The root decoder provides the callbacks hpa_to_spa and spa_to_hpa to
perform Host Physical Address (HPA) and System Physical Address
translations, respectively. The callbacks are required to convert
addresses when HPA != SPA. XOR interleaving depends on this mechanism,
and the necessary handlers are implemented.
The translation handlers are used for poison injection
(trace_cxl_poison, cxl_poison_inject_fops) and error handling
(cxl_event_trace_record).
In AMD Zen5 systems with Normalized Addressing, endpoint addresses are
not SPAs, and translation handlers are required for these features to
function correctly.
Now, as ACPI PRM translation could be expensive in tracing or error
handling code paths, do not yet enable translations to avoid its
intensive use. Instead, disable those features which are used only for
debugging and enhanced logging.
Introduce the flag CXL_REGION_F_NORM_ADDR that indicates Normalized
Addressing for a region and use it to disable poison injection and DPA
to HPA conversion.
Note: Dropped unused CXL_DECODER_F_MASK macro.
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
---
drivers/cxl/core/atl.c | 3 +++
drivers/cxl/core/region.c | 33 +++++++++++++++++++++++++--------
drivers/cxl/cxl.h | 9 ++++++++-
3 files changed, 36 insertions(+), 9 deletions(-)
diff --git a/drivers/cxl/core/atl.c b/drivers/cxl/core/atl.c
index 09d0ea1792d9..310668786189 100644
--- a/drivers/cxl/core/atl.c
+++ b/drivers/cxl/core/atl.c
@@ -169,8 +169,11 @@ static int cxl_prm_setup_root(struct cxl_root *cxl_root, void *data)
* decoders in the BIOS would prevent a capable kernel (or
* other operating systems) from shutting down auto-generated
* regions and managing resources dynamically.
+ *
+ * Indicate that Normalized Addressing is enabled.
*/
cxld->flags |= CXL_DECODER_F_LOCK;
+ cxld->flags |= CXL_DECODER_F_NORMALIZED_ADDRESSING;
ctx->hpa_range = hpa_range;
ctx->interleave_ways = ways;
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 80cd77f0842e..8e92b491d686 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -1097,14 +1097,16 @@ static int cxl_rr_assign_decoder(struct cxl_port *port, struct cxl_region *cxlr,
return 0;
}
-static void cxl_region_set_lock(struct cxl_region *cxlr,
- struct cxl_decoder *cxld)
+static void cxl_region_setup_flags(struct cxl_region *cxlr,
+ struct cxl_decoder *cxld)
{
- if (!test_bit(CXL_DECODER_F_LOCK, &cxld->flags))
- return;
+ if (test_bit(CXL_DECODER_F_LOCK, &cxld->flags)) {
+ set_bit(CXL_REGION_F_LOCK, &cxlr->flags);
+ clear_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags);
+ }
- set_bit(CXL_REGION_F_LOCK, &cxlr->flags);
- clear_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags);
+ if (test_bit(CXL_DECODER_F_NORMALIZED_ADDRESSING, &cxld->flags))
+ set_bit(CXL_REGION_F_NORMALIZED_ADDRESSING, &cxlr->flags);
}
/**
@@ -1218,7 +1220,7 @@ static int cxl_port_attach_region(struct cxl_port *port,
}
}
- cxl_region_set_lock(cxlr, cxld);
+ cxl_region_setup_flags(cxlr, cxld);
rc = cxl_rr_ep_add(cxl_rr, cxled);
if (rc) {
@@ -2493,7 +2495,7 @@ static struct cxl_region *cxl_region_alloc(struct cxl_root_decoder *cxlrd, int i
device_set_pm_not_required(dev);
dev->bus = &cxl_bus_type;
dev->type = &cxl_region_type;
- cxl_region_set_lock(cxlr, &cxlrd->cxlsd.cxld);
+ cxl_region_setup_flags(cxlr, &cxlrd->cxlsd.cxld);
return cxlr;
}
@@ -3132,6 +3134,13 @@ u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
u8 eiw = 0;
int pos;
+ /*
+ * Conversion between SPA and DPA is not supported in
+ * Normalized Address mode.
+ */
+ if (test_bit(CXL_REGION_F_NORMALIZED_ADDRESSING, &cxlr->flags))
+ return ULLONG_MAX;
+
for (int i = 0; i < p->nr_targets; i++) {
if (cxlmd == cxled_to_memdev(p->targets[i])) {
cxled = p->targets[i];
@@ -3922,6 +3931,14 @@ static int cxl_region_setup_poison(struct cxl_region *cxlr)
struct cxl_region_params *p = &cxlr->params;
struct dentry *dentry;
+ /*
+ * Do not enable poison injection in Normalized Address mode.
+ * Conversion between SPA and DPA is required for this, but it is
+ * not supported in this mode.
+ */
+ if (test_bit(CXL_REGION_F_NORMALIZED_ADDRESSING, &cxlr->flags))
+ return 0;
+
/* Create poison attributes if all memdevs support the capabilities */
for (int i = 0; i < p->nr_targets; i++) {
struct cxl_endpoint_decoder *cxled = p->targets[i];
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 20b0fd43fa7b..de30a87600be 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -332,7 +332,7 @@ int cxl_dport_map_rcd_linkcap(struct pci_dev *pdev, struct cxl_dport *dport);
#define CXL_DECODER_F_TYPE3 BIT(3)
#define CXL_DECODER_F_LOCK BIT(4)
#define CXL_DECODER_F_ENABLE BIT(5)
-#define CXL_DECODER_F_MASK GENMASK(5, 0)
+#define CXL_DECODER_F_NORMALIZED_ADDRESSING BIT(6)
enum cxl_decoder_type {
CXL_DECODER_DEVMEM = 2,
@@ -525,6 +525,13 @@ enum cxl_partition_mode {
*/
#define CXL_REGION_F_LOCK 2
+/*
+ * Indicate Normalized Addressing. Use it to disable SPA conversion if
+ * HPA != SPA and an address translation callback handler does not
+ * exist. Flag is needed by AMD Zen5 platforms.
+ */
+#define CXL_REGION_F_NORMALIZED_ADDRESSING 3
+
/**
* struct cxl_region - CXL region
* @dev: This region's device
--
2.47.3
On 1/14/26 9:48 AM, Robert Richter wrote:
> The root decoder provides the callbacks hpa_to_spa and spa_to_hpa to
> perform Host Physical Address (HPA) and System Physical Address
> translations, respectively. The callbacks are required to convert
> addresses when HPA != SPA. XOR interleaving depends on this mechanism,
> and the necessary handlers are implemented.
>
> The translation handlers are used for poison injection
> (trace_cxl_poison, cxl_poison_inject_fops) and error handling
> (cxl_event_trace_record).
>
> In AMD Zen5 systems with Normalized Addressing, endpoint addresses are
> not SPAs, and translation handlers are required for these features to
> function correctly.
>
> Now, as ACPI PRM translation could be expensive in tracing or error
> handling code paths, do not yet enable translations to avoid its
> intensive use. Instead, disable those features which are used only for
> debugging and enhanced logging.
>
> Introduce the flag CXL_REGION_F_NORM_ADDR that indicates Normalized
> Addressing for a region and use it to disable poison injection and DPA
> to HPA conversion.
>
> Note: Dropped unused CXL_DECODER_F_MASK macro.
>
> Reviewed-by: Alison Schofield <alison.schofield@intel.com>
> Signed-off-by: Robert Richter <rrichter@amd.com>
As you mentioned commit log needs updating, otherwise
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
> drivers/cxl/core/atl.c | 3 +++
> drivers/cxl/core/region.c | 33 +++++++++++++++++++++++++--------
> drivers/cxl/cxl.h | 9 ++++++++-
> 3 files changed, 36 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/cxl/core/atl.c b/drivers/cxl/core/atl.c
> index 09d0ea1792d9..310668786189 100644
> --- a/drivers/cxl/core/atl.c
> +++ b/drivers/cxl/core/atl.c
> @@ -169,8 +169,11 @@ static int cxl_prm_setup_root(struct cxl_root *cxl_root, void *data)
> * decoders in the BIOS would prevent a capable kernel (or
> * other operating systems) from shutting down auto-generated
> * regions and managing resources dynamically.
> + *
> + * Indicate that Normalized Addressing is enabled.
> */
> cxld->flags |= CXL_DECODER_F_LOCK;
> + cxld->flags |= CXL_DECODER_F_NORMALIZED_ADDRESSING;
>
> ctx->hpa_range = hpa_range;
> ctx->interleave_ways = ways;
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index 80cd77f0842e..8e92b491d686 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -1097,14 +1097,16 @@ static int cxl_rr_assign_decoder(struct cxl_port *port, struct cxl_region *cxlr,
> return 0;
> }
>
> -static void cxl_region_set_lock(struct cxl_region *cxlr,
> - struct cxl_decoder *cxld)
> +static void cxl_region_setup_flags(struct cxl_region *cxlr,
> + struct cxl_decoder *cxld)
> {
> - if (!test_bit(CXL_DECODER_F_LOCK, &cxld->flags))
> - return;
> + if (test_bit(CXL_DECODER_F_LOCK, &cxld->flags)) {
> + set_bit(CXL_REGION_F_LOCK, &cxlr->flags);
> + clear_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags);
> + }
>
> - set_bit(CXL_REGION_F_LOCK, &cxlr->flags);
> - clear_bit(CXL_REGION_F_NEEDS_RESET, &cxlr->flags);
> + if (test_bit(CXL_DECODER_F_NORMALIZED_ADDRESSING, &cxld->flags))
> + set_bit(CXL_REGION_F_NORMALIZED_ADDRESSING, &cxlr->flags);
> }
>
> /**
> @@ -1218,7 +1220,7 @@ static int cxl_port_attach_region(struct cxl_port *port,
> }
> }
>
> - cxl_region_set_lock(cxlr, cxld);
> + cxl_region_setup_flags(cxlr, cxld);
>
> rc = cxl_rr_ep_add(cxl_rr, cxled);
> if (rc) {
> @@ -2493,7 +2495,7 @@ static struct cxl_region *cxl_region_alloc(struct cxl_root_decoder *cxlrd, int i
> device_set_pm_not_required(dev);
> dev->bus = &cxl_bus_type;
> dev->type = &cxl_region_type;
> - cxl_region_set_lock(cxlr, &cxlrd->cxlsd.cxld);
> + cxl_region_setup_flags(cxlr, &cxlrd->cxlsd.cxld);
>
> return cxlr;
> }
> @@ -3132,6 +3134,13 @@ u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
> u8 eiw = 0;
> int pos;
>
> + /*
> + * Conversion between SPA and DPA is not supported in
> + * Normalized Address mode.
> + */
> + if (test_bit(CXL_REGION_F_NORMALIZED_ADDRESSING, &cxlr->flags))
> + return ULLONG_MAX;
> +
> for (int i = 0; i < p->nr_targets; i++) {
> if (cxlmd == cxled_to_memdev(p->targets[i])) {
> cxled = p->targets[i];
> @@ -3922,6 +3931,14 @@ static int cxl_region_setup_poison(struct cxl_region *cxlr)
> struct cxl_region_params *p = &cxlr->params;
> struct dentry *dentry;
>
> + /*
> + * Do not enable poison injection in Normalized Address mode.
> + * Conversion between SPA and DPA is required for this, but it is
> + * not supported in this mode.
> + */
> + if (test_bit(CXL_REGION_F_NORMALIZED_ADDRESSING, &cxlr->flags))
> + return 0;
> +
> /* Create poison attributes if all memdevs support the capabilities */
> for (int i = 0; i < p->nr_targets; i++) {
> struct cxl_endpoint_decoder *cxled = p->targets[i];
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index 20b0fd43fa7b..de30a87600be 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -332,7 +332,7 @@ int cxl_dport_map_rcd_linkcap(struct pci_dev *pdev, struct cxl_dport *dport);
> #define CXL_DECODER_F_TYPE3 BIT(3)
> #define CXL_DECODER_F_LOCK BIT(4)
> #define CXL_DECODER_F_ENABLE BIT(5)
> -#define CXL_DECODER_F_MASK GENMASK(5, 0)
> +#define CXL_DECODER_F_NORMALIZED_ADDRESSING BIT(6)
>
> enum cxl_decoder_type {
> CXL_DECODER_DEVMEM = 2,
> @@ -525,6 +525,13 @@ enum cxl_partition_mode {
> */
> #define CXL_REGION_F_LOCK 2
>
> +/*
> + * Indicate Normalized Addressing. Use it to disable SPA conversion if
> + * HPA != SPA and an address translation callback handler does not
> + * exist. Flag is needed by AMD Zen5 platforms.
> + */
> +#define CXL_REGION_F_NORMALIZED_ADDRESSING 3
> +
> /**
> * struct cxl_region - CXL region
> * @dev: This region's device
On Wed, 14 Jan 2026 11:28:31 -0700 Dave Jiang <dave.jiang@intel.com> wrote: > On 1/14/26 9:48 AM, Robert Richter wrote: > > The root decoder provides the callbacks hpa_to_spa and spa_to_hpa to > > perform Host Physical Address (HPA) and System Physical Address > > translations, respectively. The callbacks are required to convert > > addresses when HPA != SPA. XOR interleaving depends on this mechanism, > > and the necessary handlers are implemented. > > > > The translation handlers are used for poison injection > > (trace_cxl_poison, cxl_poison_inject_fops) and error handling > > (cxl_event_trace_record). > > > > In AMD Zen5 systems with Normalized Addressing, endpoint addresses are > > not SPAs, and translation handlers are required for these features to > > function correctly. > > > > Now, as ACPI PRM translation could be expensive in tracing or error > > handling code paths, do not yet enable translations to avoid its > > intensive use. Instead, disable those features which are used only for > > debugging and enhanced logging. > > > > Introduce the flag CXL_REGION_F_NORM_ADDR that indicates Normalized > > Addressing for a region and use it to disable poison injection and DPA > > to HPA conversion. > > > > Note: Dropped unused CXL_DECODER_F_MASK macro. > > > > Reviewed-by: Alison Schofield <alison.schofield@intel.com> > > Signed-off-by: Robert Richter <rrichter@amd.com> > > As you mentioned commit log needs updating, otherwise > Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Just goes to show one should always refresh email even when half way through reviewing a patch series :) Jonathan
On 14.01.26 17:48:29, Robert Richter wrote: > Introduce the flag CXL_REGION_F_NORM_ADDR that indicates Normalized > Addressing for a region and use it to disable poison injection and DPA > to HPA conversion. Just realized the patch description was not updated properly. Please change the flag to CXL_REGION_F_NORMALIZED_ADDRESSING. Otherwise I will update it when sending the next version of the series. Thanks, -Robert
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