
> ---
> include/hw/cxl/cxl_device.h | 9 +++++++--
> hw/cxl/cxl-device-utils.c | 17 +++++++++++------
> 2 files changed, 18 insertions(+), 8 deletions(-)
>
> diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
> index befb5f884b..31d2afcd3d 100644
> --- a/include/hw/cxl/cxl_device.h
> +++ b/include/hw/cxl/cxl_device.h
> @@ -202,6 +202,9 @@ typedef struct cxl_device_state {
> };
> };
>
> + /* Stash the memory device status value */
> + uint64_t memdev_status;
> +
> struct {
> bool set;
> uint64_t last_set;
> @@ -353,8 +356,10 @@ static inline void __toggle_media(CXLDeviceState
> *cxl_dstate, int val)
> {
> uint64_t dev_status_reg;
>
> - dev_status_reg = FIELD_DP64(0, CXL_MEM_DEV_STS, MEDIA_STATUS, val);
> - cxl_dstate->mbox_reg_state64[R_CXL_MEM_DEV_STS] = dev_status_reg;
> + dev_status_reg = cxl_dstate->memdev_status;
> + dev_status_reg = FIELD_DP64(dev_status_reg, CXL_MEM_DEV_STS,
> MEDIA_STATUS,
> + val);
> + cxl_dstate->memdev_status = dev_status_reg;
> }
> #define cxl_dev_disable_media(cxlds) \
> do { __toggle_media((cxlds), 0x3); } while (0)
> diff --git a/hw/cxl/cxl-device-utils.c b/hw/cxl/cxl-device-utils.c
> index 61a3c4dc2e..40b619ffd9 100644
> --- a/hw/cxl/cxl-device-utils.c
> +++ b/hw/cxl/cxl-device-utils.c
> @@ -229,12 +229,9 @@ static void mailbox_reg_write(void *opaque, hwaddr
> offset, uint64_t value,
>
> static uint64_t mdev_reg_read(void *opaque, hwaddr offset, unsigned size)
> {
> - uint64_t retval = 0;
> -
> - retval = FIELD_DP64(retval, CXL_MEM_DEV_STS, MEDIA_STATUS, 1);
> - retval = FIELD_DP64(retval, CXL_MEM_DEV_STS, MBOX_READY, 1);
> + CXLDeviceState *cxl_dstate = opaque;
>
> - return retval;
> + return cxl_dstate->memdev_status;
> }
>
> static void ro_reg_write(void *opaque, hwaddr offset, uint64_t value,
> @@ -371,7 +368,15 @@ static void mailbox_reg_init_common(CXLDeviceState
> *cxl_dstate)
> cxl_dstate->mbox_msi_n = msi_n;
> }
>
> -static void memdev_reg_init_common(CXLDeviceState *cxl_dstate) { }
> +static void memdev_reg_init_common(CXLDeviceState *cxl_dstate)
> +{
> + uint64_t memdev_status_reg;
> +
> + memdev_status_reg = FIELD_DP64(0, CXL_MEM_DEV_STS, MEDIA_STATUS, 1);
> + memdev_status_reg = FIELD_DP64(memdev_status_reg, CXL_MEM_DEV_STS,
> + MBOX_READY, 1);
> + cxl_dstate->memdev_status = memdev_status_reg;
> +}
>
> void cxl_device_register_init_t3(CXLType3Dev *ct3d)
> {
> --
> 2.39.2
>
