From 2b79b694a80513696daf072db0fd980e7573b212 Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Sun, 12 Jun 2022 20:03:52 -0500 Subject: lib: irqchip/plic: Add priority save/restore helpers These can be used by platform code to save the PLIC priority state, if it would otherwise be lost during non-retentive suspend. The platform is responsible for allocating all necessary storage. As a space optimization, store the saved priority values as 8-bit integers, since that is large enough to hold any priority value on the relevant platforms. Reviewed-by: Anup Patel Signed-off-by: Samuel Holland --- include/sbi_utils/irqchip/plic.h | 5 +++++ lib/utils/irqchip/plic.c | 19 +++++++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/include/sbi_utils/irqchip/plic.h b/include/sbi_utils/irqchip/plic.h index 21b2266..48c24f0 100644 --- a/include/sbi_utils/irqchip/plic.h +++ b/include/sbi_utils/irqchip/plic.h @@ -17,6 +17,11 @@ struct plic_data { unsigned long num_src; }; +/* So far, priorities on all consumers of these functions fit in 8 bits. */ +void plic_priority_save(const struct plic_data *plic, u8 *priority); + +void plic_priority_restore(const struct plic_data *plic, const u8 *priority); + void plic_context_save(const struct plic_data *plic, int context_id, u32 *enable, u32 *threshold); diff --git a/lib/utils/irqchip/plic.c b/lib/utils/irqchip/plic.c index 0c64078..8c25b9d 100644 --- a/lib/utils/irqchip/plic.c +++ b/lib/utils/irqchip/plic.c @@ -22,6 +22,13 @@ #define PLIC_CONTEXT_BASE 0x200000 #define PLIC_CONTEXT_STRIDE 0x1000 +static u32 plic_get_priority(const struct plic_data *plic, u32 source) +{ + volatile void *plic_priority = (char *)plic->addr + + PLIC_PRIORITY_BASE + 4 * source; + return readl(plic_priority); +} + static void plic_set_priority(const struct plic_data *plic, u32 source, u32 val) { volatile void *plic_priority = (char *)plic->addr + @@ -29,6 +36,18 @@ static void plic_set_priority(const struct plic_data *plic, u32 source, u32 val) writel(val, plic_priority); } +void plic_priority_save(const struct plic_data *plic, u8 *priority) +{ + for (u32 i = 0; i < plic->num_src; i++) + priority[i] = plic_get_priority(plic, i); +} + +void plic_priority_restore(const struct plic_data *plic, const u8 *priority) +{ + for (u32 i = 0; i < plic->num_src; i++) + plic_set_priority(plic, i, priority[i]); +} + static u32 plic_get_thresh(const struct plic_data *plic, u32 cntxid) { volatile void *plic_thresh; -- cgit v1.2.3