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feat[libcpu][t-head][c908]: Support RISC-V Standard Svpbmt Extension … #11227

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Merged
Rbb666 merged 1 commit into from
Feb 26, 2026
+60 −2
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feat[libcpu][t-head][c908]: Support RISC-V Standard Svpbmt Extension … #11227

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62 changes: 60 additions & 2 deletions libcpu/risc-v/t-head/c908/riscv_mmu.h
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Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@
* 2021-01-30 lizhirui first version
* 2021-05-03 lizhirui porting to C906
* 2023-10-12 Shell Add permission control API
* 2026-02-25 Steven Porting to Standard Svpbmt
*/

#ifndef __RISCV_MMU_H__
Expand All @@ -19,12 +20,26 @@

#undef PAGE_SIZE

/* C-SKY extend */
#if !CONFIG_XUANTIE_SVPBMT
/*
* RISC-V Standard Svpbmt Extension (Bit 61-62)
* 00: PMA (Normal Memory, Cacheable)
* 01: NC (Non-cacheable, Weakly-ordered)
* 10: IO (Strongly-ordered, Non-cacheable, Non-idempotent)
* 11: Reserved
*/
#define PTE_PBMT_MASK (3UL << 61)
#define PTE_PBMT_PMA (0UL << 61)
#define PTE_PBMT_NC (1UL << 61)
#define PTE_PBMT_IO (2UL << 61)
#else
/* XuanTie Extension (Bit 59-63) */
#define PTE_SEC (1UL << 59) /* Security */
#define PTE_SHARE (1UL << 60) /* Shareable */
#define PTE_BUF (1UL << 61) /* Bufferable */
#define PTE_CACHE (1UL << 62) /* Cacheable */
#define PTE_SO (1UL << 63) /* Strong Order */
#endif

#define PAGE_OFFSET_SHIFT 0
#define PAGE_OFFSET_BIT 12
Expand Down Expand Up @@ -60,12 +75,28 @@
#define PAGE_ATTR_USER (PTE_U)
#define PAGE_ATTR_SYSTEM (0)

#if !CONFIG_XUANTIE_SVPBMT
/*
* Default Leaf Attribute:
* RWX + User + Valid + Global + Accessed + Dirty + PMA(Cacheable)
*/
#define PAGE_DEFAULT_ATTR_LEAF \
(PAGE_ATTR_RWX | PAGE_ATTR_USER | PTE_V | PTE_G | PTE_PBMT_PMA | PTE_A | PTE_D)

/*
* Next Level Attribute:
* Svpbmt spec requires PBMT bits to be 0 for non-leaf PTEs.
*/
#define PAGE_DEFAULT_ATTR_NEXT \
(PAGE_ATTR_NEXT_LEVEL | PTE_V | PTE_G | PTE_A | PTE_D)
#else
#define PAGE_DEFAULT_ATTR_LEAF \
(PAGE_ATTR_RWX | PAGE_ATTR_USER | PTE_V | PTE_G | PTE_SHARE | PTE_BUF | \
PTE_CACHE | PTE_A | PTE_D)

#define PAGE_DEFAULT_ATTR_NEXT \
(PAGE_ATTR_NEXT_LEVEL | PTE_V | PTE_G | PTE_SHARE | PTE_BUF | PTE_CACHE | PTE_A | PTE_D)
#endif

#define PAGE_IS_LEAF(pte) __MASKVALUE(pte, PAGE_ATTR_RWX)

Expand All @@ -85,7 +116,32 @@
#define ARCH_VADDR_WIDTH 39
#define SATP_MODE SATP_MODE_SV39

//compatible to rt-smart new version
#if !CONFIG_XUANTIE_SVPBMT
/*
* Kernel Mappings
*/
/* Device: IO Mode (Strongly Ordered) */
#define MMU_MAP_K_DEVICE (PTE_PBMT_IO | PTE_A | PTE_D | PTE_G | PTE_W | PTE_R | PTE_V)

/* RW: Non-Cacheable (NC Mode) */
#define MMU_MAP_K_RW (PTE_PBMT_NC | PTE_A | PTE_D | PTE_G | PAGE_ATTR_RWX | PTE_V)

/* RWCB: Cacheable (PMA Mode) - Normal RAM */
#define MMU_MAP_K_RWCB (PTE_PBMT_PMA | PTE_A | PTE_D | PTE_G | PAGE_ATTR_RWX | PTE_V)

/*
* User Mappings
*/
/* User RW: Non-Cacheable */
#define MMU_MAP_U_RW (PTE_PBMT_NC | PTE_U | PTE_A | PTE_D | PAGE_ATTR_RWX | PTE_V)

/* User RWCB: Cacheable */
#define MMU_MAP_U_RWCB (PTE_PBMT_PMA | PTE_U | PTE_A | PTE_D | PAGE_ATTR_RWX | PTE_V)

/* Early Mapping: Cacheable */
#define MMU_MAP_EARLY \
PTE_WRAP(PAGE_ATTR_RWX | PTE_G | PTE_V | PTE_PBMT_PMA)
#else
#define MMU_MAP_K_DEVICE (PTE_BUF | PTE_SO | PTE_A | PTE_D | PTE_G | PTE_W | PTE_R | PTE_V)
#define MMU_MAP_K_RW (PTE_SHARE | PTE_A | PTE_D | PTE_G | PAGE_ATTR_RWX | PTE_V)
#define MMU_MAP_K_RWCB (MMU_MAP_K_RW | PTE_BUF | PTE_CACHE)
Expand All @@ -94,6 +150,8 @@
#define MMU_MAP_U_RWCB (MMU_MAP_U_RW | PTE_BUF | PTE_CACHE)
#define MMU_MAP_EARLY \
PTE_WRAP(PAGE_ATTR_RWX | PTE_G | PTE_V | PTE_CACHE | PTE_SHARE | PTE_BUF)
#endif

#define MMU_MAP_TRACE(attr) (attr)

#define PTE_XWR_MASK 0xe
Expand Down