From bed81ee181dd6b21171cffbb80472cc5b774c24d Mon Sep 17 00:00:00 2001 From: =?utf8?q?C=C3=A9dric=20Le=20Goater?= Date: Wed, 30 Aug 2017 21:46:15 +0200 Subject: [PATCH] powerpc/xive: introduce H_INT_ESB hcall MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The H_INT_ESB hcall() is used to issue a load or store to the ESB page instead of using the MMIO pages. This can be used as a workaround on some HW issues. The OS knows that this hcall should be used on an interrupt source when the ESB hcall flag is set to 1 in the hcall H_INT_GET_SOURCE_INFO. To maintain the frontier between the xive frontend and backend, we introduce a new xive operation 'esb_rw' to be used in the routines doing memory accesses on the ESBs. Signed-off-by: Cédric Le Goater Acked-by: Benjamin Herrenschmidt Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/xive.h | 1 + arch/powerpc/sysdev/xive/common.c | 10 ++++-- arch/powerpc/sysdev/xive/spapr.c | 44 +++++++++++++++++++++++- arch/powerpc/sysdev/xive/xive-internal.h | 1 + 4 files changed, 53 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/include/asm/xive.h b/arch/powerpc/include/asm/xive.h index 64ec9bbcf03e..371fbebf1ec9 100644 --- a/arch/powerpc/include/asm/xive.h +++ b/arch/powerpc/include/asm/xive.h @@ -56,6 +56,7 @@ struct xive_irq_data { #define XIVE_IRQ_FLAG_SHIFT_BUG 0x04 #define XIVE_IRQ_FLAG_MASK_FW 0x08 #define XIVE_IRQ_FLAG_EOI_FW 0x10 +#define XIVE_IRQ_FLAG_H_INT_ESB 0x20 #define XIVE_INVALID_CHIP_ID -1 diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c index 9ac9626c0fa6..7014ca6da4f6 100644 --- a/arch/powerpc/sysdev/xive/common.c +++ b/arch/powerpc/sysdev/xive/common.c @@ -198,7 +198,10 @@ static notrace u8 xive_esb_read(struct xive_irq_data *xd, u32 offset) if (xd->flags & XIVE_IRQ_FLAG_SHIFT_BUG) offset |= offset << 4; - val = in_be64(xd->eoi_mmio + offset); + if ((xd->flags & XIVE_IRQ_FLAG_H_INT_ESB) && xive_ops->esb_rw) + val = xive_ops->esb_rw(xd->hw_irq, offset, 0, 0); + else + val = in_be64(xd->eoi_mmio + offset); return (u8)val; } @@ -209,7 +212,10 @@ static void xive_esb_write(struct xive_irq_data *xd, u32 offset, u64 data) if (xd->flags & XIVE_IRQ_FLAG_SHIFT_BUG) offset |= offset << 4; - out_be64(xd->eoi_mmio + offset, data); + if ((xd->flags & XIVE_IRQ_FLAG_H_INT_ESB) && xive_ops->esb_rw) + xive_ops->esb_rw(xd->hw_irq, offset, data, 1); + else + out_be64(xd->eoi_mmio + offset, data); } #ifdef CONFIG_XMON diff --git a/arch/powerpc/sysdev/xive/spapr.c b/arch/powerpc/sysdev/xive/spapr.c index 0fcae7504353..43e9eeb0d39f 100644 --- a/arch/powerpc/sysdev/xive/spapr.c +++ b/arch/powerpc/sysdev/xive/spapr.c @@ -224,7 +224,46 @@ static long plpar_int_sync(unsigned long flags, unsigned long lisn) return 0; } -#define XIVE_SRC_H_INT_ESB (1ull << (63 - 60)) /* TODO */ +#define XIVE_ESB_FLAG_STORE (1ull << (63 - 63)) + +static long plpar_int_esb(unsigned long flags, + unsigned long lisn, + unsigned long offset, + unsigned long in_data, + unsigned long *out_data) +{ + unsigned long retbuf[PLPAR_HCALL_BUFSIZE]; + long rc; + + pr_devel("H_INT_ESB flags=%lx lisn=%lx offset=%lx in=%lx\n", + flags, lisn, offset, in_data); + + rc = plpar_hcall(H_INT_ESB, retbuf, flags, lisn, offset, in_data); + if (rc) { + pr_err("H_INT_ESB lisn=%ld offset=%ld returned %ld\n", + lisn, offset, rc); + return rc; + } + + *out_data = retbuf[0]; + + return 0; +} + +static u64 xive_spapr_esb_rw(u32 lisn, u32 offset, u64 data, bool write) +{ + unsigned long read_data; + long rc; + + rc = plpar_int_esb(write ? XIVE_ESB_FLAG_STORE : 0, + lisn, offset, data, &read_data); + if (rc) + return -1; + + return write ? 0 : read_data; +} + +#define XIVE_SRC_H_INT_ESB (1ull << (63 - 60)) #define XIVE_SRC_LSI (1ull << (63 - 61)) #define XIVE_SRC_TRIGGER (1ull << (63 - 62)) #define XIVE_SRC_STORE_EOI (1ull << (63 - 63)) @@ -244,6 +283,8 @@ static int xive_spapr_populate_irq_data(u32 hw_irq, struct xive_irq_data *data) if (rc) return -EINVAL; + if (flags & XIVE_SRC_H_INT_ESB) + data->flags |= XIVE_IRQ_FLAG_H_INT_ESB; if (flags & XIVE_SRC_STORE_EOI) data->flags |= XIVE_IRQ_FLAG_STORE_EOI; if (flags & XIVE_SRC_LSI) @@ -487,6 +528,7 @@ static const struct xive_ops xive_spapr_ops = { .setup_cpu = xive_spapr_setup_cpu, .teardown_cpu = xive_spapr_teardown_cpu, .sync_source = xive_spapr_sync_source, + .esb_rw = xive_spapr_esb_rw, #ifdef CONFIG_SMP .get_ipi = xive_spapr_get_ipi, .put_ipi = xive_spapr_put_ipi, diff --git a/arch/powerpc/sysdev/xive/xive-internal.h b/arch/powerpc/sysdev/xive/xive-internal.h index dd1e2022cce4..f34abed0c05f 100644 --- a/arch/powerpc/sysdev/xive/xive-internal.h +++ b/arch/powerpc/sysdev/xive/xive-internal.h @@ -47,6 +47,7 @@ struct xive_ops { void (*update_pending)(struct xive_cpu *xc); void (*eoi)(u32 hw_irq); void (*sync_source)(u32 hw_irq); + u64 (*esb_rw)(u32 hw_irq, u32 offset, u64 data, bool write); #ifdef CONFIG_SMP int (*get_ipi)(unsigned int cpu, struct xive_cpu *xc); void (*put_ipi)(unsigned int cpu, struct xive_cpu *xc); -- 2.20.1