linux/arch/riscv/mm/physaddr.c

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riscv: mm: add support for CONFIG_DEBUG_VIRTUAL This patch implements CONFIG_DEBUG_VIRTUAL to do additional checks on virt_to_phys and __pa_symbol calls. virt_to_phys used for linear mapping check, and __pa_symbol used for kernel symbol check. In current RISC-V, kernel image maps to linear mapping area. If CONFIG_DEBUG_VIRTUAL is disable, these two functions calculate the offset on the address feded directly without any checks. The result of test_debug_virtual as follows: [ 0.358456] ------------[ cut here ]------------ [ 0.358738] virt_to_phys used for non-linear address: (____ptrval____) (0xffffffd000000000) [ 0.359174] WARNING: CPU: 0 PID: 1 at arch/riscv/mm/physaddr.c:16 __virt_to_phys+0x3c/0x50 [ 0.359409] Modules linked in: [ 0.359630] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.5.0-rc3-00002-g5133c5c0ca13 #57 [ 0.359861] epc: ffffffe000253d1a ra : ffffffe000253d1a sp : ffffffe03aa87da0 [ 0.360019] gp : ffffffe000ae03b0 tp : ffffffe03aa88000 t0 : ffffffe000af2660 [ 0.360175] t1 : 0000000000000064 t2 : 00000000000000b7 s0 : ffffffe03aa87dc0 [ 0.360330] s1 : ffffffd000000000 a0 : 000000000000004f a1 : 0000000000000000 [ 0.360492] a2 : 0000000000000000 a3 : 0000000000000000 a4 : ffffffe000a84358 [ 0.360672] a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000000000 [ 0.360876] s2 : ffffffe000ae0600 s3 : ffffffe00000fc7c s4 : ffffffe0000224b0 [ 0.361067] s5 : ffffffe000030890 s6 : ffffffe000022470 s7 : 0000000000000008 [ 0.361267] s8 : ffffffe0000002c4 s9 : ffffffe000ae0640 s10: ffffffe000ae0630 [ 0.361453] s11: 0000000000000000 t3 : 0000000000000000 t4 : 000000000001e6d0 [ 0.361636] t5 : ffffffe000ae0a18 t6 : ffffffe000aee54e [ 0.361806] status: 0000000000000120 badaddr: 0000000000000000 cause: 0000000000000003 [ 0.362056] ---[ end trace aec0bf78d4978122 ]--- [ 0.362404] PA: 0xfffffff080200000 for VA: 0xffffffd000000000 [ 0.362607] PA: 0x00000000baddd2d0 for VA: 0xffffffe03abdd2d0 Signed-off-by: Zong Li <zong.li@sifive.com> Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com> Tested-by: Paul Walmsley <paul.walmsley@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-01-02 11:12:39 +08:00
// SPDX-License-Identifier: GPL-2.0
#include <linux/types.h>
#include <linux/mmdebug.h>
#include <linux/mm.h>
#include <asm/page.h>
#include <asm/sections.h>
phys_addr_t __virt_to_phys(unsigned long x)
{
/*
* Boundary checking aginst the kernel linear mapping space.
*/
WARN(!is_linear_mapping(x) && !is_kernel_mapping(x),
riscv: mm: add support for CONFIG_DEBUG_VIRTUAL This patch implements CONFIG_DEBUG_VIRTUAL to do additional checks on virt_to_phys and __pa_symbol calls. virt_to_phys used for linear mapping check, and __pa_symbol used for kernel symbol check. In current RISC-V, kernel image maps to linear mapping area. If CONFIG_DEBUG_VIRTUAL is disable, these two functions calculate the offset on the address feded directly without any checks. The result of test_debug_virtual as follows: [ 0.358456] ------------[ cut here ]------------ [ 0.358738] virt_to_phys used for non-linear address: (____ptrval____) (0xffffffd000000000) [ 0.359174] WARNING: CPU: 0 PID: 1 at arch/riscv/mm/physaddr.c:16 __virt_to_phys+0x3c/0x50 [ 0.359409] Modules linked in: [ 0.359630] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.5.0-rc3-00002-g5133c5c0ca13 #57 [ 0.359861] epc: ffffffe000253d1a ra : ffffffe000253d1a sp : ffffffe03aa87da0 [ 0.360019] gp : ffffffe000ae03b0 tp : ffffffe03aa88000 t0 : ffffffe000af2660 [ 0.360175] t1 : 0000000000000064 t2 : 00000000000000b7 s0 : ffffffe03aa87dc0 [ 0.360330] s1 : ffffffd000000000 a0 : 000000000000004f a1 : 0000000000000000 [ 0.360492] a2 : 0000000000000000 a3 : 0000000000000000 a4 : ffffffe000a84358 [ 0.360672] a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000000000 [ 0.360876] s2 : ffffffe000ae0600 s3 : ffffffe00000fc7c s4 : ffffffe0000224b0 [ 0.361067] s5 : ffffffe000030890 s6 : ffffffe000022470 s7 : 0000000000000008 [ 0.361267] s8 : ffffffe0000002c4 s9 : ffffffe000ae0640 s10: ffffffe000ae0630 [ 0.361453] s11: 0000000000000000 t3 : 0000000000000000 t4 : 000000000001e6d0 [ 0.361636] t5 : ffffffe000ae0a18 t6 : ffffffe000aee54e [ 0.361806] status: 0000000000000120 badaddr: 0000000000000000 cause: 0000000000000003 [ 0.362056] ---[ end trace aec0bf78d4978122 ]--- [ 0.362404] PA: 0xfffffff080200000 for VA: 0xffffffd000000000 [ 0.362607] PA: 0x00000000baddd2d0 for VA: 0xffffffe03abdd2d0 Signed-off-by: Zong Li <zong.li@sifive.com> Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com> Tested-by: Paul Walmsley <paul.walmsley@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-01-02 11:12:39 +08:00
"virt_to_phys used for non-linear address: %pK (%pS)\n",
(void *)x, (void *)x);
return __va_to_pa_nodebug(x);
}
EXPORT_SYMBOL(__virt_to_phys);
phys_addr_t __phys_addr_symbol(unsigned long x)
{
unsigned long kernel_start = kernel_map.virt_addr;
unsigned long kernel_end = kernel_start + kernel_map.size;
riscv: mm: add support for CONFIG_DEBUG_VIRTUAL This patch implements CONFIG_DEBUG_VIRTUAL to do additional checks on virt_to_phys and __pa_symbol calls. virt_to_phys used for linear mapping check, and __pa_symbol used for kernel symbol check. In current RISC-V, kernel image maps to linear mapping area. If CONFIG_DEBUG_VIRTUAL is disable, these two functions calculate the offset on the address feded directly without any checks. The result of test_debug_virtual as follows: [ 0.358456] ------------[ cut here ]------------ [ 0.358738] virt_to_phys used for non-linear address: (____ptrval____) (0xffffffd000000000) [ 0.359174] WARNING: CPU: 0 PID: 1 at arch/riscv/mm/physaddr.c:16 __virt_to_phys+0x3c/0x50 [ 0.359409] Modules linked in: [ 0.359630] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.5.0-rc3-00002-g5133c5c0ca13 #57 [ 0.359861] epc: ffffffe000253d1a ra : ffffffe000253d1a sp : ffffffe03aa87da0 [ 0.360019] gp : ffffffe000ae03b0 tp : ffffffe03aa88000 t0 : ffffffe000af2660 [ 0.360175] t1 : 0000000000000064 t2 : 00000000000000b7 s0 : ffffffe03aa87dc0 [ 0.360330] s1 : ffffffd000000000 a0 : 000000000000004f a1 : 0000000000000000 [ 0.360492] a2 : 0000000000000000 a3 : 0000000000000000 a4 : ffffffe000a84358 [ 0.360672] a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000000000 [ 0.360876] s2 : ffffffe000ae0600 s3 : ffffffe00000fc7c s4 : ffffffe0000224b0 [ 0.361067] s5 : ffffffe000030890 s6 : ffffffe000022470 s7 : 0000000000000008 [ 0.361267] s8 : ffffffe0000002c4 s9 : ffffffe000ae0640 s10: ffffffe000ae0630 [ 0.361453] s11: 0000000000000000 t3 : 0000000000000000 t4 : 000000000001e6d0 [ 0.361636] t5 : ffffffe000ae0a18 t6 : ffffffe000aee54e [ 0.361806] status: 0000000000000120 badaddr: 0000000000000000 cause: 0000000000000003 [ 0.362056] ---[ end trace aec0bf78d4978122 ]--- [ 0.362404] PA: 0xfffffff080200000 for VA: 0xffffffd000000000 [ 0.362607] PA: 0x00000000baddd2d0 for VA: 0xffffffe03abdd2d0 Signed-off-by: Zong Li <zong.li@sifive.com> Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com> Tested-by: Paul Walmsley <paul.walmsley@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-01-02 11:12:39 +08:00
/*
* Boundary checking aginst the kernel image mapping.
* __pa_symbol should only be used on kernel symbol addresses.
*/
VIRTUAL_BUG_ON(x < kernel_start || x > kernel_end);
return __va_to_pa_nodebug(x);
}
EXPORT_SYMBOL(__phys_addr_symbol);
riscv: Use PUD/P4D/PGD pages for the linear mapping During the early page table creation, we used to set the mapping for PAGE_OFFSET to the kernel load address: but the kernel load address is always offseted by PMD_SIZE which makes it impossible to use PUD/P4D/PGD pages as this physical address is not aligned on PUD/P4D/PGD size (whereas PAGE_OFFSET is). But actually we don't have to establish this mapping (ie set va_pa_offset) that early in the boot process because: - first, setup_vm installs a temporary kernel mapping and among other things, discovers the system memory, - then, setup_vm_final creates the final kernel mapping and takes advantage of the discovered system memory to create the linear mapping. During the first phase, we don't know the start of the system memory and then until the second phase is finished, we can't use the linear mapping at all and phys_to_virt/virt_to_phys translations must not be used because it would result in a different translation from the 'real' one once the final mapping is installed. So here we simply delay the initialization of va_pa_offset to after the system memory discovery. But to make sure noone uses the linear mapping before, we add some guard in the DEBUG_VIRTUAL config. Finally we can use PUD/P4D/PGD hugepages when possible, which will result in a better TLB utilization. Note that: - this does not apply to rv32 as the kernel mapping lies in the linear mapping. - we rely on the firmware to protect itself using PMP. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Acked-by: Rob Herring <robh@kernel.org> # DT bits Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Anup Patel <anup@brainfault.org> Tested-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20230324155421.271544-4-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-03-24 23:54:21 +08:00
phys_addr_t linear_mapping_va_to_pa(unsigned long x)
{
BUG_ON(!kernel_map.va_pa_offset);
return ((unsigned long)(x) - kernel_map.va_pa_offset);
}
EXPORT_SYMBOL(linear_mapping_va_to_pa);
void *linear_mapping_pa_to_va(unsigned long x)
{
BUG_ON(!kernel_map.va_pa_offset);
return ((void *)((unsigned long)(x) + kernel_map.va_pa_offset));
}
EXPORT_SYMBOL(linear_mapping_pa_to_va);