The branch main has been updated by markj:
URL:
https://cgit.FreeBSD.org/src/commit/?id=964bf2f902c5e05381018532e5d9d456979d4bf7
commit 964bf2f902c5e05381018532e5d9d456979d4bf7
Author: John F. Carr <j...@mit.edu>
AuthorDate: 2022-03-19 22:51:43 +0000
Commit: Mark Johnston <ma...@freebsd.org>
CommitDate: 2022-03-28 15:23:45 +0000
hpet: Allow a MMIO window smaller than 1K
Some new AMD systems provide a HPET MMIO region smaller than the 1KB
specified, and a correspondingly small number of timers. Handle this in
the HPET driver rather than requiring a 1KB window. This allows the
HPET driver to attach on such systems.
PR: 262638
Reviewed by: markj
MFC after: 1 month
---
sys/dev/acpica/acpi_hpet.c | 20 +++++++++++++++++---
sys/dev/acpica/acpi_hpet.h | 1 +
2 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/sys/dev/acpica/acpi_hpet.c b/sys/dev/acpica/acpi_hpet.c
index 0f0a16f336f2..e35e3808a980 100644
--- a/sys/dev/acpica/acpi_hpet.c
+++ b/sys/dev/acpica/acpi_hpet.c
@@ -477,6 +477,7 @@ hpet_attach(device_t dev)
struct make_dev_args mda;
int i, j, num_msi, num_timers, num_percpu_et, num_percpu_t, cur_cpu;
int pcpu_master, error;
+ rman_res_t hpet_region_size;
static int maxhpetet = 0;
uint32_t val, val2, cvectors, dvectors;
uint16_t vendor, rev;
@@ -493,10 +494,11 @@ hpet_attach(device_t dev)
if (sc->mem_res == NULL)
return (ENOMEM);
- /* Validate that we can access the whole region. */
- if (rman_get_size(sc->mem_res) < HPET_MEM_WIDTH) {
+ hpet_region_size = rman_get_size(sc->mem_res);
+ /* Validate that the region is big enough for the control registers. */
+ if (hpet_region_size < HPET_MEM_MIN_WIDTH) {
device_printf(dev, "memory region width %jd too small\n",
- rman_get_size(sc->mem_res));
+ hpet_region_size);
bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
return (ENXIO);
}
@@ -526,6 +528,18 @@ hpet_attach(device_t dev)
*/
if (vendor == HPET_VENDID_AMD && rev < 0x10 && num_timers > 0)
num_timers--;
+ /*
+ * Now validate that the region is big enough to address all counters.
+ */
+ if (hpet_region_size < HPET_TIMER_CAP_CNF(num_timers)) {
+ device_printf(dev,
+ "memory region width %jd too small for %d timers\n",
+ hpet_region_size, num_timers);
+ hpet_disable(sc);
+ bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
+ return (ENXIO);
+ }
+
sc->num_timers = num_timers;
if (bootverbose) {
device_printf(dev,
diff --git a/sys/dev/acpica/acpi_hpet.h b/sys/dev/acpica/acpi_hpet.h
index c3941c39a89a..1d6a6022230e 100644
--- a/sys/dev/acpica/acpi_hpet.h
+++ b/sys/dev/acpica/acpi_hpet.h
@@ -30,6 +30,7 @@
#define __ACPI_HPET_H__
#define HPET_MEM_WIDTH 0x400 /* Expected memory region size */
+#define HPET_MEM_MIN_WIDTH 0x100 /* Minimum memory region size */
/* General registers */
#define HPET_CAPABILITIES 0x0 /* General capabilities and ID */
