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lib: Check MSIP bit after returning from WFI

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Commit 71d2b837c4 (lib: Move all coldboot wait APIs to sbi_init.c)
caused a regression while moving the code from sbi_hart.c to sbi_init.c.

As per original commit text, WFI can be implemented as a NOP according
to the RISC-V privilege specification. Software should ensure that
relevant interrupt pending bits are set. Otherwise, loop back to WFI.
Fix the regression by applying the original patch to sbi_init.c.

Fixes: 71d2b837c4 ("lib: Move all coldboot wait APIs to sbi_init.c")

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
This commit is contained in:
Atish Patra
2020-03-20 15:10:36 -07:00
committed by Anup Patel
parent a0c88ddb31
commit 9a74a64ae0
1 changed files with 5 additions and 2 deletions
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7
lib/sbi/sbi_init.c
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@@ -79,7 +79,7 @@ static struct sbi_hartmask coldboot_wait_hmask = { 0 };
static void wait_for_coldboot(struct sbi_scratch *scratch, u32 hartid) static void wait_for_coldboot(struct sbi_scratch *scratch, u32 hartid)
{ {
unsigned long saved_mie; unsigned long saved_mie, cmip;
const struct sbi_platform *plat = sbi_platform_ptr(scratch); const struct sbi_platform *plat = sbi_platform_ptr(scratch);
/* Save MIE CSR */ /* Save MIE CSR */
@@ -97,7 +97,10 @@ static void wait_for_coldboot(struct sbi_scratch *scratch, u32 hartid)
/* Wait for coldboot to finish using WFI */ /* Wait for coldboot to finish using WFI */
while (!coldboot_done) { while (!coldboot_done) {
spin_unlock(&coldboot_lock); spin_unlock(&coldboot_lock);
wfi(); do {
wfi();
cmip = csr_read(CSR_MIP);
} while (!(cmip & MIP_MSIP));
spin_lock(&coldboot_lock); spin_lock(&coldboot_lock);
}; };