haraldwolff/qemu-patch-raspberry4
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Wiki Activity

ppc/xive: Synthesize interrupt from the saved IPB in the NVT

Browse source 
When a vCPU is dispatched on a HW thread, its context is pushed in the
thread registers and it is activated by setting the VO bit in the CAM
line word2. The HW grabs the associated NVT, pulls the IPB bits and
merges them with the IPB of the new context. If interrupts were missed
while the vCPU was not dispatched, these are synthesized in this
sequence.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20191125065820.927-18-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Cédric Le Goater 2019-11-25 07:58:17 +01:00 committed by David Gibson
parent a5b841f18c
commit d1f2a574b9
1 changed files with 52 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

52
hw/intc/xive.c
View file

@ -393,6 +393,57 @@ static uint64_t xive_tm_pull_os_ctx(XivePresenter *xptr, XiveTCTX *tctx,
return qw1w2;
}
static void xive_tctx_need_resend(XiveRouter *xrtr, XiveTCTX *tctx,
uint8_t nvt_blk, uint32_t nvt_idx)
{
XiveNVT nvt;
uint8_t ipb;
/*
* Grab the associated NVT to pull the pending bits, and merge
* them with the IPB of the thread interrupt context registers
*/
if (xive_router_get_nvt(xrtr, nvt_blk, nvt_idx, &nvt)) {
qemu_log_mask(LOG_GUEST_ERROR, "XIVE: invalid NVT %x/%x\n",
nvt_blk, nvt_idx);
return;
}
ipb = xive_get_field32(NVT_W4_IPB, nvt.w4);
if (ipb) {
/* Reset the NVT value */
nvt.w4 = xive_set_field32(NVT_W4_IPB, nvt.w4, 0);
xive_router_write_nvt(xrtr, nvt_blk, nvt_idx, &nvt, 4);
/* Merge in current context */
xive_tctx_ipb_update(tctx, TM_QW1_OS, ipb);
}
}
/*
* Updating the OS CAM line can trigger a resend of interrupt
*/
static void xive_tm_push_os_ctx(XivePresenter *xptr, XiveTCTX *tctx,
hwaddr offset, uint64_t value, unsigned size)
{
uint32_t cam = value;
uint32_t qw1w2 = cpu_to_be32(cam);
uint8_t nvt_blk;
uint32_t nvt_idx;
bool vo;
xive_os_cam_decode(cam, &nvt_blk, &nvt_idx, &vo);
/* First update the registers */
xive_tctx_set_os_cam(tctx, qw1w2);
/* Check the interrupt pending bits */
if (vo) {
xive_tctx_need_resend(XIVE_ROUTER(xptr), tctx, nvt_blk, nvt_idx);
}
}
/*
* Define a mapping of "special" operations depending on the TIMA page
* offset and the size of the operation.
@ -414,6 +465,7 @@ static const XiveTmOp xive_tm_operations[] = {
* effects
*/
{ XIVE_TM_OS_PAGE, TM_QW1_OS + TM_CPPR, 1, xive_tm_set_os_cppr, NULL },
{ XIVE_TM_HV_PAGE, TM_QW1_OS + TM_WORD2, 4, xive_tm_push_os_ctx, NULL },
{ XIVE_TM_HV_PAGE, TM_QW3_HV_PHYS + TM_CPPR, 1, xive_tm_set_hv_cppr, NULL },
{ XIVE_TM_HV_PAGE, TM_QW3_HV_PHYS + TM_WORD2, 1, xive_tm_vt_push, NULL },
{ XIVE_TM_HV_PAGE, TM_QW3_HV_PHYS + TM_WORD2, 1, NULL, xive_tm_vt_poll },