2023-10-27 22:12:26

by Jiaxun Yang

[permalink] [raw]
Subject: [PATCH v2 05/10] MIPS: Refactor mips_cps_core_entry implementation

Now the exception vector for CPS systems are allocated on-fly
with memblock as well.

It will try to allocate from KSEG1 first, and then try to allocate
in low 4G if possible.

The main reset vector is now generated by uasm, to avoid tons
of patches to the code. Other vectors are copied to the location
later.

Signed-off-by: Jiaxun Yang <[email protected]>
---
arch/mips/include/asm/mips-cm.h | 1 +
arch/mips/include/asm/smp-cps.h | 4 +-
arch/mips/kernel/cps-vec.S | 110 ++++++++-------------
arch/mips/kernel/smp-cps.c | 167 +++++++++++++++++++++++++++-----
arch/mips/kernel/traps.c | 2 +
5 files changed, 186 insertions(+), 98 deletions(-)

diff --git a/arch/mips/include/asm/mips-cm.h b/arch/mips/include/asm/mips-cm.h
index 23c67c0871b1..15d8d69de455 100644
--- a/arch/mips/include/asm/mips-cm.h
+++ b/arch/mips/include/asm/mips-cm.h
@@ -311,6 +311,7 @@ GCR_CX_ACCESSOR_RW(32, 0x018, other)
/* GCR_Cx_RESET_BASE - Configure where powered up cores will fetch from */
GCR_CX_ACCESSOR_RW(32, 0x020, reset_base)
#define CM_GCR_Cx_RESET_BASE_BEVEXCBASE GENMASK(31, 12)
+#define CM_GCR_Cx_RESET_BASE_MODE BIT(1)

/* GCR_Cx_ID - Identify the current core */
GCR_CX_ACCESSOR_RO(32, 0x028, id)
diff --git a/arch/mips/include/asm/smp-cps.h b/arch/mips/include/asm/smp-cps.h
index 22a572b70fe3..39a602e5fecc 100644
--- a/arch/mips/include/asm/smp-cps.h
+++ b/arch/mips/include/asm/smp-cps.h
@@ -24,7 +24,7 @@ struct core_boot_config {

extern struct core_boot_config *mips_cps_core_bootcfg;

-extern void mips_cps_core_entry(void);
+extern void mips_cps_core_boot(int cca, void __iomem *gcr_base);
extern void mips_cps_core_init(void);

extern void mips_cps_boot_vpes(struct core_boot_config *cfg, unsigned vpe);
@@ -32,8 +32,6 @@ extern void mips_cps_boot_vpes(struct core_boot_config *cfg, unsigned vpe);
extern void mips_cps_pm_save(void);
extern void mips_cps_pm_restore(void);

-extern void *mips_cps_core_entry_patch_end;
-
#ifdef CONFIG_MIPS_CPS

extern bool mips_cps_smp_in_use(void);
diff --git a/arch/mips/kernel/cps-vec.S b/arch/mips/kernel/cps-vec.S
index 64ecfdac6580..8870a2dbc35a 100644
--- a/arch/mips/kernel/cps-vec.S
+++ b/arch/mips/kernel/cps-vec.S
@@ -4,6 +4,8 @@
* Author: Paul Burton <[email protected]>
*/

+#include <linux/init.h>
+
#include <asm/addrspace.h>
#include <asm/asm.h>
#include <asm/asm-offsets.h>
@@ -81,40 +83,48 @@
nop
.endm

+ __INIT
+LEAF(excep_tlbfill)
+ DUMP_EXCEP("TLB Fill")
+ b .
+ nop
+ END(excep_tlbfill)

-.balign 0x1000
+LEAF(excep_xtlbfill)
+ DUMP_EXCEP("XTLB Fill")
+ b .
+ nop
+ END(excep_xtlbfill)

-LEAF(mips_cps_core_entry)
- /*
- * These first several instructions will be patched by cps_smp_setup to load the
- * CCA to use into register s0 and GCR base address to register s1.
- */
- .rept CPS_ENTRY_PATCH_INSNS
- nop
- .endr
+LEAF(excep_cache)
+ DUMP_EXCEP("Cache")
+ b .
+ nop
+ END(excep_cache)

- .global mips_cps_core_entry_patch_end
-mips_cps_core_entry_patch_end:
+LEAF(excep_genex)
+ DUMP_EXCEP("General")
+ b .
+ nop
+ END(excep_genex)

- /* Check whether we're here due to an NMI */
- mfc0 k0, CP0_STATUS
- and k0, k0, ST0_NMI
- beqz k0, not_nmi
+LEAF(excep_intex)
+ DUMP_EXCEP("Interrupt")
+ b .
nop
+ END(excep_intex)

- /* This is an NMI */
- PTR_LA k0, nmi_handler
+LEAF(excep_ejtag)
+ PTR_LA k0, ejtag_debug_handler
jr k0
nop
+ END(excep_ejtag)
+ __FINIT

-not_nmi:
- /* Setup Cause */
- li t0, CAUSEF_IV
- mtc0 t0, CP0_CAUSE
-
- /* Setup Status */
- li t0, ST0_CU1 | ST0_CU0 | ST0_BEV | STATUS_BITDEPS
- mtc0 t0, CP0_STATUS
+LEAF(mips_cps_core_boot)
+ /* Save CCA and GCR base */
+ move s0, a0
+ move s1, a1

/* We don't know how to do coherence setup on earlier ISA */
#if MIPS_ISA_REV > 0
@@ -178,49 +188,7 @@ not_nmi:
PTR_L sp, VPEBOOTCFG_SP(v1)
jr t1
nop
- END(mips_cps_core_entry)
-
-.org 0x200
-LEAF(excep_tlbfill)
- DUMP_EXCEP("TLB Fill")
- b .
- nop
- END(excep_tlbfill)
-
-.org 0x280
-LEAF(excep_xtlbfill)
- DUMP_EXCEP("XTLB Fill")
- b .
- nop
- END(excep_xtlbfill)
-
-.org 0x300
-LEAF(excep_cache)
- DUMP_EXCEP("Cache")
- b .
- nop
- END(excep_cache)
-
-.org 0x380
-LEAF(excep_genex)
- DUMP_EXCEP("General")
- b .
- nop
- END(excep_genex)
-
-.org 0x400
-LEAF(excep_intex)
- DUMP_EXCEP("Interrupt")
- b .
- nop
- END(excep_intex)
-
-.org 0x480
-LEAF(excep_ejtag)
- PTR_LA k0, ejtag_debug_handler
- jr k0
- nop
- END(excep_ejtag)
+ END(mips_cps_core_boot)

LEAF(mips_cps_core_init)
#ifdef CONFIG_MIPS_MT_SMP
@@ -428,7 +396,7 @@ LEAF(mips_cps_boot_vpes)
/* Calculate a pointer to the VPEs struct vpe_boot_config */
li t0, VPEBOOTCFG_SIZE
mul t0, t0, ta1
- addu t0, t0, ta3
+ PTR_ADDU t0, t0, ta3

/* Set the TC restart PC */
lw t1, VPEBOOTCFG_PC(t0)
@@ -603,10 +571,10 @@ dcache_done:
lw $1, TI_CPU(gp)
sll $1, $1, LONGLOG
PTR_LA \dest, __per_cpu_offset
- addu $1, $1, \dest
+ PTR_ADDU $1, $1, \dest
lw $1, 0($1)
PTR_LA \dest, cps_cpu_state
- addu \dest, \dest, $1
+ PTR_ADDU \dest, \dest, $1
.set pop
.endm

diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
index dd55d59b88db..9aad678a32bd 100644
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -7,6 +7,7 @@
#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/io.h>
+#include <linux/memblock.h>
#include <linux/sched/task_stack.h>
#include <linux/sched/hotplug.h>
#include <linux/slab.h>
@@ -25,7 +26,33 @@
#include <asm/time.h>
#include <asm/uasm.h>

+#define BEV_VEC_SIZE 0x500
+#define BEV_VEC_ALIGN 0x1000
+
+#define A0 4
+#define A1 5
+#define T9 25
+#define K0 26
+#define K1 27
+
+#define C0_STATUS 12, 0
+#define C0_CAUSE 13, 0
+
+#define ST0_NMI_BIT 19
+#ifdef CONFIG_64BIT
+#define ST0_KX_IF_64 ST0_KX
+#else
+#define ST0_KX_IF_64 0
+#endif
+
+enum label_id {
+ label_not_nmi = 1,
+};
+
+UASM_L_LA(_not_nmi)
+
static DECLARE_BITMAP(core_power, NR_CPUS);
+static uint32_t core_entry_reg;

struct core_boot_config *mips_cps_core_bootcfg;

@@ -34,10 +61,113 @@ static unsigned __init core_vpe_count(unsigned int cluster, unsigned core)
return min(smp_max_threads, mips_cps_numvps(cluster, core));
}

+static void __init *mips_cps_build_core_entry(void *addr)
+{
+ extern void (*nmi_handler)(void);
+ u32 *p = addr;
+ u32 val;
+ struct uasm_label labels[2];
+ struct uasm_reloc relocs[2];
+ struct uasm_label *l = labels;
+ struct uasm_reloc *r = relocs;
+
+ memset(labels, 0, sizeof(labels));
+ memset(relocs, 0, sizeof(relocs));
+
+ uasm_i_mfc0(&p, K0, C0_STATUS);
+ if (cpu_has_mips_r2_r6)
+ uasm_i_ext(&p, K0, K0, ST0_NMI_BIT, 1);
+ else {
+ uasm_i_srl(&p, K0, K0, ST0_NMI_BIT);
+ uasm_i_andi(&p, K0, K0, 0x1);
+ }
+
+ uasm_il_bnez(&p, &r, K0, label_not_nmi);
+ uasm_i_nop(&p);
+ UASM_i_LA(&p, K0, (long)&nmi_handler);
+
+ uasm_l_not_nmi(&l, p);
+
+ val = CAUSEF_IV;
+ uasm_i_lui(&p, K0, val >> 16);
+ uasm_i_ori(&p, K0, K0, val & 0xffff);
+ uasm_i_mtc0(&p, K0, C0_CAUSE);
+ val = ST0_CU1 | ST0_CU0 | ST0_BEV | ST0_KX_IF_64;
+ uasm_i_lui(&p, K0, val >> 16);
+ uasm_i_ori(&p, K0, K0, val & 0xffff);
+ uasm_i_mtc0(&p, K0, C0_STATUS);
+ uasm_i_ehb(&p);
+ uasm_i_ori(&p, A0, 0, read_c0_config() & CONF_CM_CMASK);
+ UASM_i_LA(&p, A1, (long)mips_gcr_base);
+#if defined(KBUILD_64BIT_SYM32) || defined(CONFIG_32BIT)
+ UASM_i_LA(&p, T9, CKSEG1ADDR(__pa_symbol(mips_cps_core_boot)));
+#else
+ UASM_i_LA(&p, T9, TO_UNCAC(__pa_symbol(mips_cps_core_boot)));
+#endif
+ uasm_i_jr(&p, T9);
+ uasm_i_nop(&p);
+
+ uasm_resolve_relocs(relocs, labels);
+
+ return p;
+}
+
+static int __init setup_cps_vecs(void)
+{
+ extern void excep_tlbfill(void);
+ extern void excep_xtlbfill(void);
+ extern void excep_cache(void);
+ extern void excep_genex(void);
+ extern void excep_intex(void);
+ extern void excep_ejtag(void);
+ phys_addr_t cps_vec_pa;
+ void *cps_vec;
+
+ /* Try to allocate in KSEG1 first */
+ cps_vec_pa = memblock_phys_alloc_range(BEV_VEC_SIZE, BEV_VEC_ALIGN,
+ 0x0, KSEGX_SIZE - 1);
+
+ if (cps_vec_pa)
+ core_entry_reg = CKSEG1ADDR(cps_vec_pa) &
+ CM_GCR_Cx_RESET_BASE_BEVEXCBASE;
+
+ if (!cps_vec_pa && mips_cm_is64) {
+ cps_vec_pa = memblock_phys_alloc_range(BEV_VEC_SIZE, BEV_VEC_ALIGN,
+ 0x0, SZ_4G - 1);
+ if (cps_vec_pa)
+ core_entry_reg = (cps_vec_pa & CM_GCR_Cx_RESET_BASE_BEVEXCBASE) |
+ CM_GCR_Cx_RESET_BASE_MODE;
+ }
+
+ if (!cps_vec_pa)
+ return -ENOMEM;
+
+ /* We want to ensure cache is clean before writing uncached mem */
+ blast_dcache_range(TO_CAC(cps_vec_pa), TO_CAC(cps_vec_pa) + BEV_VEC_SIZE);
+ bc_wback_inv(TO_CAC(cps_vec_pa), BEV_VEC_SIZE);
+ __sync();
+
+ cps_vec = (void *)TO_UNCAC(cps_vec_pa);
+ mips_cps_build_core_entry(cps_vec);
+
+ memcpy(cps_vec + 0x200, &excep_tlbfill, 0x80);
+ memcpy(cps_vec + 0x280, &excep_xtlbfill, 0x80);
+ memcpy(cps_vec + 0x300, &excep_cache, 0x80);
+ memcpy(cps_vec + 0x380, &excep_genex, 0x80);
+ memcpy(cps_vec + 0x400, &excep_intex, 0x80);
+ memcpy(cps_vec + 0x480, &excep_ejtag, 0x80);
+
+ /* Make sure no prefetched data in cache */
+ blast_inv_dcache_range(TO_CAC(cps_vec_pa), TO_CAC(cps_vec_pa) + BEV_VEC_SIZE);
+ bc_inv(TO_CAC(cps_vec_pa), BEV_VEC_SIZE);
+ __sync();
+
+ return 0;
+}
+
static void __init cps_smp_setup(void)
{
unsigned int nclusters, ncores, nvpes, core_vpes;
- unsigned long core_entry;
int cl, c, v;

/* Detect & record VPE topology */
@@ -94,10 +224,11 @@ static void __init cps_smp_setup(void)
/* Make core 0 coherent with everything */
write_gcr_cl_coherence(0xff);

- if (mips_cm_revision() >= CM_REV_CM3) {
- core_entry = CKSEG1ADDR((unsigned long)mips_cps_core_entry);
- write_gcr_bev_base(core_entry);
- }
+ if (setup_cps_vecs())
+ pr_err("Failed to setup CPS vectors\n");
+
+ if (core_entry_reg && mips_cm_revision() >= CM_REV_CM3)
+ write_gcr_bev_base(core_entry_reg);

#ifdef CONFIG_MIPS_MT_FPAFF
/* If we have an FPU, enroll ourselves in the FPU-full mask */
@@ -110,10 +241,14 @@ static void __init cps_prepare_cpus(unsigned int max_cpus)
{
unsigned ncores, core_vpes, c, cca;
bool cca_unsuitable, cores_limited;
- u32 *entry_code;

mips_mt_set_cpuoptions();

+ if (!core_entry_reg) {
+ pr_err("core_entry address unsuitable, disabling smp-cps\n");
+ goto err_out;
+ }
+
/* Detect whether the CCA is unsuited to multi-core SMP */
cca = read_c0_config() & CONF_CM_CMASK;
switch (cca) {
@@ -145,20 +280,6 @@ static void __init cps_prepare_cpus(unsigned int max_cpus)
(cca_unsuitable && cpu_has_dc_aliases) ? " & " : "",
cpu_has_dc_aliases ? "dcache aliasing" : "");

- /*
- * Patch the start of mips_cps_core_entry to provide:
- *
- * s0 = kseg0 CCA
- */
- entry_code = (u32 *)&mips_cps_core_entry;
- uasm_i_addiu(&entry_code, 16, 0, cca);
- UASM_i_LA(&entry_code, 17, (long)mips_gcr_base);
- BUG_ON((void *)entry_code > (void *)&mips_cps_core_entry_patch_end);
- blast_dcache_range((unsigned long)&mips_cps_core_entry,
- (unsigned long)entry_code);
- bc_wback_inv((unsigned long)&mips_cps_core_entry,
- (void *)entry_code - (void *)&mips_cps_core_entry);
- __sync();

/* Allocate core boot configuration structs */
ncores = mips_cps_numcores(0);
@@ -213,7 +334,7 @@ static void boot_core(unsigned int core, unsigned int vpe_id)
mips_cm_lock_other(0, core, 0, CM_GCR_Cx_OTHER_BLOCK_LOCAL);

/* Set its reset vector */
- write_gcr_co_reset_base(CKSEG1ADDR((unsigned long)mips_cps_core_entry));
+ write_gcr_co_reset_base(core_entry_reg);

/* Ensure its coherency is disabled */
write_gcr_co_coherence(0);
@@ -290,7 +411,6 @@ static int cps_boot_secondary(int cpu, struct task_struct *idle)
unsigned vpe_id = cpu_vpe_id(&cpu_data[cpu]);
struct core_boot_config *core_cfg = &mips_cps_core_bootcfg[core];
struct vpe_boot_config *vpe_cfg = &core_cfg->vpe_config[vpe_id];
- unsigned long core_entry;
unsigned int remote;
int err;

@@ -314,8 +434,7 @@ static int cps_boot_secondary(int cpu, struct task_struct *idle)

if (cpu_has_vp) {
mips_cm_lock_other(0, core, vpe_id, CM_GCR_Cx_OTHER_BLOCK_LOCAL);
- core_entry = CKSEG1ADDR((unsigned long)mips_cps_core_entry);
- write_gcr_co_reset_base(core_entry);
+ write_gcr_co_reset_base(core_entry_reg);
mips_cm_unlock_other();
}

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 230728d76d11..ea59d321f713 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -74,6 +74,8 @@

#include "access-helper.h"

+#define MAX(a, b) ((a) >= (b) ? (a) : (b))
+
extern void check_wait(void);
extern asmlinkage void rollback_handle_int(void);
extern asmlinkage void handle_int(void);
--
2.34.1


2023-10-28 07:23:30

by kernel test robot

[permalink] [raw]
Subject: Re: [PATCH v2 05/10] MIPS: Refactor mips_cps_core_entry implementation

Hi Jiaxun,

kernel test robot noticed the following build warnings:

[auto build test WARNING on linus/master]
[also build test WARNING on v6.6-rc7 next-20231027]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Jiaxun-Yang/MIPS-Export-higher-highest-relocation-functions-in-uasm/20231028-061419
base: linus/master
patch link: https://lore.kernel.org/r/20231027221106.405666-6-jiaxun.yang%40flygoat.com
patch subject: [PATCH v2 05/10] MIPS: Refactor mips_cps_core_entry implementation
config: mips-allyesconfig (https://download.01.org/0day-ci/archive/20231028/[email protected]/config)
compiler: mips-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231028/[email protected]/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

All warnings (new ones prefixed by >>):

arch/mips/kernel/smp-cps.c: In function 'setup_cps_vecs':
>> arch/mips/kernel/smp-cps.c:150:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
150 | cps_vec = (void *)TO_UNCAC(cps_vec_pa);
| ^


vim +150 arch/mips/kernel/smp-cps.c

114
115 static int __init setup_cps_vecs(void)
116 {
117 extern void excep_tlbfill(void);
118 extern void excep_xtlbfill(void);
119 extern void excep_cache(void);
120 extern void excep_genex(void);
121 extern void excep_intex(void);
122 extern void excep_ejtag(void);
123 phys_addr_t cps_vec_pa;
124 void *cps_vec;
125
126 /* Try to allocate in KSEG1 first */
127 cps_vec_pa = memblock_phys_alloc_range(BEV_VEC_SIZE, BEV_VEC_ALIGN,
128 0x0, KSEGX_SIZE - 1);
129
130 if (cps_vec_pa)
131 core_entry_reg = CKSEG1ADDR(cps_vec_pa) &
132 CM_GCR_Cx_RESET_BASE_BEVEXCBASE;
133
134 if (!cps_vec_pa && mips_cm_is64) {
135 cps_vec_pa = memblock_phys_alloc_range(BEV_VEC_SIZE, BEV_VEC_ALIGN,
136 0x0, SZ_4G - 1);
137 if (cps_vec_pa)
138 core_entry_reg = (cps_vec_pa & CM_GCR_Cx_RESET_BASE_BEVEXCBASE) |
139 CM_GCR_Cx_RESET_BASE_MODE;
140 }
141
142 if (!cps_vec_pa)
143 return -ENOMEM;
144
145 /* We want to ensure cache is clean before writing uncached mem */
146 blast_dcache_range(TO_CAC(cps_vec_pa), TO_CAC(cps_vec_pa) + BEV_VEC_SIZE);
147 bc_wback_inv(TO_CAC(cps_vec_pa), BEV_VEC_SIZE);
148 __sync();
149
> 150 cps_vec = (void *)TO_UNCAC(cps_vec_pa);
151 mips_cps_build_core_entry(cps_vec);
152
153 memcpy(cps_vec + 0x200, &excep_tlbfill, 0x80);
154 memcpy(cps_vec + 0x280, &excep_xtlbfill, 0x80);
155 memcpy(cps_vec + 0x300, &excep_cache, 0x80);
156 memcpy(cps_vec + 0x380, &excep_genex, 0x80);
157 memcpy(cps_vec + 0x400, &excep_intex, 0x80);
158 memcpy(cps_vec + 0x480, &excep_ejtag, 0x80);
159
160 /* Make sure no prefetched data in cache */
161 blast_inv_dcache_range(TO_CAC(cps_vec_pa), TO_CAC(cps_vec_pa) + BEV_VEC_SIZE);
162 bc_inv(TO_CAC(cps_vec_pa), BEV_VEC_SIZE);
163 __sync();
164
165 return 0;
166 }
167

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

2023-12-22 12:20:30

by Thomas Bogendoerfer

[permalink] [raw]
Subject: Re: [PATCH v2 05/10] MIPS: Refactor mips_cps_core_entry implementation

On Fri, Oct 27, 2023 at 11:11:01PM +0100, Jiaxun Yang wrote:
> Now the exception vector for CPS systems are allocated on-fly
> with memblock as well.
>
> It will try to allocate from KSEG1 first, and then try to allocate
> in low 4G if possible.
>
> The main reset vector is now generated by uasm, to avoid tons
> of patches to the code. Other vectors are copied to the location
> later.

this patch does way to many things in one go. What is needed to
make a kernel working with an ebase anyware in XPHYS ?

Thomas.

--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea. [ RFC1925, 2.3 ]

2023-12-22 12:40:58

by Jiaxun Yang

[permalink] [raw]
Subject: Re: [PATCH v2 05/10] MIPS: Refactor mips_cps_core_entry implementation



在 2023/12/22 12:18, Thomas Bogendoerfer 写道:
> On Fri, Oct 27, 2023 at 11:11:01PM +0100, Jiaxun Yang wrote:
>> Now the exception vector for CPS systems are allocated on-fly
>> with memblock as well.
>>
>> It will try to allocate from KSEG1 first, and then try to allocate
>> in low 4G if possible.
>>
>> The main reset vector is now generated by uasm, to avoid tons
>> of patches to the code. Other vectors are copied to the location
>> later.
> this patch does way to many things in one go. What is needed to
> make a kernel working with an ebase anyware in XPHYS ?

As we have some silly restrictions on the placement of CPS reset_base, it's
impossible to put CPS's cluster reset base "anywhere".

You'll have to make entry code in cps-vec.S relocatable to allow it to
be moved
by kernel at run time. Either patching the code or generate by uasm.

Thanks
- Jiaxun
>
> Thomas.
>