On Tue, 15 Jun 2021 17:20:39 -0700
Alison Schofield <alison.schofield@xxxxxxxxx> wrote:
> The ACPI CXL Early Discovery Table (CEDT) includes a list of CXL memory
> resources in CXL Fixed Memory Window Structures (CFMWS). Retrieve each
> CFMWS in the CEDT and add a cxl_decoder object to the root port (root0)
> for each memory resource.
>
> Signed-off-by: Alison Schofield <alison.schofield@xxxxxxxxx>
LGTM
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> ---
> drivers/cxl/acpi.c | 114 +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 114 insertions(+)
>
> diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
> index b6d9cd45428c..e3aa356d4dcd 100644
> --- a/drivers/cxl/acpi.c
> +++ b/drivers/cxl/acpi.c
> @@ -8,8 +8,120 @@
> #include <linux/pci.h>
> #include "cxl.h"
>
> +/* Encode defined in CXL 2.0 8.2.5.12.7 HDM Decoder Control Register */
> +#define CFMWS_INTERLEAVE_WAYS(x) (1 << (x)->interleave_ways)
> +#define CFMWS_INTERLEAVE_GRANULARITY(x) ((x)->granularity + 8)
> +
> static struct acpi_table_header *cedt_table;
>
> +static unsigned long cfmws_to_decoder_flags(int restrictions)
> +{
> + unsigned long flags = 0;
> +
> + if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE2)
> + flags |= CXL_DECODER_F_TYPE2;
> + if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE3)
> + flags |= CXL_DECODER_F_TYPE3;
> + if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_VOLATILE)
> + flags |= CXL_DECODER_F_RAM;
> + if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_PMEM)
> + flags |= CXL_DECODER_F_PMEM;
> + if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_FIXED)
> + flags |= CXL_DECODER_F_LOCK;
> +
> + return flags;
> +}
> +
> +static int cxl_acpi_cfmws_verify(struct device *dev,
> + struct acpi_cedt_cfmws *cfmws)
> +{
> + int expected_len;
> +
> + if (cfmws->interleave_arithmetic != ACPI_CEDT_CFMWS_ARITHMETIC_MODULO) {
> + dev_err(dev, "CFMWS Unsupported Interleave Arithmetic\n");
> + return -EINVAL;
> + }
> +
> + if (!IS_ALIGNED(cfmws->base_hpa, SZ_256M)) {
> + dev_err(dev, "CFMWS Base HPA not 256MB aligned\n");
> + return -EINVAL;
> + }
> +
> + if (!IS_ALIGNED(cfmws->window_size, SZ_256M)) {
> + dev_err(dev, "CFMWS Window Size not 256MB aligned\n");
> + return -EINVAL;
> + }
> +
> + expected_len = struct_size((cfmws), interleave_targets,
> + CFMWS_INTERLEAVE_WAYS(cfmws));
> +
> + if (expected_len != cfmws->header.length) {
> + dev_err(dev, "CFMWS interleave ways and targets mismatch\n");
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static void cxl_add_cfmws_decoders(struct device *dev,
> + struct cxl_port *root_port)
> +{
> + struct acpi_cedt_cfmws *cfmws;
> + struct cxl_decoder *cxld;
> + acpi_size len, cur = 0;
> + void *cedt_base;
> + int rc;
> +
> + len = cedt_table->length - sizeof(*cedt_table);
> + cedt_base = cedt_table + 1;
> +
> + while (cur < len) {
> + struct acpi_cedt_header *c = cedt_base + cur;
> +
> + if (c->type != ACPI_CEDT_TYPE_CFMWS) {
> + cur += c->length;
> + continue;
> + }
> +
> + cfmws = cedt_base + cur;
> +
> + if (cfmws->header.length < sizeof(*cfmws)) {
> + dev_err(dev, "Invalid CFMWS header length %u\n",
> + cfmws->header.length);
> + dev_err(dev, "Failed to add decoders\n");
> + return;
> + }
> +
> + rc = cxl_acpi_cfmws_verify(dev, cfmws);
> + if (rc) {
> + dev_err(dev, "CFMWS range %#llx-%#llx not registered\n",
> + cfmws->base_hpa, cfmws->base_hpa +
> + cfmws->window_size - 1);
> + cur += c->length;
> + continue;
> + }
> +
> + cxld = devm_cxl_add_decoder(dev, root_port,
> + CFMWS_INTERLEAVE_WAYS(cfmws),
> + cfmws->base_hpa, cfmws->window_size,
> + CFMWS_INTERLEAVE_WAYS(cfmws),
> + CFMWS_INTERLEAVE_GRANULARITY(cfmws),
> + CXL_DECODER_EXPANDER,
> + cfmws_to_decoder_flags(cfmws->restrictions));
> +
> + if (IS_ERR(cxld)) {
> + dev_err(dev, "Failed to add decoder for %#llx-%#llx\n",
> + cfmws->base_hpa, cfmws->base_hpa +
> + cfmws->window_size - 1);
> + } else {
> + dev_dbg(dev, "add: %s range %#llx-%#llx\n",
> + dev_name(&cxld->dev), cfmws->base_hpa,
> + cfmws->base_hpa + cfmws->window_size - 1);
> + }
> + cur += c->length;
> + }
> +}
> +
> static struct acpi_cedt_chbs *cxl_acpi_match_chbs(struct device *dev, u32 uid)
> {
> struct acpi_cedt_chbs *chbs, *chbs_match = NULL;
> @@ -251,6 +363,8 @@ static int cxl_acpi_probe(struct platform_device *pdev)
> if (rc)
> goto out;
>
> + cxl_add_cfmws_decoders(host, root_port);
> +
> /*
> * Root level scanned with host-bridge as dports, now scan host-bridges
> * for their role as CXL uports to their CXL-capable PCIe Root Ports.
