Re: [PATCH] tee: amdtee: add support for use of cma region

[Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>]

On 8/19/2023 4:03 PM, Alexey Kardashevskiy wrote:
> On 19/8/23 00:42, Devaraj Rangasamy wrote:
>> In systems with low memory configuration, memory gets fragmented
>> easily, and any bigger size contiguous memory allocations are likely
>> to fail.
>> Contiguous Memory Allocator (CMA) is used to overcome this
>> limitation, and to guarantee memory allocations.
>>
>> This patch adds support for CMA area exclusive to amdtee.
>> The support can be enabled if kernel have CONFIG_CMA enabled.
>> The size can be set via the AMDTEE_CMA_SIZE config option
>> at compile time or with the "amdtee_cma" kernel parameter.
>> (e.g. "amdtee_cma=32 for 32MB").
>>
>> Also, cma zone is utilized only for buffer allocation bigger than
>> 64k bytes. When such allocation fails, there is a fallback to the
>> buddy allocator. Since CMA requires a boot time initialization,
>> it is enabled only when amdtee is built as an inbuilt driver.
>>
>> Signed-off-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
>> Co-developed-by: SivaSangeetha SK <SivaSangeetha.SK@amd.com>
>> Signed-off-by: SivaSangeetha SK <SivaSangeetha.SK@amd.com>
>> Reviewed-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
>> ---
>>   .../admin-guide/kernel-parameters.txt         |  7 ++
>>   arch/x86/include/asm/setup.h                  |  6 ++
>>   arch/x86/kernel/setup.c                       |  2 +
>>   drivers/tee/amdtee/Kconfig                    |  9 +++
>>   drivers/tee/amdtee/Makefile                   |  1 +
>>   drivers/tee/amdtee/amdtee_private.h           |  6 +-
>>   drivers/tee/amdtee/core.c                     |  6 +-
>>   drivers/tee/amdtee/shm_pool.c                 | 32 ++++++--
>>   drivers/tee/amdtee/shm_pool_cma.c             | 78 +++++++++++++++++++
>>   drivers/tee/amdtee/shm_pool_cma.h             | 38 +++++++++
>>   10 files changed, 176 insertions(+), 9 deletions(-)
>>   create mode 100644 drivers/tee/amdtee/shm_pool_cma.c
>>   create mode 100644 drivers/tee/amdtee/shm_pool_cma.h
>>
>> diff --git a/Documentation/admin-guide/kernel-parameters.txt 
>> b/Documentation/admin-guide/kernel-parameters.txt
>> index 722b6eca2e93..5e38423f3d53 100644
>> --- a/Documentation/admin-guide/kernel-parameters.txt
>> +++ b/Documentation/admin-guide/kernel-parameters.txt
>> @@ -363,6 +363,13 @@
>>                 selects a performance level in this range and 
>> appropriate
>>                 to the current workload.
>>   +    amdtee_cma=nn    [HW,TEE]
>> +            Sets the memory size reserved for contiguous memory
>> +            allocations, to be used by amdtee device driver.
>> +            Value is in MB and can range from 4 to 128 (MBs)
>> +            CMA will be active only when CMA is enabled, and amdtee is
>> +            built as inbuilt driver, and not loaded as module.
>> +
>>       amijoy.map=    [HW,JOY] Amiga joystick support
>>               Map of devices attached to JOY0DAT and JOY1DAT
>>               Format: <a>,<b>
>> diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
>> index f3495623ac99..bb5e4b7134a2 100644
>> --- a/arch/x86/include/asm/setup.h
>> +++ b/arch/x86/include/asm/setup.h
>> @@ -66,6 +66,12 @@ extern void x86_ce4100_early_setup(void);
>>   static inline void x86_ce4100_early_setup(void) { }
>>   #endif
>>   +#if IS_BUILTIN(CONFIG_AMDTEE) && IS_ENABLED(CONFIG_CMA)
>> +void amdtee_cma_reserve(void);
>> +#else
>> +static inline void amdtee_cma_reserve(void) { }
>> +#endif
>> +
>>   #ifndef _SETUP
>>     #include <asm/espfix.h>
>> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>> index fd975a4a5200..e73433af3bfa 100644
>> --- a/arch/x86/kernel/setup.c
>> +++ b/arch/x86/kernel/setup.c
>> @@ -1223,6 +1223,8 @@ void __init setup_arch(char **cmdline_p)
>>       initmem_init();
>>       dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
>>   +    amdtee_cma_reserve();
>> +
>>       if (boot_cpu_has(X86_FEATURE_GBPAGES))
>>           hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
>>   diff --git a/drivers/tee/amdtee/Kconfig b/drivers/tee/amdtee/Kconfig
>> index 191f9715fa9a..5843c739a7b8 100644
>> --- a/drivers/tee/amdtee/Kconfig
>> +++ b/drivers/tee/amdtee/Kconfig
>> @@ -6,3 +6,12 @@ config AMDTEE
>>       depends on CRYPTO_DEV_SP_PSP && CRYPTO_DEV_CCP_DD
>>       help
>>         This implements AMD's Trusted Execution Environment (TEE) 
>> driver.
>> +
>> +config AMDTEE_CMA_SIZE
>> +    int "Size of Memory in MiB reserved in CMA for AMD-TEE"
>> +    default "0"
>> +    depends on CMA && (AMDTEE=y)
>> +    help
>> +      Specify the default amount of memory in MiB reserved in CMA 
>> for AMD-TEE driver
>> +      Any amdtee shm buffer allocation larger than 64k will allocate 
>> memory from the CMA
>> +      The default can be overridden with the kernel commandline 
>> parameter "amdtee_cma".
>> \ No newline at end of file
>> diff --git a/drivers/tee/amdtee/Makefile b/drivers/tee/amdtee/Makefile
>> index ff1485266117..a197839cfcf3 100644
>> --- a/drivers/tee/amdtee/Makefile
>> +++ b/drivers/tee/amdtee/Makefile
>> @@ -3,3 +3,4 @@ obj-$(CONFIG_AMDTEE) += amdtee.o
>>   amdtee-objs += core.o
>>   amdtee-objs += call.o
>>   amdtee-objs += shm_pool.o
>> +amdtee-objs += shm_pool_cma.o
>> diff --git a/drivers/tee/amdtee/amdtee_private.h 
>> b/drivers/tee/amdtee/amdtee_private.h
>> index 6d0f7062bb87..9ba47795adb6 100644
>> --- a/drivers/tee/amdtee/amdtee_private.h
>> +++ b/drivers/tee/amdtee/amdtee_private.h
>> @@ -87,11 +87,13 @@ struct shmem_desc {
>>    * struct amdtee_shm_data - Shared memory data
>>    * @kaddr:    Kernel virtual address of shared memory
>>    * @buf_id:    Buffer id of memory mapped by TEE_CMD_ID_MAP_SHARED_MEM
>> + * @is_cma:    Indicates whether memory is allocated from cma region 
>> or not
>>    */
>>   struct amdtee_shm_data {
>>       struct  list_head shm_node;
>>       void    *kaddr;
>>       u32     buf_id;
>> +    bool    is_cma;
>>   };
>>     /**
>> @@ -145,9 +147,9 @@ int amdtee_invoke_func(struct tee_context *ctx,
>>     int amdtee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 
>> session);
>>   -int amdtee_map_shmem(struct tee_shm *shm);
>> +int amdtee_map_shmem(struct tee_shm *shm, bool is_cma);
>>   -void amdtee_unmap_shmem(struct tee_shm *shm);
>> +void amdtee_unmap_shmem(struct tee_shm *shm, bool *is_cma);
>>     int handle_load_ta(void *data, u32 size,
>>              struct tee_ioctl_open_session_arg *arg);
>> diff --git a/drivers/tee/amdtee/core.c b/drivers/tee/amdtee/core.c
>> index 372d64756ed6..448802dccf13 100644
>> --- a/drivers/tee/amdtee/core.c
>> +++ b/drivers/tee/amdtee/core.c
>> @@ -336,7 +336,7 @@ int amdtee_close_session(struct tee_context *ctx, 
>> u32 session)
>>       return 0;
>>   }
>>   -int amdtee_map_shmem(struct tee_shm *shm)
>> +int amdtee_map_shmem(struct tee_shm *shm, bool is_cma)
>>   {
>>       struct amdtee_context_data *ctxdata;
>>       struct amdtee_shm_data *shmnode;
>> @@ -368,6 +368,7 @@ int amdtee_map_shmem(struct tee_shm *shm)
>>         shmnode->kaddr = shm->kaddr;
>>       shmnode->buf_id = buf_id;
>> +    shmnode->is_cma = is_cma;
>>       ctxdata = shm->ctx->data;
>>       mutex_lock(&ctxdata->shm_mutex);
>>       list_add(&shmnode->shm_node, &ctxdata->shm_list);
>> @@ -378,7 +379,7 @@ int amdtee_map_shmem(struct tee_shm *shm)
>>       return 0;
>>   }
>>   -void amdtee_unmap_shmem(struct tee_shm *shm)
>> +void amdtee_unmap_shmem(struct tee_shm *shm, bool *is_cma)
>>   {
>>       struct amdtee_context_data *ctxdata;
>>       struct amdtee_shm_data *shmnode;
>> @@ -395,6 +396,7 @@ void amdtee_unmap_shmem(struct tee_shm *shm)
>>       mutex_lock(&ctxdata->shm_mutex);
>>       list_for_each_entry(shmnode, &ctxdata->shm_list, shm_node)
>>           if (buf_id == shmnode->buf_id) {
>> +            *is_cma = shmnode->is_cma;
>>               list_del(&shmnode->shm_node);
>>               kfree(shmnode);
>>               break;
>> diff --git a/drivers/tee/amdtee/shm_pool.c 
>> b/drivers/tee/amdtee/shm_pool.c
>> index f0303126f199..9aad401387be 100644
>> --- a/drivers/tee/amdtee/shm_pool.c
>> +++ b/drivers/tee/amdtee/shm_pool.c
>> @@ -7,19 +7,30 @@
>>   #include <linux/tee_drv.h>
>>   #include <linux/psp.h>
>>   #include "amdtee_private.h"
>> +#include "shm_pool_cma.h"
>>     static int pool_op_alloc(struct tee_shm_pool *pool, struct 
>> tee_shm *shm,
>>                size_t size, size_t align)
>>   {
>>       unsigned int order = get_order(size);
>>       unsigned long va;
>> +    bool is_cma = false;
>>       int rc;
>>         /*
>>        * Ignore alignment since this is already going to be page aligned
>>        * and there's no need for any larger alignment.
>>        */
>> -    va = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
>> +
>> +    /* if CMA is available, use it for higher order allocation */
>> +    if (amdtee_get_cma_size() && order > 6)
>> +        va = amdtee_alloc_from_cma(shm, order);
>> +
>> +    if (va)
>> +        is_cma = true;
>> +    else
>> +        va = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
>> +
>>       if (!va)
>>           return -ENOMEM;
>>   @@ -28,9 +39,13 @@ static int pool_op_alloc(struct tee_shm_pool 
>> *pool, struct tee_shm *shm,
>>       shm->size = PAGE_SIZE << order;
>>         /* Map the allocated memory in to TEE */
>> -    rc = amdtee_map_shmem(shm);
>> +    rc = amdtee_map_shmem(shm, is_cma);
>>       if (rc) {
>> -        free_pages(va, order);
>> +        if (is_cma)
>> +            amdtee_free_from_cma(shm);
>> +        else
>> +            free_pages(va, order);
>> +
>>           shm->kaddr = NULL;
>>           return rc;
>>       }
>> @@ -40,9 +55,16 @@ static int pool_op_alloc(struct tee_shm_pool 
>> *pool, struct tee_shm *shm,
>>     static void pool_op_free(struct tee_shm_pool *pool, struct 
>> tee_shm *shm)
>>   {
>> +    bool is_cma = false;
>> +
>>       /* Unmap the shared memory from TEE */
>> -    amdtee_unmap_shmem(shm);
>> -    free_pages((unsigned long)shm->kaddr, get_order(shm->size));
>> +    amdtee_unmap_shmem(shm, &is_cma);
>> +
>> +    if (is_cma)
>
> No need in is_cma here and other places.
Ack.
cma_release() do have inbuilt validation, and returns true/false as 
result for valid cma buffer release.
>
>
>> +        amdtee_free_from_cma(shm);
>> +    else
>> +        free_pages((unsigned long)shm->kaddr, get_order(shm->size));
>> +
>>       shm->kaddr = NULL;
>>   }
>>   diff --git a/drivers/tee/amdtee/shm_pool_cma.c 
>> b/drivers/tee/amdtee/shm_pool_cma.c
>> new file mode 100644
>> index 000000000000..99dda9adb1c6
>> --- /dev/null
>> +++ b/drivers/tee/amdtee/shm_pool_cma.c
>> @@ -0,0 +1,78 @@
>> +// SPDX-License-Identifier: MIT
>> +/*
>> + * Copyright 2023 Advanced Micro Devices, Inc.
>> + */
>> +
>> +#if IS_BUILTIN(CONFIG_AMDTEE) && IS_ENABLED(CONFIG_CMA)
>> +
>> +#define pr_fmt(fmt) "%s: " fmt, __func__
>> +
>> +#include <linux/cma.h>
>> +#include <linux/mm.h>
>> +#include <linux/tee_drv.h>
>> +#include "shm_pool_cma.h"
>> +
>> +static struct cma *amdtee_cma;
>> +unsigned long amdtee_cma_size __initdata = CONFIG_AMDTEE_CMA_SIZE * 
>> SZ_1M;
>> +
>> +static int __init early_parse_amdtee_cma(char *p)
>> +{
>> +    int cmd_size;
>
> Not int but unsigned long long.
Ack.
We have reverted new exclusive cma zone.
>
>> +
>> +    if (!p)
>> +        return 1;
>> +
>> +    cmd_size = memparse(p, NULL);
>> +    if (cmd_size >= 4 && cmd_size <= 256)
>> +        amdtee_cma_size = cmd_size * SZ_1M;
>
> Change the doc to use 4M and 256M instead of plain 4 and 256. Or stop 
> using memparse().
>
> /me sad.
>
Ack.
Thanks for review.
>
>> +    else
>> +        pr_err("invalid amdtee_cma size: %lu\n", amdtee_cma_size);
>> +
>> +    return 0;
>> +}
>> +early_param("amdtee_cma", early_parse_amdtee_cma);
>> +
>> +void __init amdtee_cma_reserve(void)
>> +{
>> +    int ret;
>> +
>> +    ret = cma_declare_contiguous(0, amdtee_cma_size, 0, 0, 0, false, 
>> "amdtee", &amdtee_cma);
>> +    if (ret)
>> +        pr_err("Failed to reserve CMA region of size %lu\n", 
>> amdtee_cma_size);
>> +    else
>> +        pr_info("Reserved %lu bytes CMA for amdtee\n", 
>> amdtee_cma_size);
>> +}
>> +
>> +unsigned long amdtee_alloc_from_cma(struct tee_shm *shm, unsigned 
>> int order)
>> +{
>> +    struct page *page = NULL;
>> +    unsigned long va = 0;
>> +    int nr_pages = 0;
>> +
>> +    if (amdtee_cma) {
>> +        nr_pages = 1 << order;
>> +        page = cma_alloc(amdtee_cma, nr_pages, 0, false);
>> +        if (page)
>> +            va = (unsigned long)page_to_virt(page);
>> +        else
>> +            pr_debug("failed to allocate from CMA region\n");
>> +    } else {
>> +        pr_debug("CMA region is not available\n");
>> +    }
>> +    return va;
>> +}
>> +
>> +void amdtee_free_from_cma(struct tee_shm *shm)
>> +{
>> +    struct page *page;
>> +    int nr_pages = 0;
>> +
>> +    if (amdtee_cma) {
>> +        nr_pages = 1 << get_order(shm->size);
>> +        page = virt_to_page(shm->kaddr);
>> +        cma_release(amdtee_cma, page, nr_pages);
>> +    } else {
>> +        pr_err("CMA region is not available\n");
>> +    }
>> +}
>> +#endif /* IS_BUILTIN(CONFIG_AMDTEE) && IS_ENABLED(CONFIG_CMA) */
>> diff --git a/drivers/tee/amdtee/shm_pool_cma.h 
>> b/drivers/tee/amdtee/shm_pool_cma.h
>> new file mode 100644
>> index 000000000000..d1cde11cbede
>> --- /dev/null
>> +++ b/drivers/tee/amdtee/shm_pool_cma.h
>> @@ -0,0 +1,38 @@
>> +/* SPDX-License-Identifier: MIT */
>> +
>> +/*
>> + * Copyright 2023 Advanced Micro Devices, Inc.
>> + */
>> +
>> +#ifndef SHM_POOL_CMA_H
>> +#define SHM_POOL_CMA_H
>> +
>> +#if IS_BUILTIN(CONFIG_AMDTEE) && IS_ENABLED(CONFIG_CMA)
>> +
>> +extern unsigned long amdtee_cma_size;
>> +
>> +static inline unsigned long amdtee_get_cma_size(void)
>> +{
>> +    return amdtee_cma_size;
>> +}
>> +
>> +unsigned long amdtee_alloc_from_cma(struct tee_shm *shm, unsigned 
>> int order);
>> +
>> +void amdtee_free_from_cma(struct tee_shm *shm);
>> +
>> +#else /* IS_BUILTIN(CONFIG_AMDTEE) && IS_ENABLED(CONFIG_CMA) */
>> +
>> +static inline unsigned long amdtee_get_cma_size(void)
>> +{
>> +    return 0;
>> +}
>> +
>> +static inline unsigned long amdtee_alloc_from_cma(struct tee_shm 
>> *shm, unsigned int order)
>> +{
>> +    return 0;
>> +}
>> +
>> +static inline void amdtee_free_from_cma(struct tee_shm *shm) { }
>> +
>> +#endif /* IS_BUILTIN(CONFIG_AMDTEE) && IS_ENABLED(CONFIG_CMA) */
>> +#endif /* SHM_POOL_CMA_H */
>