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lib: Add IPI extension in SBI

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This patch adds new IPI extension which replaces ipi related
v0.1 extensions. This also adds a new API for ipi sending as trap
handling is not necessary in v0.2 SBI IPI related extensions.

It also modifies the IPI sending code which now accepts hart mask as a value
instead of S-mode virtual address. Thus, the caller should set it to exact hart
mask value everytime.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
This commit is contained in:
Atish Patra
2019-11-24 23:33:47 -08:00
committed by Anup Patel
parent 109266397a
commit 9777aeef41
5 changed files with 160 additions and 24 deletions
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74
include/sbi/sbi_bitops.h
View File

@@ -95,4 +95,78 @@ static inline int __ffs(unsigned long word)
*/
#define ffz(x) __ffs(~(x))
/**
* fls - find last (most-significant) bit set
* @x: the word to search
*
* This is defined the same way as ffs.
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
static inline int fls(int x)
{
int r = 32;
if (!x)
return 0;
if (!(x & 0xffff0000u)) {
x <<= 16;
r -= 16;
}
if (!(x & 0xff000000u)) {
x <<= 8;
r -= 8;
}
if (!(x & 0xf0000000u)) {
x <<= 4;
r -= 4;
}
if (!(x & 0xc0000000u)) {
x <<= 2;
r -= 2;
}
if (!(x & 0x80000000u)) {
x <<= 1;
r -= 1;
}
return r;
}
/**
* __fls - find last (most-significant) set bit in a long word
* @word: the word to search
*
* Undefined if no set bit exists, so code should check against 0 first.
*/
static inline unsigned long __fls(unsigned long word)
{
int num = BITS_PER_LONG - 1;
#if BITS_PER_LONG == 64
if (!(word & (~0ul << 32))) {
num -= 32;
word <<= 32;
}
#endif
if (!(word & (~0ul << (BITS_PER_LONG-16)))) {
num -= 16;
word <<= 16;
}
if (!(word & (~0ul << (BITS_PER_LONG-8)))) {
num -= 8;
word <<= 8;
}
if (!(word & (~0ul << (BITS_PER_LONG-4)))) {
num -= 4;
word <<= 4;
}
if (!(word & (~0ul << (BITS_PER_LONG-2)))) {
num -= 2;
word <<= 2;
}
if (!(word & (~0ul << (BITS_PER_LONG-1))))
num -= 1;
return num;
}
#endif

5
include/sbi/sbi_ipi.h
View File

@@ -27,9 +27,8 @@ struct sbi_ipi_data {
unsigned long ipi_type;
};
int sbi_ipi_send_many(struct sbi_scratch *scratch,
struct sbi_trap_info *uptrap,
ulong *pmask, u32 event, void *data);
int sbi_ipi_send_many(struct sbi_scratch *scratch, ulong hmask,
ulong hbase, u32 event, void *data);
void sbi_ipi_clear_smode(struct sbi_scratch *scratch);

70
lib/sbi/sbi_ecall.c
View File

@@ -17,6 +17,7 @@
#include <sbi/sbi_timer.h>
#include <sbi/sbi_tlb.h>
#include <sbi/sbi_trap.h>
#include <sbi/sbi_unpriv.h>
#include <sbi/sbi_hart.h>
#include <sbi/sbi_version.h>
#include <sbi/riscv_asm.h>
@@ -35,6 +36,22 @@ u16 sbi_ecall_version_minor(void)
return SBI_ECALL_VERSION_MINOR;
}
static int sbi_load_hart_mask_unpriv(struct sbi_scratch *scratch, ulong *pmask,
ulong *hmask, struct sbi_trap_info *uptrap)
{
ulong mask = 0;
if (pmask) {
mask = sbi_load_ulong(pmask, scratch, uptrap);
if (uptrap->cause)
return SBI_ETRAP;
} else {
mask = sbi_hart_available_mask();
}
*hmask = mask;
return 0;
}
int sbi_check_extension(struct sbi_scratch *scratch, unsigned long extid,
unsigned long *out_val)
{
@@ -49,7 +66,8 @@ int sbi_check_extension(struct sbi_scratch *scratch, unsigned long extid,
if ((extid >= SBI_EXT_0_1_SET_TIMER && extid <= SBI_EXT_0_1_SHUTDOWN) ||
(extid == SBI_EXT_BASE) ||
(extid == SBI_EXT_TIME)) {
(extid == SBI_EXT_TIME) ||
(extid == SBI_EXT_IPI)) {
*out_val = 1;
} else if (extid >= SBI_EXT_VENDOR_START &&
extid <= SBI_EXT_VENDOR_END) {
@@ -130,12 +148,27 @@ int sbi_ecall_time_handler(struct sbi_scratch *scratch, unsigned long funcid,
return ret;
}
int sbi_ecall_ipi_handler(struct sbi_scratch *scratch, unsigned long funcid,
unsigned long *args, unsigned long *tval)
{
int ret = 0;
if (funcid == SBI_EXT_IPI_SEND_IPI)
ret = sbi_ipi_send_many(scratch, args[0], args[1],
SBI_IPI_EVENT_SOFT, NULL);
else
ret = SBI_ENOTSUPP;
return ret;
}
int sbi_ecall_0_1_handler(struct sbi_scratch *scratch, unsigned long extid,
unsigned long *args, struct sbi_trap_info *out_trap)
{
int ret = 0;
struct sbi_tlb_info tlb_info;
u32 source_hart = sbi_current_hartid();
ulong hmask = 0;
switch (extid) {
case SBI_EXT_0_1_SET_TIMER:
@@ -156,25 +189,35 @@ int sbi_ecall_0_1_handler(struct sbi_scratch *scratch, unsigned long extid,
sbi_ipi_clear_smode(scratch);
break;
case SBI_EXT_0_1_SEND_IPI:
ret = sbi_ipi_send_many(scratch, out_trap, (ulong *)args[0],
SBI_IPI_EVENT_SOFT, NULL);
ret = sbi_load_hart_mask_unpriv(scratch, (ulong *)args[0],
&hmask, out_trap);
if (ret != SBI_ETRAP)
ret = sbi_ipi_send_many(scratch, hmask, 0,
SBI_IPI_EVENT_SOFT, NULL);
break;
case SBI_EXT_0_1_REMOTE_FENCE_I:
tlb_info.start = 0;
tlb_info.size = 0;
tlb_info.type = SBI_ITLB_FLUSH;
tlb_info.shart_mask = 1UL << source_hart;
ret = sbi_ipi_send_many(scratch, out_trap, (ulong *)args[0],
SBI_IPI_EVENT_FENCE, &tlb_info);
ret = sbi_load_hart_mask_unpriv(scratch, (ulong *)args[0],
&hmask, out_trap);
if (ret != SBI_ETRAP)
ret = sbi_ipi_send_many(scratch, hmask, 0,
SBI_IPI_EVENT_FENCE,
&tlb_info);
break;
case SBI_EXT_0_1_REMOTE_SFENCE_VMA:
tlb_info.start = (unsigned long)args[1];
tlb_info.size = (unsigned long)args[2];
tlb_info.type = SBI_TLB_FLUSH_VMA;
tlb_info.shart_mask = 1UL << source_hart;
ret = sbi_ipi_send_many(scratch, out_trap, (ulong *)args[0],
SBI_IPI_EVENT_FENCE, &tlb_info);
ret = sbi_load_hart_mask_unpriv(scratch, (ulong *)args[0],
&hmask, out_trap);
if (ret != SBI_ETRAP)
ret = sbi_ipi_send_many(scratch, hmask, 0,
SBI_IPI_EVENT_FENCE,
&tlb_info);
break;
case SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID:
tlb_info.start = (unsigned long)args[1];
@@ -183,9 +226,12 @@ int sbi_ecall_0_1_handler(struct sbi_scratch *scratch, unsigned long extid,
tlb_info.type = SBI_TLB_FLUSH_VMA_ASID;
tlb_info.shart_mask = 1UL << source_hart;
ret = sbi_ipi_send_many(scratch, out_trap, (ulong *)args[0],
SBI_IPI_EVENT_FENCE,
&tlb_info);
ret = sbi_load_hart_mask_unpriv(scratch, (ulong *)args[0],
&hmask, out_trap);
if (ret != SBI_ETRAP)
ret = sbi_ipi_send_many(scratch, hmask, 0,
SBI_IPI_EVENT_FENCE,
&tlb_info);
break;
case SBI_EXT_0_1_SHUTDOWN:
sbi_system_shutdown(scratch, 0);
@@ -225,6 +271,8 @@ int sbi_ecall_handler(u32 hartid, ulong mcause, struct sbi_trap_regs *regs,
args, &out_val, &trap);
else if (extension_id == SBI_EXT_TIME)
ret = sbi_ecall_time_handler(scratch, func_id, args);
else if (extension_id == SBI_EXT_IPI)
ret = sbi_ecall_ipi_handler(scratch, func_id, args, &out_val);
else if (extension_id >= SBI_EXT_VENDOR_START &&
extension_id <= SBI_EXT_VENDOR_END) {
ret = sbi_ecall_vendor_ext_handler(scratch, extension_id,

32
lib/sbi/sbi_ipi.c
View File

@@ -11,13 +11,13 @@
#include <sbi/riscv_asm.h>
#include <sbi/riscv_atomic.h>
#include <sbi/riscv_barrier.h>
#include <sbi/sbi_bitops.h>
#include <sbi/sbi_error.h>
#include <sbi/sbi_hart.h>
#include <sbi/sbi_ipi.h>
#include <sbi/sbi_platform.h>
#include <sbi/sbi_tlb.h>
#include <sbi/sbi_trap.h>
#include <sbi/sbi_unpriv.h>
static unsigned long ipi_data_off;
@@ -53,20 +53,34 @@ static int sbi_ipi_send(struct sbi_scratch *scratch, u32 hartid, u32 event,
return 0;
}
int sbi_ipi_send_many(struct sbi_scratch *scratch,
struct sbi_trap_info *uptrap,
ulong *pmask, u32 event, void *data)
/**
* As this this function only handlers scalar values of hart mask, it must be
* set to all online harts if the intention is to send IPIs to all the harts.
* If hmask is zero, no IPIs will be sent.
*/
int sbi_ipi_send_many(struct sbi_scratch *scratch, ulong hmask, ulong hbase,
u32 event, void *data)
{
ulong i, m;
ulong mask = sbi_hart_available_mask();
ulong tempmask;
u32 hartid = sbi_current_hartid();
unsigned long last_bit = __fls(mask);
if (pmask) {
mask &= sbi_load_ulong(pmask, scratch, uptrap);
if (uptrap->cause)
return SBI_ETRAP;
}
if (hbase > last_bit)
/* hart base is not available */
return SBI_EINVAL;
/**
* FIXME: This check is valid only ULONG size. This is oka for now as
* avaialble hart mask can support upto ULONG size only.
*/
tempmask = hmask << hbase;
tempmask = ~mask & tempmask;
if (tempmask)
/* at least one of the hart in hmask is not available */
return SBI_EINVAL;
mask &= (hmask << hbase);
/* Send IPIs to every other hart on the set */
for (i = 0, m = mask; m; i++, m >>= 1)
if ((m & 1UL) && (i != hartid))

3
lib/sbi/sbi_system.c
View File

@@ -39,7 +39,8 @@ sbi_system_shutdown(struct sbi_scratch *scratch, u32 type)
/* If that fails (or is not implemented) send an IPI on every
* hart to hang and then hang the current hart */
sbi_ipi_send_many(scratch, NULL, NULL, SBI_IPI_EVENT_HALT, NULL);
sbi_ipi_send_many(scratch, sbi_hart_available_mask(), 0,
SBI_IPI_EVENT_HALT, NULL);
sbi_hart_hang();
}