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-rw-r--r--arch/x86/mm/kaslr.c10
-rw-r--r--drivers/cxl/acpi.c11
-rw-r--r--drivers/cxl/core/hdm.c4
-rw-r--r--drivers/cxl/core/port.c2
-rw-r--r--drivers/cxl/core/region.c36
-rw-r--r--drivers/pci/Kconfig6
-rw-r--r--mm/Kconfig12
-rw-r--r--tools/testing/cxl/test/cxl_translate.c30
8 files changed, 70 insertions, 41 deletions
diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c
index 3c306de52fd4..834641c6049a 100644
--- a/arch/x86/mm/kaslr.c
+++ b/arch/x86/mm/kaslr.c
@@ -115,12 +115,12 @@ void __init kernel_randomize_memory(void)
/*
* Adapt physical memory region size based on available memory,
- * except when CONFIG_PCI_P2PDMA is enabled. P2PDMA exposes the
- * device BAR space assuming the direct map space is large enough
- * for creating a ZONE_DEVICE mapping in the direct map corresponding
- * to the physical BAR address.
+ * except when CONFIG_ZONE_DEVICE is enabled. ZONE_DEVICE wants to map
+ * any physical address into the direct-map. KASLR wants to reliably
+ * steal some physical address bits. Those design choices are in direct
+ * conflict.
*/
- if (!IS_ENABLED(CONFIG_PCI_P2PDMA) && (memory_tb < kaslr_regions[0].size_tb))
+ if (!IS_ENABLED(CONFIG_ZONE_DEVICE) && (memory_tb < kaslr_regions[0].size_tb))
kaslr_regions[0].size_tb = memory_tb;
/*
diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
index 77ac940e3013..49bba2b9a3c4 100644
--- a/drivers/cxl/acpi.c
+++ b/drivers/cxl/acpi.c
@@ -75,9 +75,16 @@ EXPORT_SYMBOL_FOR_MODULES(cxl_do_xormap_calc, "cxl_translate");
static u64 cxl_apply_xor_maps(struct cxl_root_decoder *cxlrd, u64 addr)
{
- struct cxl_cxims_data *cximsd = cxlrd->platform_data;
+ int hbiw = cxlrd->cxlsd.nr_targets;
+ struct cxl_cxims_data *cximsd;
+
+ /* No xormaps for host bridge interleave ways of 1 or 3 */
+ if (hbiw == 1 || hbiw == 3)
+ return addr;
+
+ cximsd = cxlrd->platform_data;
- return cxl_do_xormap_calc(cximsd, addr, cxlrd->cxlsd.nr_targets);
+ return cxl_do_xormap_calc(cximsd, addr, hbiw);
}
struct cxl_cxims_context {
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 1c5d2022c87a..eb5a3a7640c6 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -403,7 +403,7 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
* is not set.
*/
if (cxled->part < 0)
- for (int i = 0; cxlds->nr_partitions; i++)
+ for (int i = 0; i < cxlds->nr_partitions; i++)
if (resource_contains(&cxlds->part[i].res, res)) {
cxled->part = i;
break;
@@ -530,7 +530,7 @@ resource_size_t cxl_dpa_size(struct cxl_endpoint_decoder *cxled)
resource_size_t cxl_dpa_resource_start(struct cxl_endpoint_decoder *cxled)
{
- resource_size_t base = -1;
+ resource_size_t base = RESOURCE_SIZE_MAX;
lockdep_assert_held(&cxl_rwsem.dpa);
if (cxled->dpa_res)
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index fef3aa0c6680..3310dbfae9d6 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -1590,7 +1590,7 @@ static int update_decoder_targets(struct device *dev, void *data)
cxlsd->target[i] = dport;
dev_dbg(dev, "dport%d found in target list, index %d\n",
dport->port_id, i);
- return 1;
+ return 0;
}
}
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index ae899f68551f..5bd1213737fa 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -759,7 +759,7 @@ static ssize_t extended_linear_cache_size_show(struct device *dev,
ACQUIRE(rwsem_read_intr, rwsem)(&cxl_rwsem.region);
if ((rc = ACQUIRE_ERR(rwsem_read_intr, &rwsem)))
return rc;
- return sysfs_emit(buf, "%#llx\n", p->cache_size);
+ return sysfs_emit(buf, "%pap\n", &p->cache_size);
}
static DEVICE_ATTR_RO(extended_linear_cache_size);
@@ -3118,7 +3118,7 @@ u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent);
struct cxl_region_params *p = &cxlr->params;
struct cxl_endpoint_decoder *cxled = NULL;
- u64 dpa_offset, hpa_offset, hpa;
+ u64 base, dpa_offset, hpa_offset, hpa;
u16 eig = 0;
u8 eiw = 0;
int pos;
@@ -3136,8 +3136,14 @@ u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
ways_to_eiw(p->interleave_ways, &eiw);
granularity_to_eig(p->interleave_granularity, &eig);
- dpa_offset = dpa - cxl_dpa_resource_start(cxled);
+ base = cxl_dpa_resource_start(cxled);
+ if (base == RESOURCE_SIZE_MAX)
+ return ULLONG_MAX;
+
+ dpa_offset = dpa - base;
hpa_offset = cxl_calculate_hpa_offset(dpa_offset, pos, eiw, eig);
+ if (hpa_offset == ULLONG_MAX)
+ return ULLONG_MAX;
/* Apply the hpa_offset to the region base address */
hpa = hpa_offset + p->res->start + p->cache_size;
@@ -3146,6 +3152,9 @@ u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
if (cxlrd->ops.hpa_to_spa)
hpa = cxlrd->ops.hpa_to_spa(cxlrd, hpa);
+ if (hpa == ULLONG_MAX)
+ return ULLONG_MAX;
+
if (!cxl_resource_contains_addr(p->res, hpa)) {
dev_dbg(&cxlr->dev,
"Addr trans fail: hpa 0x%llx not in region\n", hpa);
@@ -3170,7 +3179,8 @@ static int region_offset_to_dpa_result(struct cxl_region *cxlr, u64 offset,
struct cxl_region_params *p = &cxlr->params;
struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent);
struct cxl_endpoint_decoder *cxled;
- u64 hpa, hpa_offset, dpa_offset;
+ u64 hpa_offset = offset;
+ u64 dpa, dpa_offset;
u16 eig = 0;
u8 eiw = 0;
int pos;
@@ -3187,10 +3197,13 @@ static int region_offset_to_dpa_result(struct cxl_region *cxlr, u64 offset,
* CXL HPA is assumed to equal SPA.
*/
if (cxlrd->ops.spa_to_hpa) {
- hpa = cxlrd->ops.spa_to_hpa(cxlrd, p->res->start + offset);
- hpa_offset = hpa - p->res->start;
- } else {
- hpa_offset = offset;
+ hpa_offset = cxlrd->ops.spa_to_hpa(cxlrd, p->res->start + offset);
+ if (hpa_offset == ULLONG_MAX) {
+ dev_dbg(&cxlr->dev, "HPA not found for %pr offset %#llx\n",
+ p->res, offset);
+ return -ENXIO;
+ }
+ hpa_offset -= p->res->start;
}
pos = cxl_calculate_position(hpa_offset, eiw, eig);
@@ -3207,8 +3220,13 @@ static int region_offset_to_dpa_result(struct cxl_region *cxlr, u64 offset,
cxled = p->targets[i];
if (cxled->pos != pos)
continue;
+
+ dpa = cxl_dpa_resource_start(cxled);
+ if (dpa != RESOURCE_SIZE_MAX)
+ dpa += dpa_offset;
+
result->cxlmd = cxled_to_memdev(cxled);
- result->dpa = cxl_dpa_resource_start(cxled) + dpa_offset;
+ result->dpa = dpa;
return 0;
}
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 00b0210e1f1d..e3f848ffb52a 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -225,12 +225,6 @@ config PCI_P2PDMA
P2P DMA transactions must be between devices behind the same root
port.
- Enabling this option will reduce the entropy of x86 KASLR memory
- regions. For example - on a 46 bit system, the entropy goes down
- from 16 bits to 15 bits. The actual reduction in entropy depends
- on the physical address bits, on processor features, kernel config
- (5 level page table) and physical memory present on the system.
-
If unsure, say N.
config PCI_LABEL
diff --git a/mm/Kconfig b/mm/Kconfig
index bd0ea5454af8..a992f2203eb9 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1220,10 +1220,14 @@ config ZONE_DEVICE
Device memory hotplug support allows for establishing pmem,
or other device driver discovered memory regions, in the
memmap. This allows pfn_to_page() lookups of otherwise
- "device-physical" addresses which is needed for using a DAX
- mapping in an O_DIRECT operation, among other things.
-
- If FS_DAX is enabled, then say Y.
+ "device-physical" addresses which is needed for DAX, PCI_P2PDMA, and
+ DEVICE_PRIVATE features among others.
+
+ Enabling this option will reduce the entropy of x86 KASLR memory
+ regions. For example - on a 46 bit system, the entropy goes down
+ from 16 bits to 15 bits. The actual reduction in entropy depends
+ on the physical address bits, on processor features, kernel config
+ (5 level page table) and physical memory present on the system.
#
# Helpers to mirror range of the CPU page tables of a process into device page
diff --git a/tools/testing/cxl/test/cxl_translate.c b/tools/testing/cxl/test/cxl_translate.c
index 2200ae21795c..16328b2112b2 100644
--- a/tools/testing/cxl/test/cxl_translate.c
+++ b/tools/testing/cxl/test/cxl_translate.c
@@ -68,6 +68,8 @@ static u64 to_hpa(u64 dpa_offset, int pos, u8 r_eiw, u16 r_eig, u8 hb_ways,
/* Calculate base HPA offset from DPA and position */
hpa_offset = cxl_calculate_hpa_offset(dpa_offset, pos, r_eiw, r_eig);
+ if (hpa_offset == ULLONG_MAX)
+ return ULLONG_MAX;
if (math == XOR_MATH) {
cximsd->nr_maps = hbiw_to_nr_maps[hb_ways];
@@ -258,19 +260,23 @@ static int test_random_params(void)
pos = get_random_u32() % ways;
dpa = get_random_u64() >> 12;
+ reverse_dpa = ULLONG_MAX;
+ reverse_pos = -1;
+
hpa = cxl_calculate_hpa_offset(dpa, pos, eiw, eig);
- reverse_dpa = cxl_calculate_dpa_offset(hpa, eiw, eig);
- reverse_pos = cxl_calculate_position(hpa, eiw, eig);
-
- if (reverse_dpa != dpa || reverse_pos != pos) {
- pr_err("test random iter %d FAIL hpa=%llu, dpa=%llu reverse_dpa=%llu, pos=%d reverse_pos=%d eiw=%u eig=%u\n",
- i, hpa, dpa, reverse_dpa, pos, reverse_pos, eiw,
- eig);
-
- if (failures++ > 10) {
- pr_err("test random too many failures, stop\n");
- break;
- }
+ if (hpa != ULLONG_MAX) {
+ reverse_dpa = cxl_calculate_dpa_offset(hpa, eiw, eig);
+ reverse_pos = cxl_calculate_position(hpa, eiw, eig);
+ if (reverse_dpa == dpa && reverse_pos == pos)
+ continue;
+ }
+
+ pr_err("test random iter %d FAIL hpa=%llu, dpa=%llu reverse_dpa=%llu, pos=%d reverse_pos=%d eiw=%u eig=%u\n",
+ i, hpa, dpa, reverse_dpa, pos, reverse_pos, eiw, eig);
+
+ if (failures++ > 10) {
+ pr_err("test random too many failures, stop\n");
+ break;
}
}
pr_info("..... test random: PASS %d FAIL %d\n", i - failures, failures);
generated by cgit v1.2.3 (git 2.25.1) at 2026-01-19 09:26:14 +0000