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authorEugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>2018-03-21 15:59:03 +0300
committerAlexey Brodkin <abrodkin@synopsys.com>2018-03-21 17:06:55 +0300
commit7241944a5b3069205f615f8a0a5d9f3833c80156 (patch)
tree2ef878dfec9ded1f61e5400cb0234d992bf414f3 /arch/arc
parent375945bac2b8cbb547940ad5cf1e16a0eb0ddfeb (diff)
ARC: Cache: Add more HW configuration checks
Add additional cache configuration checks and note about supported configurations. It is unlikely to face some configuration in real life but it's better to be prepared and refuse to work on those. Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Diffstat (limited to 'arch/arc')
-rw-r--r--arch/arc/lib/cache.c75
1 files changed, 75 insertions, 0 deletions
diff --git a/arch/arc/lib/cache.c b/arch/arc/lib/cache.c
index 5d7583d868..fd70ce8efe 100644
--- a/arch/arc/lib/cache.c
+++ b/arch/arc/lib/cache.c
@@ -85,6 +85,66 @@
* enabling force function inline with '__attribute__((always_inline))' gcc
* attribute to avoid any function call (and BLINK store) between cache flush
* and disable.
+ *
+ *
+ * [ NOTE 2 ]:
+ * As of today we only support the following cache configurations on ARC.
+ * Other configurations may exist in HW (for example, since version 3.0 HS
+ * supports SL$ (L2 system level cache) disable) but we don't support it in SW.
+ * Configuration 1:
+ * ______________________
+ * | |
+ * | ARC CPU |
+ * |______________________|
+ * ___|___ ___|___
+ * | | | |
+ * | L1 I$ | | L1 D$ |
+ * |_______| |_______|
+ * on/off on/off
+ * ___|______________|____
+ * | |
+ * | main memory |
+ * |______________________|
+ *
+ * Configuration 2:
+ * ______________________
+ * | |
+ * | ARC CPU |
+ * |______________________|
+ * ___|___ ___|___
+ * | | | |
+ * | L1 I$ | | L1 D$ |
+ * |_______| |_______|
+ * on/off on/off
+ * ___|______________|____
+ * | |
+ * | L2 (SL$) |
+ * |______________________|
+ * always must be on
+ * ___|______________|____
+ * | |
+ * | main memory |
+ * |______________________|
+ *
+ * Configuration 3:
+ * ______________________
+ * | |
+ * | ARC CPU |
+ * |______________________|
+ * ___|___ ___|___
+ * | | | |
+ * | L1 I$ | | L1 D$ |
+ * |_______| |_______|
+ * on/off must be on
+ * ___|______________|____ _______
+ * | | | |
+ * | L2 (SL$) |-----| IOC |
+ * |______________________| |_______|
+ * always must be on on/off
+ * ___|______________|____
+ * | |
+ * | main memory |
+ * |______________________|
*/
DECLARE_GLOBAL_DATA_PTR;
@@ -308,6 +368,14 @@ static void arc_ioc_setup(void)
/* IOC Aperture size is equal to DDR size */
long ap_size = CONFIG_SYS_SDRAM_SIZE;
+ /* Unsupported configuration. See [ NOTE 2 ] for more details. */
+ if (!slc_exists())
+ panic("Try to enable IOC but SLC is not present");
+
+ /* Unsupported configuration. See [ NOTE 2 ] for more details. */
+ if (!dcache_enabled())
+ panic("Try to enable IOC but L1 D$ is disabled");
+
flush_n_invalidate_dcache_all();
if (!is_power_of_2(ap_size) || ap_size < 4096)
@@ -338,6 +406,13 @@ static void read_decode_cache_bcr_arcv2(void)
if (slc_exists()) {
slc_cfg.word = read_aux_reg(ARC_AUX_SLC_CONFIG);
gd->arch.slc_line_sz = (slc_cfg.fields.lsz == 0) ? 128 : 64;
+
+ /*
+ * We don't support configuration where L1 I$ or L1 D$ is
+ * absent but SL$ exists. See [ NOTE 2 ] for more details.
+ */
+ if (!icache_exists() || !dcache_exists())
+ panic("Unsupported cache configuration: SLC exists but one of L1 caches is absent");
}
#endif /* CONFIG_ISA_ARCV2 */