From 4b1c0466c8fbe23d688a1f54584670a9d1dceabd Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Mon, 17 Nov 2025 07:46:10 -0700 Subject: [PATCH] cxl/test: Add cxl_test CFMWS support for extended linear cache Add a module parameter to allow activation of extended linear cache on the auto region for cxl_test. The current platform implementation for extended linear cache is 1:1 of DRAM and CXL memory. A CFMWS is created with the size of both memory together where DRAM takes the first part of the memory range and CXL covers the second part. The current CXL auto region on cxl_test consists of 2 256M devices that creates a 512M region. The new extended linear cache setup will have 512M DRAM and 512M CXL memory for a total of 1G CFMWS. The hardware decoders must have their starting offset moved to after the DRAM region to handle the CXL regions. [ dj: Fixup commenting style. (Jonathan) ] Reviewed-by: Jonathan Cameron Tested-by: Alison Schofield Reviewed-by: Alison Schofield Reviewed-by: Fabio M. De Francesco Link: https://patch.msgid.link/20251117144611.903692-3-dave.jiang@intel.com Signed-off-by: Dave Jiang --- tools/testing/cxl/test/cxl.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c index f0e7345360813..bdb7e7366b6d6 100644 --- a/tools/testing/cxl/test/cxl.c +++ b/tools/testing/cxl/test/cxl.c @@ -15,6 +15,7 @@ #include "mock.h" static int interleave_arithmetic; +static bool extended_linear_cache; #define FAKE_QTG_ID 42 @@ -429,6 +430,22 @@ static struct cxl_mock_res *alloc_mock_res(resource_size_t size, int align) return res; } +/* Only update CFMWS0 as this is used by the auto region. */ +static void cfmws_elc_update(struct acpi_cedt_cfmws *window, int index) +{ + if (!extended_linear_cache) + return; + + if (index != 0) + return; + + /* + * The window size should be 2x of the CXL region size where half is + * DRAM and half is CXL + */ + window->window_size = mock_auto_region_size * 2; +} + static int populate_cedt(void) { struct cxl_mock_res *res; @@ -453,6 +470,7 @@ static int populate_cedt(void) for (i = cfmws_start; i <= cfmws_end; i++) { struct acpi_cedt_cfmws *window = mock_cfmws[i]; + cfmws_elc_update(window, i); res = alloc_mock_res(window->window_size, SZ_256M); if (!res) return -ENOMEM; @@ -783,6 +801,8 @@ static void mock_init_hdm_decoder(struct cxl_decoder *cxld) } base = window->base_hpa; + if (extended_linear_cache) + base += mock_auto_region_size; cxld->hpa_range = (struct range) { .start = base, .end = base + mock_auto_region_size - 1, @@ -1609,6 +1629,8 @@ static __exit void cxl_test_exit(void) module_param(interleave_arithmetic, int, 0444); MODULE_PARM_DESC(interleave_arithmetic, "Modulo:0, XOR:1"); +module_param(extended_linear_cache, bool, 0444); +MODULE_PARM_DESC(extended_linear_cache, "Enable extended linear cache support"); module_init(cxl_test_init); module_exit(cxl_test_exit); MODULE_LICENSE("GPL v2"); -- 2.47.3