[PATCH v2 0/2] add TOC support

[PATCH v2 0/2] add TOC support

[Sven Schnelle]

This adds support for the TOC switches found on most PA-RISC
machines. I tested this on my c8000 and a HP 16702A, which is
basically a B160L with some logic analyzer hardware.

Changes in v2:
- fix stack allocation
- align toc_lock on 16 byte boundary
- move toc_lock declaration to processor.c

Sven Schnelle (2):
  parisc/firmware: add functions to retrieve TOC data
  parisc: add support for TOC (transfer of control)

 arch/parisc/include/asm/pdc.h       |  2 +
 arch/parisc/include/asm/processor.h |  4 ++
 arch/parisc/include/uapi/asm/pdc.h  | 28 +++++++++-
 arch/parisc/kernel/entry.S          | 74 +++++++++++++++++++++++++++
 arch/parisc/kernel/firmware.c       | 32 ++++++++++++
 arch/parisc/kernel/processor.c      | 22 ++++++++
 arch/parisc/kernel/traps.c          | 79 +++++++++++++++++++++++++++++
 7 files changed, 239 insertions(+), 2 deletions(-)

-- 
2.33.0

[PATCH 1/2] parisc/firmware: add functions to retrieve TOC data

[Sven Schnelle]

Add functions to retrieve TOC data from firmware both
for 1.1 and 2.0 PDC.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
---
 arch/parisc/include/asm/pdc.h      |  2 ++
 arch/parisc/include/uapi/asm/pdc.h | 22 ++++++++++++++++++++
 arch/parisc/kernel/firmware.c      | 32 ++++++++++++++++++++++++++++++
 3 files changed, 56 insertions(+)

diff --git a/arch/parisc/include/asm/pdc.h b/arch/parisc/include/asm/pdc.h
index b388d8176588..18b957a8630d 100644
--- a/arch/parisc/include/asm/pdc.h
+++ b/arch/parisc/include/asm/pdc.h
@@ -51,6 +51,8 @@ int pdc_spaceid_bits(unsigned long *space_bits);
 int pdc_btlb_info(struct pdc_btlb_info *btlb);
 int pdc_mem_map_hpa(struct pdc_memory_map *r_addr, struct pdc_module_path *mod_path);
 #endif /* !CONFIG_PA20 */
+int pdc_pim_toc11(struct pdc_toc_pim_11 *ret);
+int pdc_pim_toc20(struct pdc_toc_pim_20 *ret);
 int pdc_lan_station_id(char *lan_addr, unsigned long net_hpa);
 
 int pdc_stable_read(unsigned long staddr, void *memaddr, unsigned long count);
diff --git a/arch/parisc/include/uapi/asm/pdc.h b/arch/parisc/include/uapi/asm/pdc.h
index 15211723ebf5..ad51df8ba952 100644
--- a/arch/parisc/include/uapi/asm/pdc.h
+++ b/arch/parisc/include/uapi/asm/pdc.h
@@ -689,6 +689,28 @@ struct pdc_hpmc_pim_20 { /* PDC_PIM */
 	unsigned long long fr[32];
 };
 
+struct pdc_toc_pim_11 {
+	unsigned int gr[32];
+	unsigned int cr[32];
+	unsigned int sr[8];
+	unsigned int iasq_back;
+	unsigned int iaoq_back;
+	unsigned int check_type;
+	unsigned int hversion;
+	unsigned int cpu_state;
+};
+
+struct pdc_toc_pim_20 {
+	unsigned long long gr[32];
+	unsigned long long cr[32];
+	unsigned long long sr[8];
+	unsigned long long iasq_back;
+	unsigned long long iaoq_back;
+	unsigned int check_type;
+	unsigned int hversion;
+	unsigned int cpu_state;
+};
+
 #endif /* !defined(__ASSEMBLY__) */
 
 #endif /* _UAPI_PARISC_PDC_H */
diff --git a/arch/parisc/kernel/firmware.c b/arch/parisc/kernel/firmware.c
index 7034227dbdf3..9179b4409b63 100644
--- a/arch/parisc/kernel/firmware.c
+++ b/arch/parisc/kernel/firmware.c
@@ -1061,6 +1061,38 @@ int pdc_mem_pdt_read_entries(struct pdc_mem_read_pdt *pret,
 	return retval;
 }
 
+/**
+ * pdc_pim_toc11 - Fetch TOC PIM 1.1 data from firmware.
+ * @ret: pointer to return buffer
+ */
+int pdc_pim_toc11(struct pdc_toc_pim_11 *ret)
+{
+	int retval;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pdc_lock, flags);
+	retval = mem_pdc_call(PDC_PIM, PDC_PIM_TOC, __pa(pdc_result),
+			      __pa(ret), sizeof(struct pdc_toc_pim_11));
+	spin_unlock_irqrestore(&pdc_lock, flags);
+	return retval;
+}
+
+/**
+ * pdc_pim_toc20 - Fetch TOC PIM 2.0 data from firmware.
+ * @ret: pointer to return buffer
+ */
+int pdc_pim_toc20(struct pdc_toc_pim_20 *ret)
+{
+	int retval;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pdc_lock, flags);
+	retval = mem_pdc_call(PDC_PIM, PDC_PIM_TOC, __pa(pdc_result),
+			      __pa(ret), sizeof(struct pdc_toc_pim_20));
+	spin_unlock_irqrestore(&pdc_lock, flags);
+	return retval;
+}
+
 /**
  * pdc_tod_set - Set the Time-Of-Day clock.
  * @sec: The number of seconds since epoch.
-- 
2.33.0

[PATCH 2/2] parisc: add support for TOC (transfer of control)

[Sven Schnelle]

Almost all PA-RISC machines have either a button that
is labeled with 'TOC' or a BMC function to trigger a TOC.
TOC is a non-maskable interrupt that is sent to the processor.
This can be used for diagnostic purposes like obtaining a
stack trace/register dump or to enter KDB/KGDB.

As an example, on my c8000, TOC can be used with:

CONFIG_KGDB=y
CONFIG_KGDB_KDB=y

and the 'kgdboc=ttyS0,115200' appended to the command line.

Press ^( on serial console, which will enter the BMC command line,
and enter 'TOC s':

root@(none):/# (
cli>TOC s
Sending TOC/INIT.
<Cpu3> 2800035d03e00000  0000000040c21ac8  CC_ERR_CHECK_TOC
<Cpu0> 2800035d00e00000  0000000040c21ad0  CC_ERR_CHECK_TOC
<Cpu2> 2800035d02e00000  0000000040c21ac8  CC_ERR_CHECK_TOC
<Cpu1> 2800035d01e00000  0000000040c21ad0  CC_ERR_CHECK_TOC
<Cpu3> 37000f7303e00000  2000000000000000  CC_ERR_CPU_CHECK_SUMMARY
<Cpu0> 37000f7300e00000  2000000000000000  CC_ERR_CPU_CHECK_SUMMARY
<Cpu2> 37000f7302e00000  2000000000000000  CC_ERR_CPU_CHECK_SUMMARY
<Cpu1> 37000f7301e00000  2000000000000000  CC_ERR_CPU_CHECK_SUMMARY
<Cpu3> 4300100803e00000  c0000000001d26cc  CC_MC_BR_TO_OS_TOC
<Cpu0> 4300100800e00000  c0000000001d26cc  CC_MC_BR_TO_OS_TOC
<Cpu2> 4300100802e00000  c0000000001d26cc  CC_MC_BR_TO_OS_TOC
<Cpu1> 4300100801e00000  c0000000001d26cc  CC_MC_BR_TO_OS_TOC

Entering kdb (current=0x00000000411cef80, pid 0) on processor 0 due to NonMaskable Interrupt @ 0x40c21ad0
[0]kdb>

Signed-off-by: Sven Schnelle <svens@stackframe.org>
---
 arch/parisc/include/asm/processor.h |  4 ++
 arch/parisc/include/uapi/asm/pdc.h  |  6 ++-
 arch/parisc/kernel/entry.S          | 74 +++++++++++++++++++++++++++
 arch/parisc/kernel/processor.c      | 22 ++++++++
 arch/parisc/kernel/traps.c          | 79 +++++++++++++++++++++++++++++
 5 files changed, 183 insertions(+), 2 deletions(-)

diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h
index eeb7da064289..1e9a4c986921 100644
--- a/arch/parisc/include/asm/processor.h
+++ b/arch/parisc/include/asm/processor.h
@@ -294,6 +294,10 @@ extern int _parisc_requires_coherency;
 
 extern int running_on_qemu;
 
+extern void toc_handler(void);
+extern unsigned int toc_handler_size;
+extern unsigned int toc_handler_csum;
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __ASM_PARISC_PROCESSOR_H */
diff --git a/arch/parisc/include/uapi/asm/pdc.h b/arch/parisc/include/uapi/asm/pdc.h
index ad51df8ba952..acc633c15722 100644
--- a/arch/parisc/include/uapi/asm/pdc.h
+++ b/arch/parisc/include/uapi/asm/pdc.h
@@ -398,8 +398,10 @@ struct zeropage {
 	/* int	(*vec_rendz)(void); */
 	unsigned int vec_rendz;
 	int	vec_pow_fail_flen;
-	int	vec_pad[10];		
-	
+	int	vec_pad0[3];
+	unsigned int vec_toc_hi;
+	int	vec_pad1[6];
+
 	/* [0x040] reserved processor dependent */
 	int	pad0[112];
 
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index 9f939afe6b88..25ec47e9ae24 100644
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -28,6 +28,7 @@
 
 #include <linux/linkage.h>
 #include <linux/pgtable.h>
+#include <linux/threads.h>
 
 #ifdef CONFIG_64BIT
 	.level 2.0w
@@ -2414,3 +2415,76 @@ ENTRY_CFI(set_register)
 	copy    %r1,%r31
 ENDPROC_CFI(set_register)
 
+	.import toc_intr,code
+	.import toc_lock,data
+	ENTRY_CFI(toc_handler)
+	/*
+	 * synchronize CPUs and obtain offset
+	 * for stack setup.
+	 */
+	load32		PA(toc_lock),%r1
+0:	ldcw,co		0(%r1),%r2
+	cmpib,=		0,%r2,0b
+	nop
+	addi		1,%r2,%r4
+	stw		%r4,0(%r1)
+	addi		-1,%r2,%r4
+
+	load32	PA(toc_stack),%sp
+	/*
+	 * deposit CPU number into stack address,
+	 * so every CPU will have its own stack.
+	 */
+	SHLREG	%r4,14,%r4
+	add	%r4,%sp,%sp
+
+	/* setup pt_regs on stack and save the
+	 * floating point registers. PIM_TOC doesn't
+	 * save fp registers, so we're doing it here.
+	 */
+	copy	%sp,%arg0
+	ldo	PT_SZ_ALGN(%sp), %sp
+
+	/* clear pt_regs */
+	copy	%arg0,%r1
+0:	cmpb,<<,n %r1,%sp,0b
+	stw,ma	%r0,4(%r1)
+
+	ldo	PT_FR0(%arg0),%r25
+	save_fp	%r25
+
+	/* go virtual */
+	load32	PA(swapper_pg_dir),%r4
+	mtctl	%r4,%cr24
+	mtctl	%r4,%cr25
+
+	/* Clear sr4-sr7 */
+	mtsp	%r0, %sr4
+	mtsp	%r0, %sr5
+	mtsp	%r0, %sr6
+	mtsp	%r0, %sr7
+
+	tovirt_r1 %sp
+	tovirt_r1 %arg0
+	virt_map
+
+	loadgp
+#ifdef CONFIG_64BIT
+	ldo	-16(%sp),%r29
+#endif
+	b,l	toc_intr,%r2
+	nop
+0:	b	0b
+ENDPROC_CFI(toc_handler)
+
+	/*
+	 * keep this checksum here, as it is part of the toc_handler
+	 * spanned by toc_handler_size (all words in toc_handler are
+	 * added in PDC and the sum must equal to zero.
+	 */
+SYM_DATA(toc_handler_csum, .long 0)
+SYM_DATA(toc_handler_size, .long . - toc_handler)
+
+	__PAGE_ALIGNED_BSS
+	.align 64
+SYM_DATA(toc_stack, .block 16384*NR_CPUS)
diff --git a/arch/parisc/kernel/processor.c b/arch/parisc/kernel/processor.c
index 1b6129e7d776..c6e4fee79f30 100644
--- a/arch/parisc/kernel/processor.c
+++ b/arch/parisc/kernel/processor.c
@@ -28,6 +28,7 @@
 #include <asm/pdcpat.h>
 #include <asm/irq.h>		/* for struct irq_region */
 #include <asm/parisc-device.h>
+#include <asm/sections.h>
 
 struct system_cpuinfo_parisc boot_cpu_data __ro_after_init;
 EXPORT_SYMBOL(boot_cpu_data);
@@ -37,6 +38,7 @@ EXPORT_SYMBOL(_parisc_requires_coherency);
 #endif
 
 DEFINE_PER_CPU(struct cpuinfo_parisc, cpu_data);
+unsigned int __aligned(16) toc_lock = 1;
 
 /*
 **  	PARISC CPU driver - claim "device" and initialize CPU data structures.
@@ -453,6 +455,25 @@ static struct parisc_driver cpu_driver __refdata = {
 	.probe		= processor_probe
 };
 
+static __init void setup_toc(void)
+{
+	unsigned int csum = 0;
+	unsigned long toc_code = (unsigned long)dereference_function_descriptor(toc_handler);
+	int i;
+
+	PAGE0->vec_toc = __pa(toc_code) & 0xffffffff;
+#ifdef CONFIG_64BIT
+	PAGE0->vec_toc_hi = __pa(toc_code) >> 32;
+#else
+	PAGE0->vec_toc_hi = 0;
+#endif
+	PAGE0->vec_toclen = toc_handler_size;
+
+	for (i = 0; i < toc_handler_size/4; i++)
+		csum += ((u32 *)toc_code)[i];
+	toc_handler_csum = -csum;
+}
+
 /**
  * processor_init - Processor initialization procedure.
  *
@@ -460,5 +481,6 @@ static struct parisc_driver cpu_driver __refdata = {
  */
 void __init processor_init(void)
 {
+	setup_toc();
 	register_parisc_driver(&cpu_driver);
 }
diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index 747c328fb886..e847d37eda3a 100644
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -30,6 +30,8 @@
 #include <linux/ratelimit.h>
 #include <linux/uaccess.h>
 #include <linux/kdebug.h>
+#include <linux/kdb.h>
+#include <linux/reboot.h>
 
 #include <asm/assembly.h>
 #include <asm/io.h>
@@ -472,6 +474,83 @@ void parisc_terminate(char *msg, struct pt_regs *regs, int code, unsigned long o
 	panic(msg);
 }
 
+static void toc20_to_pt_regs(struct pt_regs *regs, struct pdc_toc_pim_20 *toc)
+{
+	int i;
+
+	regs->gr[0] = (unsigned long)toc->cr[22];
+
+	for (i = 1; i < 32; i++)
+		regs->gr[i] = (unsigned long)toc->gr[i];
+
+	for (i = 0; i < 8; i++)
+		regs->sr[i] = (unsigned long)toc->sr[i];
+
+	regs->iasq[0] = (unsigned long)toc->cr[17];
+	regs->iasq[1] = (unsigned long)toc->iasq_back;
+	regs->iaoq[0] = (unsigned long)toc->cr[18];
+	regs->iaoq[1] = (unsigned long)toc->iaoq_back;
+
+	regs->sar = (unsigned long)toc->cr[11];
+	regs->iir = (unsigned long)toc->cr[19];
+	regs->isr = (unsigned long)toc->cr[20];
+	regs->ior = (unsigned long)toc->cr[21];
+}
+
+static void toc11_to_pt_regs(struct pt_regs *regs, struct pdc_toc_pim_11 *toc)
+{
+	int i;
+
+	regs->gr[0] = toc->cr[22];
+
+	for (i = 1; i < 32; i++)
+		regs->gr[i] = toc->gr[i];
+
+	for (i = 0; i < 8; i++)
+		regs->sr[i] = toc->sr[i];
+
+	regs->iasq[0] = toc->cr[17];
+	regs->iasq[1] = toc->iasq_back;
+	regs->iaoq[0] = toc->cr[18];
+	regs->iaoq[1] = toc->iaoq_back;
+
+	regs->sar  = toc->cr[11];
+	regs->iir  = toc->cr[19];
+	regs->isr  = toc->cr[20];
+	regs->ior  = toc->cr[21];
+}
+
+void notrace toc_intr(struct pt_regs *regs)
+{
+	struct pdc_toc_pim_20 pim_data20;
+	struct pdc_toc_pim_11 pim_data11;
+
+	nmi_enter();
+
+	if (boot_cpu_data.cpu_type >= pcxu) {
+		if (pdc_pim_toc20(&pim_data20))
+			panic("Failed to get PIM data");
+		toc20_to_pt_regs(regs, &pim_data20);
+	} else {
+		if (pdc_pim_toc11(&pim_data11))
+			panic("Failed to get PIM data");
+		toc11_to_pt_regs(regs, &pim_data11);
+	}
+
+#ifdef CONFIG_KGDB
+	if (atomic_read(&kgdb_active) != -1)
+		kgdb_nmicallback(raw_smp_processor_id(), regs);
+	kgdb_handle_exception(KDB_REASON_SYSTEM_NMI, SIGTRAP, 0, regs);
+#endif
+	show_regs(regs);
+
+	/* give other CPUs time to show their backtrace */
+	mdelay(2000);
+	machine_restart("TOC");
+
+	nmi_exit();
+}
+
 void notrace handle_interruption(int code, struct pt_regs *regs)
 {
 	unsigned long fault_address = 0;
-- 
2.33.0

Re: [PATCH 2/2] parisc: add support for TOC (transfer of control)

[Helge Deller]

On 10/10/21 20:38, Sven Schnelle wrote:
> Almost all PA-RISC machines have either a button that
> is labeled with 'TOC' or a BMC function to trigger a TOC.
> TOC is a non-maskable interrupt that is sent to the processor.
> This can be used for diagnostic purposes like obtaining a
> stack trace/register dump or to enter KDB/KGDB.
>
> As an example, on my c8000, TOC can be used with:
>
> CONFIG_KGDB=y
> CONFIG_KGDB_KDB=y
>
> and the 'kgdboc=ttyS0,115200' appended to the command line.
>
> Press ^( on serial console, which will enter the BMC command line,
> and enter 'TOC s':
>
> root@(none):/# (
> cli>TOC s
> Sending TOC/INIT.
> <Cpu3> 2800035d03e00000  0000000040c21ac8  CC_ERR_CHECK_TOC
> <Cpu0> 2800035d00e00000  0000000040c21ad0  CC_ERR_CHECK_TOC
> <Cpu2> 2800035d02e00000  0000000040c21ac8  CC_ERR_CHECK_TOC
> <Cpu1> 2800035d01e00000  0000000040c21ad0  CC_ERR_CHECK_TOC
> <Cpu3> 37000f7303e00000  2000000000000000  CC_ERR_CPU_CHECK_SUMMARY
> <Cpu0> 37000f7300e00000  2000000000000000  CC_ERR_CPU_CHECK_SUMMARY
> <Cpu2> 37000f7302e00000  2000000000000000  CC_ERR_CPU_CHECK_SUMMARY
> <Cpu1> 37000f7301e00000  2000000000000000  CC_ERR_CPU_CHECK_SUMMARY
> <Cpu3> 4300100803e00000  c0000000001d26cc  CC_MC_BR_TO_OS_TOC
> <Cpu0> 4300100800e00000  c0000000001d26cc  CC_MC_BR_TO_OS_TOC
> <Cpu2> 4300100802e00000  c0000000001d26cc  CC_MC_BR_TO_OS_TOC
> <Cpu1> 4300100801e00000  c0000000001d26cc  CC_MC_BR_TO_OS_TOC
>
> Entering kdb (current=0x00000000411cef80, pid 0) on processor 0 due to NonMaskable Interrupt @ 0x40c21ad0
> [0]kdb>
>
> Signed-off-by: Sven Schnelle <svens@stackframe.org>
> ---
>  arch/parisc/include/asm/processor.h |  4 ++
>  arch/parisc/include/uapi/asm/pdc.h  |  6 ++-
>  arch/parisc/kernel/entry.S          | 74 +++++++++++++++++++++++++++
>  arch/parisc/kernel/processor.c      | 22 ++++++++
>  arch/parisc/kernel/traps.c          | 79 +++++++++++++++++++++++++++++
>  5 files changed, 183 insertions(+), 2 deletions(-)
>
> diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h
> index eeb7da064289..1e9a4c986921 100644
> --- a/arch/parisc/include/asm/processor.h
> +++ b/arch/parisc/include/asm/processor.h
> @@ -294,6 +294,10 @@ extern int _parisc_requires_coherency;
>
>  extern int running_on_qemu;
>
> +extern void toc_handler(void);
> +extern unsigned int toc_handler_size;
> +extern unsigned int toc_handler_csum;
> +
>  #endif /* __ASSEMBLY__ */
>
>  #endif /* __ASM_PARISC_PROCESSOR_H */
> diff --git a/arch/parisc/include/uapi/asm/pdc.h b/arch/parisc/include/uapi/asm/pdc.h
> index ad51df8ba952..acc633c15722 100644
> --- a/arch/parisc/include/uapi/asm/pdc.h
> +++ b/arch/parisc/include/uapi/asm/pdc.h
> @@ -398,8 +398,10 @@ struct zeropage {
>  	/* int	(*vec_rendz)(void); */
>  	unsigned int vec_rendz;
>  	int	vec_pow_fail_flen;
> -	int	vec_pad[10];
> -
> +	int	vec_pad0[3];
> +	unsigned int vec_toc_hi;
> +	int	vec_pad1[6];
> +
>  	/* [0x040] reserved processor dependent */
>  	int	pad0[112];
>
> diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
> index 9f939afe6b88..25ec47e9ae24 100644
> --- a/arch/parisc/kernel/entry.S
> +++ b/arch/parisc/kernel/entry.S
> @@ -28,6 +28,7 @@
>
>  #include <linux/linkage.h>
>  #include <linux/pgtable.h>
> +#include <linux/threads.h>
>
>  #ifdef CONFIG_64BIT
>  	.level 2.0w
> @@ -2414,3 +2415,76 @@ ENTRY_CFI(set_register)
>  	copy    %r1,%r31
>  ENDPROC_CFI(set_register)
>
> +	.import toc_intr,code
> +	.import toc_lock,data
> +	ENTRY_CFI(toc_handler)
> +	/*
> +	 * synchronize CPUs and obtain offset
> +	 * for stack setup.
> +	 */
> +	load32		PA(toc_lock),%r1
> +0:	ldcw,co		0(%r1),%r2
> +	cmpib,=		0,%r2,0b
> +	nop
> +	addi		1,%r2,%r4
> +	stw		%r4,0(%r1)
> +	addi		-1,%r2,%r4
> +
> +	load32	PA(toc_stack),%sp
> +	/*
> +	 * deposit CPU number into stack address,
> +	 * so every CPU will have its own stack.
> +	 */
> +	SHLREG	%r4,14,%r4
> +	add	%r4,%sp,%sp
> +
> +	/* setup pt_regs on stack and save the
> +	 * floating point registers. PIM_TOC doesn't
> +	 * save fp registers, so we're doing it here.
> +	 */
> +	copy	%sp,%arg0
> +	ldo	PT_SZ_ALGN(%sp), %sp
> +
> +	/* clear pt_regs */
> +	copy	%arg0,%r1
> +0:	cmpb,<<,n %r1,%sp,0b
> +	stw,ma	%r0,4(%r1)
> +
> +	ldo	PT_FR0(%arg0),%r25
> +	save_fp	%r25
> +
> +	/* go virtual */
> +	load32	PA(swapper_pg_dir),%r4
> +	mtctl	%r4,%cr24
> +	mtctl	%r4,%cr25
> +
> +	/* Clear sr4-sr7 */
> +	mtsp	%r0, %sr4
> +	mtsp	%r0, %sr5
> +	mtsp	%r0, %sr6
> +	mtsp	%r0, %sr7
> +
> +	tovirt_r1 %sp
> +	tovirt_r1 %arg0
> +	virt_map
> +
> +	loadgp
> +#ifdef CONFIG_64BIT
> +	ldo	-16(%sp),%r29
> +#endif
> +	b,l	toc_intr,%r2
> +	nop
> +0:	b	0b
> +ENDPROC_CFI(toc_handler)
> +
> +	/*
> +	 * keep this checksum here, as it is part of the toc_handler
> +	 * spanned by toc_handler_size (all words in toc_handler are
> +	 * added in PDC and the sum must equal to zero.
> +	 */
> +SYM_DATA(toc_handler_csum, .long 0)
> +SYM_DATA(toc_handler_size, .long . - toc_handler)
> +
> +	__PAGE_ALIGNED_BSS
> +	.align 64
> +SYM_DATA(toc_stack, .block 16384*NR_CPUS)
> diff --git a/arch/parisc/kernel/processor.c b/arch/parisc/kernel/processor.c
> index 1b6129e7d776..c6e4fee79f30 100644
> --- a/arch/parisc/kernel/processor.c
> +++ b/arch/parisc/kernel/processor.c
> @@ -28,6 +28,7 @@
>  #include <asm/pdcpat.h>
>  #include <asm/irq.h>		/* for struct irq_region */
>  #include <asm/parisc-device.h>
> +#include <asm/sections.h>
>
>  struct system_cpuinfo_parisc boot_cpu_data __ro_after_init;
>  EXPORT_SYMBOL(boot_cpu_data);
> @@ -37,6 +38,7 @@ EXPORT_SYMBOL(_parisc_requires_coherency);
>  #endif
>
>  DEFINE_PER_CPU(struct cpuinfo_parisc, cpu_data);
> +unsigned int __aligned(16) toc_lock = 1;
>
>  /*
>  **  	PARISC CPU driver - claim "device" and initialize CPU data structures.
> @@ -453,6 +455,25 @@ static struct parisc_driver cpu_driver __refdata = {
>  	.probe		= processor_probe
>  };
>
> +static __init void setup_toc(void)
> +{
> +	unsigned int csum = 0;
> +	unsigned long toc_code = (unsigned long)dereference_function_descriptor(toc_handler);
> +	int i;
> +
> +	PAGE0->vec_toc = __pa(toc_code) & 0xffffffff;
> +#ifdef CONFIG_64BIT
> +	PAGE0->vec_toc_hi = __pa(toc_code) >> 32;
> +#else
> +	PAGE0->vec_toc_hi = 0;
> +#endif
> +	PAGE0->vec_toclen = toc_handler_size;
> +
> +	for (i = 0; i < toc_handler_size/4; i++)
> +		csum += ((u32 *)toc_code)[i];
> +	toc_handler_csum = -csum;
> +}
> +
>  /**
>   * processor_init - Processor initialization procedure.
>   *
> @@ -460,5 +481,6 @@ static struct parisc_driver cpu_driver __refdata = {
>   */
>  void __init processor_init(void)
>  {
> +	setup_toc();
>  	register_parisc_driver(&cpu_driver);
>  }
> diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
> index 747c328fb886..e847d37eda3a 100644
> --- a/arch/parisc/kernel/traps.c
> +++ b/arch/parisc/kernel/traps.c
> @@ -30,6 +30,8 @@
>  #include <linux/ratelimit.h>
>  #include <linux/uaccess.h>
>  #include <linux/kdebug.h>
> +#include <linux/kdb.h>
> +#include <linux/reboot.h>
>
>  #include <asm/assembly.h>
>  #include <asm/io.h>
> @@ -472,6 +474,83 @@ void parisc_terminate(char *msg, struct pt_regs *regs, int code, unsigned long o
>  	panic(msg);
>  }
>
> +static void toc20_to_pt_regs(struct pt_regs *regs, struct pdc_toc_pim_20 *toc)
> +{
> +	int i;
> +
> +	regs->gr[0] = (unsigned long)toc->cr[22];
> +
> +	for (i = 1; i < 32; i++)
> +		regs->gr[i] = (unsigned long)toc->gr[i];
> +
> +	for (i = 0; i < 8; i++)
> +		regs->sr[i] = (unsigned long)toc->sr[i];
> +
> +	regs->iasq[0] = (unsigned long)toc->cr[17];
> +	regs->iasq[1] = (unsigned long)toc->iasq_back;
> +	regs->iaoq[0] = (unsigned long)toc->cr[18];
> +	regs->iaoq[1] = (unsigned long)toc->iaoq_back;
> +
> +	regs->sar = (unsigned long)toc->cr[11];
> +	regs->iir = (unsigned long)toc->cr[19];
> +	regs->isr = (unsigned long)toc->cr[20];
> +	regs->ior = (unsigned long)toc->cr[21];
> +}
> +
> +static void toc11_to_pt_regs(struct pt_regs *regs, struct pdc_toc_pim_11 *toc)
> +{
> +	int i;
> +
> +	regs->gr[0] = toc->cr[22];
> +
> +	for (i = 1; i < 32; i++)
> +		regs->gr[i] = toc->gr[i];
> +
> +	for (i = 0; i < 8; i++)
> +		regs->sr[i] = toc->sr[i];
> +
> +	regs->iasq[0] = toc->cr[17];
> +	regs->iasq[1] = toc->iasq_back;
> +	regs->iaoq[0] = toc->cr[18];
> +	regs->iaoq[1] = toc->iaoq_back;
> +
> +	regs->sar  = toc->cr[11];
> +	regs->iir  = toc->cr[19];
> +	regs->isr  = toc->cr[20];
> +	regs->ior  = toc->cr[21];
> +}
> +
> +void notrace toc_intr(struct pt_regs *regs)
> +{
> +	struct pdc_toc_pim_20 pim_data20;
> +	struct pdc_toc_pim_11 pim_data11;
> +
> +	nmi_enter();
> +
> +	if (boot_cpu_data.cpu_type >= pcxu) {

I wonder if this is correct.
If we boot a 32bit-kernel on a 64-bit (pcxu) machine, then
I think the code below for pdc_pim_toc11() should be executed.
So, maybe we need a #ifdef CONFIG_64BIT above...


> +		if (pdc_pim_toc20(&pim_data20))
> +			panic("Failed to get PIM data");
> +		toc20_to_pt_regs(regs, &pim_data20);
> +	} else {

... with an #else here

> +		if (pdc_pim_toc11(&pim_data11))
> +			panic("Failed to get PIM data");
> +		toc11_to_pt_regs(regs, &pim_data11);
> +	}

and #endif here. ??

Helge

Re: [PATCH 2/2] parisc: add support for TOC (transfer of control)

[Sven Schnelle]

Hi Helge,

Helge Deller <deller@gmx.de> writes:

> On 10/10/21 20:38, Sven Schnelle wrote:
>> +void notrace toc_intr(struct pt_regs *regs)
>> +{
>> +	struct pdc_toc_pim_20 pim_data20;
>> +	struct pdc_toc_pim_11 pim_data11;
>> +
>> +	nmi_enter();
>> +
>> +	if (boot_cpu_data.cpu_type >= pcxu) {
>
> I wonder if this is correct.
> If we boot a 32bit-kernel on a 64-bit (pcxu) machine, then
> I think the code below for pdc_pim_toc11() should be executed.
> So, maybe we need a #ifdef CONFIG_64BIT above...
>
>
>> +		if (pdc_pim_toc20(&pim_data20))
>> +			panic("Failed to get PIM data");
>> +		toc20_to_pt_regs(regs, &pim_data20);
>> +	} else {
>
> ... with an #else here
>
>> +		if (pdc_pim_toc11(&pim_data11))
>> +			panic("Failed to get PIM data");
>> +		toc11_to_pt_regs(regs, &pim_data11);
>> +	}
>
> and #endif here. ??

Hmm, that's what i understood from the HPMC PIM code,
transfer_pim_to_trap_frame(). If it's running a 32 Bit OS, than PDC
returns a wide frame on a 64 bit capable CPU? But maybe i have to read
the documentation/code again.

Regards
Sven

Re: [PATCH 1/2] parisc/firmware: add functions to retrieve TOC data

[Rolf Eike Beer]

[-- Attachment #1: Type: text/plain, Size: 2203 bytes --]

> --- a/arch/parisc/include/uapi/asm/pdc.h
> +++ b/arch/parisc/include/uapi/asm/pdc.h
> @@ -689,6 +689,28 @@ struct pdc_hpmc_pim_20 { /* PDC_PIM */
>  	unsigned long long fr[32];
>  };
> 
> +struct pdc_toc_pim_11 {
> +	unsigned int gr[32];
> +	unsigned int cr[32];
> +	unsigned int sr[8];
> +	unsigned int iasq_back;
> +	unsigned int iaoq_back;
> +	unsigned int check_type;
> +	unsigned int hversion;
> +	unsigned int cpu_state;
> +};
> +
> +struct pdc_toc_pim_20 {
> +	unsigned long long gr[32];
> +	unsigned long long cr[32];
> +	unsigned long long sr[8];
> +	unsigned long long iasq_back;
> +	unsigned long long iaoq_back;
> +	unsigned int check_type;
> +	unsigned int hversion;
> +	unsigned int cpu_state;
> +};
> +
>  #endif /* !defined(__ASSEMBLY__) */

Since these are defined by the hardware and have a well defined size I suggest 
using u32 and u64 to cover this.

> diff --git a/arch/parisc/kernel/firmware.c b/arch/parisc/kernel/firmware.c
> index 7034227dbdf3..9179b4409b63 100644
> --- a/arch/parisc/kernel/firmware.c
> +++ b/arch/parisc/kernel/firmware.c
> @@ -1061,6 +1061,38 @@ int pdc_mem_pdt_read_entries(struct pdc_mem_read_pdt
> *pret, return retval;
>  }
> 
> +/**
> + * pdc_pim_toc11 - Fetch TOC PIM 1.1 data from firmware.
> + * @ret: pointer to return buffer
> + */
> +int pdc_pim_toc11(struct pdc_toc_pim_11 *ret)
> +{
> +	int retval;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&pdc_lock, flags);
> +	retval = mem_pdc_call(PDC_PIM, PDC_PIM_TOC, __pa(pdc_result),
> +			      __pa(ret), sizeof(struct 
pdc_toc_pim_11));
sizeof(*ret)

> +	spin_unlock_irqrestore(&pdc_lock, flags);
> +	return retval;
> +}
> +
> +/**
> + * pdc_pim_toc20 - Fetch TOC PIM 2.0 data from firmware.
> + * @ret: pointer to return buffer
> + */
> +int pdc_pim_toc20(struct pdc_toc_pim_20 *ret)
> +{
> +	int retval;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&pdc_lock, flags);
> +	retval = mem_pdc_call(PDC_PIM, PDC_PIM_TOC, __pa(pdc_result),
> +			      __pa(ret), sizeof(struct 
pdc_toc_pim_20));
sizeof(*ret)

> +	spin_unlock_irqrestore(&pdc_lock, flags);
> +	return retval;
> +}
> +
>  /**
>   * pdc_tod_set - Set the Time-Of-Day clock.
>   * @sec: The number of seconds since epoch.


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Re: [PATCH 1/2] parisc/firmware: add functions to retrieve TOC data

[Helge Deller]

On 10/11/21 17:05, Rolf Eike Beer wrote:
>> --- a/arch/parisc/include/uapi/asm/pdc.h
>> +++ b/arch/parisc/include/uapi/asm/pdc.h
>> @@ -689,6 +689,28 @@ struct pdc_hpmc_pim_20 { /* PDC_PIM */
>>  	unsigned long long fr[32];
>>  };
>>
>> +struct pdc_toc_pim_11 {
>> +	unsigned int gr[32];
>> +	unsigned int cr[32];
>> +	unsigned int sr[8];
>> +	unsigned int iasq_back;
>> +	unsigned int iaoq_back;
>> +	unsigned int check_type;
>> +	unsigned int hversion;
>> +	unsigned int cpu_state;
>> +};
>> +
>> +struct pdc_toc_pim_20 {
>> +	unsigned long long gr[32];
>> +	unsigned long long cr[32];
>> +	unsigned long long sr[8];
>> +	unsigned long long iasq_back;
>> +	unsigned long long iaoq_back;
>> +	unsigned int check_type;
>> +	unsigned int hversion;
>> +	unsigned int cpu_state;
>> +};
>> +
>>  #endif /* !defined(__ASSEMBLY__) */
>
> Since these are defined by the hardware and have a well defined size I suggest
> using u32 and u64 to cover this.

You're right.
But in the whole file we use "unsigned int" for 32bit, and "unsigned long long"
for 64bit, so this change is consistent with the other contents.

Helge

Re: [PATCH 2/2] parisc: add support for TOC (transfer of control)

[Helge Deller]

Hi Sven,

On 10/10/21 21:36, Sven Schnelle wrote:
> Helge Deller <deller@gmx.de> writes:
>
>> On 10/10/21 20:38, Sven Schnelle wrote:
>>> +void notrace toc_intr(struct pt_regs *regs)
>>> +{
>>> +	struct pdc_toc_pim_20 pim_data20;
>>> +	struct pdc_toc_pim_11 pim_data11;
>>> +
>>> +	nmi_enter();
>>> +
>>> +	if (boot_cpu_data.cpu_type >= pcxu) {
>>
>> I wonder if this is correct.
>> If we boot a 32bit-kernel on a 64-bit (pcxu) machine, then
>> I think the code below for pdc_pim_toc11() should be executed.
>> So, maybe we need a #ifdef CONFIG_64BIT above...
>>
>>
>>> +		if (pdc_pim_toc20(&pim_data20))
>>> +			panic("Failed to get PIM data");
>>> +		toc20_to_pt_regs(regs, &pim_data20);
>>> +	} else {
>>
>> ... with an #else here
>>
>>> +		if (pdc_pim_toc11(&pim_data11))
>>> +			panic("Failed to get PIM data");
>>> +		toc11_to_pt_regs(regs, &pim_data11);
>>> +	}
>>
>> and #endif here. ??
>
> Hmm, that's what i understood from the HPMC PIM code,
> transfer_pim_to_trap_frame(). If it's running a 32 Bit OS, than PDC
> returns a wide frame on a 64 bit capable CPU? But maybe i have to read
> the documentation/code again.

No, that seems correct.
On a 64bit machine even a 32bit kernel seems to get the 64bit register PIM data:

64bit kernel:
[0]kdb> rd
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.15.0-rc5-64bit+ #1218
Hardware name: 9000/785/C3700

     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00001000000001001111001000001111 Not tainted
r00-03  000000ff0804f20f 0000000040c45720 0000000040b6dd40 0000000040f004e0
r04-07  0000000040c1c720 0000000040f004b0 0000000040f14608 0000000000000004
r08-11  0000000000000001 0000000040c45720 0000000040c45720 0000000000000003
r12-15  0000000000000000 000000004111f020 0000000040fc7810 0000000040c3cf20
r16-19  0000000040c3cf20 0000000040f00240 0000000040f00240 4000000000000000
r20-23  0000000000000008 0000000000000000 0000000000000000 0000000000000000
r24-27  0000000000000000 0000000000000000 000000000000f45c 0000000040c1c720
r28-31  0000000000000000 0000000040f00530 0000000040f00560 0000000000000004
sr00-03  0000000000000400 0000000000000000 0000000000000000 0000000000000400
sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000

IASQ: 0000000000000000 0000000000000000 IAOQ: 0000000040b6dd5c 0000000040b6dd60
 IIR: 503c0b00    ISR: 0000000000000000  IOR: 0000000000000000
 CPU:        0   CR30: 0000000040f00000 CR31: 00000000ffff55ff
 ORIG_R28: 0000000000000000
 IAOQ[0]: cpu_idle_poll.isra.0+0x94/0x100
 IAOQ[1]: cpu_idle_poll.isra.0+0x98/0x100
Backtrace:
 [<0000000040287490>] do_idle+0x1d8/0x290
 [<00000000402877a4>] cpu_startup_entry+0x7c/0x88
 [<0000000040b65ff8>] rest_init+0x220/0x248
 [<0000000040100ffc>] arch_call_rest_init+0x2c/0x40


32bit Kernel:
kdb> rd
CPU: 0 PID: 0 Comm: swapper Not tainted 5.15.0-rc5-32bit+ #804
Hardware name: 9000/785/C3700

     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00000000000001001111111100001111 Not tainted
r00-03  0004ff0f 10a03cb0 1079506c 109fd280
r04-07  00000004 10a03cb0 11e01d1a 10a03cb0
r08-11  00000000 10a06cdc 1090ea5c 10aa0cb0
r12-15  1090ea5c ffffffff 00000000 f0400004
r16-19  f0000884 f000017c f0000174 00000004
r20-23  0000000f 00000000 101c0704 00000009
r24-27  84cf5d16 109fd000 10a16f20 109474b0
r28-31  00000001 84cf7ca2 109fd2c0 101b773c
sr00-03  00000000 0000001d 00000000 0000001d
sr04-07  00000000 00000000 00000000 00000000

IASQ: 00000000 00000000 IAOQ: 1079508c 10795090
 IIR: e800001a    ISR: 00000000  IOR: 00000000
 CPU:        0   CR30: 109fd000 CR31: ffff55ff
 ORIG_R28: 00000000
 IAOQ[0]: cpu_idle_poll.isra.0+0x38/0x50
 IAOQ[1]: cpu_idle_poll.isra.0+0x3c/0x50
 RP(r2): cpu_idle_poll.isra.0+0x18/0x50
Backtrace:
 [<101bd500>] do_idle+0x88/0xd8
 [<101bd6fc>] cpu_startup_entry+0x20/0x24
 [<1078f14c>] rest_init+0xb0/0xc4
 [<10102820>] 0x10102820

Your patch is correct.

Helge

Re: [PATCH 1/2] parisc/firmware: add functions to retrieve TOC data

[Sven Schnelle]

Helge Deller <deller@gmx.de> writes:

> On 10/11/21 17:05, Rolf Eike Beer wrote:
>>> --- a/arch/parisc/include/uapi/asm/pdc.h
>>> +++ b/arch/parisc/include/uapi/asm/pdc.h
>>> @@ -689,6 +689,28 @@ struct pdc_hpmc_pim_20 { /* PDC_PIM */
>>>  	unsigned long long fr[32];
>>>  };
>>>
>>> +struct pdc_toc_pim_11 {
>>> +	unsigned int gr[32];
>>> +	unsigned int cr[32];
>>> +	unsigned int sr[8];
>>> +	unsigned int iasq_back;
>>> +	unsigned int iaoq_back;
>>> +	unsigned int check_type;
>>> +	unsigned int hversion;
>>> +	unsigned int cpu_state;
>>> +};
>>> +
>>> +struct pdc_toc_pim_20 {
>>> +	unsigned long long gr[32];
>>> +	unsigned long long cr[32];
>>> +	unsigned long long sr[8];
>>> +	unsigned long long iasq_back;
>>> +	unsigned long long iaoq_back;
>>> +	unsigned int check_type;
>>> +	unsigned int hversion;
>>> +	unsigned int cpu_state;
>>> +};
>>> +
>>>  #endif /* !defined(__ASSEMBLY__) */
>>
>> Since these are defined by the hardware and have a well defined size I suggest
>> using u32 and u64 to cover this.
>
> You're right.
> But in the whole file we use "unsigned int" for 32bit, and "unsigned long long"
> for 64bit, so this change is consistent with the other contents.

Yes, especially the 'unsigned long long' catched my eye. However, i kept
it that way so it is consistent with the other structs. I'm happy to
change the types with a cleanup patch, but i'm wondering: why is that
all uapi? IMHO this should go to include/asm? Any objections against
moving it? I don't see how userspace could use that given that only the
kernel should be able to call into firmware.

Re: [PATCH 1/2] parisc/firmware: add functions to retrieve TOC data

[Helge Deller]

On 10/12/21 22:33, Sven Schnelle wrote:
> Helge Deller <deller@gmx.de> writes:
>
>> On 10/11/21 17:05, Rolf Eike Beer wrote:
>>>> --- a/arch/parisc/include/uapi/asm/pdc.h
>>>> +++ b/arch/parisc/include/uapi/asm/pdc.h
>>>> @@ -689,6 +689,28 @@ struct pdc_hpmc_pim_20 { /* PDC_PIM */
>>>>  	unsigned long long fr[32];
>>>>  };
>>>>
>>>> +struct pdc_toc_pim_11 {
>>>> +	unsigned int gr[32];
>>>> +	unsigned int cr[32];
>>>> +	unsigned int sr[8];
>>>> +	unsigned int iasq_back;
>>>> +	unsigned int iaoq_back;
>>>> +	unsigned int check_type;
>>>> +	unsigned int hversion;
>>>> +	unsigned int cpu_state;
>>>> +};
>>>> +
>>>> +struct pdc_toc_pim_20 {
>>>> +	unsigned long long gr[32];
>>>> +	unsigned long long cr[32];
>>>> +	unsigned long long sr[8];
>>>> +	unsigned long long iasq_back;
>>>> +	unsigned long long iaoq_back;
>>>> +	unsigned int check_type;
>>>> +	unsigned int hversion;
>>>> +	unsigned int cpu_state;
>>>> +};
>>>> +
>>>>  #endif /* !defined(__ASSEMBLY__) */
>>>
>>> Since these are defined by the hardware and have a well defined size I suggest
>>> using u32 and u64 to cover this.
>>
>> You're right.
>> But in the whole file we use "unsigned int" for 32bit, and "unsigned long long"
>> for 64bit, so this change is consistent with the other contents.
>
> Yes, especially the 'unsigned long long' catched my eye. However, i kept
> it that way so it is consistent with the other structs. I'm happy to
> change the types with a cleanup patch, but i'm wondering: why is that
> all uapi? IMHO this should go to include/asm? Any objections against
> moving it? I don't see how userspace could use that given that only the
> kernel should be able to call into firmware.

I think for the palo bootloader and the qemu sources they were put in include/uapi.
Both projects have copies though, so I think it can go to include/asm.
If you send a patch I can take it.

Helge

Re: [PATCH 2/2] parisc: add support for TOC (transfer of control)

[Rolf Eike Beer]

[-- Attachment #1: Type: text/plain, Size: 580 bytes --]

> +void notrace toc_intr(struct pt_regs *regs)
> +{
> +	struct pdc_toc_pim_20 pim_data20;
> +	struct pdc_toc_pim_11 pim_data11;
> +
> +	nmi_enter();
> +
> +	if (boot_cpu_data.cpu_type >= pcxu) {
> +		if (pdc_pim_toc20(&pim_data20))
> +			panic("Failed to get PIM data");
> +		toc20_to_pt_regs(regs, &pim_data20);
> +	} else {
> +		if (pdc_pim_toc11(&pim_data11))
> +			panic("Failed to get PIM data");
> +		toc11_to_pt_regs(regs, &pim_data11);
> +	}
> +

You can move the variables into the if/else branches as they are not used 
outside. That would also reduce stack usage.

Eike

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