[PATCH 2/2] MIPS: Remove unused shadow GPR support from vector irq setup

From: Thomas Bogendoerfer
Date: Thu Dec 21 2023 - 07:59:53 EST


Using shadow GPRs for vectored interrupts has never been used,
time to remove it.

Signed-off-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
---
arch/mips/kernel/traps.c | 94 +++++++++++++---------------------------
1 file changed, 30 insertions(+), 64 deletions(-)

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index d90b18908692..c1b2b18b0505 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -2055,105 +2055,71 @@ static void do_default_vi(void)
panic("Caught unexpected vectored interrupt.");
}

-static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
+void *set_vi_handler(int n, vi_handler_t addr)
{
+ extern const u8 except_vec_vi[];
+ extern const u8 except_vec_vi_ori[], except_vec_vi_end[];
+ extern const u8 rollback_except_vec_vi[];
unsigned long handler;
unsigned long old_handler = vi_handlers[n];
int srssets = current_cpu_data.srsets;
u16 *h;
unsigned char *b;
+ const u8 *vec_start;
+ int ori_offset;
+ int handler_len;

BUG_ON(!cpu_has_veic && !cpu_has_vint);

if (addr == NULL) {
handler = (unsigned long) do_default_vi;
- srs = 0;
} else
handler = (unsigned long) addr;
vi_handlers[n] = handler;

b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);

- if (srs >= srssets)
- panic("Shadow register set %d not supported", srs);
-
if (cpu_has_veic) {
if (board_bind_eic_interrupt)
- board_bind_eic_interrupt(n, srs);
+ board_bind_eic_interrupt(n, 0);
} else if (cpu_has_vint) {
/* SRSMap is only defined if shadow sets are implemented */
if (srssets > 1)
- change_c0_srsmap(0xf << n*4, srs << n*4);
+ change_c0_srsmap(0xf << n*4, 0 << n*4);
}

- if (srs == 0) {
- /*
- * If no shadow set is selected then use the default handler
- * that does normal register saving and standard interrupt exit
- */
- extern const u8 except_vec_vi[];
- extern const u8 except_vec_vi_ori[], except_vec_vi_end[];
- extern const u8 rollback_except_vec_vi[];
- const u8 *vec_start = using_rollback_handler() ?
- rollback_except_vec_vi : except_vec_vi;
+ vec_start = using_rollback_handler() ? rollback_except_vec_vi :
+ except_vec_vi;
#if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
- const int ori_offset = except_vec_vi_ori - vec_start + 2;
+ ori_offset = except_vec_vi_ori - vec_start + 2;
#else
- const int ori_offset = except_vec_vi_ori - vec_start;
+ ori_offset = except_vec_vi_ori - vec_start;
#endif
- const int handler_len = except_vec_vi_end - vec_start;
+ handler_len = except_vec_vi_end - vec_start;

- if (handler_len > VECTORSPACING) {
- /*
- * Sigh... panicing won't help as the console
- * is probably not configured :(
- */
- panic("VECTORSPACING too small");
- }
-
- set_handler(((unsigned long)b - ebase), vec_start,
-#ifdef CONFIG_CPU_MICROMIPS
- (handler_len - 1));
-#else
- handler_len);
-#endif
- /* insert offset into vi_handlers[] */
- h = (u16 *)(b + ori_offset);
- *h = n * sizeof(handler);
- local_flush_icache_range((unsigned long)b,
- (unsigned long)(b+handler_len));
- }
- else {
+ if (handler_len > VECTORSPACING) {
/*
- * In other cases jump directly to the interrupt handler. It
- * is the handler's responsibility to save registers if required
- * (eg hi/lo) and return from the exception using "eret".
+ * Sigh... panicing won't help as the console
+ * is probably not configured :(
*/
- u32 insn;
-
- h = (u16 *)b;
- /* j handler */
-#ifdef CONFIG_CPU_MICROMIPS
- insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
-#else
- insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
-#endif
- h[0] = (insn >> 16) & 0xffff;
- h[1] = insn & 0xffff;
- h[2] = 0;
- h[3] = 0;
- local_flush_icache_range((unsigned long)b,
- (unsigned long)(b+8));
+ panic("VECTORSPACING too small");
}

+ set_handler(((unsigned long)b - ebase), vec_start,
+#ifdef CONFIG_CPU_MICROMIPS
+ (handler_len - 1));
+#else
+ handler_len);
+#endif
+ /* insert offset into vi_handlers[] */
+ h = (u16 *)(b + ori_offset);
+ *h = n * sizeof(handler);
+ local_flush_icache_range((unsigned long)b,
+ (unsigned long)(b+handler_len));
+
return (void *)old_handler;
}

-void *set_vi_handler(int n, vi_handler_t addr)
-{
- return set_vi_srs_handler(n, addr, 0);
-}
-
extern void tlb_init(void);

/*
--
2.35.3